Ion implantation apparatus and method for simultaneously accelerating ions of different mass-to-charge ratios

Abstract

The application relates to the technical field of synchrotron, in particular to an ion implantation device and method capable of accelerating ions with different mass-to-charge ratios simultaneously, wherein the ion implantation device comprises a laser ion source chamber, a multi-beam RFQ accelerator and a terminal target chamber; the laser ion source chamber can generate plasmas with different mass-to-charge ratios in sequence; the multi-beam RFQ accelerator comprises at least two acceleration channels, the plasmas accelerated by the at least two acceleration channels have different mass-to-charge ratios, each acceleration channel is provided with an on-off mechanism at an inlet end of the acceleration channel to open or close the acceleration channel, and an outlet end of each acceleration channel is communicated with the terminal target chamber; the plasmas with different mass-to-charge ratios are injected into the terminal target chamber in sequence after being accelerated in the corresponding acceleration channels; the ion implantation method comprises first layer ion implantation, second layer ion implantation and Nth layer ion implantation; thus, the ion implantation device and the ion implantation method can accelerate and transmit beam flows with different mass-to-charge ratios, and plasmas with different mass-to-charge ratios can be doped on a target material in different depths.

Description

Technical Field

[0001] This application relates to the field of synchrotron technology, specifically to an ion implantation device and method capable of simultaneously accelerating ions with different charge-to-mass ratios. Background Technology

[0002] Ion implantation is a technique that ionizes atoms of a certain element and accelerates them in an electric field to achieve high velocities before injecting them into the surface of a solid material to alter its physical or chemical properties. An ion implantation device is a device that implants ions (usually hydrogen ions or heavy ions) into semiconductor or other materials to change their electrical or other properties. It is widely used in the semiconductor industry for manufacturing integrated circuits and other microelectronic devices. The purpose of ion implantation is typically to form a desired doped layer on the material surface or to change the material's properties. However, existing ion implantation devices have limitations in transmitting beams with different charge-to-mass ratios, and cannot effectively accelerate and transmit beams with different charge-to-mass ratios. Summary of the Invention

[0003] Based on the above-mentioned technical problems, this application provides an ion implantation device and method that can simultaneously accelerate ions with different charge-to-mass ratios, which can accelerate and transport beams with different charge-to-mass ratios, allowing plasmas with different charge-to-mass ratios to be deeply or shallowly doped on the target material.

[0004] In a first aspect, this application provides an ion implantation device capable of simultaneously accelerating ions with different charge-to-mass ratios, comprising a laser ion source chamber, a multi-beam RFQ accelerator, and a terminal target chamber. The laser ion source chamber can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator includes at least two acceleration channels, the plasmas accelerated by the at least two acceleration channels having different charge-to-mass ratios. Each acceleration channel has an on / off mechanism at its inlet end to open or close the acceleration channel. The outlet end of each acceleration channel is connected to the terminal target chamber. Plasmas with different charge-to-mass ratios are sequentially accelerated in the corresponding acceleration channels and then injected into the terminal target chamber.

[0005] As a further technical solution of this application, each acceleration channel is provided with a beam input pipe at its inlet end and a beam output pipe at its outlet end. The beam input pipe is connected to the laser ion source chamber, and an on / off mechanism is provided on the beam input pipe to open the corresponding acceleration channel when a plasma with a preset charge-to-mass ratio is generated in the laser ion source chamber. The beam output pipe is connected to the terminal target chamber. The axes of the beam input pipe, acceleration channel and beam output pipe are located on the same straight line so that the plasma is collimated and injected into the terminal target chamber.

[0006] As a further technical solution of this application, the ion implantation device also includes a vacuum pump and a cooling water circuit. The cooling water circuit is installed on the surface of the multi-beam RFQ accelerator for heat dissipation. The vacuum pump is connected to the laser ion source chamber, the multi-beam RFQ accelerator, and the terminal target chamber, respectively. The vacuum level of the laser ion source chamber is controlled at 10. -3 ~10 -4 Within the Pa range, the vacuum level of the multi-beam RFQ accelerator is controlled at 10. -6 Within Pa, the vacuum level of the terminal target chamber is controlled at 5 × 10⁻⁶. -5 Pa inside.

[0007] As a further technical solution of this application, the laser ion source chamber also includes a laser emitter, a focusing lens, and a movable target surface. The focusing lens is located between the laser emitter and the target surface to focus the laser beam onto the target surface. The target surface can move relative to the focusing lens so that the desired charge-to-mass ratio plasma can be obtained by utilizing the new target surface position.

[0008] As a further technical solution of this application, the terminal target chamber includes a movable sample target, which can be moved within the terminal target chamber to change the position of ion implantation.

[0009] As a further technical solution of this application, the multi-beam RFQ accelerator includes an acceleration cavity tube, multiple stem-ring electrodes and multiple rod electrode groups. Each rod electrode group has four rod electrodes, which are arranged to form an acceleration channel. The multiple stem-ring electrodes are distributed at equal intervals along the acceleration channel, and each stem-ring electrode is connected to the acceleration cavity tube. Multiple openings are symmetrically opened in the stem-ring electrodes, and each opening allows a rod electrode group to pass through. Each rod electrode group is connected to the stem-ring electrode.

[0010] As a further technical solution of this application, the acceleration cavity tube is provided with multiple sets of tuner assemblies that are equally spaced, and each set of tuner assemblies is provided with two couplers, which are symmetrically arranged on both sides of the acceleration cavity tube.

[0011] In a second aspect, this application provides an ion implantation method, which is applied to the ion implantation apparatus of any one of the first aspects. The ion implantation apparatus includes a laser ion source chamber, a multi-beam RFQ accelerator, and a terminal target chamber. The laser ion source chamber can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator includes at least two acceleration channels, and the plasmas accelerated by the at least two acceleration channels have different charge-to-mass ratios. Each acceleration channel has an on / off mechanism at its inlet end to open or close the acceleration channel. The outlet end of each acceleration channel is connected to the terminal target chamber. Plasmas with different charge-to-mass ratios are sequentially accelerated in the corresponding acceleration channels and then injected into the terminal target chamber. The laser ion source chamber includes a laser emitter.

[0012] The method includes:

[0013] First-layer ion implantation: The laser emitter is controlled to emit a laser beam of a first preset energy, and the acceleration channel corresponding to the first preset energy laser beam is opened to realize the first-layer ion implantation terminal target chamber; after the first-layer ion implantation is completed, the acceleration channel and the laser emitter are closed.

[0014] Second-layer ion implantation: The laser emitter is controlled to emit a laser beam with a second preset energy, and the acceleration channel corresponding to the laser beam with the second preset energy is opened to realize the second-layer ion implantation terminal target chamber; after the second-layer ion implantation is completed, the acceleration channel and the laser emitter are closed.

[0015] Nth layer ion implantation: Control the laser emitter to emit a laser beam with the Nth preset energy, and open the acceleration channel corresponding to the laser beam with the Nth preset energy to realize the Nth layer ion implantation terminal target chamber; after the Nth layer ion implantation is completed, close the acceleration channel and the laser emitter.

[0016] As a further technical solution of this application, the laser ion source chamber also includes a laser emitter, a focusing lens and a movable target surface. The focusing lens is disposed between the laser emitter and the target surface to focus the laser beam onto the target surface. The target surface can move relative to the focusing lens so that the plasma with the required charge-to-mass ratio can be obtained by utilizing the new target surface position.

[0017] Before the first ion implantation step, the second ion implantation step and / or the Nth ion implantation step, the method further includes: controlling the target surface of the laser ion source to move to a preset position so as to obtain the plasma with the charge-to-mass ratio required for the second ion implantation using the new target surface position.

[0018] The first-layer ion implantation step, the second-layer ion implantation step, and / or the Nth-layer ion implantation step also include:

[0019] Online uniformity detection and real-time correction of ion implantation depth and uniformity are used to determine that ion implantation is complete once the corresponding implantation depth is reached.

[0020] As a further technical solution of this application, before the first layer ion implantation step, the second layer ion implantation step, and / or the Nth layer ion implantation step, the following is also included:

[0021] Vacuum treatment: Controlling the vacuum level in the laser ion source chamber to 10 -3 ~10 -4 Within the Pa range, the vacuum level of the multi-beam RFQ accelerator is controlled at 10. -6 Within Pa, the vacuum level of the terminal target chamber is controlled at 5 × 10⁻⁶. -5 Pa inside.

[0022] The beneficial effects of the technical solution in this application are as follows:

[0023] Compared with existing technologies, the ion implantation device of this application is designed with multiple acceleration channels. The acceleration channels are designed based on the RFQ acceleration principle. Each acceleration channel accelerates a plasma with a different charge-to-mass ratio. The plasmas accelerated by the multiple acceleration channels have different charge-to-mass ratios. Each acceleration channel is equipped with an on / off mechanism at its inlet to open and close the acceleration channel. The laser control device controls the laser emitter to generate a plasma with a specific charge-to-mass ratio in the laser ion source chamber. The acceleration channel corresponding to this charge-to-mass ratio plasma opens, while the other acceleration channels close. After being accelerated by the acceleration channels, the plasma with this charge-to-mass ratio is injected into the target material in the terminal target chamber. When the laser control device controls the laser emitter to generate the next plasma with a different charge-to-mass ratio in the laser ion source chamber, the corresponding acceleration channel opens, while the other acceleration channels close. In this way, plasmas with different charge-to-mass ratios are sequentially injected into the target material in the terminal target chamber, thereby achieving deep and shallow doping of the target material with plasmas of different charge-to-mass ratios. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the ion implantation device according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the structure of the multi-beam RFQ accelerator in the ion implantation apparatus of this application embodiment;

[0026] Figure 3 This is a longitudinal cross-sectional view of the multi-beam RFQ accelerator of the ion implantation device according to an embodiment of this application;

[0027] Figure 4 This is a schematic cross-sectional view of the multi-beam RFQ accelerator of the ion implantation device according to an embodiment of this application;

[0028] Figure 5 This is a flowchart illustrating the steps of the ion implantation method according to an embodiment of this application.

[0029] Explanation of reference numerals in the attached figures: Laser ion source chamber 100, laser emitter 101, focusing lens 102, target surface 103, multi-beam RFQ accelerator 200, acceleration channel 201, acceleration cavity tube 202, stem ring electrode 203, rod electrode group 204, rod electrode 205, coupler 206, switching mechanism 207, beam input pipe 208, beam output pipe 209, cooling water circuit 210, vacuum pump 211, terminal target chamber 300, sample target material 301. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Where there is no conflict, the embodiments and features thereof in this application can be combined with each other. For ease of description, the concepts of "first," "second," etc., mentioned in this application are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies. The modifications of "a" and "a plurality of" mentioned in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly indicated otherwise in the context, they should be understood as "one or more." The multi-beam RFQ accelerator mentioned in this application is a radio frequency quadrupole accelerator.

[0032] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0033] refer to Figure 1 This application provides an ion implantation device capable of simultaneously accelerating ions with different charge-to-mass ratios, including a laser ion source chamber 100, a multi-beam RFQ accelerator 200, and a terminal target chamber 300. The laser ion source chamber 100 can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator 200 includes at least two acceleration channels 201, and the plasmas accelerated by the at least two acceleration channels 201 have different charge-to-mass ratios. Each acceleration channel 201 has an on / off mechanism 207 at its inlet end to open or close the acceleration channel 201. The outlet end of each acceleration channel 201 is connected to the terminal target chamber 300. Plasmas with different charge-to-mass ratios are sequentially accelerated in the corresponding acceleration channels 201 and then injected into the terminal target chamber 300.

[0034] Compared with the prior art, the ion implantation device of this application is designed with multiple acceleration channels 201. The acceleration channels 201 are designed based on the RFQ acceleration principle, and each acceleration channel 201 accelerates a plasma with a different charge-to-mass ratio. The plasmas accelerated by the multiple acceleration channels 201 have different charge-to-mass ratios. Each acceleration channel 201 has an on / off mechanism 207 at its inlet end for opening and closing the acceleration channel 201. The laser control device controls the laser emitter 101 to operate, thereby generating a plasma with a specific charge-to-mass ratio in the laser ion source chamber 100, corresponding to the acceleration of that specific charge-to-mass ratio plasma. Acceleration channel 201 opens accordingly, while other acceleration channels 201 close. Plasma with a specific charge-to-mass ratio is accelerated via acceleration channel 201 and injected into the target material of the terminal target chamber 300. When the laser control device controls the laser emitter 101 to generate plasma with the next charge-to-mass ratio in the laser ion source chamber 100, the corresponding acceleration channel 201 opens accordingly, while other acceleration channels 201 close. Thus, plasmas with different charge-to-mass ratios are sequentially injected into the sample target material 301 of the terminal target chamber 300, thereby achieving deep and shallow doping of the sample target material 301 with plasmas of different charge-to-mass ratios. It is understood that the on / off mechanism 207 in this embodiment can physically open or close the acceleration channels, or it can electrically connect or disconnect the acceleration channels, energizing or de-energizing them. Therefore, when a plasma with a certain charge-to-mass ratio needs to be accelerated, the corresponding acceleration channel can operate, while other acceleration channels do not.

[0035] refer to Figure 1 and Figure 2 In this embodiment, each acceleration channel 201 has a beam input pipe 208 at its inlet end and a beam output pipe 209 at its outlet end. The beam input pipe 208 is connected to the laser ion source chamber 100, and an on / off mechanism 207 is provided on the beam input pipe 208 to open the corresponding acceleration channel 201 when the laser ion source chamber 100 generates plasma with a preset charge-to-mass ratio. The beam output pipe 209 is connected to the terminal target chamber 300. The axes of the beam input pipe 208, acceleration channel 201 and beam output pipe 209 are on the same straight line so that the plasma is injected into the terminal target chamber 300 in a collimated manner.

[0036] It should be noted that the inlet and outlet ends of the accelerating channel 201 are respectively provided with a beam input pipe 208 and a beam output pipe 209. The axes of the beam input pipe 208, the accelerating channel 201, and the beam output pipe 209 are located on the same straight line, so that after the plasma enters the accelerating channel 201 and is accelerated, the resulting beam is injected into the terminal target chamber 300 in a collimated manner, making the energy and density distribution at the impact point more uniform. That is, the purpose of ion implantation is usually to form the required doped layer on the material surface or to change the properties of the material. The multi-beam RFQ accelerator 200 based on the RFQ acceleration principle, combined with the structure of the accelerating channel 201 in this embodiment, enables the ion beam to be injected into the material surface of the terminal target chamber 300 more collimatedly, resulting in a more uniform doping depth, a more ideal concentration gradient, and a more uniform thickness of the doped layer on the material surface. This makes the material exhibit highly consistent performance in different regions, improving the surface quality and optical properties of the material.

[0037] like Figure 1 , Figure 3 and Figure 4 The ion implantation apparatus of this application embodiment further includes a vacuum pump 211 and a cooling water circuit 210. The cooling water circuit 210 is disposed on the surface of the multi-beam RFQ accelerator 200 for heat dissipation. The vacuum pump 211 is connected to the laser ion source chamber 100, the multi-beam RFQ accelerator 200, and the terminal target chamber 300, respectively. The vacuum degree of the laser ion source chamber 100 is controlled at 10. -3 ~10 -4 Within the Pa range, the vacuum level of the multi-beam RFQ accelerator 200 is controlled at 10. -6 Within Pa, the vacuum level of the terminal target chamber 300 is controlled at 5 × 10⁻⁶. -5 Within Pa. Thus, the entire system is kept under vacuum during ion implantation to prevent beam loss and ion neutralization caused by collisions between the ion beam and air, ensuring optimal uniformity of ion implantation; the cooling water circuit 210 prevents the multi-beam RFQ accelerator 200 from deforming or becoming detuned due to the large amount of heat generated during beam acceleration. In this embodiment, a vacuum pump 211 is used to evacuate the ion source before ion implantation, and the vacuum level at the ion source needs to be controlled to reach 10. -3 ~10 -4 Pa. The vacuum level of the multi-beam RFQ accelerator 200 should reach 10. -6 Pa. The vacuum level in the terminal target chamber (300°C) should be better than 5 × 10⁻⁶ Pa. -5 Pa. At the same time, it is also necessary to process the cooling water circuit 210 of the multi-beam RFQ accelerator with cooling water. When circulating the cooling water, it is important to ensure that all channels are completely unobstructed and to test the flow rate of the water circuit to ensure that it meets the required flow rate, etc.

[0038] like Figure 1 As shown, the laser ion source chamber 100 of this application embodiment also includes a laser emitter 101, a focusing lens 102, and a movable target surface 103. The focusing lens 102 is disposed between the laser emitter 101 and the target surface 103 to focus the laser beam onto the target surface 103. The target surface 103 can move relative to the focusing lens 102 so that the plasma with the required charge-to-mass ratio can be obtained by utilizing the new position of the target surface 103.

[0039] Furthermore, the interaction between the laser and the target surface 103 includes processes such as photoelectric effect, light absorption, and ionization. During these processes, defects in the target surface 103 of the target material will lead to differences in charge state. The laser is focused at a certain position on the target surface 103, and the target surface 103 position for obtaining plasma twice can be different. Alternatively, to obtain plasmas with different charge-to-mass ratios, different target surface 103 positions can be used to ensure that the types of plasma generated are roughly the same.

[0040] refer to Figure 1 The terminal target chamber 300 includes a movable sample target 301, which can be moved within the terminal target chamber 300 to change the position of ion implantation. The terminal target chamber 300 may be equipped with a target holder and a sample processing device, etc. The target holder is a platform that supports the sample target 301 and can be made of high-purity metal or ceramic materials, possessing stability and high-temperature resistance. The sample processing device is used to operate the sample target 301 and may include rotation or tilting, moving the sample target 301 to a new position as needed, which facilitates the adjustment of ion implantation uniformity. The movable implementation structure can adopt a conventional structure, which will not be described in detail here.

[0041] refer to Figure 2 , Figure 3 and Figure 4 The multi-beam RFQ accelerator 200 of this application embodiment includes an acceleration cavity 202, multiple stem-ring electrodes 203, and multiple rod electrode groups 204. Each rod electrode group 204 has four rod electrodes 205, and the four rod electrodes 205 are correspondingly arranged to form an acceleration channel 201, such as... Figure 4 As shown, the rod electrode assembly in this embodiment of the application has four groups, each group forming an acceleration channel 201, thus there are four acceleration channels 201. (Reference) Figure 3Multiple stem-ring electrodes 203 are evenly distributed along the accelerating channel 201, and each stem-ring electrode 203 is connected to the accelerating cavity tube 202. Multiple symmetrical openings are provided within each stem-ring electrode 203, each opening corresponding to a rod electrode group 204 passing through, and each rod electrode group 204 is connected to the stem-ring electrode 203. The accelerating cavity tube 202 is provided with multiple sets of tuner assemblies evenly distributed, each set of tuner assemblies having two couplers 206, symmetrically arranged on both sides of the accelerating cavity tube 202. Thus, the multi-beam RFQ accelerator 200 uses symmetrically placed rod electrodes 205, applying equal and opposite alternating voltages to opposite and adjacent electrodes to form accelerating channels 201 for accelerating ion beams. Multiple accelerating channels 201 are evenly distributed within the stem-ring electrodes 203. The symmetrical structure reduces cavity detuning, and the cooling water circuit 210 can be located on the surface of the accelerating cavity tube 202, resulting in a more compact overall structure for the multi-beam RFQ accelerator.

[0042] refer to Figure 5 This application also provides an ion implantation method that can simultaneously accelerate ions with different charge-to-mass ratios. This method is applied to the ion implantation apparatus described in the above-mentioned embodiments, combined with... Figure 1 The ion implantation device includes a laser ion source chamber 100, a multi-beam RFQ accelerator 200, and a terminal target chamber 300. The laser ion source chamber 100 can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator 200 includes at least two acceleration channels 201, and the plasmas accelerated by the at least two acceleration channels 201 have different charge-to-mass ratios. Each acceleration channel 201 has an on / off mechanism 207 at its inlet end to open or close the acceleration channel 201. The outlet end of each acceleration channel 201 is connected to the terminal target chamber 300. Plasmas with different charge-to-mass ratios are sequentially accelerated in the corresponding acceleration channels 201 and then injected into the terminal target chamber 300. The laser ion source chamber 100 includes a laser emitter 101.

[0043] Combination Figure 1 and Figure 5 As shown, based on the structure of the ion implantation device described above, the ion implantation process in this embodiment involves at least two implantations. The charge-to-mass ratio of the plasma in the two implantations can be the same or different, and can be flexibly set according to process requirements. This embodiment mainly illustrates application scenarios where the charge-to-mass ratio of the ion implantation plasma is different. The ion implantation method includes:

[0044] Step S100, first layer ion implantation: control the laser emitter 101 to emit a laser beam with a first preset energy, and open the acceleration channel 201 corresponding to the laser beam with the first preset energy to realize the first layer ion implantation terminal target chamber 300; after the first layer ion implantation is completed, close the acceleration channel 201 and the laser emitter 101.

[0045] The laser emitter 101 used in this embodiment is an Nd:YAG laser, which can generate high-density laser light with a wavelength of 1064 nm and a pulse width of 8–10 ns. By directly exciting the target surface 103, it generates ions (i.e., plasma) in different charge states, with an energy of approximately 2 J. The estimated laser power density after focusing by the target surface 103 is approximately 10 J. 12 W / cm 2 The plasma generated by the laser diffuses in an electrically neutral state and enters the plasma drift channel of the laser ion chamber. Here, it is extracted and injected into a multi-beam RFQ accelerator that can accelerate particles with different charge-to-mass ratios for focused acceleration. Since the particles are in an electrically neutral plasma state before entering the RFQ, beam loss caused by space charge effect can be effectively reduced. After acceleration by the multi-beam RFQ accelerator, the ions enter the terminal target chamber 300 and are injected into the target material.

[0046] It should be noted that the control operations in this embodiment can be performed via a terminal computer. The terminal computer controls the Nd:YAG laser to generate laser light. Different laser energies can produce ions with different valence states, corresponding to ions with different charge-to-mass ratios. The higher the laser energy generated by the Nd:YAG laser, the higher the proportion of high-valence ions produced when the laser bombards the ion source target 103. The number of ion implantations and the charge-to-mass ratio can be adjusted according to actual needs. In step S100 of this embodiment, the valence state of the implanted ions can be P. + The laser is automatically controlled via a terminal computer to generate laser light of appropriate energy. The laser bombards the target surface 103, producing a high proportion of P-ions. + After that, P ions + The ions are accelerated through one of the acceleration channels 201 in the multi-beam RFQ accelerator 200 (assuming it is the first acceleration channel; note that this acceleration channel 201 can only accelerate ions with this charge-to-mass ratio), while the other acceleration channels 201 are closed and no acceleration occurs through other channels. + Accelerated focusing is achieved through the first acceleration channel. After reaching the corresponding ion implantation depth, the terminal computer shuts down the Nd:YAG laser and the entrance of the first acceleration channel, stopping ion supply and implantation. At this point, the first layer of ion implantation is complete.

[0047] Step S200, second-layer ion implantation: control the laser emitter 101 to emit a laser beam with a second preset energy, and open the acceleration channel 201 corresponding to the laser beam with the second preset energy to realize the second-layer ion implantation terminal target chamber 300; after the second-layer ion implantation is completed, close the acceleration channel 201 and the laser emitter 101.

[0048] A laser with fixed energy is generated by a terminal computer controlling a laser to bombard the target surface 103, producing ions with the desired valence state, such as P ions implanted in the second layer. 2+ At this time, the laser bombardment of the target surface 103 produces a high proportion of P 2+ The ions are then guided through an acceleration channel 201 (let's assume it's the second acceleration channel; note that this channel can only accelerate ions with this charge-to-mass ratio) in a multi-beam RFQ accelerator 200. At this time, the other channels are closed, and acceleration is not performed through them. Acceleration and focusing are achieved through the second acceleration channel. Once the corresponding ion implantation depth is reached, the control terminal computer shuts down the Nd:YAG laser and the entrance of the second acceleration channel, stopping ion supply and implantation. At this point, the second layer of ion implantation is complete.

[0049] This application's embodiments can achieve ion implantation with different charge-to-mass ratios for two or more layers but less than four layers. If three or four layers are involved in ion implantation, such as the implantation of ion P... 3+ P 4+ Then, the following step S300 can be performed, which is the operation of step S100 or step S200.

[0050] Step S300, Nth layer ion implantation: control the laser emitter 101 to emit a laser beam with the Nth preset energy, and open the acceleration channel 201 corresponding to the laser beam with the Nth preset energy to realize the Nth layer ion implantation terminal target chamber 300; after the Nth layer ion implantation is completed, close the acceleration channel 201 and the laser emitter 101.

[0051] The implementation of step S300 can refer to the above steps S100 or S200. The multi-beam RFQ accelerator 200 of this application embodiment is provided with four acceleration channels 201, which can be labeled as the first acceleration channel, the second acceleration channel, the third acceleration channel and the fourth acceleration channel. Each acceleration channel 201 can only accelerate plasma with a specific charge-to-mass ratio. The charge-to-mass ratio of the plasma accelerated by each acceleration channel 201 is different. The number of layers or ion implantations required on the target is determined by the predefined process requirements, which will not be elaborated here.

[0052] Because the interaction between the laser and the target surface 103 involves processes such as photoelectric effect, light absorption, and ionization, defects in the target surface 103 can also lead to differences in charge states during these processes. Combined with... Figure 1The laser ion source chamber 100 also includes a laser emitter 101, a focusing lens 102, and a movable target surface 103. The focusing lens 102 is disposed between the laser emitter 101 and the target surface 103 to focus the laser beam onto the target surface 103. The target surface 103 can move relative to the focusing lens 102 to obtain plasma with the desired charge-to-mass ratio using the new target surface 103 position. In other words, in this embodiment, the target surface 103 can be moved before each ion implantation to obtain ions with new valence states using the new target surface 103, thereby reducing the difference in charge states of the obtained ions. Specifically, before the first ion implantation step, the second ion implantation step, and / or the Nth ion implantation step, the process further includes: controlling the target surface 103 of the laser ion source to move to a preset position to obtain plasma with the required charge-to-mass ratio for the second ion implantation using the new target surface 103 position. This preset position is determined based on movement trajectory rules pre-entered into the terminal computer. It should be noted that the target material in the terminal target chamber 300 is also movable. Therefore, while moving the target surface 103 of the laser ion source chamber 100, the target material in the terminal target chamber 300 can be moved to the position for the next injection to facilitate the next ion implantation. The movement trajectory of the target material is also predetermined.

[0053] After ion implantation of the target, the ion implantation depth of the material needs to be detected in real time. In this embodiment, an online uniformity detection and real-time correction control system can also be used. Therefore, the first layer ion implantation step, the second layer ion implantation step, and / or the Nth layer ion implantation step further include: online uniformity detection and real-time correction of the ion implantation depth and uniformity, so that ion implantation is considered complete after the corresponding ion implantation depth is reached. Thus, the ion implantation depth and uniformity can be monitored and adjusted in real time during the implantation process, ensuring the accuracy and uniformity of the implantation dose, accurately completing the implantation according to the angle and depth required by the process, and determining that ion implantation is complete after the corresponding ion implantation depth is reached, thereby controlling the terminal equipment to shut down the Nd:YAG laser and the inlet end of the corresponding acceleration channel 201, stopping ion supply and implantation.

[0054] The beam needs to be transported in a vacuum environment to avoid scattering losses due to collisions between the required ions and air molecules, such as... Figure 1 As shown, this embodiment of the application includes a vacuum pump 211. Before the first layer ion implantation step, the second layer ion implantation step, and / or the Nth layer ion implantation step, the following is also included:

[0055] Vacuum treatment: Control the vacuum level of the laser ion source chamber 100 at 10. -3 ~10 -4 Within the Pa range, the vacuum level of the multi-beam RFQ accelerator 200 is controlled at 10. -6 Within Pa, the vacuum level of the terminal target chamber 300 is controlled at 5 × 10⁻⁶. -5Pa inside.

[0056] That is, before ion implantation, a vacuum process is required by vacuum pump 211. In combination with the ion implantation structure of this application embodiment, preferably, the laser ion source chamber 100, the multi-beam RFQ accelerator 200 and the terminal target chamber 300 need to reach the above parameter range. At the same time, the multi-beam RFQ accelerator 200 needs to be cooled by the cooling water circuit 210. Note that when cooling water is circulated, it is necessary to pay attention to whether each channel is completely unobstructed and to detect the flow rate of the water circuit to see if it meets the water flow rate requirements. This is to avoid the cavity deformation and cavity detuning caused by the large amount of heat generated in the pipeline during the acceleration of the beam.

[0057] At the same time, attention should be paid to treatments such as low-temperature treatment and annealing, for example:

[0058] Cryogenic treatment: In ion implantation, an accelerated ion beam is irradiated onto a solid material to form a surface layer (implanted layer) with special properties. This process is usually carried out at low temperatures to reduce the generation of lattice defects.

[0059] Annealing: Since some lattice defects may be generated in the semiconductor during ion implantation, these defects need to be eliminated by low-temperature annealing or laser annealing to ensure the integrity and performance of the material.

[0060] Through the above steps S100 to S300, the ion implantation method based on the multi-beam RFQ accelerator can effectively achieve deep and shallow doping, meeting the requirements of high precision and high performance.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions created by the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions created by the present invention without departing from the essence and scope of the technical solutions created by the present invention.

Claims

1. An ion implantation device capable of simultaneously accelerating ions with different charge-to-mass ratios, characterized in that, It includes a laser ion source chamber, a multi-beam RFQ accelerator, and a terminal target chamber. The laser ion source chamber can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator includes at least two acceleration channels. The plasmas accelerated by the at least two acceleration channels have different charge-to-mass ratios. Each acceleration channel has an on / off mechanism at its inlet end to open or close the acceleration channel. The outlet end of each acceleration channel is connected to the terminal target chamber. Plasmas with different charge-to-mass ratios are accelerated sequentially in the corresponding acceleration channels and then injected into the terminal target chamber. Each acceleration channel has a beam input pipe at its inlet and a beam output pipe at its outlet. The beam input pipe is connected to the laser ion source chamber, and a switching mechanism is provided on the beam input pipe to open the corresponding acceleration channel when plasma with a preset charge-to-mass ratio is generated in the laser ion source chamber. The beam output pipe is connected to the terminal target chamber. The axes of the beam input pipe, acceleration channel, and beam output pipe are on the same straight line to ensure that the plasma is collimated and injected into the terminal target chamber. The multi-beam RFQ accelerator includes an acceleration chamber, multiple stem-ring electrodes, and multiple rod electrode groups. Each rod electrode group has four rod electrodes, which are arranged to form an acceleration channel. The multiple stem-ring electrodes are distributed at equal intervals along the acceleration channel, and each stem-ring electrode is connected to the acceleration chamber. Multiple openings are symmetrically provided inside the stem-ring electrodes, and each opening allows a rod electrode group to pass through. Each rod electrode group is connected to the stem-ring electrode.

2. The ion implantation apparatus according to claim 1, characterized in that, It also includes a vacuum pump and a cooling water circuit. The cooling water circuit is installed on the surface of the multi-beam RFQ accelerator for heat dissipation. The vacuum pump is connected to the laser ion source chamber, the multi-beam RFQ accelerator, and the terminal target chamber. The vacuum level of the laser ion source chamber is controlled at... Within a certain range, the vacuum level of the multi-beam RFQ accelerator is controlled at... Inside, the vacuum level of the terminal target chamber is controlled at... Inside.

3. The ion implantation apparatus according to claim 1, characterized in that, The laser ion source chamber also includes a laser emitter, a focusing lens, and a movable target surface. The focusing lens is located between the laser emitter and the target surface to focus the laser beam onto the target surface. The target surface can be moved relative to the focusing lens so that the desired charge-to-mass ratio plasma can be obtained using the new target surface position.

4. The ion implantation apparatus according to claim 1, characterized in that, The terminal target chamber includes a movable sample target that can be moved within the terminal target chamber to change the location of ion implantation.

5. The ion implantation apparatus according to claim 1, characterized in that, The acceleration chamber is equipped with multiple sets of tuner assemblies that are evenly spaced. Each set of tuner assemblies has two couplers, which are symmetrically arranged on both sides of the acceleration chamber.

6. An ion implantation method capable of simultaneously accelerating ions with different charge-to-mass ratios, characterized in that, The method is applied to the ion implantation device as described in any one of claims 1-5. The ion implantation device includes a laser ion source chamber, a multi-beam RFQ accelerator, and a terminal target chamber. The laser ion source chamber can sequentially generate plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator includes at least two acceleration channels. The plasmas accelerated by the at least two acceleration channels have different charge-to-mass ratios. Each acceleration channel has an on / off mechanism at its inlet end to open or close the acceleration channel. The outlet end of each acceleration channel is connected to the terminal target chamber. Plasmas with different charge-to-mass ratios are sequentially accelerated in the corresponding acceleration channels and then injected into the terminal target chamber. The laser ion source chamber includes a laser emitter. The ion implantation method includes: First-layer ion implantation: The laser emitter is controlled to emit a laser beam of a first preset energy, and the acceleration channel corresponding to the first preset energy laser beam is opened to realize the first-layer ion implantation terminal target chamber; after the first-layer ion implantation is completed, the acceleration channel and the laser emitter are closed. Second-layer ion implantation: The laser emitter is controlled to emit a laser beam with a second preset energy, and the acceleration channel corresponding to the laser beam with the second preset energy is opened to realize the second-layer ion implantation terminal target chamber; after the second-layer ion implantation is completed, the acceleration channel and the laser emitter are closed. Nth layer ion implantation: Control the laser emitter to emit a laser beam with the Nth preset energy, and open the acceleration channel corresponding to the laser beam with the Nth preset energy to realize the Nth layer ion implantation terminal target chamber; after the Nth layer ion implantation is completed, close the acceleration channel and the laser emitter. The laser ion source chamber also includes a laser emitter, a focusing lens, and a movable target surface. The focusing lens is located between the laser emitter and the target surface to focus the laser beam onto the target surface. The target surface can move relative to the focusing lens so that the plasma with the required charge-to-mass ratio can be obtained by utilizing the new target surface position. Before the first ion implantation step, the second ion implantation step and / or the Nth ion implantation step, the method further includes: controlling the target surface of the laser ion source to move to a preset position so as to obtain the plasma with the charge-to-mass ratio required for the second ion implantation using the new target surface position. The first-layer ion implantation step, the second-layer ion implantation step, and / or the Nth-layer ion implantation step also include: Online uniformity detection and real-time correction of ion implantation depth and uniformity, so as to determine that ion implantation is complete after the corresponding ion implantation depth is reached; Before the first ion implantation step, the second ion implantation step, and / or the Nth ion implantation step, the procedure also includes: Vacuum treatment: Controlling the vacuum level in the laser ion source chamber to maintain a certain level. Within a certain range, the vacuum level of the multi-beam RFQ accelerator is controlled at... Inside, the vacuum level of the terminal target chamber is controlled at... Inside.

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