JP2006023443A - Microscope system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compacted microscope system comprising a scanning probe microscope and an optical microscope. <P>SOLUTION: The microscope system 1 is provided with an atomic force microscope 10 and the optical microscope 20. An electrically driven zoom lens barrel 23 of the optical microscope 20 is arranged so as to extend in a Z axis direction at a side of a sample mounting stand 30, and an optical axis conversion mirror is arranged at an upper end part of the electrically driven zoom lens barrel 23. A lens-housing section 21 of the optical microscope 20 is attached to an optical axis conversion section 22, and the optical axis converting section 22 is attached to the upper end part of the electrically driven zoom lens barrel 23. A CCD camera (a charge-coupled device camera) 24 is provided at the lower end part of the electrically driven zoom lens barrel 23. The light reflected from a sample M is reflected by a mirror and then is reflected by the optical axis conversion mirror of the optical axis converting section 22 through a lens of the lens housing section 21. Reflected light by the optical axis conversion miller is taken in the CCD camera 24 through the electrically driven zoom lens barrel 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a microscope apparatus integrally provided with an optical microscope and a scanning probe microscope.

  In recent years, a scanning probe microscope (SPM) using a principle completely different from a conventional optical microscope or electron microscope has been developed and attracts attention.

  The scanning probe microscope includes a cantilever having a sharp pointed probe called a probe at its free end. In the atomic force microscope (AFM), which is an example of the above scanning probe microscope, when the probe is brought close to the sample, the atoms constituting the tip of the probe and the atoms constituting the sample An interatomic force is generated between This interatomic force displaces the free end of the cantilever.

  By electrically measuring the amount of displacement of the free end of the cantilever while scanning the probe along the sample, three-dimensional information indicating the surface shape of the sample can be obtained. For example, when the probe is scanned while controlling the distance between the probe and the sample so that the displacement of the free end of the cantilever is kept constant, the tip of the probe moves along the unevenness of the sample surface. It is possible to obtain three-dimensional information indicating the surface shape of the sample from the position information of the tip. As another example of a scanning probe microscope, instead of using the atomic force generated between the probe atom and the sample surface atom, a tunnel current flowing between the probe and the sample is used. Some scanning tunneling microscopes can also obtain three-dimensional information on the sample surface.

  In addition, a microscope apparatus in which an optical microscope and a scanning probe microscope are integrated has been developed.

  Here, an outline of a conventional microscope apparatus will be described with reference to the drawings. In addition, the microscope apparatus shown below is an optical microscope and an atomic force microscope that is an example of a scanning probe microscope (see, for example, Patent Document 1).

  FIG. 4 is a schematic diagram showing a conventional microscope apparatus.

  As shown in FIG. 4, the support base 201 is provided with an optical system support base 202 movably in the vertical direction via a linear guide (not shown).

  An objective lens 207, a displacement measurement optical system 206, and an observation optical system 204 are attached to the optical system support 202.

  By adjusting the optical system support base coarse movement micrometer 203 provided on the optical system support base 202, the objective lens 207, the displacement measurement optical system 206, and the observation optical system 204 can be integrally moved up and down. .

  Further, the optical system support table 202 is provided with a scanner support table 215 that can move in the vertical direction via a linear guide (not shown).

  A cylindrical piezoelectric element 208 for fine probe movement is fixed to the scanner support base 215. A probe support ring 209 is provided at the lower end of the probe fine movement cylindrical piezoelectric element 208.

  A cantilever 218 is attached to the probe support ring 209, and a probe 210 is provided at the free end of the cantilever 218. The probe 210 is provided so as to protrude from the central opening of the probe support ring 209.

  By adjusting the scanner support base coarse movement micrometer 214 provided on the scanner support base 215, the scanner support base 215 can be moved in the vertical direction with respect to the optical system support base 202.

  On the other hand, a sample scanning cylindrical piezoelectric element 213 is fixed on the support table 201. A sample table 212 is provided on the sample scanning cylindrical piezoelectric element 213, and the sample 211 is placed on the sample table 212.

With the configuration as described above, observation of a sample with an optical microscope and observation of a sample with a scanning probe microscope can be performed with a single microscope apparatus.
JP-A-5-157554

  However, in the conventional microscope apparatus described above, if the optical microscope and the scanning probe microscope are integrally configured, the height of the microscope apparatus becomes very high. For this reason, the microscope apparatus becomes large and the vibration isolation property is poor. As a result, the reliability of sample measurement and evaluation is impaired.

  In addition, for example, even if the lens barrel of the optical microscope is inclined, it is possible to reduce the height of the microscope apparatus, but the microscope apparatus increases in size in the lateral direction.

  An object of the present invention is to provide a compact microscope apparatus having a scanning probe microscope and an optical microscope.

  A microscope apparatus according to the present invention has a sample mounting table on which a sample is mounted and a probe, and scans the probe along the surface of the sample by relatively moving the sample mounting table and the probe. A scanning probe microscope, an imaging unit, a lens barrel, an optical microscope having a first reflecting member and a second reflecting member, and a holding unit for holding the scanning probe microscope and the optical microscope. The cylinder is arranged so as to extend in the vertical direction on the side of the sample mounting table, the second reflecting member is provided at the upper end portion of the lens barrel, and the imaging unit is provided at the lower end portion of the lens barrel, on the sample mounting table. Light from the placed sample is guided to the second reflecting member by the first reflecting member, and is guided to the imaging unit through the lens barrel by the second reflecting member.

  In the microscope apparatus according to the present invention, the probe of the scanning probe microscope and the sample mounting table move relatively, so that the probe is scanned along the surface of the sample. Thereby, the surface shape of the sample can be observed microscopically at a high magnification.

  In addition, light from the sample placed on the sample placing table is guided to the second reflecting member by the first reflecting member, and is guided to the imaging unit through the lens barrel by the second reflecting member. Thereby, the surface shape of the sample can be observed macroscopically at a low magnification.

  The holding probe holds the scanning probe microscope and the optical microscope. The lens barrel of the optical microscope is arranged so as to extend in the vertical direction on the side of the sample mounting table, the second reflecting member is provided at the upper end portion of the lens barrel, and the imaging unit is provided at the lower end portion of the lens barrel. . With this configuration, the microscope apparatus can be made compact.

  You may further provide the support part which supports a holding | maintenance part on an installation surface, and the vibration isolation mechanism which is provided in a support part and relieve | moderates the vibration transmitted from an installation surface to a holding part.

  In this case, the holding portion is supported on the installation surface by the support portion. In addition, the support portion is provided with a vibration isolation mechanism that reduces vibration transmitted from the installation surface to the holding portion. Thereby, the vibration from the installation surface is absorbed by the vibration isolation mechanism, and the vibration isolation of the holding unit that holds the scanning probe microscope and the optical microscope is improved.

  The support part may include at least three legs, and the vibration isolation mechanism may include an elastic member provided between the holding part and the at least three legs.

  In this case, the holding portion is supported on the installation surface by the support portion including at least three leg portions. Thereby, the scanning probe microscope and the optical microscope can be stably held.

  Further, vibrations from the installation surface are absorbed by the elastic member by the elastic members respectively provided between the holding part and the at least three leg parts, and the vibration isolating property of the holding part that holds the scanning probe microscope and the optical microscope Will be improved.

  The sample mounting table may be provided at substantially the center of the region formed by at least three legs. Thereby, the influence of the vibration from a leg part can be minimized. As a result, the measurement accuracy and reliability of the sample placed on the sample placement table are improved.

  The scanning probe microscope may include a scanning unit that holds a probe, and the scanning unit may be provided on the holding unit. In this case, since the scanning unit is provided on the holding unit having sufficient vibration isolation, the probe is scanned along the surface of the sample without being affected by vibration from the leg unit. As a result, the measurement accuracy and reliability of the sample placed on the sample placement table are further improved.

  The height of the junction between the at least three elastic members and the holding portion, the height of the holding position of the optical microscope by the holding portion, the height of the holding position of the scanning portion on the holding portion, and the height of the sample on the sample mounting table May be set approximately equal. Thereby, the vibration isolation property of the microscope apparatus is further improved. As a result, the measurement accuracy and measurement reliability of the sample placed on the sample placement table are further improved.

  The scanning probe microscope may be an atomic force microscope. In this case, the sample is measured using the atomic force generated between the sample and the probe. Thereby, the surface shape of the sample can be observed at the atomic level.

  ADVANTAGE OF THE INVENTION According to this invention, the microscope apparatus provided with the scanning probe microscope and the optical microscope can be reduced in size.

  Hereinafter, the microscope apparatus according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a microscope apparatus according to the present embodiment. Here, two directions orthogonal to each other in the horizontal plane are defined as an X axis and a Y axis, and a direction perpendicular to the X axis and the Y axis is defined as a Z axis.

  As shown in FIG. 1, the microscope apparatus 1 according to the present embodiment is integrally provided with an atomic force microscope (AFM) 10 and an optical microscope 20. The atomic force microscope 10 and the optical microscope 20 are held by a base housing unit 50.

  The base casing 50 has a bottom 54 located on a plane composed of the X axis and the Y axis.

  Support legs 52a, 52b, 52c and 52d (52c not shown) extend from the four corners of the bottom portion 54 in the Z-axis direction. Supported portions 53a and 53d are provided at the upper ends of the support legs 52a and 52d, respectively.

  On the support legs 52b and 52c, a supported portion 53 formed in an L shape in plan view is provided.

  The supported portions 53a and 53d of the base casing 50 are supported by cylindrical leg portions S1 and S4 (S4 not shown) extending in the Z-axis direction, respectively. The supported portion 53 of the base casing 50 is supported by cylindrical leg portions S2 and leg portions S3 extending in the Z-axis direction.

  The atomic force microscope 10 includes an AFM scanner 11, a sample mounting table 30, and a lifting shaft 30a.

  The supported portion 53 has a horizontal upper surface. An AFM scanner 11 is supported on this upper surface. In addition, the structure which scans the probe provided in the cantilever mentioned later of the AFM scanner 11 along a sample surface is mentioned later.

  A sample mounting table 30 is provided at the center inside the base casing 50. A sample M is mounted on the sample mounting table 30. The sample mounting table 30 moves up and down in the Z-axis direction by a lifting shaft 30a. The elevating shaft 30a is connected to a drive mechanism (not shown). Further, the sample mounting table 30 can move in the X-axis and Y-axis directions, and can rotate around the Z-axis around a probe to be described later of the AFM scanner 11.

  A mirror holder 26 is provided below the AFM scanner 11 so as to be positioned above the sample M. The mirror holder 26 holds the mirror 25. In this case, illumination light emitted from an illumination source (not shown) is applied to the sample M, and reflected light from the sample M is applied to the mirror 25.

  The optical microscope 20 is attached to the base housing unit 50. The optical microscope 20 includes a lens storage unit 21, an optical axis conversion unit 22, an electric zoom barrel 23, a CCD (Charge Coupled Device) camera 24, a mirror 25, and a mirror holder 26. An optical axis conversion mirror 22a (see FIG. 2) is provided in the optical axis conversion unit 22.

  The lens storage unit 21 of the optical microscope 20 is attached to the optical axis conversion unit 22, and the optical axis conversion unit 22 is attached to the upper end of the electric zoom lens barrel 23. A CCD camera 24 is provided at the lower end of the electric zoom lens barrel 23.

  Here, the electric zoom lens barrel 23 of the optical microscope 20 is arranged to extend in the Z-axis direction on the side of the sample mounting table 30, and the optical axis conversion mirror 22 a is arranged at the upper end of the electric zoom lens barrel 23. Yes.

  FIG. 2 is a schematic side view of the microscope apparatus 1 of FIG.

  As shown in FIG. 2, in the microscope apparatus 1, the reflected light from the sample M is reflected by the mirror 25 and reflected by the optical axis conversion mirror 22 a of the optical axis conversion unit 22 through the lens of the lens storage unit 21. The reflected light from the optical axis conversion mirror 22 a is taken into the CCD camera 24 through the electric zoom lens barrel 23, and an observation image of the sample M is formed on the CCD camera 24. The path from the reflected light from the sample M to the CCD camera 24 through the mirror 25 and the optical axis conversion mirror 22a is formed in a substantially inverted L shape as indicated by the dotted line LI.

  Elastic members 51 are respectively provided in the leg portions S1 to S4 that support the base casing 50 of the microscope apparatus 1. Vibration is absorbed by the elastic member 51, and the vibration isolation performance of the microscope apparatus 1 is improved. The elastic member 51 is made of a spring member, for example.

  Further, since the sample mounting table 30 for mounting the sample M is provided at the center of the region formed by the four legs S1 to S4 of the microscope apparatus 1, the vibration isolation performance of the microscope apparatus 1 is further improved. Is done.

  In the microscope apparatus 1 according to the present embodiment, the base casing 50 is supported by the four legs S1 to S4. However, the present invention is not limited to this, and at least three legs are provided. Thus, the base casing 50 may be supported. In this case, the sample mounting table 30 is provided at the center of the region formed by at least three legs.

  Further, the height of the holding position L2 of the optical microscope 20 by the base casing 50, the height of the mounting position L3 of the AFM scanner 11 on the base casing 50, and the observation position L4 of the sample M on the sample mounting table 30. And the height of the joint portion L5 between each elastic member 51 provided in the leg portions S1 to S4 and the base housing portion 50 is set to be substantially the same (height indicated by the one-dot chain line L1 in FIG. 2). Is done. Thereby, the vibration isolation property of the microscope apparatus 1 is further improved.

  Next, a control system of the microscope apparatus 1 according to the present embodiment will be described. Note that the control system of the atomic force microscope 10 shown in FIG. 3 described later is a control system in the case of using the contact mode.

  Here, the contact mode is a measurement mode in which, in the atomic force microscope 10, the probe is brought close to a position in contact with the sample and scanned along the sample surface.

  FIG. 3 is a block diagram showing a control system when the contact mode of the microscope apparatus 1 according to the present embodiment is used.

  The atomic force microscope 10 includes a plate spring-shaped cantilever 100, a probe 101, a piezoelectric element 110, a light source 121, reflecting mirrors 122 and 123, a photodetector 124, and a control unit 130.

  In the atomic force microscope 1, an atomic force generated between the probe 101 and the sample M, that is, a displacement amount of the cantilever 100 is detected.

  A probe 101 is provided at the tip of the cantilever 100. When the probe 101 is brought close to the sample M, an atomic force is generated between the probe 101 and the sample M, and the cantilever 100 bends in the vertical direction.

  The probe 101 is scanned along the surface of the sample M by the piezoelectric element 110 provided in the AFM scanner 11. The piezoelectric element 110 moves the cantilever 100 in the X-axis and Y-axis directions in order to scan the probe 101 along the surface of the sample M.

  Note that the probe 101 may be scanned along the surface of the sample M by moving the sample mounting table 30 in the X-axis and Y-axis directions while the probe 101 is fixed. A voice coil motor may be used instead of the piezoelectric element 110.

  The piezoelectric element 110 moves the cantilever 100 in the Z-axis direction so as to keep the displacement of the cantilever 100 constant, that is, so as to keep the atomic force generated between the probe 101 and the sample M constant. Based on the change in the voltage value applied to the piezoelectric element 110 in order to keep the atomic force between the probe 101 and the sample M constant, the three-dimensional shape information of the sample M can be imaged. Become.

  The piezoelectric element 110 is controlled by the control unit 130. The control unit 130 includes a central processing unit (CPU) 131, a displacement amount detection unit 132, a Z direction servo circuit 133, and an XY direction servo circuit 134.

  The Z-direction servo circuit 133 controls the piezoelectric element 110 so that the probe 101 of the cantilever 100 operates in the Z-axis direction. Further, the XY direction servo circuit 134 controls the piezoelectric element 110 so that the probe 101 of the cantilever 100 moves in the X axis direction and the Y axis direction. The displacement amount detection unit 132 will be described later.

  Here, the operation of the atomic force microscope 10 for keeping the displacement amount of the cantilever 100 caused by the unevenness of the surface of the sample M constant will be described.

  In order to detect a minute deflection amount (displacement) of the cantilever 100, a laser beam is irradiated to the tip of the cantilever 100 by the light source 121. In order to detect the displacement of the cantilever 100, the following optical lever method is generally used.

  The optical lever method is an example of a method for measuring the displacement of the cantilever 100, in which the cantilever 100 is irradiated with laser light, and the reflected light from the cantilever 100 is detected by the photodetector 124.

  A minute displacement of the cantilever 100 is reflected in a slight angle change of the reflected light from the cantilever 100, and this angle change is detected by the photodetector 124. Note that a two-divided photocell, a four-divided photocell, a photocell array, or the like is used as the photodetector 124. As the cantilever 100, in addition to the cantilever produced on a wafer basis by a semiconductor microfabrication technique, a part of the cantilever provided with a minute reflecting glass (reflecting mirror) or the back surface of the optical fiber probe type cantilever is flat. In this way, those provided with a reflecting surface are used.

  In the present embodiment, the laser light emitted from the light source 121 is applied to the cantilever 100 via the reflecting mirror 122, and the laser light applied to the cantilever 100 is detected as reflected light via the reflecting mirror 123. However, the present invention is not limited to this, and the cantilever 100 is directly irradiated with the laser beam emitted from the light source 121 without providing the reflecting mirror 122 and the reflecting mirror 123, and is irradiated to the cantilever 100. The detected laser light may be directly detected by the photodetector 124 as reflected light.

  The output signal of the photodetector 124 is given to the displacement amount detection unit 132 of the control unit 130. The displacement amount detection unit 132 detects the displacement amount of the cantilever 100 based on the output signal of the photodetector 124.

  Based on the displacement amount of the cantilever 100 detected by the displacement amount detection unit 132, the CPU 131 of the control unit 130 controls the piezoelectric element 110 so as to keep this displacement amount constant.

  A display 40 such as a CRT (cathode ray tube) is connected to the control unit 130. The display 40 displays a three-dimensional image of the sample M.

  In the present embodiment, the contact mode is used as the measurement mode of the atomic force microscopes 10 and 10a. However, the present invention is not limited to this, and the probe 101 is not brought into contact with the sample M. A non-contact mode in which the needle 101 is resonated and the vicinity of the surface of the sample M is scanned may be used.

  In the present embodiment, the electric zoom barrel 23 of the optical microscope 20 is disposed so as to extend in the Z-axis direction on the side of the sample mounting table 30, and the optical axis conversion mirror 22 a is the upper end of the electric zoom barrel 23. The CCD camera 24 is provided at the lower end of the electric zoom lens barrel 23. In this case, the reflected light from the sample M mounted on the sample mounting table 30 is guided to the optical axis conversion mirror 22a by the mirror 25, and is taken into the CCD camera 24 through the electric zoom lens barrel 23 by the optical axis conversion mirror 22a. . With such a configuration, the microscope apparatus 1 can be made compact in the height direction and the lateral direction.

  Further, the optical microscope 20 itself is made compact by configuring the optical microscope 20 in a substantially inverted L shape. Thereby, the microscope apparatus 1 in which the optical microscope 20 and the atomic force microscopes 10 and 10a are integrally combined can be further downsized.

  Furthermore, since the AFM scanner 11 is stably supported by the four legs S1 to S4 and held on the base casing 50, the probe 101 can be stably scanned along the surface of the sample M. It becomes possible.

  In the present embodiment, the atomic force microscopes 10 and 10a and the optical microscope 20 are integrally configured. For example, the microscope apparatus 1 may be a magnetic force microscope (MFM) or an electric force microscope. The optical microscope 20 and the magnetic force microscope or the optical microscope 20 and the electric force microscope can be integrally configured using (Electric Force Microscope: EFM).

  In the magnetic force microscope, a probe 101 made of a ferromagnetic material is used, and the probe 101 is separated from the surface of the sample M to a region where only a magnetic force works. Then, by measuring the magnetic force generated between the probe 101 and the sample M and scanning the probe 101 along the surface of the sample M, three-dimensional information of the sample M can be obtained.

  In the electric force microscope, a direct current is passed through the probe 101 to separate the probe 101 from the surface of the sample M to a region where only an electric force is applied. Then, the three-dimensional shape information of the sample M can be obtained by measuring the electric force generated between the probe 101 and the sample M and scanning the probe 101 along the surface of the sample M.

  In the present embodiment, the CCD camera 24 corresponds to the imaging unit, the electric zoom lens barrel 23 corresponds to the lens barrel, the mirror 25 corresponds to the first reflecting member, and the optical axis conversion mirror 22a corresponds to the second lens. Corresponding to a reflecting member, the base housing part 50 corresponds to a holding part, the leg parts S1 to S4 correspond to support parts and leg parts, the elastic member 51 corresponds to a vibration isolation mechanism and an elastic member, and the AFM scanner 11 Corresponds to the scanning unit.

  The present invention can be used for observation of surface shapes of various samples.

It is a perspective view which shows the microscope apparatus which concerns on this Embodiment. It is a schematic side view of the microscope apparatus of FIG. It is a block diagram which shows the control system in the case of using the contact mode of the microscope apparatus which concerns on this Embodiment. It is a schematic diagram which shows the conventional microscope apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microscope apparatus 10,10a Atomic force microscope 11 AFM scanner 20 Optical microscope 22a Optical axis conversion mirror 23 Electric zoom barrel 24 CCD camera 25 Mirror 26 Mirror holder 30, 31 Sample mounting base 50 Base housing part 51 Elastic member 52a, 52b, 52c, 52d Support leg 53, 53a, 53d Supported part 54 Bottom part 100 Cantilever 101 Probe 110 Piezoelectric element 130 Control part 131 CPU
132 Displacement detection unit 132a Amplitude detection unit LI Observation optical axis M Sample S1, S2, S3, S4 Leg

Claims (7)

A sample mounting table on which the sample is mounted;
A scanning probe microscope that has a probe and scans the probe along the surface of the sample by relatively moving the sample mounting table and the probe;
An optical microscope having an imaging unit, a lens barrel, a first reflecting member, and a second reflecting member;
A holding unit for holding the scanning probe microscope and the optical microscope,
The lens barrel of the optical microscope is disposed so as to extend in the vertical direction on the side of the sample mounting table, the second reflecting member is provided at an upper end portion of the lens barrel, and the imaging unit is disposed on the lens barrel. Provided at the lower end,
Light from the sample placed on the sample placing table is guided to the second reflecting member by the first reflecting member, and guided to the imaging unit through the lens barrel by the second reflecting member. A microscope apparatus characterized by that. A support part for supporting the holding part on an installation surface;
The microscope apparatus according to claim 1, further comprising a vibration isolation mechanism that is provided on the support portion and that relieves vibration transmitted from the installation surface to the holding portion. The support includes at least three legs,
The microscope apparatus according to claim 2, wherein the vibration isolation mechanism includes an elastic member provided between the holding portion and the at least three legs. The microscope apparatus according to claim 3, wherein the sample mounting table is provided at a substantially center of a region formed by the at least three legs. The scanning probe microscope includes a scanning unit that holds a probe,
The microscope apparatus according to claim 3 or 4, wherein the scanning unit is provided on the holding unit. The height of the joining portion between the at least three elastic members and the holding unit, the height of the holding position of the optical microscope by the holding unit, the height of the holding position of the scanning unit on the holding unit, and the sample mounting 6. The microscope apparatus according to claim 5, wherein the height of the sample on the stage is set to be substantially equal. The microscope apparatus according to claim 1, wherein the scanning probe microscope is an atomic force microscope.

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