Ion implantation system for simultaneously implanting multiple wafers

Abstract

The utility model discloses an ion implantation system capable of simultaneously implanting a plurality of wafers, which belongs to the technical field of semiconductor manufacturing, and comprises a loading cavity, a vacuum transmission cavity and a process cavity which are connected in sequence, and a scanning robot is arranged in the process cavity; the scanning robot comprises a scanning connecting seat, a scanning moving mechanism and a scanning overturning part which are connected in sequence; the scanning turnover part is rotatably connected to the scanning moving mechanism, more than two target discs are arranged on the scanning turnover part, and the more than two target discs are located on the same side of the rotating axis of the scanning turnover part. According to the utility model, a plurality of wafers can be fixedly held at the same time for scanning implantation, and time overlap exists in the process of taking and placing the wafers from different target discs and transmitting the wafers in a system, so that the total time of ion implantation is shortened on the whole; and the process result and the safe and reliable operation of equipment are not influenced, and the application value is extremely high.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of semiconductor manufacturing, and concretely relates to a kind of ion implantation system of multiple wafer simultaneous injection. BACKGROUND

[0002] Currently in ion implantation equipment, the end of common scanning robot only has a target disc, for holding a wafer in ion implantation process, and can reciprocate target disc relative to ion beam, realize scanning injection.This kind of ion implantation process scans injection to wafer one by one, is conducive to obtaining better process quality, but at the same time, it also faces the problem that output per unit time is difficult to further improve, and obviously, the improvement of output is crucial for the development of semiconductor industry and the competitiveness of production enterprise, therefore, a new type of ion implantation system capable of higher efficiency under the condition of ensuring process quality needs to be designed. SUMMARY

[0003] Based on the technical problems existing in the prior art, the utility model provides a kind of ion implantation system of multiple wafer simultaneous injection, solves the problem that existing single-chip microcomputer is difficult to further improve ion implantation process efficiency, by using the way of multiple wafer simultaneous injection, can significantly improve productivity, especially suitable for for example 150mm wafer.

[0004] According to the technical scheme of the utility model, the utility model provides a kind of ion implantation system of multiple wafer simultaneous injection, including the loading cavity, vacuum transmission cavity and process cavity that are connected in sequence, scanning robot is provided in process cavity;Scanning robot includes scanning connecting seat, scanning mobile mechanism and scanning turnover part that are connected in sequence;Scanning turnover part is rotatably connected on scanning mobile mechanism, and two or more target discs are arranged on scanning turnover part, and two or more target discs are located on the same side of the rotation axis of scanning turnover part.

[0005] Further, at least two transmission robots are provided in the vacuum transmission cavity.

[0006] Further, two transmission robots are provided in the vacuum transmission cavity;Transmission robot includes transmission connecting seat and transmission mechanical arm connected, and transmission mechanical arm end has supporting arm for supporting wafer, and transmission connecting seat is connected with vacuum transmission cavity;The positions of two transmission robots correspond to the two sides of scanning turnover part respectively.

[0007] Further, transmission mechanical arm includes transmission rear arm and transmission front arm rotatably connected, transmission rear arm is rotatably connected with transmission connecting seat, and the end of transmission front arm away from transmission rear arm is connected with supporting arm.

[0008] Further, each of the transfer robots comprises an upper mechanical arm and a lower mechanical arm which are rotatable and independently telescopic, the distal end of the upper mechanical arm away from the transfer connecting base has an upper supporting arm, the distal end of the lower mechanical arm away from the transfer connecting base has a lower supporting arm, the upper supporting arm is above the lower supporting arm, and the upper supporting arm and the lower supporting arm have a gap capable of accommodating at least one wafer.

[0009] According to some embodiments, the target discs are two adjacent ones, and the two target discs are arranged side by side along the moving direction of the scanning moving mechanism or along a direction perpendicular to the moving direction of the scanning moving mechanism.

[0010] According to yet some embodiments, the target discs are three adjacent ones, and the three target discs are distributed in a triangular shape.

[0011] According to still some embodiments, the target discs are four adjacent ones, and the four target discs are distributed in a quadrilateral shape.

[0012] Further, the four target discs are distributed in a rectangular shape, and the length direction of two sides of the rectangular shape is parallel to the moving direction of the scanning moving mechanism.

[0013] Further, the loading cavity accommodates one or more baffles.

[0014] Compared with the prior art, the beneficial technical effects of the present application are as follows:

[0015] In the ion implantation system for simultaneously implanting multiple wafers, the scanning robot has multiple target discs, and can simultaneously hold multiple wafers for scanning implantation; the processes of taking and placing wafers on different target discs and transferring wafers in the system can overlap in time, so that the total ion implantation time is shortened for a batch of multiple wafers; and the scanning process of ion implantation needs a certain over-scan to ensure the integrity of the whole implantation, so for the scheme of simultaneously scanning multiple wafers, only one over-scan distance is needed, thus the processing time of each wafer can be effectively shortened; and since the scanning distance is lengthened, the interval time of the beam current at each point on the wafer is also lengthened, so there is more self-repairing time and more cooling time, and thus the crystal lattice damage is lower and the wafer temperature is controlled lower; in addition, the present scheme can be transformed on the basis of the existing single-chip without changing the basic structure of the beam current system, is easy to implement, and will not affect the process results and the safe and reliable operation of the equipment, and has very high application value. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic view of an ion implantation system provided by the present application.

[0017] Figure 2It is a structure schematic view of a transmission robot in the embodiment provided by the utility model.

[0018] Figure 3 It is a structure schematic view of a scanning robot of the first embodiment provided by the utility model.

[0019] Figure 4 It is a structure schematic view of a scanning robot of the second embodiment provided by the utility model.

[0020] Figure 5 It is a structure schematic view of a scanning robot of the third embodiment provided by the utility model.

[0021] Figure 6 It is a schematic view of the process and moving distance of the existing single-chip microcomputer scanning injection.

[0022] Figure 7 It is a schematic view of the process and moving distance of the embodiment of the utility model for simultaneously injecting two wafers.

[0023] Explanation of reference numerals in the drawings:

[0024] 1, scanning robot;11, scanning connecting seat;12, scanning moving mechanism;121, scanning rear arm;122, scanning front arm;13, scanning turnover part;14, target disc;15, target disc fixing plate;16, scanning extension arm;2, loading cavity;3, vacuum transmission cavity;4, process cavity;5, transmission robot;51, transmission connecting seat;52, transmission rear arm;53, transmission front arm;54, upper mechanical arm;55, lower mechanical arm;56, upper supporting arm;57, lower supporting arm;6, ion beam. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme in the utility model will be described clearly and completely in combination with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0026] In addition, it also needs to be explained that, in order to facilitate the description, only the parts related to the utility model are shown in the drawings. In the case of no conflict, the embodiments in the utility model and the features in the embodiments can be combined with each other.

[0027] It needs to be noted that the "first", "second" and other concepts mentioned in the utility model are only used for distinguishing different devices, modules or units, and are not used for limiting the order or mutual dependence of the functions performed by these devices, modules or units.

[0028] It should be noted that the terms "a" and "a plurality of" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0029] This utility model discloses an ion implantation system for simultaneous implantation of multiple wafers, belonging to the field of semiconductor manufacturing technology. It includes a loading cavity, a vacuum transport cavity, and a process cavity connected in sequence. A scanning robot is installed in the process cavity. The scanning robot includes a scanning connector, a scanning moving mechanism, and a scanning flipping unit connected in sequence. The scanning flipping unit is rotatably connected to the scanning moving mechanism, and two or more target disks are arranged on the scanning flipping unit, located on the same side of the rotation axis of the scanning flipping unit. In existing technologies, single-chip microcomputer processes that perform scanning implantation on only one wafer at a time have better performance, but they have some limitations. These limitations mainly include: because ion implantation is performed wafer-by-wafer, and factors such as the distance and time required for wafer transport and the time required for ion implantation make it difficult to further shorten the process efficiency; and, especially for high-current or high-dose ion implantation processes, the temperature of the wafer rises during repeated scanning implantation, leading to significant lattice damage. Furthermore, after reaching a certain temperature, the wafer must be allowed to cool before scanning can continue, which is also not conducive to shortening the process time.

[0030] Please see Figure 1 (This is a simplified schematic diagram; specific details are not shown, and adjustments can be made in practical applications.) This invention provides an ion implantation system for simultaneous implantation of multiple wafers, comprising a loading chamber 2 (Loadlock), a vacuum transfer chamber 3, and a process chamber 4 (PTM) connected in sequence. A scanning robot 1 is installed in the process chamber 4. More specifically, the loading chamber 2 and the vacuum transfer chamber 3 are sealable, for example, connected by a valve. This allows the entire ion implantation process to be completed under high vacuum and high cleanliness conditions.

[0031] The scanning robot 1 includes a scanning connector 11, a scanning movement mechanism 12, and a scanning flipping unit 13 connected in sequence, thus forming a controllable robotic arm structure. The scanning connector 11 is used to connect to the process chamber 4. The scanning movement mechanism 12 is used to realize the reciprocating movement of the wafer during ion implantation scanning under control. The scanning flipping unit 13 is connected to a target disk 14 for carrying the wafer. The scanning flipping unit 13 can be flipped under control to make the target disk 14 lie flat or stand upright at the required angle. The scanning flipping unit 13 is rotatably connected to the scanning movement mechanism 12. Two or more target disks 14 are arranged on the scanning flipping unit 13, and the two or more target disks 14 are located on the same side of the rotation axis of the scanning flipping unit 13. The main improvement of this solution is that the existing conventional scanning robots only have one target disk and perform ion implantation on only one wafer at a time, while this solution has multiple target disks and can perform ion implantation on multiple wafers simultaneously. The scanning area of ​​the ion beam can completely cover multiple wafers located on the scanning robot.

[0032] The vacuum transfer cavity 3 contains transfer robots for wafer transfer. Preferably, at least two transfer robots 5 are provided in the vacuum transfer cavity 3, enabling them to work in coordination, simultaneously, or alternately to improve transfer efficiency. For example... Figure 1 In the illustrated embodiment, two transfer robots 5 are disposed within the vacuum transfer cavity 3. Each transfer robot 5 includes a transfer connector 51 and a transfer robotic arm connected together. The robotic arm has a support arm at its end for supporting the wafer. The transfer connector 51 is connected to the vacuum transfer cavity 3. The two transfer robots 5 are positioned on opposite sides of the scanning flip section 13, facilitating the loading and unloading of wafers from multiple target disks 14. For example… Figure 1 The illustrated embodiment has four target disks 14. The upper two target disks 14 are handled by an upper transfer robot 5, and the lower two target disks 14 are handled by a lower transfer robot 5. During the process of picking up and placing wafers on the left-hand target disk 14 and transferring wafers, the transfer robot 5 will not affect the right-hand target disk 14 or the wafers on it (if any). This can be achieved through the structural design of the transfer robot 5, such as the relative positional relationship between the transfer robot 5 and the target disk 14, or the bending or bendable design of the transfer robot 5's robotic arm or support arm. Generally, wafers are exchanged (picked up and placed) one target disk at a time. For the illustrated embodiment, or other structures, if there are target disks that can be exchanged simultaneously (e.g., the two target disks on the right in the figure), these target disks can also be selected for simultaneous exchange to further shorten the process time.

[0033] Preferably, the positions of the scanning robot 1, the transfer robot 5, and the loading cavity 2 are axially symmetrical. The paths of the two transfer robots 5 for transferring wafers are symmetrical and do not intersect at least in the vacuum transfer cavity 3 and the process cavity 4 (they may intersect at the loading cavity 2, i.e., wafers can be taken sequentially from the same loading cavity 2). This achieves a flexible and efficient wafer transfer process. In this embodiment, there are two loading cavities 2, each corresponding to one of the two transfer robots 5. The wafer transfer paths of the two transfer robots 5 do not intersect at all, so that the two transfer robots 5 can work simultaneously without affecting each other. In addition, the vacuum transfer cavity 3 or a separate cavity (not shown in the figure) connected to the vacuum transfer cavity 3 also has a wafer alignment mechanism, a heating mechanism, and / or a cooling mechanism to meet the corresponding functional requirements. The wafer alignment mechanism, heating mechanism, and / or cooling mechanism can also be selected as one / a group shared by the two transfer robots 5, or two / two groups corresponding to the two transfer robots 5 respectively.

[0034] More specifically, such as Figure 1 In the illustrated embodiment, the transfer robotic arm includes a transfer rear arm 52 and a transfer front arm 53 rotatably connected. The transfer rear arm 52 is rotatably connected to the transfer connecting seat 51, and the end of the transfer front arm 53 away from the transfer rear arm 52 is connected to the support arm. This enables the end of the support arm to pick up and place wafers at the required position and move to the required position. As a supplementary explanation, the wafer picking and placing process is generally achieved through relative lifting, such as the target plate being able to lift or the support arm being able to lift, thereby completing the wafer transfer work; for example, any part of the transfer connecting seat 51, the transfer robotic arm, the support arm, etc. in the transfer robot 5 has a lifting structure and lifting function, which can realize the control of the support arm to lift or lower.

[0035] Preferably, such as Figure 2In the illustrated embodiment, each transfer robot 5 includes a transfer arm comprising an upper robotic arm 54 and a lower robotic arm 55 capable of rotation and independent extension / retraction. The end of the upper robotic arm 54 away from the transfer connection seat 51 has an upper support arm 56, and the end of the lower robotic arm 55 away from the transfer connection seat 51 has a lower support arm 57. The upper support arm 56 is located above the lower support arm 57, and there is a gap between the upper support arm 56 and the lower support arm 57 large enough to accommodate at least one wafer, ensuring that the upper and lower robotic arms can operate independently. The upper robotic arm 54 and the lower robotic arm 55 are, for example, the aforementioned transfer rear arm and transfer front arm structures. Further, the transfer connection seat 51 includes an upper layer and a lower layer rotatably connected. The upper robotic arm 54 and the lower robotic arm 55 are both rotatably connected to the upper layer of the transfer connection seat 51, and the bottom of the lower layer of the transfer connection seat 51 is fixedly connected to the vacuum transfer cavity 3. The transfer robot can achieve overall rotation, independent extension / retraction of the upper and lower robotic arms, and the lifting and placing of wafers. This type of transfer robot can better complement the solution for transferring and picking up wafers, and helps to further improve efficiency. Specifically, for example, the lower robotic arm is used to remove wafers from the target disk, and the upper robotic arm is used to place new wafers to be processed onto the target disk, thus realizing a rapid exchange process.

[0036] like Figure 3 As shown, in the first embodiment of this invention, there are three adjacent target disks 14, and the three target disks 14 are arranged in a triangular pattern. More specifically, the three target disks 14 are arranged in an isosceles or equilateral triangle pattern, with two of them arranged side by side along the scanning direction (vertically arranged in the figure), and the third located next to the two and corresponding to the position between the two. This type of distribution is a staggered arrangement, which makes the total width of the multiple wafers smaller, and is more conducive to the ion beam completely covering the dimensions of multiple wafers. In this embodiment, the wafer size is, for example, 150 mm, and the ion beam width is, for example, 300 mm.

[0037] like Figure 4 As shown, in the second embodiment of this utility model, there are two adjacent target disks 14, and the two target disks 14 are arranged side by side along the moving direction of the scanning moving mechanism 12 (arranged vertically side by side in the figure). In this embodiment, the optional wafer size and ion beam width are, for example, 300 mm. Alternatively, as Figure 4 In a variant of the illustrated embodiment, the target disks 14 are two adjacent disks arranged side-by-side along a direction perpendicular to the moving direction of the scanning moving mechanism 12, i.e., along the ion beam width direction. In this embodiment, the wafer size is, for example, 150 mm, and the ion beam width is, for example, 300 mm (generally slightly larger than 300 mm).

[0038] like Figure 5As shown, in the third embodiment of this utility model, there are four adjacent target disks 14, and the four target disks 14 are distributed in a quadrilateral shape. More specifically, the four target disks 14 are distributed in a rectangular shape, and the length direction of two sides of the rectangle is parallel to the moving direction of the scanning moving mechanism 12. This kind of regular distribution is a relatively aligned regular arrangement; thus, the wafers are arranged in a regular two-row, two-wafer arrangement, and the two wafers in the horizontal direction are adapted to the width of the ion beam. For example, the wafer diameter is 150mm, and the ion beam width is about 300mm (generally slightly larger than 300mm).

[0039] It is conceivable that the target disks can also be selected in other quantities and / or arrangements, such as a relatively aligned regular arrangement or a combination of staggered arrangements; for example, as a variant of the third embodiment, the four target disks are arranged in a non-rectangular parallelogram, that is, in two staggered columns.

[0040] The preferred robotic arm structure of the scanning robot is described in more detail below using the first embodiment as an example. It is understood that this robotic arm structure, or other structures, may also be used in other embodiments. Please refer to... Figure 3 A target plate fixing plate 15 is connected to the scanning flipping section 13, and the back side of the target plate 14 is fixedly connected to the target plate fixing plate 15. The target plate fixing plate 15 mainly serves to connect multiple target plates 14. Optionally, all the target plates 14 are located on the same plane. In addition, the target plate fixing plate 15 can also be configured to block the ion beam. The target plate fixing plate 15 can cover the scanning flipping section 13 behind it to prevent the ion beam 6 from directly irradiating the scanning flipping section 13. All surfaces on the scanning robot that will directly contact the ion beam 6 have special treatments, such as having a graphite layer, so as to absorb the ion beam and prevent the ion beam from directly irradiating the metal and generating impurity ions that contaminate the internal environment of the ion implantation equipment. More preferably, the center of gravity of the target plate fixing plate 15 and all the target plates 14 on it corresponds to the rotation axis of the scanning flipping section 13. For example, in the illustrated embodiment, the rotation axis of the scanning flipping section 13 corresponds to the axis of the scanning extension arm 16. The projections of the center of gravity and the axis on the plane where the target plate 14 is located overlap. This structure is more balanced and helps to ensure the stability of the flipping and other operating processes.

[0041] The target disk is a component used to temporarily hold the wafer during the implantation process. Its holding structure and method include, for example, electrostatic adsorption and / or mechanical clamping. In a specific embodiment, the target disk 14 is an electrostatic chuck. The size of the target disk is generally smaller than or equal to that of the wafer. The wafer is placed with its center aligned with the center of the target disk, and there is sufficient gap between adjacent target disks so that there is a certain distance between the two wafers during the placement, holding, and removal of the two wafers, and the process will not be affected by contact.

[0042] The scanning flip unit 13 is rotatably connected to the scanning movement mechanism 12 via a scanning extension arm 16. The length direction of the scanning extension arm 16 is aligned with the rotation axis of the scanning flip unit 13, and the length direction of the scanning extension arm 16 is perpendicular to the scanning movement direction of the scanning movement mechanism 12. Preferably, the scanning extension arm 16 is provided, which allows the target disk 14 to be relatively far away from the rest of the robotic arm structure, so as to ensure that the rest of the robotic arm structure does not come into contact with the ion beam 6.

[0043] The preferred scanning movement mechanism 12 includes a scanning rear arm 121 and a scanning front arm 122 rotatably connected. The scanning rear arm 121 is rotatably connected to the scanning connection seat 11, and the end of the scanning front arm 122 away from the scanning rear arm 121 is rotatably connected to the scanning extension arm 16. All three rotatable connections are controllable, while the end of the scanning extension arm 16 is fixedly connected to the scanning flipping part 13. This concentrates the mechanical control components and keeps them away from the ion beam 6. Furthermore, this scanning movement mechanism 12 offers the advantage of more flexible operation. In the illustrated embodiment, during scanning, the scanning movement mechanism 12 primarily drives the wafer to move in the vertical direction; other actions can also be performed as needed. It is conceivable that in other feasible embodiments, the scanning movement mechanism could be a telescopic mechanism, such as other forms of electrically operated telescopic rods, which could also achieve the required movement process.

[0044] Furthermore, when employing this method, the number of wafers to be processed placed each time is generally an integer multiple of the number of target disks, or preferably, the loading cavity 2 contains one or more baffles. The baffles are, for example, sheets of the same size as the wafers, and made of materials such as silicon or graphite, or the same as or similar to the wafers, thus enabling contact with the ion beam without causing contamination. For cases requiring ion implantation of fewer wafers than the number of target disks, the baffles are used as substitutes for the wafers and transported and placed on the target disks, so that each target disk contains either a wafer or a baffle, to prevent direct ion beam irradiation of the target disks. After implantation is complete, the baffles are returned, awaiting the next application.

[0045] The main concept, working principle and beneficial technical effects of this utility model are as follows.

[0046] The present invention mainly includes the following steps in the ion implantation process.

[0047] Step one: Initially, the multiple target disks on the scanning robot are all laid flat and unloaded. Then, the wafers are transported and placed on the target disks, so that each target disk has one wafer. Of course, during these processes, neither the target disks nor the wafers come into contact with the ion beam.

[0048] Step 2: The scanning robot controls the target disk to hold the wafers and then flips them so that multiple wafers are all erected to the angle required by the process. The process angle is generally defined as the ion beam incident angle, which is the angle between the ion beam path and the plane where the wafer is located. Specifically, it is 90°, i.e., vertical incident, or it can be set to a certain angle according to the process requirements.

[0049] Step 3 involves scanning the wafers using ion implantation. The scanning area of ​​the ion beam can completely cover multiple wafers located on the scanning robot. The basic scanning method, such as the scanning robot controlling the target disk to move, can follow existing technical solutions. The main difference lies in the different scanning paths and distances. Existing microcontrollers only scan one wafer, while this solution requires scanning multiple wafers.

[0050] Step four: After completing the required ion implantation (usually after multiple scans to achieve the desired implantation dose, and in this scheme, all wafers held on the scanning robot have undergone ion implantation), the scanning robot returns to its initial flat position, waiting for the wafers to be removed. The total number of scans is usually set to an even number, so that after completing the required ion implantation in step four, the scanning robot is in the initial position or close to the initial position.

[0051] After the implanted wafer is removed, a new wafer to be processed is placed on top, and steps one through four are repeated until all the required number of wafers have been implanted with ions.

[0052] As a preferred application of this utility model, the ion beam 6 is a strip beam, and the length of the cross-sectional shape of the ion beam 6 is not less than twice the diameter of the wafer. For example, the ion beam is about 300mm wide (this size of ion beam is commonly used). Ion implantation is performed on a 150mm wafer. Each scan implantation can be performed on up to four wafers at the same time, which can significantly shorten the average implantation time of each wafer.

[0053] Please see Figure 6 , Figure 7 The following comparison is made using an existing process and the simultaneous implantation of two wafers as an example. In the simultaneous implantation of two wafers, the scanning process consists of multiple reciprocating scans. The total moving distance of each scan is not less than the sum of the diameters of the two wafers, the spacing between the two wafers, and an overscan distance; wherein the overscan distance is greater than the height of the ion beam. Taking a wafer diameter of 300 mm, a wafer spacing of 10 mm, and an overscan distance of 100 mm as an example, the total moving distance of one scan is 300 + 300 + 10 + 100 = 710 mm. For the same wafer size and overscan distance, please refer to [link to relevant documentation]. Figure 6When using an existing microcontroller for scanning, the total movement distance for one scan is 300 + 100 = 400 mm. Although this solution uses a longer scanning distance than the microcontroller during ion implantation, both microcontrollers and this solution require overscanning to ensure the integrity of the entire wafer implantation. Therefore, for this solution, under the same overscan distance conditions, the advantage is that the overscan distance for each wafer in dual-wafer implantation is equivalent to half that in single-wafer implantation. That is, with the dual-wafer simultaneous implantation scheme, the average scanning distance per wafer is 710 / 2 = 355 mm, which is 355 / 400 = 88.7% compared to the existing process, thus reducing the ion implantation time. It is understandable that simultaneous implantation of three or four wafers, with different specific dimensions, also has similar advantages. Especially for example, simultaneous implantation of four 150 mm wafers, the average scanning distance per wafer will have a more significant advantage compared to the existing process.

[0054] Furthermore, during the overall operation of the ion implantation system, since the process of picking up and placing two or more wafers on the target disk and the wafer movement and transfer process can be carried out simultaneously, this solution can save overall time compared with single-wafer transfer, comprehensively improve WPH, and this solution will not affect the process results or the safe and reliable operation of the equipment.

[0055] Furthermore, during the implantation process, because the scanning distance is longer, the interval between each point on the wafer contacting the beam is also longer. This results in: 1. more self-healing time; 2. more cooling time. Consequently, lattice damage is reduced, and the wafer temperature can be controlled at a lower level, which is beneficial to the process and the final product quality.

[0056] In some embodiments, the scanning process for ion implantation of the two wafers in step three is designed to be more flexible, for example, for Figure 4 , Figure 5 In the illustrated embodiment, the upper wafer can be scanned several times first, and then the lower wafer can be scanned. At the same time, the upper wafer is cooled, and the two wafers are scanned alternately. For single wafer implantation with a baffle, the upper target disk holds the wafer and the lower target disk holds the baffle. During operation, similar to existing microcontrollers, only the single wafer is scanned. The baffle is only used to prevent the ion beam from directly irradiating the target disk and other structures.

[0057] In other embodiments, unlike the aforementioned embodiments, during the transfer robot's actions in steps one and four, the lower robotic arm may be used to retrieve a new wafer from the loading cavity. After the transfer robot rotates to face the target plate, the unloaded upper robotic arm extends, removes the processed wafer from the target plate, and then rises slightly before or during its departure from the target plate, thereby creating space more quickly for the lower robotic arm to extend and place the new wafer, thus completing the wafer exchange process. The transfer robot structure, in which the upper and lower robotic arms can extend, retract, and rise independently, is achievable based on existing technology and will not be described in detail here.

[0058] It is understood that in some feasible embodiments, the process of placing wafers on the target disk is not performed synchronously, but is carried out sequentially or with time differences by one or more existing transfer robots. This is less efficient than the aforementioned preferred embodiment with simultaneous exchange process, but still more efficient than existing microcontroller solutions.

[0059] In some other embodiments, there is one or two loading cavities 2. During operation, two transfer robots 5 sequentially pick up / place wafers in the same loading cavity 2, while the other loading cavity 2 is used for loading / unloading / vacuuming / vacuum release. The two loading cavities 2 work alternately, which helps to improve overall efficiency.

[0060] In some embodiments, the scanning process for ion implantation of the wafer in step three is designed to be more flexible, for example, for Figure 4 , Figure 5 In the illustrated embodiment, the upper wafer can be scanned several times first, followed by the lower wafer, while the upper wafer is cooled. This alternating scanning of the two wafers can be performed. For single-wafer implantation with a baffle, the upper target disk holds the wafer, and the lower target disk holds the baffle. During operation, similar to existing microcontrollers, only this single wafer is scanned. The baffle is only used to prevent the ion beam from directly irradiating the target disk and other structures. The baffle is positioned, for example, at the top or bottom of the loading cavity 2, so that after processing wafers one by one, the last wafer will be close to the baffle position for easy and rapid pickup.

[0061] In summary, the ion implantation system for simultaneous implantation of multiple wafers of this invention features a scanning robot with multiple target disks, capable of simultaneously holding multiple wafers for scanning and implantation. The processes of picking up and placing wafers on different target disks and transferring wafers within the system overlap in time, thus shortening the overall ion implantation time for a large batch of wafers. Furthermore, the scanning process for ion implantation requires a certain overscan to ensure the integrity of the entire implantation; for the scheme of simultaneously scanning multiple wafers, only one overscan distance is needed, effectively reducing the average processing time per wafer. Additionally, due to the longer scanning distance, the interval between each point on the wafer contacting the beam also increases, resulting in more self-healing time and cooling time, leading to lower lattice damage and lower wafer temperature control. Moreover, this solution can be implemented without altering the basic structure of the beam system, can be modified from existing microcontrollers, is easy to implement, and will not affect the process results or the safe and reliable operation of the equipment, making it highly valuable for application.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An ion implantation system for simultaneous implantation of multiple wafers, characterized in that, It includes a loading cavity (2), a vacuum transfer cavity (3) and a process cavity (4) connected in sequence. A scanning robot (1) is installed in the process cavity (4). The scanning robot (1) includes a scanning connection seat (11), a scanning moving mechanism (12) and a scanning flipping part (13) connected in sequence. The scanning flipping part (13) is rotatably connected to the scanning moving mechanism (12). Two or more target disks (14) are arranged on the scanning flipping part (13). The two or more target disks (14) are located on the same side of the rotation axis of the scanning flipping part (13).

2. The ion implantation system for simultaneous implantation of multiple wafers according to claim 1, characterized in that, At least two transfer robots (5) are installed in the vacuum transfer chamber (3).

3. The ion implantation system for simultaneous implantation of multiple wafers according to claim 1, characterized in that, Two transfer robots (5) are provided in the vacuum transfer cavity (3); the transfer robot (5) includes a transfer connector (51) and a transfer robotic arm connected to each other. The end of the transfer robotic arm has a support arm for supporting the wafer. The transfer connector (51) is connected to the vacuum transfer cavity (3); the positions of the two transfer robots (5) correspond to the two sides of the scanning flip section (13).

4. The ion implantation system for simultaneous implantation of multiple wafers according to claim 3, characterized in that, The transmission robotic arm includes a transmission rear arm (52) and a transmission front arm (53) that are rotatably connected. The transmission rear arm (52) is rotatably connected to the transmission connecting seat (51), and the end of the transmission front arm (53) away from the transmission rear arm (52) is connected to the support arm.

5. The ion implantation system for simultaneous implantation of multiple wafers according to claim 3, characterized in that, Each transfer robot (5) has a transfer arm that can rotate and extend independently, including an upper arm (54) and a lower arm (55). The upper arm (54) has an upper support arm (56) at the end away from the transfer connector (51), and the lower arm (55) has a lower support arm (57) at the end away from the transfer connector (51). The upper support arm (56) is located above the lower support arm (57), and there is a gap between the upper support arm (56) and the lower support arm (57) that can accommodate at least one wafer.

6. The ion implantation system for simultaneous implantation of multiple wafers according to any one of claims 1-5, characterized in that, The target disks (14) are two adjacent targets, and the two target disks (14) are arranged side by side along the moving direction of the scanning moving mechanism (12) or along the direction perpendicular to the moving direction of the scanning moving mechanism (12).

7. The ion implantation system for simultaneous implantation of multiple wafers according to any one of claims 1-5, characterized in that, The target disks (14) are three adjacent disks, and the three target disks (14) are arranged in a triangle.

8. The ion implantation system for simultaneous implantation of multiple wafers according to any one of claims 1-5, characterized in that, The target disks (14) are four adjacent ones, and the four target disks (14) are arranged in a quadrilateral shape.

9. The ion implantation system for simultaneous implantation of multiple wafers according to claim 8, characterized in that, The four target disks (14) are arranged in a rectangular shape, and the length direction of two sides of the rectangle is parallel to the moving direction of the scanning moving mechanism (12).

10. The ion implantation system for simultaneous implantation of multiple wafers according to any one of claims 1-5, characterized in that, The loading cavity (2) contains one or more baffles.

Images