Ion implantation device and method capable of simultaneously accelerating ions with different charge-to-mass ratios

Abstract

The invention relates to the technical field of synchronous accelerators, in particular to an ion implantation device and method capable of simultaneously accelerating ions with different charge-to-mass ratios, 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 sequentially generate plasmas with different charge-to-mass ratios, and the multi-beam RFQ accelerator can sequentially generate the plasmas with different charge-to-mass ratios. The multi-beam RFQ accelerator comprises at least two acceleration pore channels, the charge-to-mass ratios of plasmas accelerated by the at least two acceleration pore channels are different, the inlet end of each acceleration pore channel is provided with an on-off mechanism to open or close the acceleration pore channel, and the outlet end of each acceleration pore channel is communicated with the terminal target chamber. The plasmas with different charge-to-mass ratios are injected into the terminal target chamber after being accelerated in the corresponding accelerating hole channels in sequence; the ion implantation method comprises the steps of first-layer ion implantation, second-layer ion implantation and Nth-layer ion implantation, according to the ion implantation device and the ion implantation method, acceleration and transmission of beams with different charge-to-mass ratios can be realized, and plasmas with different charge-to-mass ratios are doped on a target material in a deep and shallow manner.

Description

Technical Field

[0001] The present application relates to the technical field of synchrotron accelerators, and in particular to an ion implantation device and method capable of simultaneously accelerating ions of different charge-to-mass ratios. Background Art

[0002] The principle of ion implantation is to ionize the atoms of a certain element and accelerate them in an electric field. After obtaining a high speed, they are injected into the surface of a solid material to change the physical or chemical properties of the surface of the material. An ion implantation device is a device that implants ions (usually hydrogen ions or heavy ions) into semiconductor materials or other materials to change their electrical properties or other characteristics. It is widely used in the semiconductor industry to manufacture integrated circuits and other microelectronic devices. The purpose of ion implantation is usually to form a desired doping layer on the surface of a material or to change the properties of the material. However, existing ion implantation devices have limitations in transmitting beams of different charge-to-mass ratios and cannot effectively achieve the acceleration and transmission of beams of different charge-to-mass ratios. Summary of the invention

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

[0004] In a first aspect, the present application provides an ion implantation device that can simultaneously accelerate ions of different charge-to-mass ratios, comprising a laser ion source chamber, a multi-beam RFQ accelerator and a terminal target chamber, wherein the laser ion source chamber can sequentially generate plasmas of different charge-to-mass ratios, the multi-beam RFQ accelerator comprises at least two accelerating channels, the charge-to-mass ratios of the plasmas accelerated by the at least two accelerating channels are different, an on-off mechanism is provided at the inlet end of each accelerating channel to open or close the accelerating channel, and an outlet end of each accelerating channel is connected to the terminal target chamber, and plasmas of different charge-to-mass ratios are injected into the terminal target chamber after being accelerated in the corresponding accelerating channels in sequence.

[0005] As a further technical solution of the present application, the inlet end of each accelerating channel is respectively provided with a beam input pipe, and the outlet end of each accelerating channel is respectively provided with a beam output pipe, the beam input pipe is connected with the laser ion source chamber, and the on-off mechanism is arranged on the beam input pipe to open the corresponding accelerating channel when the laser ion source chamber generates a plasma with a preset charge-to-mass ratio, the beam output pipe is connected with the terminal target chamber, and the axes of the beam input pipe, the accelerating channel and the beam output pipe are located on the same straight line to allow the plasma to be injected into the terminal target chamber in a collimated manner.

[0006] As a further technical solution of the present application, the ion implantation device further includes a vacuum pump and a cooling water circuit. The cooling water circuit is arranged on the surface of the multi-beam RFQ accelerator to dissipate heat. The vacuum pump is respectively connected to the laser ion source chamber, the multi-beam RFQ accelerator and the terminal target chamber. The vacuum degree of the laser ion source chamber is controlled at 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator is controlled within 10 Pa. -6 Pa, the vacuum degree of the terminal target chamber is controlled at 5×10 -5 Pa inside.

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

[0008] As a further technical solution of the present application, the terminal target chamber includes a movable sample target material, and the sample target material can be moved in the terminal target chamber to change the position of the ion implantation effect.

[0009] As a further technical solution of the present application, a multi-beam RFQ accelerator includes an accelerating cavity, multiple stem-and-ring electrodes and multiple rod electrode groups, each rod electrode group is provided with four rod electrodes, and the four rod electrodes are arranged correspondingly to form an accelerating channel. The multiple stem-and-ring electrodes are distributed at equal intervals along the accelerating channel, and each stem-and-ring electrode is connected to the accelerating cavity. Multiple through openings are symmetrically opened in the stem-and-ring electrode, each through opening is corresponding to a rod electrode group passing through, and each rod electrode group is respectively connected to the stem-and-ring electrode.

[0010] As a further technical solution of the present application, the accelerating cavity is provided with a plurality of groups of tuner assemblies distributed at equal intervals, each group of tuner assemblies is provided with two couplers, and the two couplers are symmetrically arranged on both sides of the accelerating cavity.

[0011] In a second aspect, the present application provides an ion implantation method, which is applied to the ion implantation device of any one of the first aspects, wherein the ion implantation device comprises a laser ion source chamber, a multi-beam RFQ accelerator and a terminal target chamber, wherein the laser ion source chamber can sequentially generate plasmas with different mass-to-charge ratios, the multi-beam RFQ accelerator comprises at least two accelerating channels, the plasmas accelerated by the at least two accelerating channels have different mass-to-charge ratios, an on-off mechanism is provided at the inlet end of each accelerating channel to open or close the accelerating channel, and an outlet end of each accelerating channel is connected to the terminal target chamber, and the plasmas with different mass-to-charge ratios are sequentially accelerated in the corresponding accelerating channels and injected into the terminal target chamber, and the laser ion source chamber comprises a laser emitter;

[0012] The method comprises:

[0013] First layer ion implantation: controlling the laser emitter to emit a laser beam of a first preset energy, and opening an acceleration channel corresponding to the laser beam of the first preset energy, so as to implant the first layer ion into the terminal target chamber; after the first layer ion implantation is completed, closing the acceleration channel and the laser emitter;

[0014] Second layer ion implantation: controlling the laser emitter to emit a laser beam of a second preset energy, and opening an acceleration channel corresponding to the laser beam of the second preset energy, so as to implant the second layer ion into the terminal target chamber; after the second layer ion implantation is completed, closing the acceleration channel and the laser emitter;

[0015] Nth layer ion implantation: control the laser emitter to emit a laser beam of the Nth preset energy, and open the acceleration channel corresponding to the laser beam of the Nth preset energy to realize the Nth layer ion implantation into the 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 the present application, the laser ion source chamber also includes a laser emitter, a focusing lens and a movable target surface, wherein the focusing lens is disposed between the laser emitter and the target surface to focus the laser beam on the target surface, and the target surface can be moved relative to the focusing lens to obtain a plasma with a desired charge-to-mass ratio by utilizing a new target surface position;

[0017] Before the first layer ion implantation step, the second layer ion implantation step and / or the Nth layer 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 a plasma with a charge-to-mass ratio required for the second layer ion implantation by 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 further include:

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

[0020] As a further technical solution of the present application, before the first layer ion implantation step, the second layer ion implantation step and / or the Nth layer ion implantation step, the following steps may be further included:

[0021] Vacuum treatment: Control the vacuum degree of the laser ion source chamber to 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator is controlled within 10 Pa. -6 Pa, the vacuum degree of the terminal target chamber is controlled at 5×10 -5 Pa inside.

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

[0023] Compared with the prior art, the ion implantation device of the present application is designed with multiple acceleration channels, which are designed based on the RFQ acceleration principle. Each acceleration channel accelerates a plasma of a charge-to-mass ratio, and the charge-to-mass ratios of the plasmas accelerated by the multiple acceleration channels are different. An on-off mechanism is set at the inlet end of each acceleration channel to open and close the acceleration channel. The laser control device controls the laser emitter to work so as to generate a plasma of a charge-to-mass ratio in the laser ion source chamber, and the corresponding acceleration channel for accelerating the plasma of the charge-to-mass ratio is opened accordingly, and other acceleration channels are closed. After the plasma of the charge-to-mass ratio is accelerated through the acceleration channel, it is injected into the target material of the terminal target chamber. When the laser control device controls the laser emitter to generate the next plasma of the charge-to-mass ratio in the laser ion source chamber, the corresponding acceleration channel is opened accordingly, and the other acceleration channels are closed. Thus, multiple plasmas of different charge-to-mass ratios are sequentially injected into the target material of the terminal target chamber, thereby realizing deep and shallow doping of plasmas of different charge-to-mass ratios on the target material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of an ion implantation device according to an embodiment of the present application;

[0025] Figure 2 This is a schematic structural diagram of a multi-beam RFQ accelerator of an ion implantation device according to an embodiment of the present application;

[0026] Figure 3 A schematic longitudinal cross-sectional view of the multi-beam RFQ accelerator of the ion implantation device according to an embodiment of the present application;

[0027] Figure 4 A schematic diagram of a transverse cross-sectional structure of a multi-beam RFQ accelerator of an ion implantation device according to an embodiment of the present application;

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

[0029] Explanation of the reference numerals: laser ion source chamber 100, laser emitter 101, focusing lens 102, target surface 103, multi-beam RFQ accelerator 200, accelerating channel 201, accelerating cavity 202, stem-ring electrode 203, rod electrode group 204, rod electrode 205, coupler 206, on-off mechanism 207, beam input pipe 208, beam output pipe 209, cooling water loop 210, vacuum pump 211, terminal target chamber 300, sample target material 301. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0031] In the absence of conflict, the embodiments of the present application and the features in the embodiments 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 used to limit the order or interdependence of the functions performed by these devices, modules or units. The modifications of "one" and "multiple" mentioned in this application are schematic and non-restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more". The multi-beam RFQ accelerator mentioned in this application is a radio frequency quadrupole accelerator (Radio Frequency Quadrupole).

[0032] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0033] refer to Figure 1 The embodiment of the present application provides an ion implantation device that can simultaneously accelerate ions of 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 of different charge-to-mass ratios. The multi-beam RFQ accelerator 200 includes at least two accelerating channels 201. The plasmas accelerated by the at least two accelerating channels 201 have different charge-to-mass ratios. An on-off mechanism 207 is provided at the inlet end of each accelerating channel 201 to open or close the accelerating channel 201. The outlet end of each accelerating channel 201 is connected to the terminal target chamber 300. Plasmas of different charge-to-mass ratios are injected into the terminal target chamber 300 after being accelerated in the corresponding accelerating channel 201 in sequence.

[0034] Compared with the prior art, the ion implantation device of the present application is designed with a plurality of accelerating channels 201, which are designed based on the RFQ acceleration principle. Each accelerating channel 201 accelerates a plasma with a charge-to-mass ratio. The charge-to-mass ratios of the plasmas accelerated by the plurality of accelerating channels 201 are different. An on-off mechanism 207 is provided at the inlet end of each accelerating channel 201 to open and close the accelerating channel 201. The laser control device controls the laser emitter 101 to work so as to generate a plasma with a charge-to-mass ratio in the laser ion source chamber 100, and the corresponding acceleration of the plasma with the charge-to-mass ratio is The acceleration channel 201 is opened accordingly, and other acceleration channels 201 are closed. After the plasma of this charge-to-mass ratio is accelerated through the acceleration channel 201, it is injected into the target material of the terminal target chamber 300. When the laser control device controls the laser emitter 101 to generate the plasma of the next charge-to-mass ratio in the laser ion source chamber 100, the corresponding acceleration channel 201 is opened accordingly, and other acceleration channels 201 are closed. Thus, plasmas of multiple 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 plasmas of different charge-to-mass ratios on the sample target material 301. It can be understood that the on-off mechanism 207 of the embodiment of the present application can be physically opening or closing the acceleration channel, or it can be connected or disconnected from the circuit to make the acceleration channel energized or not energized, so that when it is necessary to accelerate a plasma of a certain charge-to-mass ratio, the corresponding acceleration channel can work, and other acceleration channels do not work.

[0035] refer to Figure 1 and Figure 2 In the embodiment of the present application, the inlet end of each accelerating channel 201 is respectively provided with a beam input pipe 208, and the outlet end of each accelerating channel 201 is respectively provided with a beam output pipe 209, the beam input pipe 208 is connected with the laser ion source chamber 100, and the on-off mechanism 207 is arranged on the beam input pipe 208 to open the corresponding accelerating channel 201 when the laser ion source chamber 100 generates a plasma with a preset charge-to-mass ratio, the beam output pipe 209 is connected with the terminal target chamber 300, and 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 to allow the plasma to be injected into the terminal target chamber 300 in a collimated manner.

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

[0037] like Figure 1 , Figure 3 and Figure 4 The ion implantation device of the embodiment of the present application further includes a vacuum pump 211 and a cooling water loop 210. The cooling water loop 210 is arranged on the surface of the multi-beam RFQ accelerator 200 to dissipate heat. The vacuum pump 211 is respectively connected to the laser ion source chamber 100, the multi-beam RFQ accelerator 200 and the terminal target chamber 300. The vacuum degree of the laser ion source chamber 100 is controlled at 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator 200 is controlled within 10 -6 Pa, the vacuum degree of the terminal target chamber 300 is controlled at 5×10 -5 Pa. In this way, the entire system is kept in a vacuum state during the operation of the ion implantation device to prevent the ion beam from colliding with the air and causing beam loss and ion neutralization, so that the ion implantation can achieve the best uniformity; the cooling water loop 210 can prevent the multi-beam RFQ accelerator 200 from generating a large amount of heat when accelerating the beam, causing cavity deformation and cavity detuning. In the embodiment of the present application, before ion implantation, a vacuum pump 211 is required to perform a vacuum treatment, in which the vacuum degree of the ion source needs to be controlled to reach 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator 200 should reach 10 -6 Pa. The vacuum degree of the terminal target chamber 300 should be better than 5×10 -5 Pa. At the same time, the cooling water circuit 210 of the multi-beam RFQ accelerator also needs to be treated with cooling water. When passing the cooling water, attention should be paid to whether each channel is fully circulated, and the flow rate of the water channel should be tested to see whether it meets the water flow rate requirements.

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

[0039] It is further explained that the interaction between the laser and the target surface 103 includes processes such as the photoelectric effect, light absorption, and ionization. In these processes, defects in the target surface 103 of the target material will lead to differences in charge states. The laser is focused on a certain position on the target surface 103. The positions of the target surface 103 for obtaining plasma twice may be different. Alternatively, to obtain plasmas with different charge-to-mass ratios, different positions of the target surface 103 may be used so 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, and the sample target 301 can be moved in the terminal target chamber 300 to change the position of the ion implantation. The terminal target chamber 300 can be provided with a target seat and a sample processing device, etc. The target seat is a platform supporting the sample target 301, which can be made of high-purity metal or ceramic material, and has stability and high temperature resistance. The sample processing device is used to operate the sample target 301, which can include rotation or tilting, and the sample target 301 is moved to a new position as needed, which is conducive to adjusting the uniformity of ion implantation. The movable implementation structure can adopt a conventional structure, which will not be repeated here.

[0041] refer to Figure 2 , Figure 3 and Figure 4 The multi-beam RFQ accelerator 200 of the embodiment of the present application includes an accelerating cavity 202, a plurality of stem-ring electrodes 203 and a plurality of rod electrode groups 204, each of which is provided with four rod electrodes 205, and the four rod electrodes 205 are arranged correspondingly to form an accelerating channel 201, such as Figure 4 As shown, the rod electrode groups of the embodiment of the present application are provided with 4 groups, each group of rod electrode groups forms an accelerating channel 201, and thus there are 4 accelerating channels 201. Figure 3, multiple stem-ring electrodes 203 are distributed at equal intervals along the accelerating channel 201, and each stem-ring electrode 203 is connected to the accelerating cavity 202. Multiple openings are symmetrically opened in the stem-ring electrode 203, and each opening is correspondingly provided for a rod electrode group 204 to pass through, and each rod electrode group 204 is connected to the stem-ring electrode 203. The accelerating cavity 202 is provided with multiple groups of tuner components distributed at equal intervals, and each group of tuner components is provided with two couplers 206, and the two couplers 206 are symmetrically arranged on both sides of the accelerating cavity 202. In this way, the multi-beam RFQ accelerator 200 uses symmetrically placed rod electrodes 205, and applies alternating voltages of equal magnitude and opposite direction to the relative electrodes and the adjacent electrodes, respectively, to form an accelerating channel 201 for accelerating ion beams. Multiple accelerating channels 201 are evenly distributed in the stem-ring electrode 203, and the symmetrical structure reduces cavity detuning. The cooling water circuit 210 can be arranged on the surface of the accelerating cavity 202, and the overall structure of the multi-beam RFQ accelerator is more compact.

[0042] refer to Figure 5 The present application also provides an ion implantation method for simultaneously accelerating ions of different charge-to-mass ratios, the method being applied in the ion implantation device of the above-mentioned application embodiment, 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 mass-to-charge ratios. The multi-beam RFQ accelerator 200 includes at least two accelerating channels 201. The plasmas accelerated by the at least two accelerating channels 201 have different mass-to-charge ratios. An on-off mechanism 207 is provided at the inlet end of each accelerating channel 201 to open or close the accelerating channel 201. The outlet end of each accelerating channel 201 is connected to the terminal target chamber 300. Plasmas with different mass-to-charge ratios are injected into the terminal target chamber 300 after being accelerated in the corresponding accelerating channels 201 in sequence. 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 above-mentioned ion implantation device, the number of ion implantations in the embodiment of the present application is at least two, and the charge-to-mass ratio of the plasma of the two ion implantations can be the same or different, and can be flexibly set according to the process requirements. The embodiment of the present application mainly illustrates the use scenarios of different charge-to-mass ratios of the plasma of ion implantation, and the ion implantation method includes:

[0044] Step S100, first layer ion implantation: control the laser emitter 101 to emit a laser beam of a first preset energy, and open the acceleration channel 201 corresponding to the laser beam of the first preset energy to implement the first layer ion implantation in the 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 the embodiment of the present application is a Nd:YAG laser, which can generate high-density laser light with a wavelength of 1064nm and a pulse width of 8-10ns. By directly exciting the target surface 103, ions (i.e., plasma) of different charge states are generated, and the energy thereof reaches about 2J. The estimated laser power density after focusing on the target surface 103 is about 10 12 W / cm 2 The plasma generated by the laser diffuses in an electrically neutral state and enters the plasma drift duct of the laser ion chamber, where it is drawn out and injected into a multi-beam RFQ accelerator that can accelerate particles of different charge-to-mass ratios for focused acceleration. Since the particles are in an electrically neutral plasma state before entering the RFQ, the beam loss caused by the space charge effect can be effectively reduced. After being accelerated 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 operation of the embodiment of the present application can be completed via a terminal computer, and the terminal computer controls the Nd:YAG laser to generate laser light. Lasers of different energies can generate ions of different valence states, corresponding to ions of different charge-to-mass ratios. The higher the laser energy generated by the Nd:YAG laser, the higher the proportion of high-valence ions generated when the laser bombards the ion source target surface 103. The number of ion injections and the charge-to-mass ratio can be operated according to actual needs. In step S100 of the embodiment of the present application, the ion valence state of the ion injection can be P + The terminal computer realizes automatic control of the laser to generate laser with appropriate energy, and the laser bombards the target surface 103 to generate high proportion of ions P + , then ion P + Through an accelerating channel 201 in the multi-beam RFQ accelerator 200 (assuming it is the first accelerating channel, note that this accelerating channel 201 can only accelerate ions of this charge-to-mass ratio), at this time, the other accelerating channels 201 are in a closed state and are not accelerated through other channels. + The first accelerating channel is used for acceleration and focusing. After the corresponding ion implantation depth is reached, the terminal computer turns off the Nd:YAG laser and the entrance of the first accelerating channel, stops ion supply and implantation. At this time, the first layer of ion implantation is completed.

[0047] Step S200, second layer ion implantation: control the laser emitter 101 to emit a laser beam of a second preset energy, and open the acceleration channel 201 corresponding to the laser beam of the second preset energy to implement 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] The laser is controlled by the terminal computer to generate a fixed energy laser, which bombards the target surface 103 to produce ions of the required valence state. For example, the ions implanted in the second layer are assumed to be P 2+ At this time, the laser bombards the target surface 103 to produce a high ratio P 2+ , and then it is transmitted to an acceleration channel 201 in the multi-beam RFQ accelerator 200 (assuming it is the second acceleration channel, note that this channel can only accelerate ions of this charge-to-mass ratio). At this time, other channels are in a closed state and are not accelerated through other channels. Acceleration and focusing are performed through the second acceleration channel. After reaching the corresponding ion injection depth, the control terminal computer turns off the Nd:YAG laser and the entrance end of the second acceleration channel, and stops ion supply and injection. At this time, the second layer of ion injection is completed.

[0049] The embodiment of the present application can realize ion implantation of two or more layers but less than four layers with different charge-to-mass ratios. If ion implantation of three or four layers is involved, for example, ion P 3+ , P 4+ Then, the following step S300 may be executed, that is, the operation of step S100 or step S200.

[0050] Step S300, N-th layer ion implantation: control the laser emitter 101 to emit a laser beam of the N-th preset energy, and open the acceleration channel 201 corresponding to the laser beam of the N-th preset energy to implement the N-th layer ion implantation terminal target chamber 300; after the N-th 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-mentioned step S100 or step S200. The multi-beam RFQ accelerator 200 of the embodiment of the present application is provided with four accelerating channels 201, which can be marked as the first accelerating channel, the second accelerating channel, the third accelerating channel and the fourth accelerating channel. One accelerating channel 201 can only accelerate plasma with a specific charge-to-mass ratio. The charge-to-mass ratio of the plasma accelerated by each accelerating channel 201 is different. The number of layers or the number of times of ion implantation that need to be completed on the target material is determined by the pre-defined process requirements, which will not be repeated here.

[0052] Because the interaction between the laser and the target surface 103 includes processes such as photoelectric effect, light absorption, and ionization, defects in the target surface 103 of the target material in these processes may also lead to differences in charge states. Figure 1, the 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 on the target surface 103. The target surface 103 can be moved relative to the focusing lens 102 so that a plasma with a desired charge-to-mass ratio can be obtained using a new target surface 103 position. That is, in the embodiment of the present application, the target surface 103 can be moved before each ion injection, and ions with a new valence state can be obtained using a new target surface 103, so that the difference in the charge state of the obtained ions is reduced. Specifically, before the first layer ion injection step, the second layer ion injection step and / or the Nth layer ion injection step, it also includes: controlling the target surface 103 of the laser ion source to move to a preset position so as to obtain a plasma with a charge-to-mass ratio required for the second layer ion injection using a new target surface 103 position. The preset position is determined based on a movement trajectory rule pre-entered into the terminal computer. It should be noted that the target material in the terminal target chamber 300 can also be moved. 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 operated to move to the position of the next injection to facilitate the next ion injection. The moving trajectory of the target material is also predetermined.

[0053] After ion implantation of the target material, it is necessary to detect the ion implantation depth of the material in real time. The embodiment of the present application can also use an online uniformity detection and real-time correction control system. Therefore, 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 the depth and uniformity of ion implantation, so as to judge that the ion implantation is completed after reaching the corresponding ion implantation depth. Thus, the depth and uniformity of ion implantation can be monitored and adjusted in real time during the implantation process to ensure the accuracy and uniformity of the implantation dose, and the implantation is completed accurately according to the angle and depth required by the process. After reaching the corresponding ion implantation depth, it is judged that the ion implantation is completed, so as to control the terminal device to close the Nd:YAG laser and the corresponding entrance end of the acceleration channel 201, and stop the ion supply and implantation.

[0054] The beam needs to be transported in a vacuum environment to avoid scattering losses caused by collisions between the desired ions and air molecules, such as Figure 1 As shown, the embodiment of the present application is provided with 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, it also includes:

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

[0056] That is, before ion implantation, vacuum treatment needs to be performed by the vacuum pump 211. In combination with the ion implantation structure of the embodiment of the present application, preferably, the laser ion source chamber 100, the multi-beam RFQ accelerator 200 and the terminal target chamber 300 need to be within the above-mentioned parameter range. At the same time, the cooling water circuit 210 of the multi-beam RFQ accelerator 200 also needs to be subjected to cooling water treatment. When passing the cooling water, attention should be paid to whether each channel is fully circulated, and the flow rate of the water channel should be detected to see whether the water flow rate requirements are met, thereby avoiding cavity deformation and cavity detuning due to the large amount of heat generated by the pipeline when accelerating the beam.

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

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

[0059] Annealing treatment: Since some lattice defects may be generated in the semiconductor during the ion implantation process, these defects need to be eliminated through 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 solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An ion implantation device capable of simultaneously accelerating ions of different charge-to-mass ratios, characterized in that: The invention comprises 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 mass-charge ratios. The multi-beam RFQ accelerator comprises at least two accelerating channels. The plasmas accelerated by the at least two accelerating channels have different mass-charge ratios. An on-off mechanism is arranged at the inlet end of each accelerating channel to open or close the accelerating channel. The outlet end of each accelerating channel is connected to the terminal target chamber. The plasmas with different mass-charge ratios are sequentially accelerated in the corresponding accelerating channels and injected into the terminal target chamber.

2. The ion implantation device according to claim 1, characterized in that: The inlet end of each accelerating channel is respectively provided with a beam input pipe, and the outlet end of each accelerating channel is respectively provided with a beam output pipe, the beam input pipe is connected with the laser ion source chamber, and the on-off mechanism is arranged on the beam input pipe to open the corresponding accelerating channel when the laser ion source chamber generates plasma with a preset charge-to-mass ratio, the beam output pipe is connected with the terminal target chamber, and the axes of the beam input pipe, the accelerating channel and the beam output pipe are located on the same straight line, so that the plasma can be injected into the terminal target chamber in a collimated manner.

3. The ion implantation device according to claim 1, characterized in that: The accelerator also includes a vacuum pump and a cooling water circuit. The cooling water circuit is arranged on the surface of the multi-beam RFQ accelerator to dissipate heat. The vacuum pump is connected to the laser ion source chamber, the multi-beam RFQ accelerator and the terminal target chamber respectively. The vacuum degree of the laser ion source chamber is controlled at 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator is controlled within 10 Pa. -6 Pa, the vacuum degree of the terminal target chamber is controlled at 5×10 -5 Pa inside.

4. The ion implantation device 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 arranged between the laser emitter and the target surface to focus the laser beam on the target surface. The target surface can move relative to the focusing lens so that a plasma with a desired charge-to-mass ratio can be obtained using a new target surface position.

5. The ion implantation device according to claim 1, characterized in that: The terminal target chamber includes a movable sample target material, and the sample target material can be moved in the terminal target chamber to change the position of the ion implantation effect.

6. The ion implantation device according to claim 1, characterized in that: The multi-beam RFQ accelerator includes an accelerating cavity, a plurality of stem-and-ring electrodes and a plurality of rod electrode groups. Each rod electrode group is provided with four rod electrodes. The four rod electrodes are arranged correspondingly to form an accelerating channel. The plurality of stem-and-ring electrodes are distributed at equal intervals along the accelerating channel, and each stem-and-ring electrode is connected to the accelerating cavity. A plurality of through openings are symmetrically opened in the stem-and-ring electrode, and each through opening is correspondingly provided for a rod electrode group to pass through, and each rod electrode group is connected to the stem-and-ring electrode.

7. The ion implantation device according to claim 6, characterized in that: The accelerating cavity is provided with a plurality of groups of tuner components which are equally spaced, each group of tuner components is provided with two couplers, and the two couplers are symmetrically arranged on both sides of the accelerating cavity.

8. An ion implantation method capable of simultaneously accelerating ions of different charge-to-mass ratios, characterized in that: The method is applied to the ion implantation device according to any one of claims 1 to 7, 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 sequentially generate plasmas with different mass-to-charge ratios, the multi-beam RFQ accelerator comprises at least two accelerating channels, the plasmas accelerated by the at least two accelerating channels have different mass-to-charge ratios, an on-off mechanism is provided at the inlet end of each accelerating channel to open or close the accelerating channel, the outlet end of each accelerating channel is connected to the terminal target chamber, and the plasmas with different mass-to-charge ratios are sequentially accelerated in the corresponding accelerating channels and injected into the terminal target chamber, and the laser ion source chamber comprises a laser emitter; The ion implantation method comprises: First layer ion implantation: controlling the laser emitter to emit a laser beam of a first preset energy, and opening an acceleration channel corresponding to the laser beam of the first preset energy, so as to implant the first layer ion into the terminal target chamber; after the first layer ion implantation is completed, closing the acceleration channel and the laser emitter; Second layer ion implantation: controlling the laser emitter to emit a laser beam of a second preset energy, and opening an acceleration channel corresponding to the laser beam of the second preset energy, so as to implant the second layer ion into the terminal target chamber; after the second layer ion implantation is completed, closing the acceleration channel and the laser emitter; Nth layer ion implantation: control the laser emitter to emit a laser beam of the Nth preset energy, and open the acceleration channel corresponding to the laser beam of the Nth preset energy to realize the Nth layer ion implantation into the terminal target chamber; after the Nth layer ion implantation is completed, close the acceleration channel and the laser emitter.

9. The ion implantation method according to claim 8, 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 arranged between the laser emitter and the target surface to focus the laser beam on the target surface. The target surface can move relative to the focusing lens so that a plasma with a desired charge-to-mass ratio can be obtained by using a new target surface position. Before the first layer ion implantation step, the second layer ion implantation step and / or the Nth layer 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 a plasma with a charge-to-mass ratio required for the second layer ion implantation by 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 further include: Online uniformity detection and real-time correction of the depth and uniformity of ion implantation are performed to determine that the ion implantation is complete after the corresponding ion implantation depth is reached.

10. The ion implantation method according to claim 8, characterized in that: Before the first layer ion implantation step, the second layer ion implantation step and / or the Nth layer ion implantation step, the method further comprises: Vacuum treatment: Control the vacuum degree of the laser ion source chamber to 10 -3 ~10 -4 The vacuum degree of the multi-beam RFQ accelerator is controlled within 10 Pa. -6 Pa, the vacuum degree of the terminal target chamber is controlled at 5×10 -5 Pa inside.

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