Optical path system and ion implanter using same
By integrating collimation and acceleration units into the optical path system design, the problems of beam divergence and loss in medium-current ion implanters are solved, achieving efficient ion beam transmission under low-speed or low-energy conditions, improving beam quality and utilization, and reducing energy consumption.
Patent Information
- Application Number
- CN202423321913.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2034-12-31
AI Technical Summary
In the optical path system of a medium-current ion implanter, the beam gradually diverges and is lost during long-distance transmission, resulting in reduced beam quality and utilization, especially severe current loss under low-speed or low-energy conditions.
By employing an integrated collimation unit and acceleration unit, the travel distance of the ion beam in the optical path is shortened. The collimation electric field generated by the arc-shaped electrode plate group is used for initial acceleration and focusing. Combined with the suppression electrode and the filter unit, divergence is suppressed and impurity ions are removed, reducing current loss.
It significantly reduces ion beam current loss under low-speed or low-energy conditions, improves beam quality and utilization, reduces optical path system energy consumption, and reduces radiation pollution.
Smart Images
Figure CN223809108U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of ion implantation, in particular to an optical path system and an ion implanter using the same BACKGROUND
[0002] In the process of manufacturing semiconductor wafers, doping is needed to be carried out by an ion implanter to precisely control the conductivity of the semiconductor wafers. Ion implanters are mainly divided into three categories: low-energy large-beam ion implanters, high-energy ion implanters, and medium-beam ion implanters. For medium-beam ion implanters, the optical path is arranged in the order of ionization extraction, screening, acceleration, scanning, and collimation. The beam will gradually diverge and be lost during long-distance transmission, greatly reducing the quality and utilization rate of the beam. The lower the plasma velocity in the beam, the greater the probability of collision with impurity ions during transmission, and the greater the flow intensity loss. After scanning and collimation, the flow intensity loss is often more than 50%. CONTENT OF THE UTILITY MODEL
[0003] In order to solve the problems in the prior art, the present application provides an optical path system and an ion implanter using the same, which can reduce the flow intensity loss of the target ion beam under low-speed or low-energy conditions.
[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:
[0005] In a first aspect, the present application provides an optical path system for an ion implanter, comprising:
[0006] An ionization extraction module for ionizing neutral atoms and molecules into ions and extracting a beam formed by the ions;
[0007] A screening module for screening target ions in the beam;
[0008] A scanning module for correcting the direction of a target ion beam composed of target ions, and focusing or widening the target ion beam so that the target ion beam is within a set scanning range; and
[0009] An acceleration and collimation module, which is arranged downstream of the scanning module. The acceleration and collimation module comprises an integrated collimation unit and an acceleration unit. The collimation unit is arranged before the acceleration unit. After the collimation unit focuses the divergent target ions in the target ion beam, the target ions are accelerated to have a target energy by the acceleration unit.
[0010] Further, the collimation unit can receive an electrical signal and generate a corresponding collimation electric field. The target ions passing through the collimation unit are deflected and preliminarily accelerated under the action of the collimation electric field.
[0011] Further, the collimating unit comprises two oppositely arranged electrode plates, when the target ion beam passes through the collimating unit, the two electrode plates are distributed on both sides of the target ion beam, and the side edge of the electrode plate close to the accelerating unit is arranged in an arc shape.
[0012] Further, the light path system comprises a plurality of sets of suppression electrodes, and the plurality of sets of suppression electrodes are arranged in the ionization extraction module, the scanning module and the accelerating collimating module respectively.
[0013] Further, the ionization extraction module comprises an ionization arc chamber and an extraction electrode, and the suppression electrode comprises a first suppression electrode, the first suppression electrode is arranged between the ionization arc chamber and the extraction electrode, and the magnetic field generated by the suppression electrode suppresses the beam divergence.
[0014] Further, the suppression electrode comprises a second suppression electrode and a third suppression electrode, the second suppression electrode is arranged before the collimating unit to suppress the divergence of the target ion beam passing through the scanning module, and the third suppression electrode is arranged behind the accelerating unit to suppress the divergence of the target ion beam with the target energy.
[0015] Further, the accelerating collimating module further comprises a filtering unit, the filtering unit is arranged at the rear end of the third suppression electrode, the filtering unit is used to generate an electric field, the direction of the electric field is perpendicular to the direction of the target ion beam, so as to eliminate the impurity ions in the target ion beam, and the energy of the impurity ions is different from the target energy.
[0016] Further, the scanning module comprises a detection unit, the detection unit has an insulating outer wall, the outer wall has a screening slit penetrating through opposite two end faces, the screening slit is used for the target ion beam to pass through, and the light path system is provided with a current detection device, and the outer wall is connected with the current detection device.
[0017] Further, the scanning module comprises a deflection electrode and a four-stage lens, and the detection unit, the deflection electrode and the four-stage lens are arranged in sequence along the direction of the target ion beam.
[0018] In a second aspect, the application further provides an ion implanter, which comprises the light path system of any one of the first aspect.
[0019] The light path system provided by the application shortens the movement distance of the target ion beam in the light path by integrating the collimating unit and the accelerating unit, and the integrated accelerating collimating module is arranged downstream of the scanning module, thereby reducing the flow loss of the ion beam, especially under low speed or low energy conditions. In addition, the target ion can be collimated during acceleration, thereby reducing the movement time of the target ion beam in the light path. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 FIG. 1 is a schematic diagram of the movement of the target ion beam in the light path system in the embodiment of the application;
[0021] Figure 2 Fig. 1 is a structural schematic diagram of an optical path system in an embodiment of the present application;
[0022] Figure 3 Fig. 2 is a structural schematic diagram of a scanning module in an embodiment of the present application.
[0023] Fig. 1 is a structural schematic diagram of an optical path system in an embodiment of the present application. Fig. 2 is a structural schematic diagram of a scanning module in an embodiment of the present application. DETAILED DESCRIPTION
[0024] In order to make the personnel in the art better understand the scheme of the present application, the technical scheme in the specific embodiment of the present application will be described clearly and completely below by combining the drawings in the embodiment of the present application.
[0025] In this document, the terms“first” and“second” are used merely to distinguish one entity or action from another entity or action, and do not necessarily require or imply that there is any such actual relationship or order between these entities or actions. Moreover, the terms“include” and“contain” or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device.
[0026] As shown in Fig. 1, the optical path system 100 comprises an ionization extraction module 11, a screening module 12, a scanning module 13, an acceleration collimation module 14 and a suppression electrode 15. Figure 1 And Figure 2As shown, the present application provides an optical path system 100 for an ion implanter, which comprises an ionization extraction module 11, a screening module 12, a scanning module 13 and an acceleration collimation module 14. The ionization extraction module 11 is configured to ionize neutral atoms and molecules into ions and extract a beam formed by the ions; the screening module 12 is configured to screen target ions in the beam; the scanning module 13 is configured to correct the direction of a target ion beam 200 composed of the target ions and focus or widen the target ion beam 200 so that the target ion beam 200 is within a set scanning range; the acceleration collimation module 14 is arranged downstream of the scanning module 13 and comprises an integrated collimation unit 141 and an acceleration unit 142, the collimation unit 141 being arranged before the acceleration unit 142, the collimation unit 141 focusing divergent target ions in the target ion beam 200 and then accelerating the target ions to have a target energy through the acceleration unit 142.
[0027] By the above arrangement, the collimation unit 141 and the acceleration unit 142 are integrated and arranged between the scanning module 13 and the acceleration unit 142. On the one hand, the target ions can be collimated during acceleration, reducing the motion time of the target ion beam 200 in the optical path. On the other hand, since the collimation unit 141 and the acceleration unit 142 are integrated, the motion distance of the target ion beam 200 in the optical path is shortened, especially under low speed or low energy conditions, reducing the loss of ion beam current.
[0028] Specifically, the collimation unit 141 can receive an electric signal and generate a corresponding collimation electric field, and the target ions passing through the collimation unit 141 are deflected and preliminarily accelerated under the action of the collimation electric field. The collimation unit 141 comprises two electrode plate groups arranged oppositely, and when the target ion beam 200 passes through the collimation unit 141, the two electrode plate groups are distributed on both sides of the target ion beam 200. When the ion beam moves in the optical path, the electrode plate groups are powered to generate corresponding electric or magnetic fields, and the target ions are focused and deflected under the action of the electric or magnetic fields. Each electrode plate group comprises at least one electrode plate, and any electrode plate in the electrode plate group has an arc-shaped edge. By setting the edge of the electrode plate to be arc-shaped, it is helpful to form a more uniform and reasonable electric field distribution when the electrode plate is powered. Compared with a straight edge, the arc-shaped edge can reduce the edge effect of the electric field, making the transition of the electric field around the electrode more smooth, thereby avoiding sudden changes and unevenness of the electric field.
[0029] For example, taking any one electrode plate group as an example, the electrode plate group includes a first electrode plate 1411 and a second electrode plate 1412, and the first electrode plate 1411 and the second electrode plate 1412 are arranged in sequence along the movement direction of the target ion beam 200, that is, the second electrode plate 1412 is closer to the acceleration unit 142 than the first electrode plate 1411. The opposite edges of the first electrode plate 1411 and the second electrode plate 1412 are both arranged in an arc shape, and the radii of the edges of the two are consistent, and the centers of the arcs are towards the same side of the electrode plate group. In the case of energizing the first electrode plate 1411 and the second electrode plate 1412, by respectively applying different voltages to the first electrode plate 1411 and the second electrode plate 1412, an electric field gradient is generated between the first electrode plate 1411 and the second electrode plate 1412, which improves the focusing effect on the target ion beam 200, and at the same time, the target ions are preliminarily accelerated, so as to reduce the allowable energy of the acceleration unit 142.
[0030] In the embodiments of the present application, the edge is parallel to the horizontal plane.
[0031] Further, the acceleration and collimation module 14 further includes a filtering unit 143 for generating a filtering electric field, the direction of the filtering electric field being perpendicular to the direction of the target ion beam 200, so as to eliminate impurity ions in the target ion beam 200, the energy of the impurity ions being different from the target energy.
[0032] As an implementation manner, the optical path system 100 includes a plurality of sets of suppression electrodes 15, and the plurality of sets of suppression electrodes 15 are respectively arranged in the ionization extraction module 11, the scanning module 13 and the acceleration and collimation module 14.
[0033] It should be noted that during the transmission of the target ion beam 200, the target ions diverging at the edge of the target ion beam 200 will inevitably hit the electrode surface, resulting in a large number of secondary electrons overflowing, and the secondary electrons will hit other electrode surfaces after being accelerated by the electric field to thousands of ev, causing a large amount of radiation pollution. The suppression electrode 15 can adjust the intensity and stability of the target ion beam 200 by applying a suitable electric field, prevent the beam current of the target ion beam 200 from being too large or too small, and ensure that the ion beam is within a suitable range.
[0034] The ionization extraction module 11 includes an ionization arc chamber 111 and an extraction electrode 112. The ionization arc chamber 111 is a key place for generating ions, and by means of applying a high-voltage, high-frequency electric field or introducing an electron beam in the ionization arc chamber 111, gas discharge forms a plasma (Al, N, B, P, etc.), in which atoms or molecules collide with electrons or high-energy particles to be ionized, generating a large number of ions. The extraction electrode 112 is arranged outside the ionization arc chamber 111, and by applying a set voltage or electric field on the extraction electrode 112, the ions in the plasma move directionally under the action of the electric field force, and are extracted from the ionization arc chamber 111 to form a beam.
[0035] In the embodiments of the present application, the suppression electrode 15 includes a first suppression electrode 151, which is arranged between the ionization arc chamber 111 and the extraction electrode 112, and the magnetic field generated by the suppression electrode 15 suppresses the divergence of the beam.
[0036] The suppression electrode 15 further includes a second suppression electrode 152 and a third suppression electrode 153, the second suppression electrode 152 is arranged before the collimation unit 141 to suppress the divergence of the target ion beam 200 passing through the scanning module 13, and the third suppression electrode 153 is arranged behind the acceleration unit 142 to suppress the divergence of the target ion beam 200 with the target energy.
[0037] According to the above, the acceleration collimation module 14 further includes a filtering unit 143, and the third suppression electrode 153 is arranged in front of the filtering unit 143.
[0038] As an implementation manner, the scanning module 13 includes a detection unit 131, a deflection electrode 132, a four-stage lens 133, and a scanning electrode 134, and the detection unit 131, the deflection electrode 132, the four-stage lens 133, the scanning electrode 134, and the second suppression electrode 152 are arranged in sequence along the direction of the target ion beam 200.
[0039] The detection unit 131 has a screening slit 1311 through which the target ion beam 200 passes. The target ion beam 200 is energy-screened through the screening slit 1311. Target ions of different energies have different motion trajectories and deflection angles when passing through the screening slit 1311. Only target ions within a specific energy range can accurately pass through the screening slit 1311, thereby achieving preliminary screening and filtering of the energy of the target ion beam 200. The propagation direction of the target ion beam 200 is changed by applying an electric field to the deflection electrode 132. The quadrupole lens 133 is composed of two pairs of mutually perpendicular electrodes and is distributed in a quadrupole symmetry. When a certain direct current voltage and radio frequency voltage are applied to the electrodes, a specific electric field distribution is generated inside the quadrupole lens 133. The target ion beam 200 is subjected to the action of the electric field force when passing through the quadrupole lens 133. Due to the non-uniformity of the electric field, target ions at different positions are subjected to forces of different sizes and directions, thereby focusing or diverging the target ion beam 200 in the transverse direction. By applying a certain voltage or current signal to the scanning electrode, an electric field or magnetic field is generated, thereby deflecting the target ion beam 200 in the transverse direction, ensuring that the target ions can be uniformly injected into the entire surface or a specific area of the target material.
[0040] Through the above arrangement, the suppression electrode 15 is added in front of the extraction electrode 112, behind the scanning electrode 134, and behind the acceleration unit 142, which can effectively suppress the acceleration of the target ions and reduce the radiation pollution caused by the target ions.
[0041] As an implementation manner, the detection unit 131 has an insulating outer wall 1312, and the outer wall 1312 has a screening slit 1311 penetrating through opposite two end faces thereof. The light path system 100 is provided with a current detection device, and the outer wall 1312 is connected with the current detection device.
[0042] When the target ions hit the outer wall 1312, the current generated by the target ions flows through the current detection device. The current detection device is set as an ammeter, and the current detection device is used to timely extract the indicators such as current and energy of the target ion beam 200 during debugging.
[0043] In summary, by integrating the collimating unit 141 and the accelerating unit 142, the integrated accelerating collimating module 14 is arranged downstream of the scanning module 13, which shortens the movement distance of the target ion beam 200 in the optical path, and the space occupied by the whole optical path system 100 is smaller. Especially under low speed or low energy conditions, the flow loss of the target ion beam 200 is reduced. In addition, since the target ions can be collimated during acceleration, the movement time of the target ion beam 200 in the optical path is reduced. In addition, the allowable energy of the ionization extraction module 11, the screening module 12, the scanning module 13 and the accelerating collimating module 14 is smaller before the target ion beam 200 enters the accelerating collimating module 14, and is below 60kv, which reduces the energy consumption of the optical path system 100.
[0044] The embodiments of the present application also provide an ion implanter, which comprises the optical path system 100 described above.
[0045] It should be understood that for those skilled in the art, improvements or changes can be made according to the above description, and all these improvements and changes shall belong to the protection scope of the claims attached to the present application.
Claims
1. An optical path system for an ion implanter, characterized by, The ionization and extraction module (11) is configured to ionize neutral atoms and molecules into ions and extract a beam formed by the ions. The screening module (12) is configured to screen target ions from the beam. The scanning module (13) is configured to correct the direction of a target ion beam composed of the target ions and focus or widen the target ion beam so that the target ion beam is within a set scanning range. The acceleration and collimation module (14) is arranged downstream of the scanning module (13) and includes an integrated collimation unit (141) and an acceleration unit (142). The collimation unit (141) is arranged before the acceleration unit (142). After the collimation unit (141) focuses the divergent target ions in the target ion beam, the target ions are accelerated to a target energy by the acceleration unit (142).
2. The optical path system of claim 1, wherein The collimation unit (141) is capable of receiving an electric signal and generating a corresponding collimation electric field. The target ions passing through the collimation unit (141) are deflected and initially accelerated under the action of the collimation electric field.
3. The optical path system of claim 1, wherein The collimation unit (141) is composed of two oppositely arranged electrode plate groups. When the target ion beam passes through the collimation unit (141), the two electrode plate groups are distributed on both sides of the target ion beam. Any electrode plate in the electrode plate group has an arc-shaped edge.
4. The optical path system of claim 1, wherein The optical path system includes multiple sets of suppression electrodes (15), and each set of suppression electrodes (15) is arranged in the ionization and extraction module (11), the scanning module (13), and the acceleration and collimation module (14).
5. The optical path system of claim 4, wherein The ionization and extraction module (11) includes an ionization arc chamber (111) and an extraction electrode (112). The suppression electrodes (15) include a first suppression electrode (151). The first suppression electrode (151) is arranged between the ionization arc chamber (111) and the extraction electrode (112). A magnetic field generated by the suppression electrodes (15) suppresses the divergence of the beam.
6. The optical path system of claim 4, wherein The suppression electrodes (15) include a second suppression electrode (152) and a third suppression electrode (153). The second suppression electrode (152) is arranged before the collimation unit (141) to suppress the divergence of the target ion beam passing through the scanning module (13). The third suppression electrode (153) is arranged behind the acceleration unit (142) to suppress the divergence of the target ion beam with the target energy.
7. The optical path system of claim 6, wherein The acceleration collimation module (14) further comprises a filtering unit (143) arranged at the rear end of the third suppression electrode (153), the filtering unit (143) is used to generate a filtering electric field, the direction of the filtering electric field is perpendicular to the direction of the target ion beam, so as to eliminate impurity ions in the target ion beam, the energy of the impurity ions is different from the target energy.
8. The optical path system according to claim 4, characterized in that, The scanning module (13) comprises a detection unit (131), the detection unit (131) has an insulating outer wall (1311), the outer wall (1311) has a screening slit (1312) penetrating through the opposite two end faces, the screening slit (1312) is used for the target ion beam to pass through, and the optical path system is provided with a current detection device, and the outer wall (1311) is connected with the current detection device.
9. The optical path system according to claim 8, characterized in that, The scanning module (13) comprises a deflection electrode (132), a quadrupole lens (133) and a scanning electrode (134), and the suppression electrode (15) comprises a second suppression electrode (152), and the detection unit (131), the deflection electrode (132), the quadrupole lens (133), the scanning electrode (134) and the second suppression electrode (152) are sequentially arranged along the direction of the target ion beam.
10. An ion implanter, comprising: The optical path system comprises the optical path system according to any one of claims 1-9.