Radio frequency acceleration section and ion implanter

Abstract

The invention belongs to the technical field of semiconductors, and discloses a radio frequency acceleration section and an ion implanter, the radio frequency acceleration section comprises a plurality of bunching units arranged along the movement direction of an ion beam current and acceleration units arranged between adjacent bunching units, each bunching unit comprises a bunching lens, and the bunching lens of at least the last bunching unit comprises a cylindrical lens. The ion implanter comprises an ion source, a mass analyzer and the radio frequency acceleration section. According to the invention, the cylindrical bunching lens is adopted, the transverse divergence of the beam is restrained in 360 degrees in all directions, the possibility of generating exaggerated special-shaped beam spots is greatly reduced, and the possibility of changing spot beams into strip beams does not exist; unnecessary sputtering is reduced while the bunching capability is maintained, and the service life of the device is prolonged; the number of related power supplies is reduced, and the structure and connection are simpler; only one voltage (positive voltage or negative voltage) needs to be connected, and the voltage withstanding performance is improved in the same space range.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more specifically, to a radio frequency acceleration section and an ion implanter. Background Art

[0002] The beam current is a very important parameter in the RF high-energy ion implanter. The ion beam is focused and accelerated through the RF acceleration section. The RF acceleration section uses multiple focusing lenses arranged along the direction of ion beam movement to focus the ion beam. Acceleration electrodes are set between the focusing lenses to accelerate the ion beam to the preset energy. The focusing lens is mostly a quadrupole lens, which is used to constrain the beam in the lateral direction and escort the main part of the beam through the RF area.

[0003] like Figure 1 As shown, the quadrupole lens is composed of four electrodes 84a, 84b, 84c and 84d, which are opposite to each other in pairs. It mainly has the following disadvantages: 1. The two electrodes opposite to each other are connected with copper wire to keep the voltage the same. The four electrodes need to be applied with one positive and one negative voltage. They also need to maintain a sufficient insulation distance between each other and the ground. The connection structure is complex, which increases the difficulty of installation and connection in a small space. Moreover, from the perspective of beam optics, it is better to apply a higher voltage, but from the perspective of electrical insulation, the higher the voltage, the easier it is to spark and instantly make the quadrupole lens ineffective. The two are contradictory. Therefore, the quadrupole lens is easily damaged during long-term operation and needs to be replaced frequently.

[0004] 2. A single set of quadrupole lenses can only converge the beam in one direction (such as the X direction), and has to diverge the beam in another direction (such as the Y direction); the four electrodes are generally connected in such a way that a pair of electrodes (such as the X direction) are connected to positive voltage, and another pair (such as the Y direction) are connected to negative voltage. The absolute values ​​of the positive and negative voltages are equal, but they can also be unequal or one pair can be grounded. This produces many variants, and accordingly, the requirements for the power supply are also different; when multiple sets of quadrupole lenses are arranged in series along the direction of ion beam movement, they are generally connected in an alternating manner, but there are still many ways to connect them. Moreover, due to the diversity of beam types, there is no situation where a certain connection method is applicable to all types of beams. There are many variables, which increases the actual debugging time.

[0005] 3. Since the quadrupole lens has the effect of compressing one dimension of the beam cross section and diverging the other dimension, the beam presents various shapes. As the adjustable degrees of freedom increase, the problems caused by the special-shaped beam spot also begin to increase. For example, due to excessive compression of one dimension, when the other dimension diverges more exaggeratedly, the ions will be ejected through the gap between the electrodes, and the ejected ions will be intercepted by the ground electrode behind, resulting in sputtering, contaminating the surrounding insulating columns, causing the insulation column's withstand voltage performance to decrease, and then the high voltage cannot be applied to the electrode normally, and the quadrupole lens gradually fails.

[0006] In summary, when using the RF acceleration section of a quadrupole lens for beam focusing, the beam loss is often large. On the one hand, this is because the longitudinal beam grouping cannot concentrate all ions 100% near the optimal acceleration phase, and on the other hand, this is because the lateral beam focusing measures cannot effectively resist the space charge force between ions. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention innovatively provides a radio frequency acceleration section and an ion implanter, which adopt a cylindrical focusing lens to constrain the lateral divergence of the beam in all directions at 360°, greatly reducing the possibility of producing exaggerated and irregular beam spots, and eliminating the possibility of the spot beam turning into a ribbon beam; while maintaining the focusing capability, unnecessary sputtering is reduced, thereby extending the service life of the device; the number of related power supplies is reduced, and the structure and connection are simpler; only one voltage (positive or negative voltage) needs to be connected, and the voltage resistance performance is improved within the same spatial range.

[0008] In order to achieve the above technical objectives, the present invention discloses, in a first aspect, a radio frequency acceleration section, comprising a plurality of bunching units arranged along the moving direction of the ion beam and an acceleration unit arranged between adjacent bunching units. The condenser units include condenser lenses, and at least the condenser lens of the last condenser unit includes a cylindrical lens.

[0009] Furthermore, the inner cavity of the cylindrical lens is cylindrical.

[0010] Furthermore, the entrance of the cylindrical lens is elliptical and the exit is circular.

[0011] Furthermore, the focusing lens also includes a first cylindrical lens arranged on both sides of the cylindrical lens along the moving direction of the ion beam, and the power-on voltage of the cylindrical lens is greater than the power-on voltage of the first cylindrical lens.

[0012] Furthermore, the beam-forming unit further comprises a ground electrode, and the ground electrode is disposed on both the inlet side and the outlet side of the beam-forming unit.

[0013] Furthermore, the focusing lenses of the remaining focusing units are quadrupole lenses, and the focusing units provided with quadrupole lenses and the focusing units provided with cylindrical lenses are arranged alternately.

[0014] Furthermore, the condenser lens is connected to the ground electrode on its side via a metal bracket, and the condenser lens is fixedly connected to the metal bracket via an insulating column.

[0015] Furthermore, the outer surface of the insulating column is provided with a spiral groove or a plurality of annular grooves arranged axially along the insulating column, the bottoms of the spiral groove and the annular groove extend toward the central axis of the insulating column and the groove depth direction is inclined relative to the central axis.

[0016] To achieve the above technical objectives, the second aspect of the present invention discloses an ion implanter, comprising an ion source, a mass analyzer and the radio frequency acceleration section described in the first aspect. The ion source is used to generate an ion beam; The mass analyzer is arranged downstream of the ion source, and is used to perform mass analysis on the ion beam generated by the ion source and screen out the ion species required for injection to obtain a purified beam; The radio frequency acceleration section is arranged downstream of the mass analyzer, and is used to form a bunched beam and accelerate the beam to obtain a beam with a preset energy.

[0017] The beneficial effects of the present invention are: The radio frequency acceleration section of the present invention adopts a cylindrical focusing lens to constrain the lateral divergence of the beam in all directions at 360 degrees, greatly reducing the possibility of generating exaggerated and irregular beam spots, and eliminating the possibility of the spot beam turning into a ribbon beam; while maintaining the focusing capability, unnecessary sputtering is reduced, thereby extending the service life of the device; the number of related power supplies is reduced, and the structure and connection are simpler; only one voltage (positive voltage or negative voltage) needs to be connected, and the voltage resistance performance is improved within the same spatial range. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of an existing quadrupole lens.

[0019] Figure 2 It is a structural schematic diagram of the radio frequency acceleration section of an embodiment of the present invention.

[0020] Figure 3 Schematic diagram of the structure of a cylindrical lens according to an embodiment of the present invention.

[0021] Figure 4 It is a structural schematic diagram and beam morphology diagram of a bunching unit according to an embodiment of the present invention.

[0022] Figure 5 It is a structural schematic diagram and beam morphology diagram of a bunching unit according to another embodiment of the present invention.

[0023] Figure 6 It is a structural schematic diagram of a radio frequency acceleration section according to another embodiment of the present invention.

[0024] Figure 7 It is a half-section simulation diagram of the beam state under the axisymmetric structure of the radio frequency acceleration section of an embodiment of the present invention.

[0025] Figure 8 Schematic diagram of the installation of the cylindrical lens according to the embodiment of the present invention.

[0026] Fig. 9 This is a schematic diagram of the installation of the quadrupole lens.

[0027] Fig.10 It is a schematic structural diagram of an insulating column according to an embodiment of the present invention.

[0028] Fig.11 4 is a longitudinal cross-sectional view of an insulating column according to an embodiment of the present invention.

[0029] Fig.12a This is a simulation diagram of the half-section of the ion beam passing through the bunching unit under a power supply voltage of 10kV.

[0030] Figure 12b This is a simulation diagram of the half-section of the ion beam passing through the bunching unit under a power supply voltage of 20kV.

[0031] Fig.12c This is a simulation diagram of the half-section of the ion beam passing through the bunching unit under a power supply voltage of 30kV.

[0032] Fig.12d This is a simulation diagram of the half-section of the ion beam passing through the bunching unit at a power supply voltage of -10kV.

[0033] Fig.12e This is a simulation diagram of the half-section of the ion beam passing through the bunching unit at a power supply voltage of -20kV.

[0034] Fig.12f This is a simulation diagram of the half-section of the ion beam passing through the bunching unit at a power supply voltage of -30kV.

[0035] In the figure, 10. beam focusing unit; 101. cylindrical lens; 101'. first cylindrical lens; 102. ground electrode; 103. metal bracket; 104. insulating column; 105. lead wire; 20. accelerating unit; 30. beam current. DETAILED DESCRIPTION

[0036] The radio frequency acceleration section and ion implanter provided by the present invention are explained and illustrated in detail below in conjunction with the accompanying drawings of the specification.

[0037] This embodiment specifically discloses a radio frequency acceleration section, such as Figure 2 As shown, it includes a plurality of bunching units 10 arranged along the moving direction of the ion beam and an acceleration unit 20 arranged between adjacent bunching units 10. The bunching units 10 include bunching lenses, and at least the bunching lens of the last bunching unit 10 includes a cylindrical lens 101. The bunching lenses of the remaining bunching units 10 are quadrupole lenses.

[0038] The cylindrical lens 101 of the present application is a cylindrical focusing lens, and its longitudinal length is determined according to design requirements and simulation results.

[0039] In the present application, the direction of ion beam movement is the longitudinal direction, and the direction perpendicular to the ion beam movement is the transverse direction.

[0040] The focusing unit 10 is used to constrain the lateral divergence of the beam 30, and the acceleration unit 20 is used to accelerate the beam 30 to a preset energy. In this embodiment, the acceleration unit 20 is a cylindrical acceleration electrode, and a radio frequency barrel and a radio frequency power supply are provided behind the acceleration electrode to realize the generation of a high peak radio frequency voltage on the acceleration electrode. A DC voltage is applied to the focusing lens, which has the ability to constrain the beam 30 laterally; an alternating voltage is applied to the acceleration electrode, which has the ability to accelerate and cluster the beam 30 longitudinally. The ion beam moves along the axis of the acceleration electrode and is continuously accelerated by each acceleration electrode. In this process, the ion beam will diverge laterally. The focusing lens of each focusing unit 10 constrains the beam 30 to minimize the loss of the beam 30. The focusing lens of the present application partially or entirely adopts a cylindrical focusing lens, and still adopts an electrostatic method, which can constrain the lateral divergence of the beam 30 in all directions at 360°, compensate for the beam spot distortion caused by the non-axisymmetry of the quadrupole lens, and reduce unnecessary sputtering. The inner diameter of the focusing lens is equal to or slightly larger than the inner diameter of the acceleration electrode.

[0041] In an optional embodiment, the inner cavity of the cylindrical lens 101 is cylindrical, and the inner cavity of the cylindrical lens 101 is a constant diameter inner cavity, which can constrain the lateral divergence of the beam 30 in all directions of 360°.

[0042] In an optional embodiment, if Figure 3 As shown, the entrance of the cylindrical lens 101 is elliptical and the exit is circular. The inner diameter of the cylindrical lens 101 is a gradual change, and the shape of the inner cavity gradually transitions from an ellipse to a circle. The beam spot shape at the entrance of the radio frequency acceleration section of the high-energy ion implanter is often a strip spot rather than a circular spot. The beam spot at the exit of the radio frequency acceleration section is close to a circular spot. In practical applications, it is expected that the main flow intensity is kept in the circular spot to minimize the loss. Therefore, the application sets the entrance of the cylindrical lens 101 to an ellipse and the exit to a circle. The strip beam 30 to be shaped enters from the elliptical entrance and flows out from the circular entrance. The elliptical entrance can almost completely accommodate the strip beam. Moreover, the cylindrical lens 101 has a bunching effect on the beam 30 at 360°. The gradual cylindrical lens 101 makes the beam spot of the beam 30 also complete a gradual change when passing through, and finally becomes a circular spot.

[0043] In some embodiments, Figure 4 As shown, the focusing lens only includes a cylindrical lens 101, and the cylindrical lens 101 is connected to a DC high voltage power supply. Figure 4 As shown, a ground electrode 102 is disposed on each side of the cylindrical lens 101 .

[0044] In some embodiments, Figure 1 As shown, both the front and rear sides of the focusing lens are accelerating electrodes. Figure 1The embodiment shown combines the ground electrode 102 and the accelerating electrode into one, and the accelerating electrode cooperates with the focusing lens to both focus and accelerate, greatly shortening the length of the RF acceleration section. There are gaps between the focusing lens and the electrodes before and after it to ensure withstand voltage.

[0045] When the beam 30 passes through the inner cavity of the focusing lens and the electrodes on the front and rear sides of the focusing lens (the ground electrode 102 or the accelerating electrode), the beam 30 is affected by the radial electric field distribution at the two gaps before and after the focusing lens, and produces a converging effect, which is similar to the effect of a convex lens on light in optics.

[0046] In some embodiments, Figure 5 As shown, the focusing lens also includes a first cylindrical lens 101' arranged on both sides of the cylindrical lens 101 along the movement of the ion beam, and the power-on voltage of the cylindrical lens 101 is greater than the power-on voltage of the first cylindrical lens 101'. The power-on voltages of the two first cylindrical lenses 101' are the same. Preferably, the inner cavity shape of the first cylindrical lens 101' is the same as the inner cavity shape and size of the cylindrical lens 101, and both are cylindrical cavities of equal diameter. The length of the first cylindrical lens 101' is less than the length of the cylindrical lens 101. The front side of the first cylindrical lens 101' at the front side and the rear side of the first cylindrical lens 101' at the rear side are both provided with a ground electrode 102 or an accelerating electrode. The cylindrical lens 101 is connected to a DC high-voltage power supply as the main electrode of the focusing unit 10, and the first cylindrical lens 101' is used as an auxiliary electrode to play a fine-tuning role, so the voltage applied to the first cylindrical lens 101' is low, and can even be 0. There is a gap between each electrode. When the beam 30 passes through the inner cavity of each electrode, it is affected by the radial electric field distribution at multiple gaps, and the beam 30 produces a convergence effect, which is similar to the effect of a convex lens on light in optics. Since the three cylindrical lenses (the first cylindrical lens 101' and the cylindrical lens 101) have a larger structural size and complexity than a single cylindrical lens (cylindrical lens 101), but the basic capabilities are equivalent, generally a single cylindrical lens can meet the needs in compact occasions.

[0047] In some embodiments, Figure 4-6 As shown, the beam-forming unit 10 further includes a ground electrode 102. The ground electrode 102 is disposed on both the inlet side and the outlet side of the beam-forming unit 10. The inner diameter of the beam-forming lens is the same as the inner diameter of the ground electrode 102.

[0048] In practical applications, only the last focusing lens of the focusing unit 10 may be the cylindrical lens 101 or a combination of the cylindrical lens 101 and the first cylindrical lens 101', or all the focusing lenses of the focusing units 10 may be the cylindrical lens 101 (eg Figure 2 and 6The beam focusing unit 10 may be a quadrupole lens, and the beam focusing lens of the rear beam focusing unit 10 may be a cylindrical lens 101 or a combination of the cylindrical lens 101 and the first cylindrical lens 101'. The lengths of the front and rear sections may be adjusted according to actual needs. The beam focusing units 10 with quadrupole lenses and the beam focusing units 10 with cylindrical lenses 101 or a combination of the cylindrical lens 101 and the first cylindrical lens 101' may be arranged alternately. The specific arrangement is set according to actual beam focusing needs. When the beam focusing lenses of all the beam focusing units 10 only use the cylindrical lens 101, and the front and rear ground electrodes 102 are removed, and the front and rear acceleration electrodes are directly facing each other, the length of the RF acceleration section is the shortest.

[0049] It has been verified that, under the same conditions, the length of the RF acceleration section of the beam focusing unit 10 using only cylindrical lenses 101 is shortened by 1 / 4 to 1 / 3 compared with the RF acceleration section using only quadrupole lenses, thereby reducing the occupied space.

[0050] like Figure 7 As shown, the focusing unit 10 uses a cylindrical lens 101, and a ground electrode 102 is provided at the front and rear of the cylindrical lens 101. Multiple focusing units 10 are arranged along the moving direction of the ion beam to offset the lateral expansion caused by the internal space charge repulsion of the beam 30. Figure 7 As shown in the half-section simulation diagram of the beam state under the axisymmetric structure, the cylindrical lens 101 effectively suppresses the divergence trend of the beam 30, allowing more beam 30 to flow through the channels formed by the inner cavities of each electrode. Figure 7 This fully demonstrates that the cylindrical focusing lens has a converging effect on the beam 30 in 360°, while the quadrupole lens cannot have a converging effect on the beam 30 in 360° and can only be used in groups.

[0051] like Figure 8 As shown, the condenser lens is connected to the ground electrode 102 on its side through a metal bracket 103, and the condenser lens is fixedly connected to the metal bracket 103 through an insulating column 104. The metal bracket 103 is a square frame, and the ground electrodes 102 on the front and rear sides of the condenser lens are set at the front and rear openings of the metal bracket 103. Figure 8 The ground electrode 102 at the front opening is omitted in the figure to show the internal structure of the beam focusing unit. The side of the cylindrical lens 101 is connected to the ground electrode 102 through the insulating column 104. Specifically, one end of the insulating column 104 is fixedly connected to the side wall of the cylindrical lens 101, and the other end of the insulating column 104 is fixedly connected to a metal plate, and the metal plate is connected to the ground electrode 102. In this way, the cylindrical lens 101 and the ground electrode 102 are fixed and the cylindrical lens 101 is insulated from the metal bracket 103 and the ground electrode 102. In order to ensure the firmness of the fixation, two insulating columns 104 are provided. Fig. 9As shown, each electrode of the quadrupole lens is connected to the ground electrode 102 via two insulating columns 104, so a total of 8 insulating columns 104 are required to achieve the connection between the electrode and the metal bracket 103. The present application reduces the number of insulating columns 104 that are prone to failure by 3 / 4 by setting the focusing lens to be cylindrical, simplifies the structure, and facilitates installation in a small space.

[0052] If the focusing lens also includes a first cylindrical lens 101', the cylindrical lens 101 and the first cylindrical lens 101' can be fixed in the metal bracket 103 through a connecting plate arranged inside the metal bracket 103 and parallel to the ground electrode, and the cylindrical lens 101 and the connecting plate, as well as the first cylindrical lens 101' and the connecting plate, are connected to the metal bracket through insulating columns 104 to achieve insulated connections.

[0053] When the ground electrode and the accelerating electrode are combined into one, the metal fixing plate can be used to directly fix the cylindrical lens 101, and the cylindrical lens 101 is connected to the metal fixing plate through the insulating column 104. The first cylindrical lens 101' can be fixed in the same way.

[0054] Moreover, in contrast Figure 8 and Fig. 9 , Figure 8 The middle cylindrical lens 101 only needs one lead wire 105 to connect to the DC power supply. Fig. 9 In the process, the electrodes facing each other need to be connected by wires first, and then a positive voltage and a negative voltage are connected respectively by two lead wires 105. Figure 8 The cylindrical beam-forming lens significantly reduces the number of wiring connections, which greatly improves the convenience of installation in a small space. Compared with the quadrupole lens, the cylindrical lens has fewer parts when installed, and the electrode pressure-resistant space is increased, which allows it to work at a higher voltage.

[0055] The insulating column 104 can be made of materials such as Al 2 O 3 ceramics or quartz glass, and the specific shape of the insulating column 104 is not particularly limited.

[0056] Fig. 9 There are gaps between the four electrodes of the quadrupole lens shown. Ions will be sputtered to the outside of the quadrupole lens through the gaps between the electrodes and hit the insulating column 104, causing the insulating column 104 to turn black and form a short circuit, resulting in the failure of the insulation effect.

[0057] like Fig.10 and 11As shown, the outer surface of the insulating column 104 is provided with a spiral groove or a plurality of annular grooves arranged along the axial direction of the insulating column 104, the bottom of the spiral groove and the annular groove extend in the direction of the central axis of the insulating column 104 and the groove depth direction is inclined relative to the central axis, that is, the groove depth direction of the spiral groove or the annular groove is inclined upward or downward, so that when ions hit the surface of the insulating column 104, they cannot enter the groove, even if the surface of the insulating column 104 turns black, it cannot form a short circuit, and still has an insulating effect, extending the service life of the insulating column 104. The groove depth of the spiral groove and the annular groove and the inclination angle of the groove depth direction relative to the central axis of the insulating column are set according to actual needs. The deeper the groove depth and the smaller the acute angle formed by the extension line of the groove depth direction and the central axis of the insulating column, the better the insulation effect and the longer the service life of the insulating column.

[0058] The lead wire 105 can be a thicker metal wire, or a thinner metal wire with a layer of fine and long tension spring, which helps to reduce the electric field on the surface of the lead wire 105 and thus reduce sparks.

[0059] Figure 12a-12f The incident energy is 160 keV divalent aluminum ion Al +2 The convergence of a group of three cylindrical lenses (cylindrical lens 101 and first cylindrical lenses 101' on both sides of cylindrical lens 101, the voltage of the two first cylindrical lenses 101' is set to zero, degenerating into a single cylindrical lens, and the ground electrode 102 is in front and behind) is used as an example to illustrate that when the voltage of the middle cylindrical lens 101 changes, the focal position of the ion beam also changes, showing the difference in focusing ability. Figure 12a to Figure 12f , the voltages of the middle cylindrical lens 101 are 10KV, 20KV, 30KV, -10KV, -20KV and -30KV respectively. It can be seen from the figure that no matter whether the voltage of the middle cylindrical lens 101 is positive or negative, it has a convergence effect on the ion beam; for the positive ion beam, the convergence effect will be more obvious when the voltage of the middle cylindrical lens 101 is positive; the convergence effect of the negative voltage is relatively poor compared to the positive voltage. The function of the focusing lens is often to correct the state of the beam 30, and it will not actively cause the diameter of the beam 30 to fluctuate greatly, so the voltage upper limit of the middle cylindrical lens 101 is set to 20kV, which is adjustable within this limit, and it can be guaranteed to work for this example. The voltage upper limit of the previous quadrupole lens is also set to 20kV. It is found in actual measurements that the voltage often needs to be adjusted to close to the upper limit for various ions, indicating that the beam 30 needs a higher voltage to focus, but in practice it is difficult to ensure that the positive and negative 20kV electrodes do not spark in a limited space. By using a single cylindrical focusing lens, in the same spatial dimensions, confining positive ions only requires ensuring that there is no spark between the positive 20kV and the ground, and there is still a margin.

[0060] The beam focusing unit 10 of the RF acceleration section of the present application can use quadrupole lenses for the first few and cylindrical lenses 101 or a combination of cylindrical lenses 101 and first cylindrical lenses 101' for the latter; or quadrupole lenses can be used for all the front ones and cylindrical lenses 101 or a combination of cylindrical lenses 101 and first cylindrical lenses 101' can be used for the latter, so that the beam spot is closer to a circular spot and the uniformity is easier to adjust after scanning; or cylindrical lenses 101 or a combination of cylindrical lenses 101 and first cylindrical lenses 101' can be used alternately with quadrupole lenses, which not only has a high degree of freedom to maintain a strong shaping ability, but also can constrain the beam 30 in all directions of 360° in the cross section so that it is not too exaggerated.

[0061] In a specific embodiment, the RF acceleration section of the ion implanter includes 12 accelerating electrodes and 13 electrostatic cylindrical lenses 101. The inner diameter of the cylindrical lens 101 is 32 mm and the length is 50 mm. Each cylindrical lens 101 has an independent power supply control, and the voltage range is -20 kV~20 kV and can be continuously and finely adjusted. In actual work, multiple sets of lens voltage parameters can be adjusted using the SIMPLEX algorithm or other algorithms.

[0062] In a specific embodiment, the radio frequency acceleration section of the high-energy ion implanter includes 14 accelerating electrodes and 8 electrostatic cylindrical lenses 101 and 7 quadrupole lenses placed alternately. The inner diameter of the cylindrical lens 101 is 32 mm and the length is 50 mm. The length of the quadrupole lens is 50 mm. Each cylindrical lens 101 has an independent power supply control, and the voltage range is -20kV~20kV, which can be continuously and finely adjusted; each quadrupole lens also has an independent power supply control, and the positive and negative voltages are output to the relative electrodes, with an amplitude range of 0~20kV, which can be finely adjusted; in actual work, the voltage parameters of multiple groups of lenses can be adjusted by adjusting the adjacent database and scanning in sequence in multiple dimensions.

[0063] In a specific embodiment, the radio frequency acceleration section of the high-energy ion implanter includes 12 accelerating electrodes, the ground electrode 102 of the beam-forming unit 10 is combined with the accelerating electrode, the inner diameter of the cylindrical lens 101 is 25.4 mm, each cylindrical lens 101 has an independent power supply control, and the voltage range of -20 kV to 20 kV can be continuously and finely adjusted. In actual work, multiple sets of lens voltage parameters can be adjusted using the SIMPLEX algorithm or other algorithms.

[0064] The present application discloses an ion implanter, comprising an ion source, a mass analyzer and a radio frequency acceleration section of the above embodiment. An ion source is used to generate an ion beam; The mass analyzer is arranged downstream of the ion source, and is used to perform mass analysis on the ion beam generated by the ion source and screen out the ion species required for injection to obtain a purified beam; The radio frequency acceleration section is arranged downstream of the mass analyzer and is used to form a focused beam and accelerate the beam to obtain a beam with a preset energy.

[0065] The design of the cylindrical focusing lens of the present application reduces the overall volume of the ion implanter, makes the structure simpler, reduces ion sputtering, extends the service life of the insulating column, and improves the ion transmission efficiency.

[0066] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any at least one embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and simple improvements made to the essential contents of the present invention should be included in the protection scope of the present invention.

Claims

1. A radio frequency acceleration section, characterized in that: It comprises a plurality of bunching units (10) arranged along the moving direction of the ion beam and an acceleration unit (20) arranged between adjacent bunching units (10), The beam-forming unit (10) comprises a beam-forming lens, and at least the beam-forming lens of the last beam-forming unit (10) comprises a cylindrical lens (101).

2. The radio frequency acceleration section according to claim 1, characterized in that: The inner cavity of the cylindrical lens (101) is cylindrical.

3. The radio frequency acceleration section according to claim 1, characterized in that: The entrance of the cylindrical lens (101) is elliptical and the exit is circular.

4. The radio frequency acceleration section according to claim 1, characterized in that: The focusing lens further comprises a first cylindrical lens (101') arranged on both sides of the cylindrical lens (101) along the moving direction of the ion beam, and the power-on voltage of the cylindrical lens (101) is greater than the power-on voltage of the first cylindrical lens (101').

5. The radio frequency acceleration section according to claim 1, characterized in that: The beam-forming unit (10) further comprises a ground electrode (102), and the ground electrode (102) is provided on both the inlet side and the outlet side of the beam-forming unit (10).

6. The radio frequency acceleration section according to any one of claims 1 to 5, characterized in that: The focusing lenses of the remaining focusing units (10) are quadrupole lenses, and the focusing units (10) provided with quadrupole lenses and the focusing units (10) provided with cylindrical lenses (101) are arranged alternately.

7. The radio frequency acceleration section according to claim 5, characterized in that: The condenser lens is connected to the ground electrode (102) on its side via a metal bracket (103), and the condenser lens is fixedly connected to the metal bracket (103) via an insulating column (104).

8. The radio frequency acceleration section according to claim 7, characterized in that: The outer surface of the insulating column (104) is provided with a spiral groove or a plurality of annular grooves arranged along the axial direction of the insulating column (104); the bottoms of the spiral groove and the annular groove extend in the direction of the central axis of the insulating column (104), and the groove depth direction is inclined relative to the central axis.

9. An ion implanter, characterized in that: comprising an ion source, a mass analyzer and a radio frequency acceleration section according to any one of claims 1 to 8, The ion source is used to generate an ion beam; The mass analyzer is arranged downstream of the ion source, and is used to perform mass analysis on the ion beam generated by the ion source and screen out the ion species required for injection to obtain a purified beam; The radio frequency acceleration section is arranged downstream of the mass analyzer, and is used to form a bunched beam and accelerate the beam to obtain a beam with a preset energy.

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