Ion source system

Abstract

The utility model provides an ion source system which comprises a discharge cavity, a separation part, a positive ion beam extraction grid mesh and an electron beam extraction grid mesh, the separation part divides the discharge cavity into a plurality of partitions which are not communicated with one another, the same ends of the partitions are respectively provided with an extraction port, the partitions are further respectively provided with an air inlet, and the positive ion beam extraction grid mesh and the electron beam extraction grid mesh are arranged in the discharge cavity. A positive ion beam leading-out grid mesh is arranged at the leading-out port of at least one subarea so as to lead out a positive ion beam, an electron beam leading-out grid mesh is arranged at the leading-out port of at least one subarea so as to lead out an electron beam, and the positive ion beam leading-out grid mesh and the electron beam leading-out grid mesh are arranged at an included angle larger than 0 degree and smaller than 180 degrees; according to the ion source system, a neutralizer does not need to be additionally arranged outside the discharge cavity, the space occupation of the neutralizer and the maintenance cost of the neutralizer are saved, so that the overall occupied space of the ion source system is reduced, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ion beam processing, in particular to an ion source system. BACKGROUND

[0002] Ion beam processing is a kind of micro-nano ultra-fine processing technology, which uses the plasma generated by gas glow discharge to form a neutral particle beam in a single direction through extraction, beam formation, acceleration and neutralization. The neutral particle beam is used to polish, clean, etch, sputter, deposit, coat and implant workpieces made of metal, alloy, oxide, compound, mixed material, semiconductor, insulator and superconductor at room temperature or high temperature and in an ultra-high vacuum environment.

[0003] The ion source system is a key component of ion beam processing. The current ion source system is provided with a neutralizer. The neutralizer is separately arranged outside the discharge cavity of the ion source system. The neutralizer radiates electrons to the positive ion beam drawn from the discharge cavity to neutralize the positive ion beam and form a neutral ion beam. The neutralizer mainly has a filament type and a radio frequency type. The filament type neutralizer has a short service life and needs to be frequently replaced. The maintenance cycle is short. Although the radio frequency type has a long service life, it is relatively large in size and occupies a large space. Whether the filament type or the radio frequency type, it is necessary to additionally reserve space outside the discharge cavity for placement and to separately maintain the neutralizer, resulting in high maintenance cost and large space occupation of the ion source system.

[0004] Therefore, how to reduce the maintenance cost and the space occupation of the ion source system is a technical problem to be solved by those skilled in the art. CONTENT OF THE INVENTION

[0005] To solve the above technical problems, the present application provides an ion source system. The ion source system comprises a discharge cavity, a partition, a positive ion beam extraction grid and an electron beam extraction grid. The partition divides the discharge cavity into a plurality of non-communicating sub-zones. Each of the plurality of sub-zones is provided with an outlet and an inlet. The outlet of at least one of the sub-zones is provided with a positive ion beam extraction grid to extract a positive ion beam. The outlet of at least one of the sub-zones is provided with an electron beam extraction grid to extract an electron beam. The positive ion beam extraction grid and the electron beam extraction grid are arranged at an angle greater than 0° and less than 180°, so that the extracted electron beam and the positive ion beam intersect.

[0006] In an embodiment of the ion source system, the positive ion beam extraction grid comprises an ion screen grid and an ion acceleration grid, the ion acceleration grid is arranged downstream of the ion screen grid, the ion source system comprises a positive voltage applying unit and a negative voltage applying unit, the positive voltage applying unit applies a positive voltage to the ion screen grid, and the negative voltage applying unit applies a negative voltage to the ion acceleration grid; the electron beam extraction grid comprises an electron screen grid and an electron acceleration grid, the electron acceleration grid is arranged downstream of the electron screen grid, the positive voltage applying unit applies a negative voltage to the electron screen grid, and the negative voltage applying unit applies a positive voltage to the electron acceleration grid.

[0007] In an embodiment of the ion source system, the positive ion extraction grid comprises an ion deceleration grid, the ion deceleration grid is arranged downstream of the ion acceleration grid, and the ion deceleration grid is grounded.

[0008] In an embodiment of the ion source system, the positive voltage applying unit and the negative voltage applying unit each comprise a direct current power supply, and the electron screen grid, the electron acceleration grid, the ion screen grid, and the ion acceleration grid are each conductively connected to one of the direct current power supplies.

[0009] In an embodiment of the ion source system, the electron acceleration grid, the ion screen grid, and the ion acceleration grid are each connected to a filter and a vacuum electrode on a connection circuit of the corresponding direct current power supply, and the ion deceleration grid is connected to a vacuum electrode on a grounding circuit.

[0010] In an embodiment of the ion source system, one end of the partition is connected to an end wall of the discharge cavity, and opposite sides of the partition are connected to side walls of the discharge cavity, so that each of the sub-zones is formed by the partition, the end wall of the discharge cavity, and the side walls of the discharge cavity; or one end of the partition is connected to an end wall of the discharge cavity, and at least one of the sub-zones is formed by the partition and the end wall of the discharge cavity.

[0011] In an embodiment of the ion source system, a central region of the partition and the end wall of the discharge cavity together form one of the sub-zones, and an exit of the sub-zone is provided with a positive ion beam extraction grid; and an edge region of the partition, the end wall of the discharge cavity, and the side walls of the discharge cavity together form another annular sub-zone, and an exit of the sub-zone is provided with an electron beam extraction grid.

[0012] In an embodiment of the ion source system, the ion source system comprises an ion source cavity, a radio frequency power supply, and a helical coil, the radio frequency power supply is conductively connected to the helical coil, the discharge cavity is fixed in the ion source cavity, and the helical coil is fixed in a space between the discharge cavity and the ion source cavity.

[0013] In an embodiment of the ion source system, the helical coil is a planar helical coil and is fixed between the end wall of the discharge cavity and the end wall of the ion source cavity by a coil fixing frame; or the helical coil is a tubular helical coil and is fixed between the side wall of the discharge cavity and the side wall of the ion source cavity by a coil fixing frame.

[0014] In an embodiment of the ion source system, a radio frequency matching device is connected to the connection circuit of the radio frequency power supply and the helical coil.

[0015] The ion source system provided by the present application divides the discharge cavity into multiple partitions that are not communicated with each other, sets an electron beam extraction grid at the extraction outlet of at least one partition, sets a positive ion beam extraction grid at the extraction outlet of at least one partition, and arranges the electron extraction grid and the positive ion extraction grid at an included angle greater than 0° and less than 180°, so that the extracted electron beam and the positive ion beam can intersect and neutralize each other to form a neutral particle beam. In this way, a neutralizer does not need to be additionally arranged outside the discharge cavity, and the space occupied by the neutralizer and the maintenance cost of the neutralizer are saved, so that the overall space occupied by the ion source system is reduced and the maintenance cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A cross-sectional view of a first embodiment of the ion source system provided by the present application;

[0017] Figure 2 A cross-sectional view of a second embodiment of the ion source system provided by the present application; Figure 1 A perspective view of the discharge cavity and the partition;

[0018] Figure 3 A cross-sectional view of a second embodiment of the ion source system provided by the present application;

[0019] Figure 4 A cross-sectional view of a second embodiment of the ion source system provided by the present application; Figure 3 A perspective view of the discharge cavity and the partition;

[0020] Figure 5 A perspective view of the electron screen grid of the electron beam extraction grid; Figure 3

[0021] The reference signs are explained as follows:

[0022] 10 discharge cavity, 10c limiting ring, 10d gas inlet, 20 partition, 30 positive ion beam extraction grid, 301 ion screen grid, 302 ion acceleration grid, 303 ion deceleration grid, 40 electron beam extraction grid, 401 electron screen grid, 402 electron acceleration grid, 501 first direct current power supply, 502 second direct current power supply, 503 third direct current power supply, 504 fourth direct current power supply, 505 filter, 506 vacuum electrode, 60 ion source cavity, 60c fixing ring, 70 helical coil, 80 fixing frame, 90 gas inlet pipe, 100 radio frequency power supply, 110 radio frequency matching device.​ DETAILED DESCRIPTION

[0023] The present application provides an ion source system. In order to make the skilled in the art better understand the technical solutions of the present application, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0024] As shown in Figures 1-4 The ion source system provided by the present application comprises a discharge cavity 10, a partition 20, a positive ion beam extraction grid 30, and an electron beam extraction grid 40. The partition 20 divides the discharge cavity 10 into multiple non-communicating sub-zones, and the multiple sub-zones refer to two or more sub-zones.

[0025] The same end of the multiple sub-zones is respectively provided with an extraction port, Figure 1 and Figure 3 Among them, the extraction port is located at the right end of the corresponding sub-zone. The multiple sub-zones are also respectively provided with a gas inlet 10d, and gas can enter the inside of the corresponding sub-zone from the gas inlet 10d.

[0026] Among them, the extraction port of at least one sub-zone is provided with the positive ion beam extraction grid 30. By changing the geometric characteristics, relative position, and potential distribution of the positive ion beam extraction grid 30, the positive ions can be extracted, and the positive ions have a certain spatial concentration and spatial distribution shape.

[0027] Among them, the extraction port of at least one sub-zone is provided with the electron beam extraction grid 40. By changing the geometric characteristics, relative position, and potential distribution of the electron beam extraction grid 40, the electrons can be extracted, and the electrons have a certain spatial concentration and spatial distribution shape.

[0028] The positive ion beam extraction grid 30 and the electron beam extraction grid 40 are arranged at an included angle greater than 0° and less than 180°, so that the extracted electron beam and the positive ion beam intersect.

[0029] The ion source system described above can intersect the electron beam and the positive ion beam extracted from different sub-zones of the discharge cavity 10, so as to neutralize each other to form a neutral particle beam. Therefore, it is not necessary to additionally provide a neutralizer outside the discharge cavity 10, thereby saving the space occupation of the neutralizer and the maintenance cost of the neutralizer. Therefore, the overall space occupation of the ion source system is reduced, and the maintenance cost is reduced.

[0030] Specifically, as shown in Figures 1-4 The cavity wall of the discharge cavity 10 is made of high-temperature-resistant insulating materials such as quartz and ceramic. The cavity wall of the discharge cavity 10 includes an end wall (indicated by 10a in the figure) and a side wall (indicated by 10b in the figure) surrounding the periphery of the end wall. The cavity opening of the discharge cavity 10 is located at one end of the side wall away from the end wall, and one end of the partition 20 is located at the other end of the side wall close to the end wall. Figure 1 and Figure 3The left end of the middle partition 20 is connected with the end wall of the discharge cavity 10, and the right end of the middle partition 20 extends to the vicinity of the cavity opening of the discharge cavity 10. Figure 1 And Figure 3 The right end of the middle partition 20 extends to the vicinity of the cavity opening of the discharge cavity 10.

[0031] In some embodiments, the opposite sides of the partition 20 are connected with the side walls of the discharge cavity 10 respectively, so that each sub-zone is formed by the partition 20, the end wall of the discharge cavity 10 and the side wall of the discharge cavity 10, for example Figure 1 And Figure 2 In the embodiment shown in FIG. 2, the A sub-zone is formed by the partition 20, the middle and lower side region of the end wall of the discharge cavity 10 and the middle and lower side region of the side wall of the discharge cavity 10, and the B sub-zone is formed by the partition 20, the upper side region of the end wall of the discharge cavity 10 and the upper side region of the side wall of the discharge cavity 10. More specifically, the partition 20 can be a flat structure, for example Figure 1 And Figure 2 In the embodiment shown in FIG. 2, the partition 20 is a flat plate, or the partition 20 can also be a curved structure, for example, an arc-shaped plate, a stepped plate, etc.

[0032] In some embodiments, at least one sub-zone is formed by the partition 20 and the end wall of the discharge cavity 10, for example Figure 3 And Figure 4 In the embodiment shown in FIG. 3, the partition 20 is a circular ring, the C sub-zone is formed by the partition 20 and the central region of the end wall of the discharge cavity 10, and the D sub-zone is formed by the partition 20, the edge region of the end wall of the discharge cavity 10 and the side wall of the discharge cavity 10.

[0033] Figure 1 And Figure 2 In the embodiment shown in FIG. 4, the A sub-zone and the B sub-zone are located on the two sides of the partition 20 respectively, the electron beam extraction grid 40 is arranged at the extraction opening of the A sub-zone, the positive ion beam extraction grid 30 is arranged at the extraction opening of the B sub-zone, the positive ion beam extraction grid 30 is arranged substantially perpendicular to the partition 20, and the electron beam extraction grid 40 is arranged obliquely relative to the partition 20, and the angle a between the electron beam extraction grid 40 and the partition 20 is in the range of 0< a < 90°, so that the electron beam N extracted by the electron beam extraction grid 40 intersects with the positive ion beam M extracted by the positive ion beam extraction grid 30.

[0034] Figure 3 And Figure 4 In the embodiment shown in FIG. 5, the C sub-zone is located in the partition 20, and the D sub-zone is a ring-shaped sub-zone surrounding the partition 20. The positive ion beam extraction grid 30 is arranged at the extraction opening of the C sub-zone, and the electron beam extraction grid 40 is arranged at the extraction opening of the D sub-zone. The positive ion beam extraction grid 30 is arranged substantially perpendicular to the partition 20, and the electron beam extraction grid 40 is arranged obliquely relative to the partition 20. The electron beam extraction grid 40 is a conical ring structure (combined withFigure 5 As can be understood, the angle β between the electron beam extraction grid 40 and the partition 20 is in the range of 0<β<90°, so that the electron beam N extracted by the electron beam extraction grid 40 intersects the positive ion beam M extracted by the positive ion beam extraction grid 30. In this way, the positive ion beam is intersected by the electron beam all around, and thus the neutralization efficiency is high.

[0035] Specifically, as shown in Figure 1 or Figure 3 The ion source system includes a positive voltage applying part and a negative voltage applying part. The positive ion beam extraction grid 30 is a porous mesh structure, and is made of a plasma sputtering resistant conductive material such as molybdenum or graphite. The positive ion beam extraction grid 30 includes at least an ion screen grid 301 and an ion acceleration grid 302. The ion acceleration grid 302 is arranged downstream of the ion screen grid 301. The downstream is relative to the gas flow direction, and the area through which the gas flows first is the upstream, and the area through which the gas flows later is the downstream. The positive voltage applying part applies a positive voltage to the ion screen grid 301, and the ion screen grid 301 focuses the plasma. The negative voltage applying part applies a negative voltage to the ion acceleration grid 302, and the ion acceleration grid 302 accelerates the positive ion beam, and extracts the positive ion with positive charge under the action of the acceleration electric field. In the illustrated embodiment, the negative voltage applying part specifically includes a first direct current power supply 501, and the positive voltage applying part specifically includes a second direct current power supply 502. The first direct current power supply 501 is conductively connected to the ion acceleration grid 302 through a filter 505 and a vacuum electrode 506, so as to apply a negative voltage to the ion acceleration grid 302. The second direct current power supply 502 is conductively connected to the ion screen grid 301 through another filter 505 and another vacuum electrode 506, so as to apply a positive voltage to the ion screen grid 301. In addition, the positive ion beam extraction grid 30 can selectively be provided with an ion deceleration grid 303. The ion deceleration grid 303 is arranged downstream of the ion acceleration grid 302, and is grounded through a vacuum electrode 506. The potential of the ion deceleration grid 303 is zero, and the ion deceleration grid 303 can effectively protect the ion acceleration grid 302, reduce the divergence angle of the positive ion beam, and adjust the beam trajectory of the positive ion beam.

[0036] Specifically, as shown in Figure 1 or Figure 3As shown, the electron beam extraction grid 40 is a porous mesh structure, and is made of molybdenum or graphite or other conductive material that is resistant to electron body sputtering. The electron beam extraction grid 40 includes at least an electron screen grid 401 and an electron acceleration grid 402. The electron acceleration grid 402 is arranged downstream of the electron screen grid 401. A negative voltage applying unit applies a negative voltage to the electron screen grid 401, and the electron screen grid 401 focuses electrons. A positive voltage applying unit applies a positive voltage to the electron acceleration grid 402, and the electron acceleration grid 402 accelerates the electron beam, and extracts electrons under the action of the acceleration electric field. In the illustrated embodiment, the positive voltage applying unit specifically includes a third DC power supply 503, and the negative voltage applying unit specifically includes a fourth DC power supply 504. The third DC power supply 503 is conductively connected to the electron acceleration grid 402 through a filter 505 and a vacuum electrode 506, so as to apply a positive voltage to the electron acceleration grid 402. The fourth DC power supply 504 is conductively connected to the electron screen grid 401 through another filter 505 and another vacuum electrode 506, so as to apply a negative voltage to the electron screen grid 401.

[0037] The electron screen grid 401, the electron acceleration grid 402, the ion screen grid 301, and the ion acceleration grid 302 are respectively conductively connected to different DC power supplies. In this way, the potentials of the electron screen grid 401, the electron acceleration grid 402, the ion screen grid 301, and the ion acceleration grid 302 can be independently adjusted, so as to ensure the neutralization effect of the extracted positive ions and electrons.

[0038] Specifically, the ion source system includes an ion source cavity 60. The cavity wall of the ion source cavity 60 includes an end wall (indicated by 60a in the figure) and a side wall (indicated by 60b in the figure) arranged around the periphery of the end wall. The discharge cavity 10 is fixed in the ion source cavity 60. The side wall of the discharge cavity 10 and the side wall of the ion source cavity 60 are spaced apart from each other. The end wall of the discharge cavity 10 and the end wall of the ion source cavity 60 are spaced apart from each other.

[0039] In the illustrated embodiment, the inner side of the side wall of the ion source cavity 60 is provided with a fixing ring 60c, and the outer side of the side wall of the discharge cavity 10 is provided with a limiting ring 10c. The discharge cavity 10 is inserted into the inner hole of the fixing ring 60c, and the limiting ring 10c abuts against the fixing ring 60c, so as to realize the relative fixation of the ion cavity and the discharge cavity 10.

[0040] In the illustrated embodiment, the gas inlet 10d is arranged on the end wall of the discharge cavity 10. The ion source system includes a gas inlet pipe 90. A through hole is arranged on the end wall of the ion source cavity 60. One end of the gas inlet pipe 90 is inserted into the gas inlet 10d, and the other end of the gas inlet pipe 90 extends to the outside of the ion source cavity 60 through the through hole, so as to be connected to a gas source.

[0041] Specifically, the ion source system further comprises a helical coil 70 and a radio frequency power source 100, the helical coil 70 is located in the space between the cavity wall of the discharge cavity 10 and the cavity wall of the ion source cavity 60, the radio frequency power source 100 is in conductive connection with the helical coil 70, and the radio frequency power source 100 is powered on to the helical coil 70 during ion beam processing, so that an induced radio frequency electric field is generated in the discharge cavity 10, the induced electric field accelerates the movement of electrons, which continuously collide with gas molecules to ionize, thereby generating dense plasma, so that the radio frequency energy in the induction coil is coupled to the ionized gas to maintain plasma discharge. In the illustrated embodiment, a radio frequency matcher 110 is connected to the connection circuit of the radio frequency power source 100 and the helical coil 70, which is used to match the load impedance with the impedance of the radio frequency power source 100, thereby reducing the reflected power and ensuring that the transmission power of the radio frequency power source 100 reaches the maximum.

[0042] In some embodiments, the helical coil 70 is a planar helical coil, in which case the helical coil 70 is fixed in the space between the end wall of the discharge cavity 10 and the end wall of the ion source cavity 60 by the coil fixing frame 80, for example Figure 1 and Figure 2 as shown in the embodiments.

[0043] In some embodiments, the helical coil 70 is a tubular helical coil, in which case the helical coil 70 can be fixed in the space between the side wall of the discharge cavity 10 and the side wall of the ion source cavity 60 by the coil fixing frame 80, for example Figure 3 and Figure 4 as shown in the embodiments.

[0044] The above embodiments can be freely combined without conflict.

[0045] The above applies specific examples to describe the principles and implementation modes of the present application. The above embodiment descriptions are only used to help understand the method and its core idea of the present application. It should be noted that for ordinary skilled persons in the technical field, some improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. An ion source system, characterized by, The ion source system comprises a discharge cavity (10), a partition (20), a positive ion beam extraction grid (30), and an electron beam extraction grid (40). The partition (20) separates the discharge cavity (10) into multiple non-communicating sub-zones. The same end of the multiple sub-zones is respectively provided with an extraction port. The multiple sub-zones are respectively provided with an air inlet (10d). At least one of the extraction ports of the sub-zones is provided with the positive ion beam extraction grid (30) to extract a positive ion beam. At least one of the extraction ports of the sub-zones is provided with the electron beam extraction grid (40) to extract an electron beam. The positive ion beam extraction grid (30) and the electron beam extraction grid (40) are arranged at an included angle greater than 0° and less than 180°, so that the extracted electron beam and the positive ion beam intersect.

2. The ion source system of claim 1, wherein, The positive ion beam extraction grid (30) comprises an ion screen grid (301) and an ion acceleration grid (302). The ion acceleration grid (302) is arranged downstream of the ion screen grid (301). The ion source system comprises a positive voltage applying part and a negative voltage applying part. The positive voltage applying part applies a positive voltage to the ion screen grid (301). The negative voltage applying part applies a negative voltage to the ion acceleration grid (302). The electron beam extraction grid (40) comprises an electron screen grid (401) and an electron acceleration grid (402). The electron acceleration grid (402) is arranged downstream of the electron screen grid (401). The positive voltage applying part applies a negative voltage to the electron screen grid (401). The negative voltage applying part applies a positive voltage to the electron acceleration grid (402).

3. The ion source system of claim 2, wherein, The positive ion extraction grid comprises an ion deceleration grid (303). The ion deceleration grid (303) is arranged downstream of the ion acceleration grid (302). The ion deceleration grid (303) is grounded.

4. The ion source system of claim 3, wherein, The positive voltage applying part and the negative voltage applying part each comprise a direct current power supply. The electron screen grid (401), the electron acceleration grid (402), the ion screen grid (301), and the ion acceleration grid (302) are each conductively connected to one of the direct current power supplies.

5. The ion source system of claim 4, wherein, The electron acceleration grid (402), the ion screen grid (301), and the ion acceleration grid (302) are each connected to a filter (505) and a vacuum electrode (506) on the connection circuit of the corresponding direct current power supply. The ion deceleration grid (303) is connected to a vacuum electrode (506) on the grounding circuit.

6. The ion source system of any one of claims 1-5, wherein, One end of the partition (20) is connected to the end wall of the discharge cavity (10). The opposite sides of the partition (20) are connected to the side walls of the discharge cavity (10), so that each of the sub-zones is formed by the partition (20), the end wall of the discharge cavity (10), and the side walls of the discharge cavity (10). Alternatively, One end of the partition (20) is connected to the end wall of the discharge cavity (10). At least one of the sub-zones is formed by the partition (20) and the end wall of the discharge cavity (10).

7. The ion source system of claim 6, wherein, The partition (20) and the center area of the end wall of the discharge cavity (10) together enclose one of the said partitions and the outlet of the said partition is provided with a positive ion beam extraction grid (30), the edge area of the end wall of the discharge cavity (10) and the side wall of the discharge cavity (10) together enclose another annular said partition and the outlet of the said partition is provided with an electron beam extraction grid (40).

8. The ion source system of any one of claims 1-5, wherein, The ion source system comprises an ion source cavity (60), a radio frequency power supply (100) and a spiral coil (70), the radio frequency power supply (100) is in conductive connection with the spiral coil (70), the discharge cavity (10) is fixed in the ion source cavity (60), and the spiral coil (70) is fixed in the space between the discharge cavity (10) and the ion source cavity (60).

9. The ion source system of claim 8, wherein, The spiral coil (70) is a planar spiral coil (70) and is fixed between the end wall of the discharge cavity (10) and the end wall of the ion source cavity (60) through a coil fixing frame (80); or, The spiral coil (70) is a tubular spiral coil (70) and is fixed between the side wall of the discharge cavity (10) and the side wall of the ion source cavity (60) through a coil fixing frame (80).

10. The ion source system of claim 8, wherein, A radio frequency matching device (110) is connected to the connection circuit of the radio frequency power supply (100) and the spiral coil (70).

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