CN118712037A - Charged particle beam extraction device and method - Google Patents

Abstract

The invention discloses a charged particle beam extraction device and a charged particle beam extraction method, which are applicable to an ion implanter in the technical field of semiconductor processing. The invention relates to a charged particle beam extraction device, which comprises an ion source cavity and an extraction electrode group, wherein the ion source cavity is provided with a fourth electrode, and the extraction electrode group sequentially comprises a third electrode, a second electrode and a first electrode in the advancing direction of a charged particle beam. The charged particle beam extraction method can extract the beam with larger current range under the same electrode structure by utilizing the device, and can simultaneously meet the requirements of stable focus, uniformity and small divergence angle.

Description

Charged particle beam extraction device and method

Technical Field

The present invention relates generally to the field of semiconductor processing equipment, and more particularly, to a charged particle beam extraction apparatus and method.

Background

In an ion implanter, a common extraction electrode system is a three-electrode system, and mainly comprises a plasma electrode, a suppression electrode and a ground electrode. The plasma electrode is a high voltage to ground for extracting and accelerating ions. The suppression electrode is a negative voltage to ground for suppressing electrons returning downstream from the beam current, protecting ion source components at high potential from electron bombardment, thereby improving ion source lifetime. Another function of the suppression electrode is to adjust the voltage difference between the plasma electrode and the suppression electrode to achieve an electric field lens effect, thereby achieving control of the divergence angle and focus of the beam.

When the beam size is within a certain range, the three-electrode system can realize stable control of the beam divergence angle and the focus so as to ensure steady-state operation of the beam. However, with the development of the ion implanter, steady-state operation of large beam and small beam needs to be realized on the same system, while the three-electrode system cannot simultaneously maintain the steady focusing state of the beam under the conditions of small beam and large beam, and beam fluctuation easily occurs under the conditions of extreme beam.

Disclosure of Invention

Based on the technical problems in the prior art, the invention provides a charged particle beam extraction device and a charged particle beam extraction method, and aims to solve the problem that an ion implanter cannot keep beam stability under the conditions of maximum beam and minimum beam simultaneously.

According to one aspect of the present invention, there is provided a charged particle beam extraction apparatus. The device comprises: an ion source chamber for generating plasma, the ion source chamber being provided with a fourth electrode having an extraction opening for emitting a charged particle beam outwards; and an extraction electrode group including a third electrode, a second electrode, and a first electrode in this order in the advancing direction of the charged particle beam, the third electrode, the second electrode, and the first electrode each having an opening through which the charged particle beam passes. When the charged particle beam is positive ion beam, the first electrode is grounded, the potential difference between the second electrode and the first electrode is negative, the potential difference between the fourth electrode and the first electrode is positive, and the potential difference between the third electrode and the fourth electrode is negative; when the charged particle beam is negative ion beam, the first electrode is grounded, the potential difference between the second electrode and the first electrode is positive, the potential difference between the fourth electrode and the first electrode is negative, and the potential difference between the third electrode and the fourth electrode is positive.

Alternatively, the level adjustment range of the third electrode is set to a numerical range obtained by multiplying the level of the fourth electrode by a coefficient smaller than 1.

Further, the coefficient is greater than 0 but not greater than 99.9%.

Optionally, the outlet of the fourth electrode has a shape on the side facing the third electrode, the shape comprising a chamfer shape and/or a circular arc shape.

Optionally, the opening of the third electrode has a shape on a side facing the second electrode, the shape comprising a chamfer shape and/or a circular arc shape.

Further, the angle of the chamfer shape is greater than 0 degrees and less than 90 degrees, and the radius of the circular arc shape is not less than 1 millimeter and not more than 30 millimeters.

Optionally, the charged particle beam extraction apparatus further comprises a detection assembly for measuring the divergence angle of the charged particle beam.

Optionally, the third electrode, the second electrode and the first electrode are fixed in distance, and the third electrode, the second electrode and the first electrode can move synchronously.

Alternatively, in the case where the distance between the third electrode and the second electrode is fixed, the third electrode and the second electrode may be moved synchronously and the first electrode is fixed, or the third electrode and the second electrode may be moved synchronously and the first electrode may be moved, or the third electrode and the second electrode may be fixed and the first electrode may be moved.

Alternatively, in the case where the distance between the second electrode and the first electrode is fixed, the second electrode and the first electrode may be moved synchronously and the third electrode may be fixed, or the second electrode and the first electrode may be moved synchronously and the third electrode may be moved, or the second electrode and the first electrode may be fixed and the third electrode may be moved.

Alternatively, in the case where the distance between the third electrode and the first electrode is fixed, the third electrode and the first electrode may be moved synchronously and the second electrode is fixed, or the third electrode and the first electrode may be moved synchronously and the second electrode may be moved, or the third electrode and the first electrode may be fixed and the second electrode may be moved.

Alternatively, the third electrode, the second electrode, and the first electrode are all independently movable.

According to another aspect of the present invention, there is provided an ion implanter comprising the charged particle beam extraction apparatus described above.

According to yet another aspect of the present invention, there is provided a drawing method using the foregoing apparatus. The method comprises the following steps: applying a set voltage to the fourth electrode; applying an initial voltage to the third electrode; applying an initial voltage to the second electrode; setting an initial distance between the third electrode and the fourth electrode according to a voltage difference between the fourth electrode and the third electrode; and repeatedly adjusting the distance between the third electrode and the fourth electrode, the voltage of the third electrode and the voltage of the second electrode according to the measured divergence angle of the charged particle beam so that the divergence angle meets the requirement.

According to still another aspect of the present invention, there is provided a drawing method using the foregoing apparatus. The method comprises the following steps: applying a set voltage to the fourth electrode; applying an initial voltage to the third electrode; applying an initial voltage to the second electrode; setting an initial distance between the third electrode and the fourth electrode according to a voltage difference between the fourth electrode and the third electrode; setting an initial distance between the third electrode and the second electrode according to a voltage difference between the third electrode and the second electrode; and repeatedly adjusting the distance between the third electrode and the fourth electrode, the distance between the third electrode and the second electrode, the voltage of the third electrode and the voltage of the second electrode according to the measured divergence angle of the charged particle beam, so that the divergence angle meets the requirement.

Compared with the prior art, the charged particle beam extraction device and the charged particle beam extraction method have the following beneficial technical effects:

1. The four-electrode system specially designed by the invention can meet the requirements of stable focus, uniformity and small divergence angle of the charged particle beam. In the invention, besides the fourth electrode, the second electrode and the first electrode form a lens system, the third electrode, the second electrode and the first electrode form an additional lens system, and the lens system can realize secondary focusing on the charged particle beam, so that the focus and the divergence angle of the beam can be more conveniently adjusted on the premise that the beam does not strike the electrodes, and the focus of the beam can be controlled at a specific position and the divergence angle can be ensured to be small enough.

2. The invention can realize steady-state operation of large beam current and small beam current on the same device, and can lead out beam current with larger current range under the same electrode structure, thereby improving the operation stability of the ion source.

Drawings

The disclosed exemplary embodiments of the invention may be better understood by reading the following detailed description in conjunction with the drawings in which:

FIG. 1 is a schematic diagram of a charged particle beam extraction apparatus according to one embodiment of the present invention;

FIG. 2 is a schematic diagram showing an operation state of the charged particle beam extracting apparatus according to an embodiment of the present invention;

FIG. 3 is a first exemplary schematic view of the opening shape of an electrode in the charged particle beam extraction apparatus of the present invention;

FIG. 4 is a second exemplary schematic view of the shape of the opening of the electrode in the charged particle beam extracting apparatus of the present invention;

FIG. 5 is a third exemplary schematic view of the shape of the opening of the electrode in the charged particle beam extracting apparatus of the present invention;

fig. 6 is a fourth exemplary schematic view of the opening shape of an electrode in the charged particle beam extracting apparatus of the present invention;

fig. 7 is a fifth exemplary schematic view of the opening shape of an electrode in the charged particle beam extracting apparatus of the present invention;

Fig. 8 is a sixth exemplary schematic view of the opening shape of an electrode in the charged particle beam extracting apparatus of the present invention;

FIG. 9 is a graph of simulation results of equipotential line distribution for a first exemplary opening shape according to an embodiment of the present invention;

FIG. 10 is a graph of simulation results of equipotential line distribution for a second exemplary opening shape according to an embodiment of the present invention;

FIG. 11 is a graph of simulation results of equipotential line distribution for a third exemplary opening shape according to an embodiment of the present invention;

FIG. 12 is a graph of simulation results of equipotential line distribution for a fourth exemplary opening shape according to an embodiment of the present invention;

FIG. 13 is a graph of simulation results of equipotential line distribution for a fifth exemplary opening shape according to an embodiment of the present invention; and

Fig. 14 is a diagram showing the result of simulation of the equipotential line distribution for the sixth exemplary opening shape according to an embodiment of the present invention.

Reference numerals in the drawings illustrate: 1: an ion source chamber; 100: a plasma; 11: a fourth electrode; 110: an outlet port; 2: a set of extraction electrodes; 21: a third electrode; 210: an opening of the third electrode; 22: a second electrode; 220: an opening of the second electrode; 23: a first electrode; 230: an opening of the first electrode; 3: a charged particle beam; a: the direction of travel of the charged particle beam.

For simplicity of explanation, the drawings show a general manner of construction, and descriptions and details of well-known features and techniques are omitted so as to not unnecessarily obscure the discussion of the embodiments of the invention. Furthermore, the elements of the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention. The same reference numbers in different drawings identify the same elements, and similar reference numbers may, but do not necessarily, identify similar elements.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings. It should be appreciated that the following detailed description is merely exemplary in nature and is not intended to limit the subject matter or the application embodiments and the uses of such embodiments. As used herein, the phrase "exemplary" means "serving as an example, instance, or illustration. Any implementation described herein as exemplary should not be construed as necessarily preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

The terms "first," second, "" third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other sequences than described or illustrated herein. Similarly, if the method described herein comprises a series of steps, the order of the steps presented herein is not necessarily the only order in which the steps may be performed, and some of the stated steps may be omitted and/or some other steps not described herein may be added to the method. Furthermore, the terms "comprises," "comprising," "includes," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

In one aspect, embodiments of the present invention provide a charged particle beam extraction apparatus that is applicable to ion implanters in the field of semiconductor processing technology. The device can realize steady-state operation of large beam current and small beam current simultaneously, and simultaneously meets the requirements of stable focus, uniformity and small divergence angle of charged particle beam current. In an embodiment of the invention, a charged particle beam extraction apparatus includes an ion source chamber and an extraction electrode set. Fig. 1 shows a schematic structure of a charged particle beam extracting apparatus according to an embodiment of the present invention. As shown in fig. 1, the exemplary apparatus includes an ion source chamber 1 and an extraction electrode group 2, wherein the ion source chamber 1 is provided with a fourth electrode 11, and the extraction electrode group 2 is provided at one side of the ion source chamber 1 and sequentially includes a third electrode 21, a second electrode 22, and a first electrode 23 in a traveling direction a of a charged particle beam. Among them, the fourth electrode 11 may be referred to as a "plasma electrode", the third electrode 21 may be referred to as an "accelerating electrode", the second electrode 22 may be referred to as a "suppressing electrode", and the first electrode 23 may be referred to as a "ground electrode".

The ion source chamber 1 is used to generate a plasma 100. In one example, the ion source chamber 1 may be an arc striking chamber and may contain gas inlets, cathodes, repellers, filaments, magnets, etc. structures or components as desired. As an example, to generate a plasma, a set flow rate of gas may be introduced into the arc striking chamber; applying a current to the filament to cause the filament to reach a temperature at which electrons are emitted; applying voltage between the filament and the cathode, and directionally accelerating electrons emitted by the filament to make the electrons emitted by the filament shoot to the cathode; the cathode is heated by the electron flow emitted by the filament to a temperature at which electrons are emitted; applying voltage between the arc striking chamber and the cathode to accelerate electrons emitted by the cathode so as to move into the arc striking chamber; after electrons emitted by the cathode are accelerated, the electrons do spiral motion under the action of a magnetic field; the electrons move within the striking chamber, collide with gas particles, ionize the gas, and thereby generate plasma 100 within the striking chamber. It should be appreciated that other embodiments of the present invention are not limited to arc source type ion sources, but may employ rf, microwave, etc. sources.

As shown in fig. 1, one side of the ion source chamber 1 is provided with an opening 110 through which ions in the chamber are emitted outwardly under the influence of an electric field. This side of the ion source chamber 1 constitutes a fourth electrode 11 and the opening 110 may be referred to as an "exit opening", i.e. the fourth electrode 11 has an exit opening 110 for the outward emission of the charged particle beam 3. In some specific examples, the outlet 110 may be a hole or slit, and the number may be one or more. Since the fourth electrode 11 is disposed on the ion source chamber 1, the fourth electrode 11 is in close contact with the plasma 100 in the ion source chamber 1, and the potential of the fourth electrode 11 determines the potential of the plasma 100.

The extraction electrode group 2 is provided in a direction perpendicular to the beam extraction surface, i.e., in the beam advancing direction a. The set of extraction electrodes 2 comprises a third electrode 21, a second electrode 22 and a first electrode 23, each having an opening for the charged particle beam 3 to pass through. As shown in fig. 1, the third electrode 21 has an opening 210, the second electrode 22 has an opening 220, and the first electrode 23 has an opening 230. In some specific examples, the center of the fourth electrode 11 has an outlet 110 for passing the beam, and accordingly, the centers of the third electrode 21, the second electrode 22, and the first electrode 23 also form openings 210, 220, and 230, respectively, for passing the beam. The centerlines of the openings 210, 220, and 230 may coincide with the centerlines of the outlet 110. Openings 210, 220, and 230 may be holes or slits, and the number may be one or more, corresponding to outlet 110.

In some embodiments of the invention, the charged particle beam extraction apparatus is suitable for use with electrodes of a variety of opening shapes. For example, for an electrode with a slit opening, the extracted beam is in a long shape (such as a wide beam), the long side direction of the beam is the direction perpendicular to the paper surface in fig. 1, and the short side direction of the beam is the direction perpendicular to a in the paper surface; for an electrode with a round hole opening, the opening can be of a circularly symmetrical structure; the charged particle beam extraction device is also applicable to an electrode having a mesh-like opening. The charged particle beam 3 may take any suitable shape, all of which are within the scope of the present invention.

In one specific example, each electrode in the set of extraction electrodes may be formed using two equipotential electrodes, one above the other. As an example, the material of the electrode is selected from high temperature rare metal materials such as tungsten, molybdenum, and the like. In the case of an electrode of gradually increasing size, a high purity graphite material may also be selected as the electrode material in consideration of cost and weight factors. According to different practical application requirements, the electrode material can also adopt a combination of high-temperature nonferrous metal and graphite.

In the present embodiment, when the charged particle beam 3 is a positive ion beam, the first electrode 23 is grounded, the potential difference between the second electrode 22 and the first electrode 23 is negative, the potential difference between the fourth electrode 11 and the first electrode 23 is positive, and the potential difference between the third electrode 21 and the fourth electrode 11 is negative. In one example, the first electrode 23 furthest from the outlet 110 is at a reference level, or referred to as "ground"; the second electrode 22, which is the second electrode, is connected to a negative voltage in the direction from the reference electrode to the outlet 110 in this order, and the level thereof is negative; the third electrode, third electrode 21, may be connected to a positive voltage, the level of which is positive; and the fourth electrode 11, which is the fourth electrode, is connected to a positive voltage, the level of which is positive, and the level of the fourth electrode 11 is higher than that of the third electrode 21. In another example, the first electrode 23 is grounded, being a reference level; the second electrode 22 is connected with negative voltage, and the level of the second electrode is negative; the third electrode 21 may be connected to a negative voltage, the level of which is negative; and the fourth electrode 11 is connected to a positive voltage, the level of which is positive.

When the charged particle beam 3 is a positive ion beam, the level of the fourth electrode 11 may be set to be highest. The fourth electrode 11 may be configured with different level adjustable ranges according to the application scenario. As an example, the level adjustment range of the fourth electrode 11 may be selected from one of the following ranges: greater than 0 but not greater than 60 kilovolts; greater than 0 but not greater than 80 kilovolts; greater than 0 but not greater than 100 kilovolts; greater than 0 but not greater than 120 kilovolts; greater than 0 but not greater than 150 kilovolts; greater than 0 but not greater than 200 kilovolts, and so forth. In addition, as an example, the level adjustment range of the third electrode 21 may be set to a numerical range obtained by multiplying the level of the fourth electrode 11 by a coefficient smaller than 1, which may be larger than 0 but not larger than 99.9%, for example, 60%, 70%, 80%, or the like; and the level adjustment range of the second electrode 22 may be set to less than 0 but not less than minus 30 kv. In a specific example, the level of the fourth electrode 11 may be set to 60 kv, the level of the third electrode 21 may be set to 42 kv, and the level of the second electrode 22 may be set to minus 5 kv.

In the present embodiment, when the charged particle beam 3 is a negative ion beam, the first electrode 23 is grounded, the potential difference between the second electrode 22 and the first electrode 23 is positive, the potential difference between the fourth electrode 11 and the first electrode 23 is negative, and the potential difference between the third electrode 21 and the fourth electrode 11 is positive. In one example, the first electrode 23 furthest from the outlet 110 is grounded at a reference level; the second electrode 22, which is the second electrode, is connected to a positive voltage in the direction from the reference electrode to the outlet 110 in this order, and the level thereof is positive; the third electrode, third electrode 21, can be connected to a negative voltage, the level of which is negative; and the fourth electrode 11, which is the fourth electrode, is connected to a negative voltage, the level of which is negative, and the level of the fourth electrode 11 is lower than that of the third electrode 21. In another example, the first electrode 23 is grounded, being a reference level; the second electrode 22 is connected with positive voltage, and the level thereof is positive; the third electrode 21 may be connected to a positive voltage, the level of which is positive; and the fourth electrode 11 is connected to a negative voltage, the level of which is negative.

When the charged particle beam 3 is a negative ion beam, the level of the fourth electrode 11 may be set to be the lowest. As an example, the level adjustment range of the third electrode 21 may be set to a numerical range obtained by multiplying the level of the fourth electrode 11 by a coefficient smaller than 1, which may be larger than 0 but not larger than 99.9%, for example, 60%, 70%, 80%, or the like.

In the embodiment of the invention, the fourth electrode, the second electrode and the first electrode form a first lens electric field, and the third electrode, the second electrode and the first electrode form a second lens electric field, and the second lens electric field can realize secondary focusing on the charged particle beam. More specifically, the lens electric field formed by the third electrode, the second electrode and the first electrode has a specific electric field structure, which can produce the following technical effects: first, the charged particle beam may be refocused; secondly, the charged particle beam can not strike the electrode; and thirdly, the focus and the divergence angle of the charged particle beam can be adjusted more conveniently, namely, the focus of the beam is controlled at a specific position, and the divergence angle can be ensured to be small enough, so that the loss of the beam in the transmission process is reduced. In one embodiment shown in fig. 2, the electric field formed by the third electrode 21, the second electrode 22 and the first electrode 23 is used to secondarily focus the charged particle beam 3, so that the originally divergent beam is refocused to be nearly parallel, thereby optimizing the control of the beam divergence angle and focus. In one example, in addition to controlling the divergence angle and focus of the beam, the charged particle beam extraction device may also prevent electrons from downstream of the beam from entering the ion source chamber 1 through the opening of the extraction electrode set 2 and the opening of the fourth electrode 11.

The shape of the electrode opening can influence the distribution of potential equipotential lines, so as to influence the extraction and transmission of the charged particle beam, and further influence the divergence angle of the beam. Therefore, selecting and setting a reasonable electrode opening shape is very important for controlling the divergence angle of the beam.

For the fourth electrode 11, the outlet 110 may have a suitable shape on the side facing the third electrode 21, which may comprise a chamfer shape and/or a circular arc shape.

As shown in fig. 3, in the first example, the shape of the outlet 110 may be a chamfer shape, and the angle may be more than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, and so on.

As shown in fig. 4, in the second example, the shape of the outlet 110 may be a circular arc shape, and the radius of the circular arc may be not less than 1 mm and not more than 30 mm, for example, 5mm, 10 mm, 20mm, etc.

As shown in fig. 5, in a third example, the shape of the outlet 110 may be a double chamfer shape, and the angles of the two chamfers may be greater than 0 degrees and less than 90 degrees. As a specific example, the angle of the outside chamfer may be greater than the angle of the inside chamfer. For example, the angle of the outside chamfer may be 60 degrees, while the angle of the inside chamfer may be 30 degrees.

As shown in fig. 6, in the fourth example, the shape of the outlet 110 may be a double circular arc shape, and the circular arc radii of both may be not less than 1mm and not more than 30 mm. As a specific example, the outside arc radius may be greater than the inside arc radius. For example, the outside radius of the arc may be 10 millimeters and the inside radius of the arc may be 5 millimeters.

As shown in fig. 7, in the fifth example, the shape of the outlet 110 may be a combination of a circular arc and a chamfer. Wherein the outer side is arc-shaped, and the arc radius may be not less than 1mm and not more than 30 mm, such as 5mm, 10 mm, 20 mm, etc.; the inner side is chamfer-shaped, and the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.

As shown in fig. 8, in the sixth example, the shape of the outlet 110 may be a combination shape of a chamfer and an arc. Wherein the outer side is chamfer-shaped, the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.; the inner side is in the shape of a circular arc, and the radius of the circular arc may be not less than 1mm and not more than 30 mm, for example, 5mm, 10 mm, 20 mm, etc.

Similarly, for the third electrode 21, the opening 210 thereof may have a suitable shape including a chamfer shape and/or a circular arc shape on the side facing the second electrode 22. As shown in fig. 3, the shape of the opening 210 may be a chamfer shape, and the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc. As shown in fig. 4, the shape of the opening 210 may be a circular arc shape, and the radius of the circular arc may be not less than 1mm and not more than 30mm, for example, 5mm, 10mm, 20 mm, etc. As shown in fig. 5, the shape of the opening 210 may be a double chamfer shape, and the angles of the two chamfers may be greater than 0 degrees and less than 90 degrees. As a specific example, the angle of the outside chamfer may be greater than the angle of the inside chamfer, for example, the angle of the outside chamfer may be 60 degrees and the angle of the inside chamfer may be 30 degrees. As shown in fig. 6, the shape of the opening 210 may be a double circular arc shape, and the circular arc radius of both may be not less than 1mm and not more than 30 mm. As a specific example, the outside arc radius may be greater than the inside arc radius, e.g., the outside arc radius may be 10 millimeters and the inside arc radius may be 5 millimeters. As shown in fig. 7, the shape of the opening 210 may be a combination of circular arcs and chamfers. Wherein the outer side is arc-shaped, and the arc radius may be not less than 1mm and not more than 30mm, such as 5mm, 10mm, 20 mm, etc.; the inner side is chamfer-shaped, and the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc. As shown in fig. 8, the shape of the opening 210 may be a combination of a chamfer and an arc. Wherein the outer side is chamfer-shaped, the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.; the inner side is in the shape of a circular arc, and the radius of the circular arc may be not less than 1mm and not more than 30mm, for example, 5mm, 10mm, 20 mm, etc.

In other examples, the outlet 110 of the fourth electrode 11 and the opening 210 of the third electrode 21 may have any three or more chamfer and/or arc combination shapes, for example, a three chamfer shape, a three arc shape, a two arc one chamfer shape, a two chamfer one arc shape, a four chamfer shape, a four arc shape, and the like. The outlet 110 of the fourth electrode 11 and the opening 210 of the third electrode 21 may have the same or similar shape, or may have completely different shapes. In one embodiment, all of the foregoing types of shapes may have a thickness in the axial direction of not less than 1mm and not more than 30 mm. It should be appreciated that other embodiments of the present invention are not limited to the aforementioned combination of chamfer and/or circular arc shapes, as other suitable shapes may be selected.

Fig. 9 to 14 are diagrams showing the results of simulation of the equipotential line distribution for the first to sixth exemplary opening shapes, respectively, according to an embodiment of the present invention. Referring to fig. 9 to 14, the abscissa represents the distance along the advancing direction of the charged particle beam, and the ordinate represents the distance from the center of the beam in the direction perpendicular to the advancing direction of the beam. Wherein the three electrodes are illustrated as a first electrode, a second electrode and a third electrode in sequence from right to left, lines of different colors represent equipotential lines of the electric potential, and lines with darker colors represent lower electric potential. As shown in the figure, the shape of the opening of the third electrode is different, and the shape of the equipotential lines formed is also different, so that the focusing effect of the charged particle beam is different. In this embodiment, the electric field formed by the third electrode, the second electrode and the first electrode is used to secondarily focus the charged particle beam, and a desired focusing manner can be achieved by adjusting the opening shape of the third electrode, thereby achieving a focusing function of the beam in a larger current range.

In one embodiment, the charged particle beam extraction apparatus may further comprise a detection assembly. As an example, in the charged particle beam extraction direction, a detection assembly may be provided at a suitable location remote from the first electrode for measuring the divergence angle of the charged particle beam. In another example, the detection assembly may measure parameters such as the size of the charged particle beam, the current magnitude, and the like, in addition to measuring the divergence angle.

In the embodiment of the invention, the lens electric field formed by the electrodes can be adjusted by adjusting the interval between the electrodes, so that the focus and the divergence angle of the beam current are controlled. As an example, the spacing between the electrodes, designed according to the configured maximum potential difference, may have a relationship to the potential difference of less than 5 kv/mm. The fourth electrode is typically stationary, and all or a portion of the third electrode, the second electrode, and the first electrode are arranged to be movable. In an ion implantation apparatus, the ion source, the beam transport system and the charged particle beam extraction apparatus of the present invention are all operated in a vacuum environment, and in general, the control apparatus is disposed in an atmospheric environment, the fewer objects that need to be moved, the more advantageous the design is for the connection between the control apparatus and the vacuum system.

In the first exemplary configuration of electrode spacing adjustment, the third electrode 21, the second electrode 22, and the first electrode 23 are fixed in distance from each other, and the third electrode 21, the second electrode 22, and the first electrode 23 can move synchronously. In this exemplary configuration, the third electrode 21, the second electrode 22 and the first electrode 23 may be provided on the same holder, with the three being fixed in distance from each other and electrically isolated by an insulating member, and the extraction electrode group 2 constituted of the three may be moved back and forth in the beam direction as a whole, so that the distance between the third electrode 21 and the fourth electrode 11 can be adjusted. Therefore, the divergence angle and the focal point of the charged particle beam can be controlled by adjusting the pitch between the third electrode 21 and the fourth electrode 11 by moving the extraction electrode group 2 as a whole.

In the second exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 and the second electrode 22 are movable in synchronization, and the first electrode 23 is stationary. In this exemplary configuration, the third electrode 21 and the second electrode 22 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the third electrode 21 and the second electrode 22 may be moved back and forth in the beam direction in synchronization, so that the distance between the third electrode 21 and the fourth electrode 11 and the distance between the second electrode 22 and the first electrode 23 can be adjusted.

In a third exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 and the second electrode 22 are movable in synchronization, and the first electrode 23 is movable. In this exemplary configuration, the third electrode 21 and the second electrode 22 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the third electrode 21 and the second electrode 22 may be moved back and forth in the beam direction in synchronization, so that the distance between the third electrode 21 and the fourth electrode 11 can be adjusted. In this exemplary configuration, the first electrode 23 can be independently moved back and forth in the beam direction, so that the distance between the first electrode 23 and the second electrode 22 can be adjusted.

In a fourth exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 is stationary with the second electrode 22, and the first electrode 23 is movable. In this exemplary configuration, the first electrode 23 can be independently moved back and forth in the beam direction, so that the distance between the first electrode 23 and the second electrode 22 can be adjusted.

In a fifth exemplary configuration of electrode spacing adjustment, the distance between the second electrode 22 and the first electrode 23 is fixed, the second electrode 22 and the first electrode 23 are movable in synchronization, and the third electrode 21 is stationary. In this exemplary configuration, the second electrode 22 and the first electrode 23 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the second electrode 22 and the first electrode 23 may be moved back and forth in the beam direction in synchronization, so that the distance between the second electrode 22 and the third electrode 21 can be adjusted.

In a sixth exemplary configuration of electrode spacing adjustment, the distance between the second electrode 22 and the first electrode 23 is fixed, the second electrode 22 and the first electrode 23 are movable in synchronization, and the third electrode 21 is movable. In this exemplary configuration, the second electrode 22 and the first electrode 23 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the second electrode 22 and the first electrode 23 may be moved back and forth in the beam direction in synchronization, so that the distance between the second electrode 22 and the third electrode 21 can be adjusted. In this exemplary configuration, the third electrode 21 can be independently moved back and forth in the beam direction, so that the distance between the third electrode 21 and the fourth electrode 11 and the distance between the third electrode 21 and the second electrode 22 can be adjusted.

In a seventh exemplary configuration of electrode spacing adjustment, the distance between the second electrode 22 and the first electrode 23 is fixed, the second electrode 22 is stationary with the first electrode 23, and the third electrode 21 is movable. In this exemplary configuration, the third electrode 21 can be independently moved back and forth in the beam direction, so that the distance between the third electrode 21 and the fourth electrode 11 and the distance between the third electrode 21 and the second electrode 22 can be adjusted. In this exemplary configuration, only the third electrode 21 needs to be moved to adjust the divergence angle of the beam and the focal point.

In the eighth exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the first electrode 23 is fixed, the third electrode 21 and the first electrode 23 are movable in synchronization, and the second electrode 22 is fixed. In this exemplary configuration, the third electrode 21 and the first electrode 23 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the third electrode 21 and the first electrode 23 may be moved back and forth in the beam direction in synchronization, so that the distance between the third electrode 21 and the fourth electrode 11 and the distance between the third electrode 21 and the second electrode 22 can be adjusted.

In the ninth exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the first electrode 23 is fixed, the third electrode 21 and the first electrode 23 are movable in synchronization, and the second electrode 22 is movable. In this exemplary configuration, the third electrode 21 and the first electrode 23 may be disposed on the same holder with a fixed distance from each other and electrically isolated by an insulating member, and the third electrode 21 and the first electrode 23 may be moved back and forth in the beam direction in synchronization, so that the distance between the third electrode 21 and the fourth electrode 11 can be adjusted. In this exemplary configuration, the second electrode 22 can be independently moved back and forth in the beam direction, so that the distance between the second electrode 22 and the third electrode 21 can be adjusted.

In a tenth exemplary configuration of electrode spacing adjustment, the distance between the third electrode 21 and the first electrode 23 is fixed, the third electrode 21 is stationary with the first electrode 23, and the second electrode 22 is movable. In this exemplary configuration, the second electrode 22 can be independently moved back and forth in the beam direction, so that the distance between the second electrode 22 and the third electrode 21 and the distance between the second electrode 22 and the first electrode 23 can be adjusted.

In an eleventh exemplary configuration of electrode spacing adjustment, the third electrode 21, the second electrode 22, and the first electrode 23 are each independently movable. In this exemplary configuration, the third electrode 21, the second electrode 22, and the first electrode 23 are each independently movable back and forth in the beam direction, so that the distance between the respective electrodes can be adjusted.

In another aspect, embodiments of the present invention provide an ion implanter comprising the charged particle beam extraction apparatus described above.

In addition, the embodiment of the invention also provides a charged particle beam extraction method. The method utilizes the charged particle beam extraction device, can extract beam current with larger current range under the same electrode structure, further improves the running stability of the ion source, and can simultaneously meet the requirements of stable focus, uniformity and small divergence angle.

In one embodiment, the method uses the aforementioned apparatus to direct a charged particle beam, which may include the steps of:

Step 1: a set voltage is applied to the fourth electrode 11. In one example, a set voltage is applied to the fourth electrode 11 according to the process requirements, i.e., the extraction energy of the ion beam.

Step 2: an initial voltage is applied to the third electrode 21. In one example, the level adjustment range of the third electrode 21 may be set to a range of values obtained by multiplying the level of the fourth electrode 11 by a coefficient smaller than 1, which may be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, or the like.

Step 3: an initial voltage is applied to the second electrode 22. In one example of a positive ion beam current, the second electrode 22 may be connected to a negative voltage, which may generally range from no more than negative 1 kv to no less than negative 30 kv, for example, may be negative 5 kv.

Step 4: the initial distance between the third electrode 21 and the fourth electrode 11 is set according to the voltage difference between the fourth electrode 11 and the third electrode 21. In one example, the ratio of the distance between the third electrode 21 and the fourth electrode 11 to the voltage difference between the two may be generally set to be greater than 0.2 mm/kv.

Step 5: according to the measured divergence angle of the charged particle beam, the distance between the third electrode 21 and the fourth electrode 11, the voltage of the third electrode 21 and the voltage of the second electrode 22 are repeatedly adjusted so that the divergence angle meets the requirements. In practical applications, it is generally required to adjust the divergence angle to a minimum, but in some special application scenarios, it may also be required that the divergence angle be within a certain range or that the beam size be within a certain range.

In another embodiment, the method uses the aforementioned apparatus to direct a charged particle beam, which may include the steps of:

Step 1: a set voltage is applied to the fourth electrode 11. In one example, a set voltage is applied to the fourth electrode 11 according to the process requirements, i.e., the extraction energy of the ion beam.

Step 2: an initial voltage is applied to the third electrode 21. In one example, the level adjustment range of the third electrode 21 may be set to a range of values obtained by multiplying the level of the fourth electrode 11 by a coefficient smaller than 1, which may be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, or the like.

Step 3: an initial voltage is applied to the second electrode 22. In one example of a positive ion beam current, the second electrode 22 may be connected to a negative voltage, which may generally range from no more than negative 0.1 kv but no less than negative 30 kv, for example, may be negative 0.5 kv.

Step 4: the initial distance between the third electrode 21 and the fourth electrode 11 is set according to the voltage difference between the fourth electrode 11 and the third electrode 21. In one example, the ratio of the distance between the third electrode 21 and the fourth electrode 11 to the voltage difference between the two may be generally set to be greater than 0.2 mm/kv.

Step 5: the initial distance between the third electrode 21 and the second electrode 22 is set according to the voltage difference between the third electrode 21 and the second electrode 22. In one example, the ratio of the distance between the third electrode 21 and the second electrode 22 to the voltage difference between the two may be generally set to be greater than 0.2 mm/kv.

Step 6: according to the measured divergence angle of the charged particle beam, the distance between the third electrode 21 and the fourth electrode 11, the distance between the third electrode 21 and the second electrode 22, the voltage of the third electrode 21 and the voltage of the second electrode 22 are repeatedly adjusted, so that the divergence angle meets the requirements. In practical applications, it is generally required to adjust the divergence angle to a minimum, but in some special application scenarios, it may also be required that the divergence angle be within a certain range or that the beam size be within a certain range.

In the above-described method of the present invention, the order of the steps listed is not necessarily the only order in which the steps may be performed. For example, the initial voltage may be applied to the second electrode 22 after the initial voltage is applied to the third electrode 21; the initial voltage may be applied to the third electrode 21 after the initial voltage is applied to the second electrode 22; the initial voltage may also be applied to the third electrode 21 and the second electrode 22 simultaneously. In addition, in some embodiments, the distance between the second electrode 22 and the third electrode 21, the voltage of the third electrode 21, and the voltage of the second electrode 22 may be repeatedly adjusted to make the divergence angle meet the requirement. It should be understood that the method of the present invention is not limited to the order of execution listed, and that some steps may be omitted or some other steps not described herein added, as desired.

The detailed description is given herein with reference to specific exemplary embodiments. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. While particular embodiments of the present invention have been shown and described, it would be obvious to those skilled in the art that various changes, modifications and adaptations may be made without departing from the scope of the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Moreover, the foregoing use of embodiment and other exemplary language does not necessarily refer to the same embodiment or the same example, but may refer to different and distinct embodiments, as well as the same embodiment. The appended claims are to encompass within their scope all such changes, variations, and modifications as are within the true scope and spirit of this invention.

Claims (15)

1. A charged particle beam extraction apparatus comprising:

The ion source cavity is used for generating plasma and is provided with a fourth electrode, and the fourth electrode is provided with an extraction port used for emitting charged particle beams outwards; and

The extraction electrode group sequentially comprises a third electrode, a second electrode and a first electrode in the advancing direction of the charged particle beam, wherein the third electrode, the second electrode and the first electrode are all provided with openings for the charged particle beam to pass through,

When the charged particle beam is positive ion beam, the first electrode is grounded, the potential difference between the second electrode and the first electrode is negative, the potential difference between the fourth electrode and the first electrode is positive, and the potential difference between the third electrode and the fourth electrode is negative;

When the charged particle beam is negative ion beam, the first electrode is grounded, the potential difference between the second electrode and the first electrode is positive, the potential difference between the fourth electrode and the first electrode is negative, and the potential difference between the third electrode and the fourth electrode is positive.

2. The charged-particle beam extracting apparatus according to claim 1, wherein the level adjustment range of the third electrode is set to a range of values obtained by multiplying the level of the fourth electrode by a coefficient smaller than 1.

3. The charged-particle beam extracting apparatus according to claim 2, wherein the coefficient is greater than 0 but not greater than 99.9%.

4. The charged-particle beam extracting apparatus according to claim 1, wherein the extraction opening of the fourth electrode has a shape including a chamfer shape and/or a circular arc shape on a side facing the third electrode.

5. The charged-particle beam extracting apparatus according to claim 1, wherein the opening of the third electrode has a shape including a chamfer shape and/or a circular arc shape on a side facing the second electrode.

6. The charged-particle beam extracting apparatus according to claim 4 or 5, wherein the angle of the chamfer shape is more than 0 degrees and less than 90 degrees, and the radius of the circular arc shape is not less than 1mm and not more than 30 mm.

7. The charged-particle beam extracting apparatus of claim 1, further comprising a detection assembly for measuring a divergence angle of the charged-particle beam.

8. The charged-particle beam extracting apparatus according to claim 1, wherein the third electrode, the second electrode, and the first electrode are fixed in distance from each other, and the third electrode, the second electrode, and the first electrode are movable in synchronization.

9. The charged-particle beam extracting apparatus according to claim 1, wherein in a case where a distance between the third electrode and the second electrode is fixed, the third electrode and the second electrode are movable synchronously and the first electrode is fixed, or the third electrode and the second electrode are movable synchronously and the first electrode is movable, or the third electrode and the second electrode are fixed and the first electrode is movable.

10. The charged-particle beam extracting apparatus according to claim 1, wherein in a case where a distance between the second electrode and the first electrode is fixed, the second electrode and the first electrode are movable synchronously and the third electrode is fixed, or the second electrode and the first electrode are movable synchronously and the third electrode is movable, or the second electrode and the first electrode are fixed and the third electrode is movable.

11. The charged-particle beam extracting apparatus according to claim 1, wherein in a case where a distance between the third electrode and the first electrode is fixed, the third electrode is movable in synchronization with the first electrode and the second electrode is fixed, or the third electrode is movable in synchronization with the first electrode and the second electrode is movable, or the third electrode is fixed in synchronization with the first electrode and the second electrode is movable.

12. The charged-particle beam extracting apparatus according to claim 1, wherein the third electrode, the second electrode, and the first electrode are each independently movable.

13. An ion implanter comprising a charged particle beam extraction apparatus according to any of claims 1 to 12.

14. A drawing method using the charged particle beam drawing apparatus according to any one of claims 1 to 12, comprising the steps of:

applying a set voltage to the fourth electrode;

applying an initial voltage to the third electrode;

applying an initial voltage to the second electrode;

Setting an initial distance between the third electrode and the fourth electrode according to a voltage difference between the fourth electrode and the third electrode; and

And repeatedly adjusting the distance between the third electrode and the fourth electrode, the voltage of the third electrode and the voltage of the second electrode according to the measured divergence angle of the charged particle beam, so that the divergence angle meets the requirement.

15. A drawing method using the charged particle beam drawing apparatus according to any one of claims 1 to 12, comprising the steps of:

applying a set voltage to the fourth electrode;

applying an initial voltage to the third electrode;

applying an initial voltage to the second electrode;

setting an initial distance between the third electrode and the fourth electrode according to a voltage difference between the fourth electrode and the third electrode;

Setting an initial distance between the third electrode and the second electrode according to a voltage difference between the third electrode and the second electrode; and

And repeatedly adjusting the distance between the third electrode and the fourth electrode, the distance between the third electrode and the second electrode, the voltage of the third electrode and the voltage of the second electrode according to the measured divergence angle of the charged particle beam so that the divergence angle meets the requirements.