Charged particle beam extraction device and method

Abstract

The present invention discloses a charged particle beam extraction device and method applicable to ion implanters in the field of semiconductor processing technology. The charged particle beam extraction device of the present invention comprises an ion source chamber and an extraction electrode assembly, wherein the ion source chamber is provided with a fourth electrode, and the extraction electrode assembly comprises a third electrode, a second electrode, and a first electrode, in the direction of travel of the charged particle beam. By utilizing the aforementioned device, the charged particle beam extraction method of the present invention can extract a beam with a wider current range using the same electrode structure, while simultaneously meeting the requirements of focus stability, uniformity, and a small divergence angle.

Description

Technical Field

[0001] The present invention generally relates to the field of semiconductor processing equipment, and more particularly to a charged particle beam extraction device and method. Background Art

[0002] In ion implanters, a common extraction electrode system is a three-electrode system, consisting primarily of a plasma electrode, a suppression electrode, and a ground electrode. The plasma electrode, which is at a high voltage relative to ground, is used to extract and accelerate ions. The suppression electrode, which is at a negative voltage relative to ground, is used to suppress electrons returning from the downstream beam, protecting ion source components at high potential from electron bombardment and thus improving ion source life. 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 controlling the beam divergence angle and focus.

[0003] When the beam current is within a certain range, this three-electrode system can achieve stable control of the beam divergence angle and focus to ensure steady-state beam operation. However, with the development of ion implanters, it is necessary to achieve stable operation of both large and small beam currents on the same system. However, the three-electrode system cannot maintain a stable beam focus under both small and large beam current conditions, and is prone to beam fluctuations under extreme beam current conditions. Summary of the Invention

[0004] Based on the technical problems existing in the prior art, the present invention provides a charged particle beam extraction device and method, aiming to solve the problem that an ion implanter cannot maintain beam stability under both extremely large beam current and extremely small beam current conditions.

[0005] According to one aspect of the present invention, a charged particle beam extraction device is provided. The device comprises: an ion source chamber for generating plasma, the ion source chamber being provided with a fourth electrode having an extraction port for emitting the charged particle beam; and an extraction electrode group, the extraction electrode group comprising, in order along the direction of travel of the charged particle beam, a third electrode, a second electrode, and a first electrode, each of the third electrode, the second electrode, and the first electrode having an opening for the charged particle beam to pass through. When the charged particle beam is a 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 a 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.

[0006] Optionally, 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 less than 1.

[0007] Further, the coefficient is greater than 0 but not greater than 99.9%.

[0008] Optionally, the outlet of the fourth electrode has a shape on a side facing the third electrode, and the shape includes a chamfered shape and / or an arc shape.

[0009] Optionally, the opening of the third electrode has a shape on a side facing the second electrode, and the shape includes a chamfered shape and / or an arc shape.

[0010] Furthermore, the angle of the chamfered shape is greater than 0 degrees and less than 90 degrees, and the radius of the arc shape is not less than 1 mm and not more than 30 mm.

[0011] Optionally, the charged particle beam extraction device further includes a detection component for measuring the divergence angle of the charged particle beam.

[0012] Optionally, the distances between the third electrode, the second electrode and the first electrode are fixed, and the third electrode, the second electrode and the first electrode can move synchronously.

[0013] Optionally, when the distance between the third electrode and the second electrode is fixed, the third electrode and the second electrode can move synchronously and the first electrode is fixed, or the third electrode and the second electrode can move synchronously and the first electrode is movable, or the third electrode and the second electrode are fixed and the first electrode is movable.

[0014] Optionally, when the distance between the second electrode and the first electrode is fixed, the second electrode and the first electrode can move synchronously and the third electrode is fixed, or the second electrode and the first electrode can move synchronously and the third electrode can move, or the second electrode and the first electrode are fixed and the third electrode is movable.

[0015] Optionally, when the distance between the third electrode and the first electrode is fixed, the third electrode and the first electrode can move synchronously and the second electrode is fixed, or the third electrode and the first electrode can move synchronously and the second electrode is movable, or the third electrode and the first electrode are fixed and the second electrode is movable.

[0016] Optionally, the third electrode, the second electrode, and the first electrode can all move independently.

[0017] According to another aspect of the present invention, the present invention provides an ion implanter, which includes the aforementioned charged particle beam extraction device.

[0018] According to another aspect of the present invention, a method for extracting charged particles using the aforementioned device is provided. 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 based on the 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 based on the measured divergence angle of the charged particle beam to ensure that the divergence angle meets the requirements.

[0019] According to another aspect of the present invention, there is provided an extraction method using the aforementioned device. 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 based on the voltage difference between the fourth electrode and the third electrode; setting an initial distance between the third electrode and the second electrode based on the 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 based on the measured divergence angle of the charged particle beam, so that the divergence angle meets the requirements.

[0020] Compared with the prior art, the charged particle beam extraction device and method of the present invention have the following beneficial technical effects:

[0021] 1. The specially designed four-electrode system of the present invention meets the requirements for stable, uniform, and small divergence angles of the charged particle beam's focus. In the present invention, in addition to the lens system formed by the fourth electrode, the second electrode, and the first electrode, the third electrode, the second electrode, and the first electrode also form an additional lens system. This lens system achieves secondary focusing of the charged particle beam, allowing for more convenient adjustment of the beam's focus and divergence angle without the beam striking the electrodes. This allows the beam's focus to be controlled at a specific location while also ensuring a sufficiently small divergence angle.

[0022] 2. The present invention can simultaneously achieve steady-state operation of large beam current and small beam current on the same device, and can draw out a beam current with a larger current range under the same electrode structure, thereby improving the operating stability of the ion source. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The exemplary embodiments disclosed herein may be better understood by reading the following detailed description in conjunction with the accompanying drawings, in which:

[0024] Figure 1 is a schematic structural diagram of a charged particle beam extraction device according to an embodiment of the present invention;

[0025] Figure 21 is a schematic diagram of the working state of a charged particle beam extraction device according to an embodiment of the present invention;

[0026] Figure 3 is a first exemplary schematic diagram of the opening shape of the electrode in the charged particle beam extraction device of the present invention;

[0027] Figure 4 is a second exemplary schematic diagram of the opening shape of the electrode in the charged particle beam extraction device of the present invention;

[0028] Figure 5 is a third exemplary schematic diagram of the shape of the opening of the electrode in the charged particle beam extraction device of the present invention;

[0029] Figure 6 is a fourth exemplary schematic diagram of the shape of the opening of the electrode in the charged particle beam extraction device of the present invention;

[0030] Figure 7 is a fifth exemplary schematic diagram of the shape of the opening of the electrode in the charged particle beam extraction device of the present invention;

[0031] Figure 8 is a sixth exemplary schematic diagram of the shape of the opening of the electrode in the charged particle beam extraction device of the present invention;

[0032] Figure 9 is a schematic diagram of equipotential line distribution simulation results of a first exemplary opening shape according to an embodiment of the present invention;

[0033] Figure 10 is a schematic diagram of equipotential line distribution simulation results of a second exemplary opening shape according to an embodiment of the present invention;

[0034] Figure 11 is a schematic diagram of equipotential line distribution simulation results of a third exemplary opening shape according to an embodiment of the present invention;

[0035] Figure 12 is a schematic diagram of equipotential line distribution simulation results of a fourth exemplary opening shape according to an embodiment of the present invention;

[0036] Figure 13 is a schematic diagram of equipotential line distribution simulation results of a fifth exemplary opening shape according to an embodiment of the present invention; and

[0037] Figure 14 FIG. 4 is a schematic diagram of simulation results of equipotential line distribution of a sixth exemplary opening shape according to an embodiment of the present invention.

[0038] Explanation of the reference numerals in the accompanying drawings: 1: ion source chamber; 100: plasma; 11: fourth electrode; 110: extraction port; 2: extraction electrode group; 21: third electrode; 210: opening of the third electrode; 22: second electrode; 220: opening of the second electrode; 23: first electrode; 230: opening of the first electrode; 3: charged particle beam; A: forward direction of the charged particle beam.

[0039] For the sake of brevity, the drawings illustrate general constructional aspects and omit descriptions and details of well-known features and techniques to avoid unnecessarily obscuring the discussion of the embodiments of the present invention. Furthermore, the elements in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be exaggerated relative to other elements to help improve understanding of the embodiments of the present invention. Identical reference numerals in different figures represent identical elements, while similar reference numerals may, but do not necessarily, represent similar elements. DETAILED DESCRIPTION

[0040] The present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the following detailed description is merely exemplary in nature and is not intended to limit the embodiments of the subject matter or applications and the uses of these embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as exemplary should not be construed as necessarily preferred or superior to other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the aforementioned technical field, background technology, summary of the invention, or the following detailed description.

[0041] The terms "first", "second", "third" and the like in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe a specific order or chronological order. It is to be understood that these terms used in this manner are interchangeable where appropriate, such as to enable the embodiments of the invention described herein to operate in other orders than those described or shown herein. Similarly, if the method described herein comprises a series of steps, the order of these steps presented herein is not necessarily the only order in which these steps can 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. In addition, the terms "comprise", "include", "have" and any variations thereof are intended to be applicable to non-exclusive inclusion, such that the process, method, product or device comprising a series of elements is not necessarily limited to those elements, but may include other elements that are not explicitly listed or inherent to these processes, methods, products or devices.

[0042] In one aspect, embodiments of the present invention provide a charged particle beam extraction device suitable for use in ion implanters used in semiconductor processing technology. This device can simultaneously achieve steady-state operation of both high and low beam currents, while simultaneously meeting the requirements for focal stability, uniformity, and a small divergence angle of the charged particle beam. In embodiments of the present invention, the charged particle beam extraction device includes an ion source chamber and an extraction electrode assembly. Figure 1 FIG. 1 shows a schematic structure of a charged particle beam extraction device according to an embodiment of the present invention. Figure 1 As shown, the exemplary device 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 on one side of the ion source chamber 1 and includes a third electrode 21, a second electrode 22, and a first electrode 23 in the forward direction A of the charged particle beam. Among them, the fourth electrode 11 can be called a "plasma electrode", the third electrode 21 can be called an "acceleration electrode", the second electrode 22 can be called a "suppression electrode", and the first electrode 23 can be called a "ground electrode".

[0043] The ion source chamber 1 is used to generate plasma 100. In one example, the ion source chamber 1 can be an arc chamber and can include structures or components such as an air inlet, a cathode, a reflector, a filament, and a magnet as needed. As an example, to generate plasma, a set flow rate of gas can be introduced into the arc chamber; a current is applied to the filament to cause the filament to reach a temperature at which it emits electrons; a voltage is applied between the filament and the cathode to directionally accelerate the electrons emitted by the filament toward the cathode; the cathode is heated to a temperature at which it emits electrons by the electron flow emitted by the filament; a voltage is applied between the arc chamber and the cathode to accelerate the electrons emitted by the cathode to move into the arc chamber; after being accelerated, the electrons emitted by the cathode perform a spiral motion under the action of a magnetic field; the electrons move within the arc chamber, collide with gas particles, ionize the gas, and thereby generate plasma 100 within the arc chamber. It should be understood that other embodiments of the present invention are not limited to ion sources of the arc discharge type, and ion sources using radio frequency, microwave, or other methods may also be used.

[0044] like Figure 1 As shown, an opening 110 is provided on one side of the ion source chamber 1, through which ions in the chamber are emitted outward under the action of the electric field. This side of the ion source chamber 1 constitutes the fourth electrode 11, and the opening 110 can be referred to as an "extraction port", that is, the fourth electrode 11 has an extraction port 110 for emitting the charged particle beam 3 outward. In some specific examples, the extraction ports 110 can be holes or slits, and the number can be one or more. Since the fourth electrode 11 is provided 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.

[0045] The extraction electrode group 2 is arranged in a direction perpendicular to the beam extraction surface, that is, in the beam forward direction A. The extraction electrode group 2 includes a third electrode 21, a second electrode 22 and a first electrode 23, and all three electrodes have openings for the charged particle beam 3 to pass through. Figure 1 As shown, 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 fourth electrode 11 has an extraction port 110 at its center for the beam to pass through. Correspondingly, the third electrode 21, the second electrode 22, and the first electrode 23 also have openings 210, 220, and 230 at their centers, respectively, for the beam to pass through. The centerlines of the openings 210, 220, and 230 may coincide with the centerline of the extraction port 110. Corresponding to the extraction port 110, the openings 210, 220, and 230 may be holes or slits, and may be one or more in number.

[0046] In some embodiments of the present invention, the charged particle beam extraction device is applicable to electrodes with various opening shapes. For example, for an electrode with a slit opening, the extracted beam is in the shape of a long strip (such as a wide beam), and the long side of the beam is perpendicular to the electrode. Figure 1 The direction of the short side of the beam is perpendicular to the direction A in the paper. For electrodes with circular openings, the openings can be circularly symmetrical. Furthermore, the charged particle beam extraction device is also applicable to electrodes with mesh-like openings. The charged particle beam 3 can take any suitable shape, all of which are within the scope of protection of the present invention.

[0047] In one specific example, each electrode in the extraction electrode group can be formed from two electrodes with equal potential, one above the other. For example, the electrode material can be high-temperature rare metals, such as tungsten and molybdenum. As electrode size increases, high-purity graphite can also be used for cost and weight considerations. Depending on the specific application requirements, a combination of high-temperature nonferrous metals and graphite can also be used as the electrode material.

[0048] In this 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, which is farthest from the extraction port 110, is at a reference potential, or "ground." From this reference electrode toward the extraction port 110, the second electrode, or second electrode 22, is connected to a negative voltage and has a negative potential. The third electrode, or third electrode 21, can be connected to a positive voltage and has a positive potential. The fourth electrode, or fourth electrode 11, is connected to a positive voltage and has a positive potential, and the potential of the fourth electrode 11 is higher than that of the third electrode 21. In another example, the first electrode 23 is grounded and is at a reference potential. The second electrode 22 is connected to a negative voltage and has a negative potential. The third electrode 21 can be connected to a negative voltage and has a negative potential. The fourth electrode 11 is connected to a positive voltage and has a positive potential.

[0049] When the charged particle beam 3 is a positive ion beam, the level of the fourth electrode 11 can be set to the highest. Depending on the application scenario, the fourth electrode 11 can be configured with different level adjustment ranges. As an example, the level adjustment range of the fourth electrode 11 can be selected from one of the following ranges: greater than 0 but not greater than 60 kV; greater than 0 but not greater than 80 kV; greater than 0 but not greater than 100 kV; greater than 0 but not greater than 120 kV; greater than 0 but not greater than 150 kV; greater than 0 but not greater than 200 kV, etc. In addition, as an example, the level adjustment range of the third electrode 21 can be set to the range of values ​​obtained by multiplying the level of the fourth electrode 11 by a coefficient less than 1. This coefficient can be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, etc.; while the level adjustment range of the second electrode 22 can be set to less than 0 but not less than -30 kV. In a specific example, the level of the fourth electrode 11 may be set to 60 kilovolts, the level of the third electrode 21 may be set to 42 kilovolts, and the level of the second electrode 22 may be set to negative 5 kilovolts.

[0050] In this 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, which is farthest from the extraction port 110, is grounded, representing a reference potential. From this reference electrode toward the extraction port 110, the second electrode, i.e., the second electrode 22, is connected to a positive voltage, representing a positive potential. The third electrode, i.e., the third electrode 21, may be connected to a negative voltage, representing a negative potential. The fourth electrode, i.e., the fourth electrode 11, is connected to a negative voltage, representing a negative potential, and the potential of the fourth electrode 11 is lower than that of the third electrode 21. In another example, the first electrode 23 is grounded, representing a reference potential. The second electrode 22 is connected to a positive voltage, representing a positive potential. The third electrode 21 may be connected to a positive voltage, representing a positive potential. The fourth electrode 11 is connected to a negative voltage, representing a negative potential.

[0051] When the charged particle beam 3 is a negative ion beam, the level of the fourth electrode 11 can be set to the lowest. As an example, the level adjustment range of the third electrode 21 can be set to a numerical range obtained by multiplying the level of the fourth electrode 11 by a coefficient less than 1. The coefficient can be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, etc.

[0052] In an embodiment of the present 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, which can achieve secondary focusing of 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 can be focused secondary; second, the charged particle beam can be prevented from hitting the electrode; third, the focus and divergence angle of the charged particle beam can be adjusted more conveniently, that is, while controlling the focus of the beam at a specific position, the divergence angle can also be ensured to be small enough, thereby reducing the loss of the beam during transmission. Figure 2 In the illustrated embodiment, the electric field formed by the third electrode 21, the second electrode 22, and the first electrode 23 is used to secondary focus the charged particle beam 3, refocusing the originally diverging beam to a nearly parallel state, thereby optimizing control of the beam divergence angle and focus. In one example, in addition to controlling the beam divergence angle and focus, the charged particle beam extraction device can also prevent electrons from downstream of the beam from passing through the opening of the extraction electrode assembly 2 and the opening of the fourth electrode 11 and entering the ion source chamber 1.

[0053] The shape of the electrode opening can affect the distribution of potential equipotential lines, which in turn affects the extraction and transmission of the charged particle beam, and thus the beam divergence angle. Therefore, selecting and setting a reasonable electrode opening shape is very important for controlling the beam divergence angle.

[0054] For the fourth electrode 11 , the outlet 110 thereof may have a suitable shape on the side facing the third electrode 21 , and the shape may include a chamfered shape and / or an arc shape.

[0055] like Figure 3 As shown, in the first example, the outlet 110 may have a chamfered shape, and the angle may be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, and the like.

[0056] like Figure 4 As shown, in the second example, the shape of the outlet 110 can be an arc shape, and the arc radius can be not less than 1 mm and not more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc.

[0057] like Figure 5 As shown, in a third example, the outlet 110 may have a double chamfered 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 outer chamfer may be greater than the angle of the inner chamfer. For example, the angle of the outer chamfer may be 60 degrees, while the angle of the inner chamfer may be 30 degrees.

[0058] like Figure 6 As shown, in a fourth example, the outlet 110 may be in the shape of a double arc, and the radius of both arcs may be no less than 1 mm and no more than 30 mm. As a specific example, the outer arc radius may be greater than the inner arc radius. For example, the outer arc radius may be 10 mm, while the inner arc radius may be 5 mm.

[0059] like Figure 7 As shown in the fifth example, the shape of the outlet 110 can be a combination of an arc and a chamfer. The outer side is an arc with a radius of not less than 1 mm and not more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc.; the inner side is a chamfer with an angle greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.

[0060] like Figure 8As shown in the sixth example, the shape of the outlet 110 can be a combination of a chamfer and an arc. The outer side is a chamfered shape, and the angle can be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.; the inner side is an arc shape, and the arc radius can be no less than 1 mm and no more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc.

[0061] Similarly, for the third electrode 21, the opening 210 thereof may have a suitable shape on the side facing the second electrode 22, such shape including a chamfered shape and / or an arc shape. Figure 3 As shown, the shape of the opening 210 can be a chamfered shape, and the angle can be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc. Figure 4 As shown, the shape of the opening 210 can be an arc shape, and the arc radius can be not less than 1 mm and not more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc. Figure 5 As shown, the shape of the opening 210 can be a double chamfered shape, and the angles of the two chamfers can be greater than 0 degrees and less than 90 degrees. As a specific example, the angle of the outer chamfer can be greater than the angle of the inner chamfer, for example, the angle of the outer chamfer can be 60 degrees, while the angle of the inner chamfer can be 30 degrees. Figure 6 As shown, the shape of the opening 210 can be a double arc shape, and the radius of the arcs of the two can be not less than 1 mm and not more than 30 mm. As a specific example, the outer arc radius can be larger than the inner arc radius, for example, the outer arc radius can be 10 mm, and the inner arc radius can be 5 mm. Figure 7 As shown, the shape of the opening 210 can be a combination of an arc and a chamfer. The outer side is an arc shape, and the arc radius can be no less than 1 mm and no more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc.; the inner side is a chamfer shape, and the angle can be greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc. Figure 8 As shown, the shape of the opening 210 can be a combination of a chamfer and an arc. The outer side is a chamfered shape with an angle greater than 0 degrees and less than 90 degrees, such as 30 degrees, 45 degrees, 60 degrees, etc.; the inner side is an arc shape with a radius of not less than 1 mm and not more than 30 mm, such as 5 mm, 10 mm, 20 mm, etc.

[0062] In other examples, the outlet 110 of the fourth electrode 11 and the opening 210 of the third electrode 21 may have a shape formed by a combination of any three or more chamfers and / or arcs, for example, a three-chamfer shape, a three-arc shape, a two-arc and one-chamfer shape, a two-chamfer and 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 shapes, or they may have completely different shapes. In a specific embodiment, the thickness of all the aforementioned shapes in the axial direction may be not less than 1 mm and not more than 30 mm. It should be understood that other embodiments of the present invention are not limited to the aforementioned combination of chamfers and / or arcs, and other suitable shapes may also be selected.

[0063] Figures 9 to 14 Schematic diagrams showing the equipotential line distribution simulation results of the first to sixth exemplary opening shapes according to an embodiment of the present invention are shown respectively. Figures 9 to 14 The horizontal axis represents the distance along the direction of travel of the charged particle beam, and the vertical axis represents the distance from the center of the beam in a direction perpendicular to the direction of travel of the beam. The three electrodes shown in the figure are, from right to left, the first electrode, the second electrode, and the third electrode. Lines of different colors represent equipotential lines of electric potential, with darker lines indicating lower potentials. As shown in the figure, different opening shapes of the third electrode will form different equipotential lines, resulting in different focusing effects on the charged particle beam. In this embodiment, the electric field formed by the third electrode, the second electrode, and the first electrode is used to achieve secondary focusing of the charged particle beam, and the desired focusing method can be achieved by adjusting the opening shape of the third electrode, thereby realizing the focusing function of a beam with a larger current range.

[0064] In one embodiment, the charged particle beam extraction device may further include a detection component. For example, the detection component may be positioned in the extraction direction of the charged particle beam, at a suitable location away from the first electrode, to measure the divergence angle of the charged particle beam. In another example, in addition to measuring the divergence angle, the detection component may also measure parameters such as the size and current of the charged particle beam.

[0065] In an embodiment of the present invention, by adjusting the spacing between the electrodes, the lens electric field formed by the electrodes can be adjusted, thereby controlling the focus and divergence angle of the beam. As an example, the spacing between the electrodes is designed according to the configured maximum potential difference, and the relationship between the spacing and the potential difference can be less than 5 kV / mm. The fourth electrode is usually fixed, while all or part of the third electrode, the second electrode and the first electrode are configured to be movable. In the ion implantation equipment, the ion source, the beam transport system and the charged particle beam extraction device of the present invention all operate in a vacuum environment, and generally speaking, the control equipment is arranged in an atmospheric environment. Therefore, the fewer objects that need to be moved, the more advantageous the design is for the connection between the control equipment and the vacuum system.

[0066] In a first exemplary configuration for adjusting the electrode spacing, the distances between the third electrode 21, the second electrode 22, and the first electrode 23 are fixed, and the three electrodes 21, 22, and 23 can move synchronously. In this exemplary configuration, the third electrode 21, the second electrode 22, and the first electrode 23 can be mounted on the same bracket, with the distances between them fixed and electrically isolated by insulating components. The extraction electrode assembly 2 formed by the three electrodes can be moved back and forth as a whole in the beam direction, thereby adjusting the distance between the third electrode 21 and the fourth electrode 11. Therefore, the divergence angle and focus of the charged particle beam can be controlled simply by moving the extraction electrode assembly 2 as a whole to adjust the distance between the third electrode 21 and the fourth electrode 11.

[0067] In a second exemplary configuration for adjusting the electrode spacing, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 and the second electrode 22 can move synchronously, and the first electrode 23 is stationary. In this exemplary configuration, the third electrode 21 and the second electrode 22 can be mounted on the same bracket, with a fixed distance between them and electrically isolated by insulating components. The third electrode 21 and the second electrode 22 can move synchronously back and forth in the beam direction, thereby enabling adjustment of the distance between the third electrode 21 and the fourth electrode 11, as well as the distance between the second electrode 22 and the first electrode 23.

[0068] In a third exemplary configuration for adjusting the electrode spacing, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 and the second electrode 22 can move synchronously, and the first electrode 23 can move. In this exemplary configuration, the third electrode 21 and the second electrode 22 can be mounted on the same support, with a fixed distance between them and electrically isolated by insulating components. The third electrode 21 and the second electrode 22 can move synchronously back and forth in the beam direction, thereby adjusting the distance between the third electrode 21 and the fourth electrode 11. In this exemplary configuration, the first electrode 23 can independently move back and forth in the beam direction, thereby adjusting the distance between the first electrode 23 and the second electrode 22.

[0069] In a fourth exemplary configuration for adjusting the electrode spacing, the distance between the third electrode 21 and the second electrode 22 is fixed, the third electrode 21 and the second electrode 22 are stationary, 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, thereby enabling adjustment of the distance between the first electrode 23 and the second electrode 22.

[0070] In a fifth exemplary configuration for adjusting the electrode spacing, the distance between the second electrode 22 and the first electrode 23 is fixed, the second electrode 22 and the first electrode 23 can move synchronously, and the third electrode 21 is stationary. In this exemplary configuration, the second electrode 22 and the first electrode 23 can be mounted on the same support, with a fixed distance between them and electrically isolated by insulating components. The second electrode 22 and the first electrode 23 can move synchronously back and forth in the beam direction, thereby enabling adjustment of the distance between the second electrode 22 and the third electrode 21.

[0071] In a sixth exemplary configuration for adjusting the electrode spacing, 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 synchronously, and the third electrode 21 is movable. In this exemplary configuration, the second electrode 22 and the first electrode 23 are mounted on the same support, with a fixed distance between them and electrically isolated by insulating components. The second electrode 22 and the first electrode 23 are movable synchronously back and forth in the beam direction, thereby adjusting the distance between the second electrode 22 and the third electrode 21. In this exemplary configuration, the third electrode 21 is independently movable back and forth in the beam direction, thereby adjusting the distance between the third electrode 21 and the fourth electrode 11, as well as the distance between the third electrode 21 and the second electrode 22.

[0072] In a seventh exemplary configuration for adjusting the electrode spacing, the distance between the second electrode 22 and the first electrode 23 is fixed, the second electrode 22 and the first electrode 23 are stationary, 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, thereby adjusting the distance between the third electrode 21 and the fourth electrode 11, as well as the distance between the third electrode 21 and the second electrode 22. In this exemplary configuration, the beam divergence angle and focus can be adjusted simply by moving the third electrode 21.

[0073] In an eighth exemplary configuration for adjusting the electrode spacing, the distance between the third electrode 21 and the first electrode 23 is fixed, the third electrode 21 and the first electrode 23 can move synchronously, and the second electrode 22 is stationary. In this exemplary configuration, the third electrode 21 and the first electrode 23 can be mounted on the same bracket, with a fixed distance between them and electrically isolated by insulating components. The third electrode 21 and the first electrode 23 can move synchronously back and forth in the beam direction, thereby enabling adjustment of the distance between the third electrode 21 and the fourth electrode 11, as well as the distance between the third electrode 21 and the second electrode 22.

[0074] In a ninth exemplary configuration for adjusting the electrode spacing, 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 synchronously, and the second electrode 22 is movable. In this exemplary configuration, the third electrode 21 and the first electrode 23 are mounted on the same support, with a fixed distance between them and electrically isolated by insulating components. The third electrode 21 and the first electrode 23 are movable synchronously back and forth in the beam direction, thereby adjusting the distance between the third electrode 21 and the fourth electrode 11. In this exemplary configuration, the second electrode 22 is independently movable back and forth in the beam direction, thereby adjusting the distance between the second electrode 22 and the third electrode 21.

[0075] In the tenth exemplary configuration for adjusting the electrode spacing, the distance between the third electrode 21 and the first electrode 23 is fixed, the third electrode 21 and the first electrode 23 are stationary, 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, thereby enabling adjustment of the distance between the second electrode 22 and the third electrode 21, as well as the distance between the second electrode 22 and the first electrode 23.

[0076] In the eleventh exemplary configuration for adjusting the electrode spacing, the third electrode 21, the second electrode 22, and the first electrode 23 can all be independently moved. In this exemplary configuration, the third electrode 21, the second electrode 22, and the first electrode 23 can all be independently moved back and forth in the beam direction, thereby adjusting the distance between the electrodes.

[0077] In another aspect, an embodiment of the present invention provides an ion implanter, which includes the aforementioned charged particle beam extraction device.

[0078] Furthermore, embodiments of the present invention provide a charged particle beam extraction method. This method utilizes the aforementioned charged particle beam extraction device to extract a beam with a wider current range using the same electrode structure, thereby improving the operational stability of the ion source and simultaneously meeting the requirements of focus stability, uniformity, and a small divergence angle.

[0079] In one embodiment, the method utilizes the aforementioned device to draw a charged particle beam, which may include the following steps:

[0080] Step 1: Applying a set voltage to the fourth electrode 11. In one example, a set voltage is applied to the fourth electrode 11 according to process requirements, that is, the extraction energy of the ion beam.

[0081] Step 2: Apply an initial voltage to the third electrode 21. In one example, the voltage level adjustment range of the third electrode 21 can be set to a numerical range obtained by multiplying the voltage level of the fourth electrode 11 by a coefficient less than 1. The coefficient can be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, etc.

[0082] Step 3: Apply an initial voltage to the second electrode 22. In an example of a positive ion beam, the second electrode 22 may be connected to a negative voltage, which generally ranges from not higher than -1 kV but not lower than -30 kV, such as -5 kV.

[0083] Step 4: Set an initial distance between the third electrode 21 and the fourth electrode 11 based on 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 therebetween can be set to be greater than 0.2 mm / kV.

[0084] Step 5: Based on the measured divergence angle of the charged particle beam, repeatedly adjust 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 to ensure that the divergence angle meets the requirements. In practical applications, the divergence angle is generally required to be adjusted to the minimum, but some special applications may also require the divergence angle or beam size to be within a certain range.

[0085] In another embodiment, the method uses the aforementioned device to draw a charged particle beam, which may include the following steps:

[0086] Step 1: Applying a set voltage to the fourth electrode 11. In one example, a set voltage is applied to the fourth electrode 11 according to process requirements, that is, the extraction energy of the ion beam.

[0087] Step 2: Apply an initial voltage to the third electrode 21. In one example, the voltage level adjustment range of the third electrode 21 can be set to a numerical range obtained by multiplying the voltage level of the fourth electrode 11 by a coefficient less than 1. The coefficient can be greater than 0 but not greater than 99.9%, for example, 60%, 70%, 80%, etc.

[0088] Step 3: Apply an initial voltage to the second electrode 22. In an example of a positive ion beam, the second electrode 22 may be connected to a negative voltage, which generally ranges from not higher than -0.1 kV but not lower than -30 kV, such as -0.5 kV.

[0089] Step 4: Set an initial distance between the third electrode 21 and the fourth electrode 11 based on 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 therebetween can be set to be greater than 0.2 mm / kV.

[0090] Step 5: Set an initial distance between the third electrode 21 and the second electrode 22 based on 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 therebetween can be set to be greater than 0.2 mm / kV.

[0091] Step 6: Based on the measured divergence angle of the charged particle beam, repeatedly adjust the distance between the third electrode 21 and the fourth electrode 11, the distance between the third electrode 21 and the second electrode 22, and the voltage of the third electrode 21 and the voltage of the second electrode 22 to ensure that the divergence angle meets the requirements. In practical applications, the divergence angle is generally required to be adjusted to the minimum, but some special applications may also require the divergence angle or beam size to be within a certain range.

[0092] In the above-described method of the present invention, the order of the steps listed is not necessarily the only order in which these steps can 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; or the initial voltage may be applied to the third electrode 21 and the second electrode 22 simultaneously. Furthermore, 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 ensure that the divergence angle meets the requirements. It should be understood that the method of the present invention is not limited to the order listed, and steps may be omitted or additional steps not described herein may be added as needed.

[0093] A detailed description is provided herein with reference to specific exemplary embodiments. However, it will be apparent that various modifications and variations may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Although specific embodiments of the invention have been shown and described, it will be apparent that those skilled in the art may make many changes, variations, and modifications without departing from the scope of the appended claims. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense. Moreover, the above-mentioned use of embodiments and other exemplary language does not necessarily refer to the same embodiment or the same example, but may refer to different and unique embodiments, or may be the same embodiment. The appended claims will encompass within their scope all such changes, variations, and modifications that fall within the true scope and spirit of the invention.

Claims

1. A charged particle beam extraction device, characterized in that: include: An ion source chamber, for generating plasma, wherein the ion source chamber is provided with a fourth electrode, and the fourth electrode has an outlet for emitting a charged particle beam outward; as well as an extraction electrode group, wherein the extraction electrode group includes a third electrode, a second electrode, and a first electrode in the forward direction of the charged particle beam, and the third electrode, the second electrode, and the first electrode all have an opening for the charged particle beam to pass through. Wherein, when the charged particle beam is a 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; Wherein, when the charged particle beam is a 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; 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. The second lens electric field can achieve secondary focusing of the charged particle beam.

2. The charged particle beam extraction device according to claim 1, wherein: 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 less than 1.

3. The charged particle beam extraction device according to claim 2, wherein: The coefficient is greater than 0 but not greater than 99.9%.

4. The charged particle beam extraction device according to claim 1, wherein: The outlet of the fourth electrode has a shape on a side facing the third electrode, and the shape includes a chamfered shape and / or an arc shape.

5. The charged particle beam extraction device according to claim 1, wherein: The opening of the third electrode has a shape on a side facing the second electrode, and the shape includes a chamfered shape and / or an arc shape.

6. The charged particle beam extraction device according to claim 4 or 5, characterized in that: The angle of the chamfered shape is greater than 0 degrees and less than 90 degrees, and the radius of the arc shape is not less than 1 mm and not more than 30 mm.

7. The charged particle beam extraction device according to claim 1, wherein: The invention also includes a detection component for measuring the divergence angle of the charged particle beam.

8. The charged particle beam extraction device according to claim 1, wherein: The distances between the third electrode, the second electrode and the first electrode are fixed, and the third electrode, the second electrode and the first electrode can move synchronously.

9. The charged particle beam extraction device according to claim 1, wherein: When the distance between the third electrode and the second electrode is fixed, the third electrode and the second electrode can move synchronously and the first electrode is fixed, or the third electrode and the second electrode can move 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 extraction device according to claim 1, wherein: When the distance between the second electrode and the first electrode is fixed, the second electrode and the first electrode can move synchronously and the third electrode is fixed, or the second electrode and the first electrode can move 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 extraction device according to claim 1, wherein: When the distance between the third electrode and the first electrode is fixed, the third electrode and the first electrode can move synchronously and the second electrode is fixed, or the third electrode and the first electrode can move synchronously and the second electrode is movable, or the third electrode and the first electrode are fixed and the second electrode is movable.

12. The charged particle beam extraction device according to claim 1, wherein: The third electrode, the second electrode, and the first electrode can all move independently.

13. An ion implanter, characterized in that: The device comprises the charged particle beam extraction device according to any one of claims 1 to 12.

14. A charged particle beam extraction method using the charged particle beam extraction device according to any one of claims 1 to 12, It is characterized by: The following steps are involved: 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; as well as According to the measured divergence angle of the charged particle beam, the distance between the third electrode and the fourth electrode, the voltage of the third electrode, and the voltage of the second electrode are repeatedly adjusted to make the divergence angle meet the requirements.

15. A charged particle beam extraction method using the charged particle beam extraction device according to any one of claims 1 to 12, It is characterized by: The following steps are involved: 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; as well as According to the measured divergence angle of the charged particle beam, 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 are repeatedly adjusted to make the divergence angle meet the requirements.

Images