WO2011081188A1 - Quadrupole mass spectroscope - Google Patents

Abstract

Provided is a quadrupole mass spectroscope capable of increasing sensitivity (S/N) by reducing the incidence of stray light from an ion source on a detector. Specifically disclosed is a quadrupole mass spectroscope (100) provided with an ion source (101), a quadrupole mass spectrometer (102) which has annular metal films, and a detector (103) which detects, as a signal, an ion which has passed through the quadrupole mass spectrometer. The quadrupole mass spectrometer is nonlinear, and thanks to the nonlinear quadrupole mass spectrometer, the quadrupole mass spectrometer is configured so that the detector cannot be seen through the quadrupole mass spectrometer from the ion source. The metal films are formed on insulating supports, and assembled by mating the insulating supports with each other.

Description

Quadrupole mass spectrometer

The present invention relates to a quadrupole mass spectrometer that performs mass separation of ions passing through four electrodes.

In the mass spectrometer, neutral molecules are ionized by an ion source, the mass of the ions is separated by a mass analyzer, and the separated ions are measured as current by a collector. FIG. 1A is a configuration diagram of a conventional quadrupole analyzer, where reference numeral 1 is an ion source, reference numeral 2 is a mass analyzer, and reference numeral 3 is a detector. The mass analyzer 2 has four cylindrical electrodes 4, and ions 5 emitted from the ion source 1 pass between the four cylindrical electrodes 4 and enter the detector 3. At this time, of the four cylindrical electrodes, the opposing electrodes (facing each other with the central axis of the mass analyzer in between) are electrically coupled (conducted), and a direct-current voltage (DC) and a high-frequency voltage ( RF) is applied to form a quadrupole electric field (“U-quadrupole electric field” to be described later) 7, and only ions having a mass number corresponding to each voltage, frequency, etc. It is made to pass in the longitudinal direction of the electrode 4.

In such mass analysis, in addition to the ions 5, vacuum ultraviolet rays may be incident on the detector 3 from the ion source 1 as described above. This is because vacuum ultraviolet light (light with high energy) is generated in the ion source 1. Further, when the ions 5 collide with the cylindrical electrode 4, soft X-rays (light having higher energy) may be generated and enter the detector 3. Such high-energy light that has entered the detector 3 due to vacuum ultraviolet rays, soft X-rays, or other factors will be collectively referred to as “stray light”. That is, the stray light 6 may enter the mass analyzer 2 together with the ions 5.

Thus, in the most common quadrupole mass spectrometer, a high-frequency voltage and a DC voltage are applied to four parallel electrodes.

However, how accurately the quadrupole electric field is realized by the four electrodes greatly affects the resolution performance, so that the curvature (thickness) and position of the electrodes satisfy a specific relationship while satisfying a specific relationship. Parallelism must be very high. The required accuracy of parallelism is several microns (micrometers) or less, which must be satisfied in the length of the electrodes (several tens to hundreds of mm). Therefore, as shown in FIGS. 1B to 1E, various devices have been conventionally used in the electrode fixing method.

For example, in FIG. 1B, a rectangular frame-shaped insulating support 14 having an inner dimensional accuracy is used, and each of the four cylindrical electrodes 11a to 11d is brought into close contact with the inner surface of the insulating support 14 by tightening screws 13. ing. This method has a problem that the accuracy (internal dimensional accuracy) of the insulating support 14 is difficult to obtain and is high in cost, and that the screw tightening force must be within a range.

In FIG. 1C, a metal film formed on the surface of an insulator processed into an arc shape is used instead of a metal cylinder as a cylinder electrode (see Patent Document 1). That is, the metal films 16a to 16d are formed on the surfaces of the insulating supports 15a to 15d, respectively. Although various methods can be used for the structure of the four insulating supports 15a to 15d, it is general that the outer sides of the insulating supports 15a to 15d are pressed together with the fixtures 17a to 17d. In this method, there are many places where the accuracy of the insulating support is required, and it is also difficult to arrange the metal films 16a to 16d in parallel with each other, and the cost is high.

In FIG. 1D, two metal films are formed on one insulator (see Patent Document 2). That is, two protrusions 19a and 19b are formed on the insulating support 18a, and metal films 20a and 20b are formed on the protrusions 19a and 19b. Similarly, two protrusions 19c and 19d are formed on the insulating support 18b, and metal films 20c and 20d are formed on the protrusions 19c and 19d. Various methods can be used for positioning and assembling the two insulating supports 18a and 18b, but it is general that the spacers are pressed with a thickness accuracy between them. In this method, the number of parts is reduced, but it is difficult to obtain the accuracy of the insulating support so that the four protrusions 19a to 19d are parallel to each other, and the problem of high cost is not improved so much.

In FIG. 1E, four metal films are formed on one insulator (see Patent Documents 3 and 4). That is, the insulating support 21 is a hollow insulating support 21 having four regions recessed in a hyperbola inward along the longitudinal direction, and inside the four recessed regions of the insulating support 21. Metal films 22a to 22d are formed. This method is excellent in that the number of parts is extremely small and assembly is not required, but the insulating support 21 when forming the hyperbolic depressions so that the formed metal films 22a to 22d are parallel to each other. It is difficult to ensure the accuracy of the system, and the cost problem is increasing.

All of the conventional fixing methods, including these examples, have a basic structure that “directly” the “necessary accuracy of the center of the quadrupole field, that is, the trajectory of ions,” which is finally required. It is difficult to obtain sufficient accuracy at a low cost due to the practical problems of the structure and assembly.

On the other hand, as shown in FIG. 1A, not only the ions 5 to be signals are emitted from the ion source 1, but unavoidably high energy such as vacuum ultraviolet light or soft X-rays (that is, the ionization process) , Stray light 6) is emitted. Since the stray light 6 has no electric charge, it is incident on the detector 3 without being separated by the mass analyzer 2 and is detected as a false signal by the detector 3 because of its high energy. Since this is not an original signal, it becomes a background (noise) and deteriorates the performance of sensitivity (S / N). In particular, the conventional quadrupole mass spectrometer has a problem of stray light because the electrodes are straight (the detector can be expected from the ion source).

Therefore, as shown in FIG. 2A, there is an example in which the stray light 6 from the ion source 1 is difficult to enter the detector 3 by installing a curved ion guide 1 in front of the mass analyzer 2. In FIG. 2A, a bent ion guide 30 is provided between the ion source 1 and the mass analyzer 2. The ion guide 30 has four curved cylindrical electrodes (metal cylinders) 31, and the ion 5 passes between the four cylindrical electrodes 31. Further, since only the high-frequency voltage is applied to the cylindrical electrode 31 of the ion guide 30, a quadrupole electric field (“U-less quadrupole electric field” described later) 32 is formed between the cylindrical electrodes 31. . Accordingly, the ions 5 travel while bending along the curve of the cylindrical electrode 31 (curve of the ion guide). However, since the stray light 6 travels straight through the ion guide 30, the ions 5 pass between the cylindrical electrodes 31 or at the cylindrical electrode 31. It will be absorbed and reflected. Therefore, the stray light 6 incident on the detector 3 can be reduced.

However, since the stray light 6 is reflected on the surface of the cylindrical electrode 31 with a reflectivity of about several tens of percent, some of the reflected stray light is reflected to the detector 3 side. Therefore, the stray light problem has not been significantly improved.

The ion guide allows all ions to pass through without mass separation, and the quadrupole mass analyzer has the same mechanical structure and coupling (conduction) state, but only high-frequency voltage. Is applied and no DC voltage is applied. The high frequency voltage is customarily called the V voltage and the DC voltage is called the U voltage. In this specification, a quadrupole electric field having a mass analysis function as a mass analyzer is referred to as “a quadrupole electric field with U”, an ion guide. A quadrupole electric field having no mass spectrometric function is referred to as “U-less quadrupole electric field”.

Since the ion guide does not perform mass fractionation, the accuracy of the electrodes (particularly, the accuracy with which the four electrodes are arranged in parallel) is not as required as the mass analyzer. Therefore, although the conventional ion guide uses an electrode having a curvature, the fixing method is basically the same as the method of the mass analyzer (FIGS. 1B to 1E).

2B to 2E are cross-sectional views showing how a conventional ion guide is fixed.
For example, in FIG. 2B, the cylindrical electrodes 33a to 33d of the ion guide are fixed by screws 34 inside the insulating support 35 having a hollow structure. FIG. 2B is a cross-sectional view of FIG.
Although the same fixing method as that shown in FIG. 2C, since the insulating support bodies 2 to 3 having a short length in the longitudinal direction are arranged with an inclination as shown in FIG. 2C, the cost increases. FIG. 2D) also shows a structure in which the metal parts 39a to 39d are fixed to the insulating support 38 by screws 34 (see Patent Document 6).

However, in FIG. 2D, the insulating support 38 has a very complicated shape, and the cost problem is counterproductive even if the number of parts is reduced. Note that not only the structure shown in FIG. 2D but also in FIGS. 2A and 2B, the influence of “bending” is strong, and it is difficult to achieve accuracy throughout. Therefore, in this state, the structure shown in FIGS. 2A to 2D can be used as an ion guide, but cannot be used as a mass analyzer.

On the other hand, Patent Document 5 discloses an ion filter in which a curved ion guide and a curved quadrupole mass spectrometer are arranged between an ion source and a detector.
2E is a perspective view of the curved quadrupole mass spectrometer disclosed in Patent Document 5, and FIG. 2F illustrates how to assemble the curved quadrupole mass spectrometer shown in FIG. 2E. It is a figure for doing.

2E, the curved quadrupole mass spectrometer 40 includes an insulating support 41 and metal parts 43 to 46 fixed to the insulating support 41 with screws 42. These metal parts 43 to 46 function as quadrupole electrodes and have hyperbolic surfaces 43c to 46c. In this way, the surfaces 43c to 46c are arranged so as to face each other, thereby forming a quadrupole electric field.

More specifically, as shown in FIG. 2F, a plurality of through holes 49 are provided in the first surface 47 of the insulating support 41 and the second surface 48 facing the first surface 47. It has been. Each of the metal parts 43 to 46 functions as a quadrupole electrode and is curved. The metal part 43 has a hyperbolic surface 43c and a plurality of support spokes 43a, and a through hole 43b is formed in each of the support spokes 43a. The metal part 44 has a hyperbolic surface 44c and a plurality of support spokes 44a, and through holes (not shown) are formed in each of the support spokes 44a. Similarly, the metal parts 45 and 46 have hyperbolic surfaces 45c and 46c and a plurality of support spokes 45a and 46a, respectively, and through holes 45b and 46b are formed in the support spokes 45a and 46a, respectively. ing.

In Patent Document 5, each of the support spokes 43a is provided on the first surface 47 side of the insulating support 41 by passing the screws 42 through the through holes 43b, the through holes 49, and the through holes formed in the support spokes 44a. The support spokes 44 a are fixed to the second surface 48 side of the insulating support 41. Similarly, each of the support spokes 45a is fixed to the first surface 47 side of the insulating support body 41 by passing the screw 42 through the through hole 45b, the through hole 49, and the through hole 46b. The support spoke 46a is fixed to the second surface 48 side.

Japanese Patent Laid-Open No. 5-74411 JP 2006-33003 A JP-A-63-152846 JP-A-8-96709 US Pat. No. 5,559,327 US Pat. No. 6,576,897

As described above, in the technique disclosed in Patent Document 5, since the metal parts to be the quadrupole electrodes are fixed to the insulating support body 41 by the plurality of support spokes, the parallelism with respect to each of the surfaces 43c to 46c is improved. It is very difficult to do. This is because each of the four metal parts 43 to 46 to be arranged in parallel has a plurality of support spokes and through holes formed in the support spokes so that the surfaces 43c to 46c are parallel to each other. In addition, each of the many through holes must be formed accurately. That is, each of the metal parts 43 to 46 has three objects to be adjusted so as to establish a parallel relationship so that the surfaces 43c to 46c are parallel to each other. For example, the metal part 43 establishes the positional relationship with the metal part 44 so that the surface 43c and the surface 44c are parallel, and the positional relation with the metal part 45 so that the surface 43c and the surface 45c become parallel. In addition, it is necessary to establish a positional relationship with the metal part 46 so that the surface 43c and the surface 46c are parallel to each other. Thus, positioning must be performed while aligning with the through holes of other metal parts positioned in this manner.

Further, even if the through holes formed in the support spokes are positioned, there are a plurality of support spokes that should form the through holes, so each through hole must be accurately formed in the support spoke. Very high strictness is required for through-hole forming processing. Furthermore, since each support spoke is fixed to the insulating support body 41 through a plurality of through holes 49, the above through holes 49 are also required to be processed very strictly.

As described above, in Patent Document 5, there are many reference points (such as through holes formed in the support spokes and through holes formed in the insulating support 41) as factors that determine the parallelism of the surfaces 43c to 46c. There will be a separate reference point. Therefore, unless the through holes, each of the metal parts having the support spokes, and the insulating support 41 are made precisely, the parallelism of the surfaces 43c to 46c cannot be expected. Further, as described above, since there are many factors that determine the parallelism, the process of adjusting them is complicated and takes a lot of time and effort.

Further, in Patent Document 5, the metal parts 43 to 46 have a very complicated shape, which increases costs.

Furthermore, in Patent Document 5, each of the metal parts 43 to 46 serving as the quadrupole electrodes has support spokes, so there is a limit to downsizing the quadrupole mass spectrometer 40. As can be seen from FIGS. 4 and 5, the support spoke has a complicated structure and is difficult to manufacture. Therefore, when the support spoke is further reduced, it becomes more difficult to produce the support spoke. Further, the support spoke must be formed with a through hole for fixing the support spoke to the insulating support 41, and in order to stably fix the support spoke to the insulating support 41 while forming the through hole. The support spokes need to secure a certain length.

The present invention has been made in view of such problems, and the object of the present invention is to reduce the incidence of stray light from the ion source on the detector and to increase the sensitivity (S / N). It is an object of the present invention to provide a quadrupole mass spectrometer that can be miniaturized.

Furthermore, another object of the present invention is to reduce the incidence of stray light from the ion source to the detector while improving the accuracy of the parallelism of the quadrupole electrode and increasing the resolution. It is an object of the present invention to provide a quadrupole mass spectrometer that can be configured.

In order to achieve such an object, one embodiment of the present invention is a quadrupole mass spectrometer that includes an ion source that ionizes neutral molecules and emits ions, and four non-linear electrodes. A quadripole in a region surrounded by the four electrodes by applying a voltage in which a DC voltage and a high-frequency voltage are superimposed between two opposing electrode sets of the four electrodes. A mass separation region for performing mass fractionation of the ions passing through the quadrupole field by forming an electric field; a detector for detecting the ions that have passed through the mass separation region as signals; and a concentric fit A plurality of plate-like insulating supports having mating portions, wherein the mass fractionation region is non-linear, and the non-linear mass fractionation region allows the detector to pass through the mass fractionation region from the ion source. So as not to expect The mass separation region is configured, and the four electrodes are at least a part of four concentric annular electrodes, and each of the four annular electrodes is formed on a part of the insulating support. The conductive film is assembled by a circularly symmetrical fitting between the insulating supports by the fitting portion.

Another aspect of the present invention is a quadrupole mass spectrometer, a mass fractionation region having an ion source that ionizes neutral molecules and emits ions, and four non-linear electrodes, A quadrupole electric field is formed in a region surrounded by the four electrodes by applying a voltage in which a DC voltage and a high-frequency voltage are superimposed between two opposing electrode sets among the four electrodes, and the quadrupole electric field is formed. A mass fractionation region for mass fractionation of the ions passing through the polar electric field; and a detector for detecting the ions that have passed through the mass fractionation region as signals. The mass fractionation region is non-linear. The mass fractionation region is configured such that the non-linear mass fractionation region prevents the detector from being viewed from the ion source through the mass fractionation region, and the four electrodes are concentric four annular rings. Less of electrode Also part, the four annular electrodes, characterized in that it is assembled by fitting the plate-like insulating support having a concentric fitting portion.

According to the present invention, the detector is configured such that the detector cannot be expected through a portion surrounded by four electrodes for forming a quadrupole electric field having a U necessary for mass spectrometry from the ion source. Incident stray light can be reduced. Furthermore, by forming the four electrodes in a concentric ring shape, the four electrodes can be arranged with high parallelism.

It is a block diagram of the conventional quadrupole-type mass spectrometer to which a DC voltage is applied. It is sectional drawing which shows a mode that the electrode of the conventional quadrupole-type mass spectrometer to which a DC voltage is applied is fixed. It is sectional drawing which shows a mode that the electrode of the conventional quadrupole-type mass spectrometer to which a DC voltage is applied is fixed. It is sectional drawing which shows a mode that the electrode of the conventional quadrupole-type mass spectrometer to which a DC voltage is applied is fixed. It is sectional drawing which shows a mode that the electrode of the conventional quadrupole-type mass spectrometer to which a DC voltage is applied is fixed. It is a block diagram of the conventional quadrupole-type mass spectrometer provided with the ion guide to which a DC voltage is not applied. It is sectional drawing which shows a mode that the conventional ion guide is fixed. It is sectional drawing which shows a mode that the conventional ion guide is fixed. It is sectional drawing which shows a mode that the conventional ion guide is fixed. It is a perspective view of the conventional curved quadrupole mass spectrometer. It is a figure for demonstrating how to assemble the curved quadrupole-type mass spectrometer shown by FIG. 2E. It is a figure which shows the structure of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. FIG. 3B is a cross-sectional view of the quadrupole mass spectrometer shown in FIG. 3A. FIG. 3B is a circuit diagram of the quadrupole mass spectrometer shown in FIG. 3A. It is a figure which shows the structure of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer shown to FIG. 3D, Comprising: The mode of fitting with an annular electrode and an annular | circular shaped insulation support body, and an annular shape It is a figure which shows the mode of fitting of other insulation support bodies. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer shown to FIG. 3D, Comprising: The mode of fitting with an annular electrode and an annular | circular shaped insulation support body, and an annular shape It is a figure which shows the mode of fitting of other insulation support bodies. It is a figure which shows the structure of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is a figure which shows each insulation support body of the quadrupole-type mass spectrometer shown to FIG. 4A. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer shown to FIG. 4B, Comprising: It is a figure which shows the mode of each fitting of an annular | circular shaped insulation support body. It is a figure which shows the structure of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is a figure which shows each insulation support body of the quadrupole-type mass spectrometer shown to FIG. 5A. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer shown to FIG. 5B, Comprising: It is a figure which shows the mode of each fitting of an annular | circular shaped insulation support body. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention, Comprising: It is a figure which shows the mode of each fitting of an annular | circular shaped insulation support body. is there. It is a figure explaining the mode of fitting of the circularly symmetric thing of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention, Comprising: It is a figure which shows the mode of each fitting of an annular | circular shaped insulation support body. is there. It is sectional drawing seen from the upper direction of the annular ring of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is sectional drawing seen from the upper direction of the annular ring of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is sectional drawing seen from the upper direction of the annular ring of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is sectional drawing seen from the upper direction of the annular ring of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is sectional drawing seen from the upper direction of the annular ring of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. It is sectional drawing of the orthogonal | vertical direction of the flight direction of ion of the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention. In the quadrupole mass spectrometer shown in FIG. 3A, it is a figure for demonstrating the form which provides a spacer in the fitting part of a cylindrical electrode and an insulation support body. It is a figure which shows the mode of the fitting of the electrode which concerns on one Embodiment of this invention, and an insulation support body, and the fitting of insulation support bodies. It is a figure which shows the example which attaches the quadrupole-type mass spectrometer which concerns on one Embodiment of this invention to a sputtering device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.
In one embodiment of the present invention, the four electrodes (quadrupole electrode) provided in the quadrupole mass spectrometer are configured so that the cross section of the quadrupole electrode satisfies a specific relationship regarding the curvature and position of the electrode in each cross section. The longitudinal direction is concentric "annular" so that stray light from the ion source does not enter the detector or reduces the incidence of the stray light, and these quadrupole electrodes are fitted to each other so ] To improve the accuracy of the parallelism of the electrodes.

Conventional mass spectrometers have a basic structure that uses a straight electrode as a quadrupole electrode to “directly” provide “accuracy regarding the center of the quadrupole electric field, that is, the trajectory of ions”. On the other hand, in one embodiment of the present invention, an "indirect" is obtained by using an annular electrode as a quadrupole electrode to obtain "accuracy with respect to an annular concentric point". Has a higher accuracy with respect to the center of the quadrupole electric field, that is, the ion trajectory, and can be realized more easily. In other words, accuracy could not be achieved with the conventional ion guide due to “bending of the electrode”, but in one embodiment of the present invention, the “bending of electrode” was successfully developed to “fit”. Yes.

Further, in the quadrupole mass spectrometer according to one embodiment of the present invention, since the four quadrupole electrodes are arranged by the fitting structure, the quadrupole electrode is bent so as to reduce stray light incidence. The quadrupole mass spectrometer having the above structure can be easily downsized. For example, conventionally, as disclosed in Patent Document 5, in a structure having a curved quadrupole electrode, a support spoke and an insulating support for fixing the support spoke are required. In one embodiment, the support spokes that are difficult to reduce in size are not required by adopting the fitting structure. Therefore, it is easy to reduce the size of the quadrupole mass spectrometer.

The merit of miniaturization of the apparatus according to the present invention relating to a quadrupole mass spectrometer has the intrinsic value of expanding the upper limit of the atmospheric pressure that can be measured, in addition to saving space and reducing weight.
In order for a quadrupole mass spectrometer to operate normally, the upper limit of the pressure that can be measured is the pressure at which the mean free path of the atmosphere is approximately the same as or longer than the orbital distance (movement distance) of ions. There must be. Sputtering equipment is frequently used in advanced industries such as semiconductors, but the operating pressure of the sputtering equipment is about 0.3 Pa, and the mean free path at that time is about 10 to 20 mm. That is, a small quadrupole mass spectrometer with an orbital distance of ions of about 10 to 20 mm is required.

Since the conventional quadrupole mass spectrometer has an orbital distance of about 100 to 200 mm, downsizing of 1/10 is required. In one embodiment of the present invention, the quadrupole mass spectrometer is used. Can be reduced in size, so that the orbital distance of ions can be shortened. More importantly, in one embodiment of the present invention, even if the quadrupole electrodes are bent so as to reduce stray light incidence on the detector, the parallelism between the quadrupole electrodes is improved, The downsizing can be realized.

Now, as the atmospheric pressure is increased, the mean free path is shortened. Therefore, it is necessary to reduce the orbital distance of ions in the quadrupole mass spectrometer, but the curved quadrupole mass as shown in Patent Document 5 is required. In the analyzer, as described above, there has been a limit to the miniaturization of the quadrupole mass spectrometer, that is, the reduction of the orbital distance of ions. On the other hand, in one embodiment of the present invention, a curved quadrupole mass spectrometer can be easily downsized. Therefore, it is possible to expand the upper limit of the atmospheric pressure at which mass analysis can be performed while suppressing attenuation due to the atmosphere while reducing detection of stray light.

(First embodiment)
The element configuration of the first embodiment of the present invention is shown in FIGS. 3A to 3F.
The quadrupole mass spectrometer 100 includes an ion source 101, a quadrupole mass analyzer 102, and a detector 103. The ion source 101 and the detector 103 are surrounded by cases 108a and 108b with openings, respectively. The component to be measured (neutral molecule) becomes an ion 105 in the ion source 101, and only specific ions that meet the set conditions pass through the quadrupole mass analyzer 102 and reach the detector 103 as a signal. Detected. The ion source 101 can be the most common electron impact (EI) type ion, and the detector 103 can be a microchannel type electron multiplier plate (MCP).

As shown in FIG. 3C, the quadrupole mass analyzer 102 of the present embodiment basically has four electrodes 104a to 104d (in this specification, electrodes 104a to 104d) that are, for example, metal cylinders. A high-frequency voltage (RF) and a direct-current voltage (DC) are applied to the electrode 104 (also generally referred to as an electrode 104). Specifically, the opposing electrodes 104a and 104d (facing each other with the central axis of the mass analyzer in between) and electrodes 104b and 104c are coupled (conducted), respectively, and a DC voltage is generated between the two electrode sets. By applying a voltage superimposed with a high-frequency voltage, a quadrupole electric field 107 is formed in a region U (region where ions 105 fly) surrounded by the electrodes 104a to 104d. The center voltage of the DC voltage and the high-frequency voltage (the center potential of the quadrupole electric field) determines the axial velocity of the ions, and is determined by other requirements.

In such an electrode 104, in the cross section perpendicular to the flight direction, the curvature of each electrode and each position satisfy a specific relationship known in the art, while the longitudinal direction of the electrode is a concentric “circular ring”. (3/4 laps). In other words, in the present embodiment, the four electrodes 104 are non-linear and are annular, so the quadrupole mass analyzer 102 is also a linear ring. Therefore, the present embodiment is configured such that the detector 103 cannot be expected from the ion source 101 by the non-linear quadrupole mass analyzer 102.

Each of the four electrodes 104 is a concentric annular electrode, and two of the four electrodes 104 ( reference numerals 104a and 104c in FIG. 3B) have the same first radius, and the remaining 2 Two electrodes ( reference numerals 104b and 104d in FIG. 3B) are larger than the first radius and have the same second radius. Therefore, as shown in FIG. 3B, the parallelism between the annular electrodes 104a and 104b can be improved by arranging the annular electrodes 104a and 104b to be concentric. Similarly, by arranging the annular electrodes 104c and 104d to be concentric, the parallelism between the annular electrodes 104c and 104d can be improved. In addition to these arrangement requirements, by arranging the annular electrode 104a (104b) and the annular electrode 104c (104d) to be concentric, the annular electrode 104a (104b) and the annular electrode are arranged. The degree of parallelism with 104c (104d) can be improved, and as a result, the four annular electrodes 104a to 104d can be arranged in parallel with each other or with the degree of parallelism improved.

That is, in the present embodiment, the electrodes 104a to 104a are arranged such that the annular surface of the electrode 104a (104c) having the first radius coincides with the annular surface of the electrode 104b (104d) having the second radius. 104d are arranged concentrically. Therefore, the electrodes 104a to 104d can be arranged with high parallelism.

It is desirable that the metal cylinder used as the cylinder electrode 104 is made of stainless steel (SUS) or molybdenum (Mo). In any cross section, the curvature of each electrode and the position of each electrode maintain a system of several microns (micrometers) or less. Therefore, ions exiting the ion source 101 enter the detector 103 with a 270 ° curve.

In the annular electrode 104, the ions 105 are converged while vibrating with a high frequency voltage of several hundreds V or more and about several MHz in the cross-sectional direction, but proceed with a voltage difference of only about several V in the longitudinal direction. . Therefore, the centrifugal force generated in the ions due to the curve in the traveling direction is almost canceled by the high potential in the cross-sectional direction, so the adverse effect due to the curve is very slight. Therefore, the ion incident from the ion source 101 is detected by detecting the ion 105 to be detected by traveling in the quadrupole electric field 107 with U and being separated by mass while the annular electrode 104 is curved. Incident on the vessel 103.

On the other hand, since the ion source 101 and the detector 103 are installed in cases 108a and 108b that are closed except for the surface on the quadrupole mass spectrometer 102 side, the stray light 106 from the ion source 101 is quadruple. There is a possibility of being incident on the detector 103 only by reflection inside the polar mass analyzer 102. However, since the quadrupole mass spectrometer 102 is curved as much as 270 °, the incident light to the detector 103 is limited to only one reflected several times. Since the reflectivity is several tens of percent and each of the electrodes 104 is round, the amount of light attenuates and spreads outward each time it is reflected, so that the amount of stray light 106 that finally enters the detector 103 is extremely small. As described above, in this embodiment, the quadrupole mass analyzer 102 that can perform mass analysis by applying both a DC voltage and a high-frequency voltage is non-linear, and the non-linear quadrupole. The ion source 101 and the detector are prevented from being detected by the polar mass analyzer 102 through the portion surrounded by the four electrodes 104 that are components of the quadrupole mass analyzer 102 from the ion source 101. 103 and the quadrupole mass analyzer 102 are configured. For example, in the present embodiment, since the ion source 101 has the case 108a and the detector 103 has the case 108b, the ions 105 and the stray light 106 are on the left side of the ion source 101 in FIG. 3A. Since the cases 108a and 108b are obstructed, a configuration in which the detector 103 cannot be expected from the ion source 101 is realized. Further, on the right side of the ion source 101 in FIG. 3A, the quadrupole mass analyzer 102 is formed in a non-linear annular shape, so that a configuration in which the detector 103 cannot be expected from the ion source 101 is realized. ing. Therefore, the ions 105 that are desired to be detected can reach the detector 103, and the amount of stray light 106 that is not desired to be detected can be reduced. Therefore, detection of noise in the detector 103 can be reduced, and sensitivity (S / N ratio) can be increased.

In this way, by bending the quadrupole mass analyzer 102 itself, through the portion surrounded by the four electrodes 104a to 10d (bent electrodes) of the quadrupole mass analyzer 102 from the ion source 101. This is preferable because the detector can be prevented from being expected and the incidence of the stray light 106 on the detector 103 can be reduced. Here, considering that the quadrupole mass analyzer 102 operates well, it is more preferable to arrange the four bent electrodes with high parallelism. In order to achieve this, it is required to arrange at least the electrodes 104a to 104d with the parallelism required for the user to perform a desired measurement.

Conventionally, as shown in FIG. 2A, the electrode is bent in order to reduce the incidence of stray light on the detector, but the configuration of bending this electrode is to form a U-less quadrupole field. It is an ion guide, not a mass analyzer with a U-containing quadrupole field. That is, conventionally, in order to reduce the incidence of the stray light 6 on the detector 3, it is necessary to provide an ion guide 30 that is curved separately from the mass analyzer 2. This is because even if the cylindrical electrode 4 of the mass analyzer 2 is bent, it is still required to arrange the four electrodes necessary for the mass analysis in parallel as much as possible, and the four bent electrodes are highly parallel to each other. Arranging at a degree is associated with considerable difficulty. That is, as described in the explanation of FIGS. 1B to 1E, it is costly and troublesome to arrange only four straight electrodes, but arranging bent electrodes with improved parallelism is more costly and troublesome. Will take. On the other hand, since the ion guide does not perform mass spectrometry, it is not necessary for the four bent electrodes to have high parallelism. Therefore, conventionally, the mass analyzer itself is configured with straight electrodes in view of labor and cost, and the ion guide that does not cost and labor is arranged separately from the mass analyzer to reduce the influence of stray light. Yes. In this way, considering productivity and cost in consideration of the parallelism of the four electrodes included in the mass spectrometer, it is further costly to arrange four electrodes that are costly and troublesome even with linear electrodes as much as possible. There is no motivation to reduce the effect of stray light by realizing it in a bent electrode which takes time and effort, and there is no need to worry about the parallel arrangement of electrodes in order to reduce the effect of stray light. Conventionally, a guide is provided separately.

In contrast to such a conventional technique, in this embodiment, two annular electrodes ( electrodes 104a and 104c) having a first radius and two annular electrodes having a second radius larger than the first radius are used. A quadrupole mass spectrometer 102 is formed using electrodes ( electrodes 104b and 104d). Therefore, by arranging the four electrodes concentrically, the electrodes can be arranged with high parallelism simply and at low cost. This is because a technique for processing an annular object with high accuracy has been established, and by using this technique, concentric annular electrodes having a uniform radius (a pair of electrodes 104a and 104c, and electrodes 104b and 104d). Since the electrodes are annular, when the four electrodes 104a to 104d are arranged, the reference points for the arrangement of the respective electrodes can be set at the same point. is there.

That is, in the case of the conventional linear electrode, when four electrodes are arranged in parallel, there is no reference point for parallel arrangement (the reference point does not exist in the electrode). It was necessary to put out accuracy. However, in the present embodiment, two annular electrodes 104a and 104c (inner electrodes arranged on the inside) having the same diameter and two annular electrodes 104b and 104d (outside) having a larger diameter than the inner electrodes. Four annular electrodes with the arranged outer electrode) are prepared, and two pairs are arranged in which the inner electrode is arranged concentrically inside the outer electrode (first pair (electrode 104a and electrode 104b) and second pair Pair (electrode 104c and electrode 104d), and these pairs are spaced apart in the left-right direction (the in-plane vertical direction of the annular electrode, the left-right direction in FIG. 3D). Since the inner electrode and the outer electrode are annular, the parallelism between the outer electrode and the inner electrode can be improved by arranging them concentrically.

In the left-right direction, the first pair of inner electrodes and the second pair of inner electrodes face each other (facing each other with the central axis of the mass analyzer in between), and the first pair of outer electrodes and the second pair Of the first pair of inner electrodes and the second pair of inner electrodes, and between the first pair of outer electrodes and the second pair of outer electrodes. As described later, a spacer having the same thickness (for example, insulating supports 111a and 111b described later) is inserted between the first pair and the second pair as much as possible. it can.
As a result, in the present embodiment, it is possible to arrange the bent electrodes with high parallelism by a simple method.

Here, as shown in FIG. 3C, the electrodes 104a and 104d are electrically coupled, and the electrodes 104b and 104c are electrically coupled, and a high frequency voltage (RF) and a direct current are connected between these two electrode sets. By applying a voltage superimposed with a voltage (DC), a quadrupole electric field 107 with U is formed, and mass spectrometry can be performed. That is, each electrode is arranged concentrically using an annular electrode 104, and further, a high frequency voltage and a direct current voltage are applied to the annular electrode 104, so that the quadrupole mass analyzer 102 has a stray light reduction function. And a mass spectrometric function.

As described above, in the present embodiment, by arranging the four annular electrodes concentrically, the portions surrounded by the four electrodes 104a to 104d from the ion source 101 while arranging each electrode with high parallelism. Thus, it is possible to realize a configuration in which the detector 103 cannot be expected. In other words, in the present embodiment, by incorporating a stray light reduction function into the mass analyzer, it is possible to suppress the incidence of stray light to the detector without providing an ion guide separately as in the prior art. In other words, even if a stray light reduction function is added to the quadrupole mass spectrometer, it is not necessary to separately provide a complicated configuration such as an ion guide, thereby realizing cost reduction and downsizing of the apparatus. Can do.

Hereinafter, a method for assembling the annular electrode and its merit will be described in detail. That is, in the following, a configuration in which an annular electrode can be arranged with high parallelism by a simple method will be described.
FIG. 3D is a diagram illustrating a configuration for arranging the annular electrodes 104 provided in the quadrupole mass spectrometer according to the present embodiment with high parallelism. The left figure of FIG. 3D is a cross-sectional view perpendicular to the flight direction of the ions 105 (3β cross-section of the right figure of FIG. 3D), and the right figure of FIG. (3α cross section in the left figure of 3D).

For the assembly in this embodiment, in addition to the four annular electrodes, an insulating support that determines the position while insulating them is important. Examples of the insulating support include machinable ceramics (ceramics that can be machined, such as Macor, Photovale, Macerite, etc.) in view of electrical insulation and workability. In the present embodiment, the insulating supports 111a, 111b, 112a, and 112b are formed of such materials.

The insulating supports 112a and 112b are formed in the same concentric annular shape as the annular electrode 104, and their cross sections have this character shape. The position of the electrode having a large ring diameter is determined by the surface facing the center direction on the outside of the character, and the position of the electrode having a small ring diameter is determined by the surface facing the outside direction on the inside. For example, in the insulating support 112a, the position of the electrode 104a having a small diameter is determined by the surface 113a facing the outer direction inside the character, and the diameter is determined by the surface 113b facing the center direction outside the character. The position of the large electrode 104b is determined. Similarly, in the insulating support 112b, the position of the electrode 104c having a small diameter is determined by the surface 113c facing the outer direction inside the character, and the surface 113d facing the central direction outside the character. Thus, the position of the electrode 104d having a large diameter is determined. These are all positioning in the radial direction of the ring (vertical direction in the figure), and the method is based on fitting of circularly symmetric objects. That is, each of the annular electrode 104 and the insulating supports 112a and 112b is a concentric annular shape, and the annular electrode 104 is fitted to this character structure of the annular insulating supports 112a and 112b. Yes.

The positioning of the ring in the axial direction (left-right direction in the figure) is not a fit but a method similar to the conventional method. That is, the axial positioning is performed using an annular insulating support 111a and an annular insulating support 111b having a diameter smaller than that of the insulating support 111a as spacers.

3E and 3F show details of an assembling method by fitting circularly symmetric objects of the quadrupole mass spectrometer shown in FIG. 3D. The electrodes 104a to 104d are positioned by the respective surfaces of the corresponding insulating supports 112a and 112b. Furthermore, the insulating supports 112a and 112b are also positioned by fitting circularly symmetrical objects. Therefore, each of the electrodes 104a to 104d has a structure that provides accuracy with reference to a common center point (concentric point).

For example, in the case of <electrode 104bvs insulating support 112a>, as shown in FIG. 3E, when the annular electrode 104b is fitted to the insulating support 112a, the insulating support is provided along the circumferential direction of the annular electrode 104b. A fitting portion is formed between the surface 113b of the body 112a and the electrode 104b. Here, the electrode 104b is fitted by the presence of the surface 113b by producing the electrode 104b and the insulating support 112a so that the outer wall surface (surface 113b) of this character in the cross section of the insulating support 112a is fitted. The insulating support 112a is fixed in place. On the other hand, in the case of <electrode 104avs insulating support 112a>, as shown in FIG. 3E, when the annular electrode 104a is fitted to the insulating support 112a, the insulating support is provided along the circumferential direction of the annular electrode 104a. A fitting portion is formed between the surface 113a of the body 112a and the electrode 104a. Here, the electrode 104a is fitted by the presence of the surface 113a by making the electrode 104b and the insulating support 112a so as to be fitted to the inner wall surface (surface 113a) of this character in the cross section of the insulating support 112a. The insulating support 112a is fixed in place.

At this time, each of the insulating support 112a and the electrode 104b and the insulating support 112a and the electrode 104a, which are fittings of circularly symmetrical objects, are positioned with reference to a common center point (concentric point). Therefore, as a result, the electrodes 104a and 104b are also positioned with respect to a common center point (concentric point). Therefore, the electrode 104a and the electrode 104b can be arranged with high parallelism.
Although the description is omitted here, the same applies to <electrode 104cvs insulating support 112b> and <electrode 104dvs insulating support 112b> in FIG. 3F. Further, by providing a structure in which the insulating supports 112a and 112b are fitted to each other, as shown in <Insulating Support 112avs Insulating Support 112b> in FIG. 3F, circular symmetry with respect to a common center point (concentric point). A fitting part of the object is formed. As a result, the electrode 104a and the electrode 104c are positioned with respect to a common center point (concentric point). Similarly, the electrodes 104b and 104d are also positioned with reference to a common center point (concentric point). Accordingly, the electrode 104a and the electrode 104c, and the electrode 104b and the electrode 104d can be arranged with high parallelism, and as a result, the electrodes 104a to 104d can be arranged with high parallelism with each other.

Conventionally, as disclosed in Patent Document 5 (see FIGS. 2E and 2F), when forming a curved quadrupole mass spectrometer, a reference for arranging four quadrupole electrodes in parallel with each other Since there are a plurality of points, the parallelism of the quadrupole electrode cannot be improved unless each of the plurality of reference points is formed with high accuracy. Therefore, it is necessary to accurately position the plurality of reference points. The through holes formed in the support spokes 43a to 46a and the insulating support 41 for fixing the support spokes are used as reference points. It is necessary to precisely process the through hole.

In contrast, in the present embodiment, each of the annular electrodes 104a to 104d included in the quadrupole mass spectrometer 100 is fitted to one of the annular insulating supports 112a and 112b, and The insulating supports 112a and 112b are fitted together. Since the fitting is a fitting of a circularly symmetric object, as a result, each of the annular electrodes 104a to 104d and the annular insulating supports 112a and 112b is based on the same reference point (concentric point). Thus, the electrodes 104a to 104d can be arranged with a high degree of parallelism.

Further, in the present embodiment, since the electrodes 104a to 104d are fixed by the fitting structure as described above, a support spoke that extends inward and is difficult to be miniaturized is required as in Patent Document 5. do not do. In other words, the curved electrodes 104a to 104d (quadrupole electrodes) can be fixed with high parallelism without using support spokes that are rate-limiting for downsizing. Therefore, it is possible to reduce the size of the apparatus while reducing the detection of stray light and improving the parallelism of the quadrupole electrode.

In this embodiment, as shown in FIG. 3D, the electrode 104a and the electrode 104b are fitted to the insulating support 112a, and the electrode 104c and the electrode 104d are fitted to the insulating support 112b. Then, the insulating support 112a and the insulating support 112b are fitted together via the insulating supports 111a and 111b, and the insulating supports 112a and 112b are fixed to the insulating supports 111a and 111b with screws 114. In this way, the quadrupole mass analyzer 102 in which the annular electrodes 104a to 104d are arranged with high parallelism is formed.

As described above, the essential merit of the annular shape is a significant improvement in accuracy due to “fitting of circularly symmetric objects”. The main reasons for this are as follows.
1) A circularly symmetric object can achieve high accuracy with respect to the size of the diameter.
In particular, it is important that not only the absolute value of the dimension but also the variation in dimension at each point on the circumference is very small. This is natural from the principle of processing such as a lathe that rotates the workpiece to cut. In addition, in a quadrupole mass spectrometer, the absolute value of the dimension itself may vary by several tens of μ to several hundreds of μ, but the value must match within a few microns in the longitudinal direction of the electrode. I must. This demands that there is little dimensional variation at each point on the circumference, which is in good agreement with the processing characteristics of a circularly symmetric object.

2) The gap in the fitting can be made very small.
There is always a gap required for fitting, which is a deviation, but there is a technology established by many years of research on this value for fittings that are circularly symmetric, and design, processing, and assembly are performed accordingly. If this is done, the minimum gap can be realized. Specifically, a gap of several tens of micrometers or less is sufficiently possible.

3) Even if there is a gap, the final position is likely to be a concentric correct position.
For circularly symmetric objects, unless a force is applied in a direction perpendicular to the axis, the concentric position is stable and almost always fits there. Therefore, even if there is a gap, it is actually fixed at an original position in the middle, that is, a concentric correct position.

4) Less affected by deformation due to thermal expansion and internal stress.
Since they are circularly symmetric and fitted, even if they are deformed by thermal expansion or internal stress, they are not in the direction of mutual axis misalignment (deterioration of parallel accuracy of electrodes). Even if it is deformed, only the absolute value of the diameter changes, and it becomes irrelevant to the parallel accuracy in the longitudinal direction, which is important in a quadrupole mass spectrometer.

In the vicinity of the ion source 101 and the detector 103, the electrodes 104a to 104d, which are metal cylinders, are partially cut away to avoid interference. That is, the notch 110 a is provided in the electrode 104 around the ion source 101, and the notch 110 b is provided in the electrode 104 around the detector 103. This may have some effect on the accuracy of a circularly symmetric object, but mass separation is not performed at the notched part, and the circular shape of the metal cylinder remains unchanged (the ring is broken). Is not considered to be a big problem.

Now, in this embodiment, in order to realize a mass analysis function in the quadrupole mass analyzer 102 formed by the four electrodes 104, it is an object to arrange the four electrodes 104 with high parallelism to each other. Although it is one, it is not intended to be completely parallel. Although it is of course a preferred embodiment to be perfectly parallel, the above object of the present invention can be achieved even if it is not perfectly parallel. For example, even if the annular electrode 104 and the insulating supports 112a and 112b are manufactured with high accuracy, an error always occurs. Therefore, even if the quadrupole mass analyzer is configured by the method of this embodiment, the electrode 104 is It may be displaced from parallel. However, even if it is not completely parallel, it suffices if the degree of parallelism can be realized so that the measurement desired by the user at that time can be performed. In other words, if the electrodes bent in order to reduce the influence of the stray light 106 are arranged with a low degree of parallelism, the mass spectrometry function may not be achieved. Therefore, if the electrodes 104a to 104d can be arranged with a high degree of parallelism, the mass analyzer formed by the electrodes can realize a mass analysis function sufficient for performing the measurement desired by the user, and is favorable. Mass spectrometry can be performed. Therefore, in this embodiment, it is only necessary that the longitudinal directions of the respective electrodes are aligned to such an extent that a desired measurement accuracy can be realized, and the electrodes need not be completely parallel.

In one embodiment of the present invention, the four quadrupole electrodes for forming a quadrupole electric field with U, which are constituent elements of a quadrupole mass spectrometer, are non-linear (annular or the like). These four electrodes (an annular cylindrical electrode as in the present embodiment, an annular conductive film as in the second embodiment, etc.) are used. That is, as described above, in order to incorporate the stray light reduction function into the quadrupole mass analyzer for mass separation, the four quadrupole electrodes are formed into an annular shape, and the closed loop of the annular electrode of the quadrupole electrode is formed. Ion source and detector are built in. Therefore, in the present invention, as in the sixth to eighth embodiments to be described later, a part of the quadrupole electrode (region between the ion source and the detector) is cut off, Thus, there exists a form in which the quadrupole electrodes are connected in a closed loop shape.

In the form in which the quadrupole electrodes are connected in a closed loop shape as in this embodiment, a high-frequency voltage and a direct-current voltage may be applied to a region where ions do not actually pass. In the present invention, the quadrupole electrode is formed in an annular shape, an ion source and a detector are incorporated in the annular quadrupole electrode, and the quadrupole mass analyzer itself has a function of reducing stray light. However, the fact that the ions emitted from the ion source are separated by mass in a quadrupole electric field with U and made incident on the detector is the same as before. Therefore, in the present invention, a region in which a quadrupole electric field with U is formed and ions fly (pass through) (that is, a mass separation region) is called a quadrupole mass analyzer.

(Second Embodiment)
A quadrupole mass spectrometer according to a second embodiment of the present invention will be described with reference to FIGS. 4A, 4B, and 4C. In this embodiment, a metal film coated on the surface of an insulating support is used as an electrode of a quadrupole mass spectrometer, not a metal cylinder. Although the metal film is not limited, gold (Au) or chromium (Cr) can be used, and the thickness is preferably about 1 micrometer. Further, the member formed on the surface of the insulating support is formed to form a quadrupole electric field with U, and a conductive material that can form a quadrupole electric field with U by applying a high-frequency voltage and a DC voltage. If it is a film | membrane, it may not be a metal film.

The portion of the insulating support on which the electrode film is formed is processed into a shape in which a quadrupole electric field is formed. This shape is not an arc shape but a hyperbolic shape capable of forming a more accurate quadrupole electric field. Incidentally, it is very difficult to form a hyperbolic shape when using a metal cylinder, but it is feasible when the coating surface of the insulating support is used as in this embodiment. Explaining the difficulty of processing, the portion of the insulating support corresponding to the electrode is circularly symmetric with respect to the concentric point. It is only necessary to slowly shift the cutting blade (bite) applied to to the concentric point direction. Therefore, a hyperbolic shape is realized in the insulating support by simply matching the shift shape of the cutting blade to the hyperbola, but this is not a problem at all if it is an NC (numerical) control type processing apparatus. In addition, rotating around the concentric point greatly contributes to the improvement of parallelism. Even when a die is used instead of cutting each time, the same merit is obtained in the production of the die. Others are the same as those in the first embodiment.

FIG. 4A is a diagram showing a configuration of a quadrupole mass spectrometer according to the present embodiment. 4A is a cross-sectional view perpendicular to the flight direction of the ions 105 (4β cross-section of the right view of FIG. 4A), and the right view of FIG. 4A is a cross-sectional view of the ions 105 on the annular flight surface (FIG. 4). 4A (the 4α cross section in the left figure).

4A, each of the insulating supports 141a to 141d is a concentric annular shape and has a hyperbolic surface. The hyperbolic surfaces are each formed in an annular shape. The annular insulating supports 141a and 141c have the same diameter, and the annular insulating supports 141b and 141d have the same diameter. Metal films 140a to 140d are formed in an annular shape on the hyperbolic surfaces of the insulating supports 141a to 141d, respectively. In this embodiment, since a high frequency voltage and a direct current voltage are applied between the electrode sets of the metal coatings 140a and 140d and the electrode sets of the metal coatings 140b and 140c, the region surrounded by the metal coatings 140a to 140d (ion 105 A quadrupole electric field 107 is formed in the U).

FIG. 4B is a diagram showing the insulating supports 141a to 141d shown in FIG. 4A. As shown in FIG. 4B, the insulating supports 141d and 141b are just in a mirror image relationship (first mirror image relationship), and the insulating supports 141a and 141c are just in a mirror image relationship (second mirror image relationship). is there. The insulating support 141a is configured to fit with the insulating support 141b, and the insulating support 141c in a second mirror image relationship with the insulating support 141a is configured to fit with the insulating support 141d. ing. The insulating support 141b is configured to be fitted to both of the insulating supports 141a and 141d, and the insulating support 141d in a first mirror image relation with the insulating support 141b is the insulating support 141b. It is configured to fit both sides.

FIG. 4C shows how the insulating supports 141a to 141d are fitted.
As shown in FIG. 4C, a fitting portion is formed by fitting the annular insulating supports 141b and 141d in a mirror image relationship, and the fitting portion is fixed using screws 114. Further, the insulating support 141a and the insulating support 141b are fitted together so as to be concentric to form a fitting portion, and the fitting portion is fixed by using a screw 114. Similarly, the insulating support 141c and the insulating support 141d are fitted together so as to be concentric to form a fitting portion, and the fitting portion is fixed using a screw 114.

That is, in the present embodiment, the insulating support 141a having the second mirror image relationship and the insulating support 141b having the first mirror image relationship are positioned by fitting the circularly symmetrical objects, and the second mirror image relationship is obtained. The insulating support 141c which is the first mirror image and the insulating support 141d which is the first mirror image relationship are positioned by fitting the circularly symmetrical objects. Therefore, the first structure of the fitted insulating support 141a and the insulating support 141b and the second structure of the fitted insulating support 141c and the insulated support 141d are just the third. Since the first structure and the second structure that are in the third mirror image relationship are fitted together, the hyperbolic surfaces of the insulating supports 141a to 141d have high parallelism. Can be arranged. Therefore, the metal films 140a to 140d can be arranged with a high degree of parallelism.

As described above, in this embodiment, each of the annular insulating supports 141a to 141d on which a conductive film such as a metal film is formed is configured to be fitted with at least one of the other insulating supports. With such a configuration, each of the annular insulating supports 141a to 141d is arranged with reference to the same reference point (concentric point), and as a result, the metal films 140a to 140d are made highly parallel to each other. Can be arranged. Therefore, a configuration in which the four conductive films are arranged in a highly parallel state and the detector cannot be seen through the portion surrounded by the four conductive films (for example, metal films 140a to 140d) from the ion source is realized. it can. Therefore, it is possible to reduce the incidence of stray light on the detector without providing an ion guide, and to perform mass analysis satisfactorily.

(Third embodiment)
A quadrupole mass spectrometer according to a third embodiment of the present invention will be described with reference to FIGS. 5A, 5B, and 5C. In this embodiment, there are two insulating supports, and metal films as two conductive films are formed on each insulating support. Others are the same as those in the second embodiment.

FIG. 5A is a diagram showing a configuration of a quadrupole mass spectrometer according to the present embodiment. 5A is a cross-sectional view perpendicular to the flight direction of the ions 105 (5β cross-section of the right view of FIG. 5A), and the right view of FIG. 5A is a cross-sectional view of the ions 105 on the annular flight surface (FIG. 5). 5A in the left figure of 5A).

In FIG. 5A, the insulating support 151a has an annular shape, and has two hyperbolic surfaces formed in an annular shape in the in-plane vertical direction of the annular shape. Each has an annular metal coating 150a, 150b. Similarly, the insulating support 151b has an annular shape, and has two hyperbolic surfaces formed in an annular shape in the in-plane vertical direction, and each of the hyperbolic surfaces. Are formed with an annular metal coating 150c, 150d. In the present embodiment, since a high frequency voltage and a direct current voltage are applied between the electrode sets of the metal coatings 150a and 150d and the electrode sets of the metal coatings 150b and 150c, the region surrounded by the metal coatings 150a to 150d (ion 105 A quadrupole electric field 107 is formed in a region where U is flying.

FIG. 5B is a diagram showing the insulating supports 151a and 151b shown in FIG. 5A. As shown in FIG. 5B, the insulating supports 151a and 151b are just mirror images of each other, and the insulating supports 151a and 151b are opposed to the formed metal film (with the central axis of the mass analyzer in between). Are configured to fit each other. In addition, hyperbolic surfaces 152a and 152b are formed in the in-plane vertical direction of the ring of the insulating support 151a. These hyperbolic surfaces 152a and 152b have an annular shape concentric with the insulating support 151a, and are formed so as to be arranged with a high degree of parallelism. Similarly, hyperbolic surfaces 152c and 152d are formed in the in-plane vertical direction of the ring of the insulating support 151b. These hyperbolic surfaces 152c and 152d have an annular shape concentric with the insulating support 151b, and are formed so as to be arranged with a high degree of parallelism.

FIG. 5C shows how the insulating supports 151a and 151b are fitted together.
As shown in FIG. 5C, a fitting portion is formed by fitting annular insulating supports 151a and 151b having a mirror image relationship, and the fitting portion is fixed using screws 114. In other words, in the present embodiment, the insulating support 151a and the insulating support 151b that are mirror images are set to have the same reference point (concentric point) so that the metal films 150a and 150b and the metal films 150c and 150d face each other. Fits to the standard. Therefore, the pair of metal films 150a and 150b arranged with high parallelism and the pair of metal films 150c and 150d arranged with high parallelism can be arranged with high parallelism.

As described above, in this embodiment, the annular insulating supports 151a and 151b on which a conductive film such as a metal film is formed are configured to fit with each other. With such a configuration, the annular insulating supports 151a and 151b are arranged with reference to the same reference point (concentric point), and as a result, the metal films 150a to 150d can be made highly parallel to each other. Can be arranged. Therefore, a configuration in which the four conductive films are arranged in a highly parallel state and the detector cannot be seen through the portion surrounded by the four conductive films (for example, metal films 150a to 150d) from the ion source is realized. it can. Therefore, it is possible to reduce the incidence of stray light on the detector without providing an ion guide, and to perform mass analysis satisfactorily.

In the present embodiment, while reducing the number of insulating supports on which the metal film is formed and the fitting portions, four conductive films are arranged with high parallelism, and four conductive films (for example, from the ion source 1) Further, it is possible to realize a configuration in which the detector cannot be seen through a portion surrounded by the metal films 150a to 150d). Therefore, further cost reduction can be achieved.

In the second and third embodiments, the number of insulating supports on which the metal film is formed is two and four, but may be three. In this case, for example, two hyperbolic surfaces are formed on one insulating support, one hyperbolic surface is formed on the remaining two insulating supports, and the three insulating supports are connected to each other. What is necessary is just to comprise so that it may fit.

(Fourth embodiment)
A quadrupole mass spectrometer according to the fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, in the quadrupole mass spectrometer according to the third embodiment, the shape of the portion of the insulating support where the electrode film (conductive film such as a metal film) is formed is different between the outside and the inside. Others are the same as those in the third embodiment.

In this embodiment, a relatively large hyperbolic surface 161a is formed on the inside of the ring of the insulating support 151a, and a relatively small hyperbolic surface 161b is formed on the outside of the ring. Yes. A relatively large metal film 160a is formed on the hyperbolic surface 161a, and a relatively small metal film 160b is formed on the hyperbolic surface 161b. Similarly, a relatively large hyperbolic surface 161c is formed inside the ring of the insulating support 151b, and a relatively small hyperbolic surface 161d is formed outside the ring. A relatively large metal film 160c is formed on the hyperbolic surface 161c, and a relatively small metal film 160d is formed on the hyperbolic surface 161d. That is, in this embodiment, as can be seen from FIG. 6, the metal coatings 160a and 161d arranged inside the ring and the metal coatings 160b and 160c arranged outside the ring The cross-sectional shape in the perpendicular direction is different.

In the present embodiment, since a high frequency voltage and a direct current voltage are applied between the electrode sets of the metal films 160a and 160d and the electrode sets of the metal films 160b and 160c, the region surrounded by the metal films 160a to 160d (the ions are A quadrupole electric field is formed with U in the flying region.

In this embodiment, since the insulating supports 151a and 151b on which the metal films 160a to 160d are formed are annular and curved, the traveling direction of the ions 105 is curved. The centrifugal force generated in the ions 105 due to the curve in the traveling direction is almost canceled by the high potential in the cross-sectional direction, but strictly speaking, there is a force toward the outside. In addition, although the electrode shape is symmetric in every cross section, the electric field in a certain cross section is an accumulation of the electric fields from not only the surface but also the electrodes before and after that, so strictly speaking, the electric field is not symmetric and distortion is generated. It has occurred. Therefore, the shapes of the electrodes (conductive films) on the outer side and the inner side of the ring are determined so as to correct these effects. That is, in this embodiment, the influence of the centrifugal force is further reduced by making the size of the metal films 160a and 160c inside the ring larger than the size of the metal films 160b and 160d outside the ring. be able to. Considering the influence of the centrifugal force in this way is unique to the present invention in which the electrode of the mass analyzer is bent. In the present embodiment, in consideration of the phenomenon peculiar to the present invention, the outer and inner shapes of the conductive film formed in an annular shape are set to be different.

Incidentally, when using a metal cylinder, it is very difficult to make different electrode shapes, but when using a coating surface of an insulating support as in this embodiment, it can be easily realized. However, it goes without saying that a cylindrical electrode may be used.

In this embodiment, the inner hyperbolic surfaces 161a and 161b and the outer hyperbolic surfaces 161b and 161d are changed in size, but the inner hyperbolic surfaces and the outer hyperbolic surfaces 161b and 161d are changed in size. It is not essential to change the size of the curved surface, but to change the shape of the inner electrode (conductive film) and the outer electrode (conductive film). Therefore, as long as the shape can be changed between the metal films 160a and 160c and the metal films 160b and 160d, the shapes and sizes of the hyperbolic surfaces 161a to 161d are not limited.

(Fifth embodiment)
A quadrupole mass spectrometer according to a fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, in the quadrupole mass spectrometer according to the third embodiment, the entire position of the electrode (conductive film) is rotated by 45 ° as a whole, and the electrode film of the insulating support is formed. The shape is different on the outside, middle and inside. Others are the same as those in the fourth embodiment.

In the present embodiment, the insulating support 151a is formed with two hyperbolic surfaces 171a and 171b formed along the ring of the insulating support 151a, and the hyperbolic surfaces 171a, 171a, The metal films 170a and 170b are formed on 171b. The metal film 170b corresponds to the outer electrode of the ring, and the metal film 170a corresponds to the intermediate electrode. Therefore, the metal film 170b has the smallest shape and the metal film 170c has the intermediate size. Have. Similarly, two hyperbolic surfaces 171c and 171d formed along the ring of the insulating support 151b are formed on the insulating support 151b, and the hyperbolic surfaces 171c and 171d are formed on the hyperbolic surfaces 171c and 171d. Are formed with metal films 170c and 170d. The metal film 170c corresponds to the inner electrode of the ring, and the metal film 170c corresponds to the intermediate electrode. Therefore, the metal film 170c has the largest shape, and the metal film 170d has the intermediate size. Have. Thus, in this embodiment, the four electrodes for forming a U-shaped quadrupole electric field have three radii (the largest radius electrode, the middle radius electrode, and the smallest radius electrode). Electrode). That is, in this embodiment, as can be seen from FIG. 7, the metal film 170c disposed inside the ring, the metal film 170b disposed outside the ring, and the metal films 170a and 170d disposed in the middle. Are different from each other in the cross-sectional shape in the direction perpendicular to the ion traveling direction.

In the present embodiment, since a high frequency voltage and a direct current voltage are applied between the electrode sets of the metal coatings 170a and 170d and the electrode sets of the metal coatings 170b and 170c, the region surrounded by the metal coatings 170a to 170d (the ions are A quadrupole electric field is formed with U in the flying region.

In this embodiment, the insulating supports 151a and 151b on which the metal films 170a to 170d are formed are annular and curved, so that the traveling direction of the ions 105 is curved. The shape of the three types of electrodes is determined so as to more accurately correct the influence of the centrifugal force generated in the ions and the distortion of the electric field due to the curved traveling direction.

In the present embodiment, three types of electrodes are used, but it is needless to say that all may have the same shape, or two types or four types. Furthermore, cylindrical electrodes having different shapes may be used.

(Sixth embodiment)
A quadrupole mass spectrometer according to the sixth embodiment of the present invention will be described with reference to FIG. Since a large ion source and a large detector are used, at least a part of the metal film is cut out over 1/4. Others are the same as those in the third embodiment.

FIG. 8 is a diagram showing a quadrupole mass spectrometer according to the present embodiment. In the present embodiment, an ion source 181 larger than the ion source 101 is arranged in a case 184a larger than the case 108a, and a detector 183 larger than the detector 103 is arranged in a case 184b larger than the case 108b. Yes. In the present embodiment, a notch 182 is formed in a part of a region (for example, hyperbolic surfaces 152a to 152d) along the circumference of the annular insulating supports 151a and 151b. Therefore, the notch 182 is also formed in a part (1/4 region) of the metal films 150a to 150d formed on the hyperbolic surfaces 152a to 152d. Note that the insulating supports 151a and 151b are only partially removed from the surface, so there is almost no deterioration in accuracy.

In the present embodiment, by providing the notch portion 182 and notching at least part of the metal film, a large ion source and a large detector can be provided, and formation of a useless metal film can be suppressed. it can. Since the notch 182 of this embodiment is not a region that should function as a mass separation region, it is not necessary to form an essential metal film in the mass separation region. Accordingly, by avoiding the formation of the metal film in the region other than the region functioning as the mass separation region, it is possible to reduce the formation of useless metal film, thereby further reducing the cost.

Therefore, in this embodiment, it is important to provide the notch 182 in a part of the metal films 150a to 150d, and it is not essential to form the notch 182 in the hyperbolic surfaces 152a to 152d. That is, in this embodiment, by providing a notch in at least a part of the metal film, the restriction on the size of the ion source and the detector can be relaxed, and the formation of a useless metal film can be suppressed.

(Seventh embodiment)
A quadrupole mass spectrometer according to the seventh embodiment of the present invention will be described with reference to FIG. Furthermore, since a large ion source and a large detector are used, the metal film and the insulating support are completely cut out over 1/4. Others are the same as in the sixth embodiment.

FIG. 9 is a diagram showing a quadrupole mass spectrometer according to the present embodiment. In the present embodiment, an ion source 191 larger than the ion source 181 is arranged in a case 194a larger than the case 184a, and a detector 193 larger than the detector 183 is arranged in a case 194b larger than the case 184b. Yes. In the present embodiment, a cutout portion 192 is formed in a partial region along the circumference of the annular insulating supports 151a and 151b and the metal films 150a to 150d. Note that, unlike the metal body, the insulating support is made of a very hard ceramic. Therefore, even if there is a cutout in a part, it is considered that there is little deterioration in accuracy and does not pose a major problem.

(Eighth embodiment)
A quadrupole mass spectrometer according to the eighth embodiment of the present invention will be described with reference to FIG. In order to reduce the size of the entire mass analyzer, the notch 200 is formed, and the metal films 150a to 150d and the insulating supports 151a and 151b are completely cut out over 1/2. Others are the same as those in the seventh embodiment. However, since the annular portion is half, the position is not fixed independently by fitting, so a mechanism (not shown) for pressing the insulating support 151b against the insulating support 151a is added.

As described above, in the sixth to eighth embodiments, at least one of the insulating supports 151a and 151b and the metal films 150a to 150d formed in the closed loop of the ring by forming the notches 182 192, and 200, etc. The ion source and the detector are arranged in the notch, and the insulating supports 151a and 151b and the metal films 150a to 150d may be arranged based on the same reference point (concentric point). This is one of the features of the present invention. Therefore, if the insulating supports 151a and 151b and the metal coatings 150a to 150d can be arranged concentrically, the ring will be a closed loop, but it does not matter whether a notch is partly formed. . That is, in one embodiment of the present invention, the annular metal coatings 150a to 150d are used to form a U-equipped quadrupole electric field, but the electrode portion for mass separation has a quadrupole mass. What is necessary is just to be formed at least in the area | region corresponding to a separator (mass fractionation area). Therefore, in one embodiment of the present invention, it can be said that the four electrodes included in the quadrupole mass separator (mass separation region) are at least a part of the metal films 150a to 150d. The same can be said for the cylindrical electrode of the first embodiment.

(Ninth embodiment)
A quadrupole mass spectrometer according to the ninth embodiment of the present invention will be described with reference to FIG.
In FIG. 11, an ion source 211 capable of emitting ions in two opposing directions is arranged in a case 218a having openings on opposing surfaces. A detector 213 is arranged in a case 128b having openings on the opposing surfaces. In the case 218a, an extraction electrode 211a having an opening spaced from one ion emission portion of the ion source 211 is disposed, and an extraction electrode 211b having an opening spaced from the other ion emission portion is disposed. . The ion 215a (ion that flies clockwise in FIG. 11) is emitted from the one ion emission part, and the ion 215b (ion that flies counterclockwise in FIG. 11) is emitted from the other ion emission part. Reference numeral 214 denotes four annular electrodes for forming a quadrupole electric field with U, which are the cylindrical electrodes or metal films described in the first to fifth embodiments. The annular electrodes 214 are arranged concentrically. A high-frequency voltage is applied to two of the four annular electrodes 214 facing each other, and a high-frequency voltage and a direct-current voltage between the remaining two electrode sets (facing each other with the central axis of the mass analyzer in between). Is applied to form a quadrupole electric field 217 with U.

In the present embodiment, mass separation can be performed either clockwise or counterclockwise using the ion source 211 that can emit ions in both directions and the detector 213 that can detect ions from both directions. It is the extraction electrodes 211a and 211b that can switch the voltage application to determine the ion emission. That is, when a predetermined voltage is applied to the extraction electrode 211a and 211b on the side from which ions are emitted, ions are extracted to the extraction electrode to which the voltage is applied, and formed on the extraction electrode. Ions are released through the openings.

At this time, for example, when a predetermined voltage is applied to the extraction electrode 211a and the clockwise ions 215a are emitted, the ions 215a are curved by 270 ° in the ring of the quadrupole electric field 217 with U, and the detector 218. Will be incident on. Similarly, when a predetermined voltage is applied to the extraction electrode 211b and counterclockwise ions 215b are emitted, the ions 215b enter the detector 218 after being curved by 90 ° in the ring of the quadrupole electric field 217 with U. Will do. Thus, in this embodiment, in the same quadrupole mass spectrometer, there are two mass separation regions having different lengths.

In addition, since mass separation by the quadrupole electric field 217 with U does not matter the direction of ion travel, the applied voltages to the two sets of electrodes are common in the clockwise mass analyzing unit and the counterclockwise mass analyzing unit. Yes. Therefore, although it is structurally the same as one set of mass analyzers, two types of mass analyzers having different characteristics can be made to function. The specific assembly structure uses any of the first to fifth embodiments.

Since the optimal length (longitudinal direction) of the electrode of the quadrupole mass spectrometer varies depending on the atmospheric pressure, select either one according to the pressure and perform measurement. Thereby, the measurable pressure range can be widened.

(Tenth embodiment)
A quadrupole mass spectrometer according to the tenth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, the quadrupole mass spectrometer (mass separation region) described in the above-described embodiment is arranged in multiple lanes in the radial direction of the annular electrode. In FIG. 12, an ion source 221a is disposed in the case 222a, and a detector 223a is disposed in the case 222b. Reference numeral 224a denotes four annular electrodes for forming a U-folded quadrupole electric field, which are the cylindrical electrodes or metal films described in the first to fifth embodiments. Each of the annular electrodes 224a is disposed concentrically. By applying a high-frequency voltage and a direct-current voltage between two electrode sets (facing each other with the central axis of the mass analyzer facing each other) among the four annular electrodes 224a, a quadrupole electric field 227a with U is generated. It is formed. By these components, a quadrupole mass spectrometer of the inner lane is formed, and the ions 225a emitted from the ion source 221a are detected by a detector 223a arranged so as not to be expected from the ion source 221a.

Similarly, the ion source 221b is arranged in the case 222c arranged outside the case 222a, and the detector 223b is arranged in the case 222d arranged outside the case 222b. Reference numeral 224b denotes four annular electrodes for forming a U-shaped quadrupole electric field, which are the cylindrical electrodes or metal films described in the first to fifth embodiments. Each of the annular electrodes 224b is disposed concentrically with the annular electrode 224a outside the annular electrode 224a. A high-frequency voltage and a direct-current voltage are applied between two opposing electrode sets among the four annular electrodes 224b, whereby a U-containing quadrupole electric field 227b is formed. These components form a quadrupole mass spectrometer in the outer lane, and ions 225b emitted from the ion source 221b are detected by a detector 223b arranged so as not to be expected from the ion source 221b.

Thus, in this embodiment, two sets of annular electrodes (4 × 2; 224a, 224b) having different radii have a fitting structure with respect to the same concentric point and are assembled by the same insulating support. However, in the two sets of electrodes 224a and 224b, the radial distance between the electrodes is changed. Therefore, two types of mass analyzers having different characteristics can be made to function although they are structurally substantially the same as one set of mass analyzers. The specific assembly structure uses any of the first to fifth embodiments.
Since not only the length in the longitudinal direction of the electrodes but also the distance in the radial direction between the electrodes varies depending on the required performance, the applicable range can be widened by making a difference in the distance between the electrodes.

As described above, in this embodiment, two U-quadrupole electric fields 227a and 227b are formed by disposing a two-lane quadrupole mass spectrometer in the radial direction of the annular electrode. Since ions are passed through a region where a quadrupole electric field with U is formed, the radial direction of an annular electrode (quadrupole mass spectrometer formed in an annular shape) There will be two mass fractionation regions. In the present embodiment, two lanes (quadrupole mass spectrometer) are arranged in the radial direction, but two or more lanes (quadrupole mass spectrometer) may be arranged. At this time, two or more mass separation regions exist in the radial direction.

(Eleventh embodiment)
A quadrupole mass spectrometer according to the eleventh embodiment of the present invention will be described with reference to FIG.

In the present embodiment, the quadrupole mass spectrometer (mass separation region) described in the above-described embodiment is arranged in multiple lanes in the axial direction of the annular electrode (the vertical direction in the plane of the ring). In FIG. 13, the insulating support 231a has an annular shape, and has two hyperbolic surfaces formed in an annular shape in the in-plane vertical direction of the annular shape. Each has an annular metal coating 230a, 230b. The insulating support 231b has an annular shape, and has two hyperbolic surfaces formed in an annular shape on opposite surfaces in the axial direction of the annular shape. Each is formed with an annular metal coating 230c to 230f. Further, the insulating support 231c has an annular shape, and has two hyperbolic surfaces formed in an annular shape in the in-plane vertical direction, and each of the hyperbolic surfaces has an annular shape. Are formed with metal films 230g and 230h in an annular shape.

With such a configuration, a quadrupole mass spectrometer formed of the metal films 230a to 230d and a quadrupole mass spectrometer formed of the metal films 230e to 230h are arranged in the axial direction of the ring. A structure arranged in parallel is formed. In the present embodiment, since a high frequency voltage and a direct current voltage are applied between the electrode sets of the metal coatings 230a and 230d and the electrode sets of the metal coatings 230b and 230c, the region surrounded by the metal coatings 230a to 230d (the ions fly). The quadrupole electric field is formed in the region U). Similarly, since a high frequency voltage and a DC voltage are applied between the electrode sets of the metal coatings 230e and 230h and the electrode sets of the metal coatings 230f and 230g, the region surrounded by the metal coatings 230e to 230h (the region where ions fly) ) And a quadrupole electric field is formed.

In this embodiment, two sets of annular electrodes having the same radius (4 × 2; set of metal films 230a, 230c, 230e, and 230g, and set of metal films 230b, 230d, 230f, and 230h) are related to the same concentric point. In addition to a fitting structure, a single insulating support 231b is used as a common structure. The two sets of electrodes are all the same including the length and the distance between the electrodes, but the voltage applied to the two sets of electrodes can be set independently, that is, ions of different mass numbers can be passed. Yes. Therefore, although it is structurally close to one set of mass analyzers, it is possible to function two sets of mass analyzers that are independent and have the same characteristics. The specific assembly structure is the same as that of the third embodiment.

Since the two sets of mass spectrometers have the same characteristics, changes in different components (mass number) can be measured exactly at the same time and accurately.

As described above, in this embodiment, by arranging a two-lane quadrupole mass spectrometer in the axial direction of the annular electrode (vertical direction in the plane of the ring), two U-equipped quadrupoles are provided. An electric field is formed. Since ions are passed through a region where a quadrupole electric field with U is formed, the axial direction of an annular electrode (a quadrupole mass spectrometer formed in an annular shape) There will be two mass fractionation regions. In this embodiment, two lanes (quadrupole mass spectrometer) are arranged in the axial direction, but two or more lanes (quadrupole mass spectrometer) may be arranged. At this time, two or more mass separation regions exist in the axial direction.

When N (N is an integer of 2 or more) mass analysis regions are formed in the axial direction, the insulating supports 231a and 231c (on one of the opposing surfaces in the axial direction) An insulating support having two metal films formed thereon is disposed, and N−1 insulating supports 231b (the metal films are formed on each of the axially opposed surfaces) between the insulating supports 231a and 231c. Insulating supports formed by two) are arranged. Then, in the arrangement of N-1 insulating supports 231b, the insulating support 231b and the insulating support 231a at one end in the axial direction are fitted together, and the insulating support 231b and the insulating support 231c at the other end are fitted together. And the remaining insulating supports 231b are fitted together. By arranging in this way, N U-quadrupole electric fields can be formed, and N mass analysis regions can be formed in the axial direction. When N = 2, the configuration is as shown in FIG. 13, so that one insulating support 231 b is arranged between the insulating support 231 a and the insulating support 231 c. The insulating support that is fitted into each of the insulating supports 231a and 231c is the same insulating support 231b.

In addition, by combining the ninth to eleventh embodiments, two or more mass separation regions having different lengths can exist in the same quadrupole mass spectrometer. For example, when the ninth embodiment is incorporated in the tenth embodiment, the operation is as follows. In FIG. 12, a detector 223b is provided at a position 180 ° from the ion source 221b, the ion sources 221a and 221b are changed to the ion source 211, and extraction electrodes 211a and 211b are provided in the respective ion sources. Further, the detectors 223a and 223b are changed to the detector 213. By doing so, in the same quadrupole mass spectrometer, three mass fractionation regions having different lengths can exist. Similarly, by arranging quadrupole mass analyzers (mass fractionation regions) in multiple lanes and changing the position of the detector in each lane, a large number of mass fractionation regions can exist.

(Twelfth embodiment)
A quadrupole mass spectrometer according to the twelfth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, as shown in FIG. 14, an annular soft spacer 241 is provided at the fitting portion between the electrode 104b and the insulating support 112a, and the insulating support 112a and the insulating support 112b are fitted. An annular soft spacer 242 is provided at the mating portion. Similarly, in each of the fitting portion between the electrode 104a and the insulating support 112a, the fitting portion between the electrode 104c and the insulating support 112b, and the fitting portion between the electrode 104d and the insulating support 112b, the soft spacer 241 is used. Is provided.

Thus, in the present embodiment, an annular spacer (soft spacer) made of a soft material is sandwiched between the fitting portions. The soft spacer is preferably made of aluminum (Al), copper (Cu), or indium (In). In addition, the thickness should be within the range that can be assembled (usually equal to or more than twice the gap between the two to be accurate) but less uneven thickness (circular symmetry variation). Therefore, it is preferable to use one having an average thickness of about 10 micrometers and non-uniformity within about several tens of percent. In addition, since it is difficult to obtain a complete annular shape without causing nonuniformity, a ribbon slightly shorter than the circumferential length to be actually used is used.

Although the soft spacer extends and thins by assembly, the force applied between the two should be equal, that is, circularly symmetrical, so that the accuracy of concentricity of the two sandwiching the soft spacer can be further increased. it can.

(Other embodiments)
Needless to say, these are not limited to the above embodiments, and may be used in combination.
In the above embodiment, the fitting portions are all cylindrical (the cross section is parallel to the axis). However, as shown in FIG. 15, this is tapered (the cross section is inclined with respect to the axis). Positioning of the ring in the axial direction (left-right direction in the figure) can be realized at the same time.
Further, in the above embodiment, not only the electrodes but also the insulating support and soft spacer are all annular, but if the quadrupole electric field is formed with high accuracy, the fitting portion of the insulating support and soft spacer is not necessarily provided. There is no need to be strictly circularly symmetric, and there is no necessity for the overall shape to be annular. For example, the electrodes 104a to 104d for forming the U-folded quadrupole electric field 107 described in the first embodiment are concentric toric rings, but the embodiment is modified so that the electrodes 104a to 104d It can be fitted to an insulating support at the top few points. Further, by modifying the twelfth embodiment, several small pieces of soft spacers can be arranged and sandwiched.

In addition, in any case, the points are arranged so that the intervals between the points are as uniform as possible. In these examples, since one of the fittings is a point, the fitting is not strictly circularly symmetric. However, since the fitting is almost circularly symmetric as a whole, the electrodes 104a to 104d are made highly parallel. Can be arranged in degrees. Therefore, in the present invention, it is sufficient that the fitting is almost circularly symmetric as a whole. Therefore, although the electrode is basically an annular shape, the insulating support may be a plate having a fitting portion that is nearly circularly symmetric. . In addition, the soft spacer may have any shape as long as it can be finally arranged in the fitting portion in a shape close to circular symmetry.

In the above embodiment, all can be easily fitted as they are, but it is possible to apply conventionally known fitting techniques such as a shrink fitting method in which one part is assembled while being heated and expanded. it can.

(Further other embodiments)
The quadrupole mass spectrometer according to an embodiment of the present invention may be attached to various apparatuses. FIG. 16 is a diagram illustrating an example in which the quadrupole mass spectrometer according to the above-described embodiment is attached to a sputtering apparatus.

In FIG. 16, reference numeral 160 denotes a sputtering apparatus provided with a vacuum vessel, a film forming mechanism, an exhaust mechanism and the like, and a commonly used apparatus can be applied. The sputtering apparatus 160 is provided with an opening 161, and a pipe 162 having a vacuum flange 163 (for example, a vacuum flange (70 ICF) having an outer diameter of 70 mm) is connected to the opening 161. . Further, a vacuum pipe 165 (for example, a vacuum pipe with an inner diameter of 38 mm) is connected to the vacuum flange 164 (for example, 70 ICF), and one embodiment of the present invention is included in the vacuum pipe 165. A quadrupole mass spectrometer 166 according to the embodiment is incorporated. In such a configuration, the quadrupole mass spectrometer 166 is attached to the sputtering apparatus 160 by connecting the vacuum flange 163 and the vacuum flange 164.

Thus, the quadrupole mass spectrometer 166 can be incorporated in the vacuum flange 164 and attached to a film forming apparatus such as the sputtering apparatus 160. In particular, since the quadrupole mass spectrometer 166 according to an embodiment of the present invention is easy to downsize, it is incorporated into a vacuum flange (φ70 ICF) having a general outer diameter of φ70 mm in a vacuum device such as a sputtering device. It is possible to attach.

Claims (21)

1. An ion source that ionizes neutral molecules to release ions;
   A mass separation region having four non-linear electrodes, surrounded by the four electrodes by applying a voltage in which a DC voltage and a high-frequency voltage are superimposed between two opposing electrode sets of the four electrodes. A mass separation region for forming a quadrupole electric field in the region, and performing mass fractionation of the ions passing through the quadrupole field;
   A detector that detects the ions that have passed through the mass fractionation region and serves as a signal;
   A plurality of plate-like insulating supports having concentric fitting portions;
   The mass fractionation region is non-linear, and the mass fractionation region is configured such that the non-linear mass fractionation region prevents the detector from being expected from the ion source through the mass fractionation region;
   The four electrodes are at least part of four concentric annular electrodes;
   Each of the four annular electrodes is a conductive film formed on a part of the insulating support,
   The quadrupole mass spectrometer is assembled by circularly symmetric fitting between insulating supports by the fitting portion.
2. The insulating support is a plate-like insulating support having a plurality of concentric fitting portions,
   2. The plate-like insulating support having the plurality of fitting portions is fitted with at least one of the plate-like insulating supports having other fitting portions. Quadrupole mass spectrometer.
3. Each of the insulating supports has a hyperbolic surface formed in an annular shape,
   The conductive film is formed on the hyperbolic surface;
   The quadrupole mass spectrometer according to claim 1, wherein each of the insulating supports is fitted with at least one of the other insulating supports so that the conductive film faces each other.
4. The insulating support is a plate-shaped insulating support having two concentric fitting portions,
   Each of the plate-like insulating supports having the two fitting portions has two hyperbolic surfaces formed in an annular shape,
   The conductive films are respectively formed on two hyperbolic surfaces formed on each of the two insulating supports,
   4. The quadrupole mass spectrometer according to claim 3, wherein the two insulating supports are fitted to each other so that the conductive film faces each other.
5. Of the four annular electrodes, the electrode disposed on the inner side of the ring and the shape of the electrode disposed on the outer side of the ring are different shapes,
   2. The quadrupole type according to claim 1, wherein an electrode disposed inside the annular ring and an electrode disposed outside the annular ring have different cross-sectional shapes in the direction perpendicular to the progression of ions. Mass spectrometer.
6. The quadrupole mass spectrometer according to claim 1, wherein a cutout portion is formed in a part of the insulating support.
7. The quadrupole mass spectrometer according to claim 1, wherein there are two or more mass separation regions having different lengths in the traveling direction of the ions.
8. The quadrupole mass spectrometer according to claim 1, wherein there are two or more mass separation regions having different radii of the four annular electrodes.
9. The quadrupole mass spectrometer according to claim 1, wherein there are two or more mass separation regions having different positions in the axial direction of the four annular electrodes.
10. The quadrupole mass spectrometer according to claim 1, wherein a spacer is sandwiched between fitting gaps between the insulating supports.
11. An ion source that ionizes neutral molecules to release ions;
    A mass separation region having four non-linear electrodes, surrounded by the four electrodes by applying a voltage in which a DC voltage and a high-frequency voltage are superimposed between two opposing electrode sets of the four electrodes. A mass separation region for forming a quadrupole electric field in the region, and performing mass fractionation of the ions passing through the quadrupole field;
    A detector that detects the ions that have passed through the mass fractionation region and uses them as a signal;
    The mass fractionation region is non-linear, and the mass fractionation region is configured such that the non-linear mass fractionation region prevents the detector from being expected from the ion source through the mass fractionation region;
    The four electrodes are at least part of four concentric annular electrodes;
    4. The quadrupole mass spectrometer according to claim 4, wherein the four annular electrodes are assembled by fitting with a plate-like insulating support having concentric fitting portions.
12. The quadrupole mass spectrometry according to claim 11, wherein the four annular electrodes are assembled by a circularly symmetric fitting with a plate-like insulating support having a fitting portion. apparatus.
13. The quadrupole mass spectrometer according to claim 11, wherein each of the four annular electrodes is a concentric annular cylindrical electrode.
14. Of the four annular electrodes, the electrode disposed on the inner side of the ring and the shape of the electrode disposed on the outer side of the ring are different shapes,
    12. The quadrupole type according to claim 11, wherein an electrode disposed inside the annular ring and an electrode disposed outside the annular ring have different cross-sectional shapes in the direction perpendicular to the progression of ions. Mass spectrometer.
15. The quadrupole mass spectrometer according to claim 11, wherein a cutout portion is formed in a part of the insulating support.
16. The quadrupole mass spectrometer according to claim 11, wherein there are two or more mass separation regions having different lengths in the traveling direction of the ions.
17. The quadrupole mass spectrometer according to claim 11, wherein there are two or more mass separation regions having different radii of the four annular electrodes.
18. The quadrupole mass spectrometer according to claim 1, wherein there are two or more mass separation regions having different positions in the axial direction of the four annular electrodes.
19. The quadrupole mass spectrometer according to claim 11, wherein a spacer is sandwiched between gaps between the four annular electrodes and the insulating support.
20. In a film forming apparatus comprising a vacuum container, a film forming mechanism provided in the vacuum container, and a mass spectrometer attached to the vacuum container,
    The film forming apparatus according to claim 1, wherein the mass spectrometer is a quadrupole mass spectrometer according to claim 1.
21. In a film forming apparatus comprising a vacuum container, a film forming mechanism provided in the vacuum container, and a mass spectrometer attached to the vacuum container,
    12. The film forming apparatus according to claim 11, wherein the mass spectrometer is a quadrupole mass spectrometer according to claim 11.

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