Multi-target disc scanning robot for ion implantation

Abstract

The utility model discloses a multi-target disc scanning robot for ion implantation, which belongs to the technical field of semiconductor manufacturing and 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. The scanning robot provided by the utility model can simultaneously hold a plurality of wafers for scanning injection, and can effectively shorten the average processing time of each wafer; meanwhile, the time interval for each point on the wafer to be in contact with the ion beam is also prolonged, so that more self-repairing time and more cooling time are provided; according to the scheme, the whole beam current system does not need to be changed, the device can be formed by modifying an existing single-chip microcomputer, implementation is easy, the process result and safe and reliable operation of equipment cannot be affected, and the device has extremely high application value.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, and specifically relates to a multi-target disk scanning robot for ion implantation. Background Technology

[0002] In existing ion implantation equipment, the scanning robot has a target disk at its end to hold the wafer during ion implantation and can reciprocate relative to the ion beam to achieve scanning implantation. While this type of ion implantation equipment, with its wafer-by-wafer scanning implantation method, is increasingly favored for its superior process quality, it also faces the challenge of limiting throughput per unit time. Clearly, increased throughput is crucial for the development of the semiconductor industry and the competitiveness of manufacturing companies. Therefore, a novel scanning robot ion implantation process is needed to simultaneously meet both quality and throughput requirements. Utility Model Content

[0003] Based on the technical problems existing in the prior art, this utility model provides a multi-target disk scanning robot for ion implantation, which solves the problem that the process efficiency of the existing solution is difficult to improve, and can further shorten the average processing time of each wafer while ensuring process quality.

[0004] According to the technical solution of this utility model, this utility model provides a multi-target disk scanning robot for ion implantation, including a scanning connection seat, a scanning moving mechanism and a scanning flipping part connected in sequence; the scanning flipping part is rotatably connected to the scanning moving mechanism, and two or more target disks are arranged on the scanning flipping part, with the two or more target disks located on the same side of the rotation axis of the scanning flipping part.

[0005] According to some embodiments, there are two adjacent target disks, and the two target disks are arranged side by side along the moving direction of the scanning moving mechanism or in a direction perpendicular to the moving direction of the scanning moving mechanism.

[0006] According to some other embodiments, there are three adjacent target disks, and the three target disks are arranged in a triangle.

[0007] According to other embodiments, there are four adjacent target disks, and the four target disks are arranged in a quadrilateral shape.

[0008] Furthermore, the four target disks are arranged in a rectangular pattern, and the length direction of two sides of the rectangle is parallel to the moving direction of the scanning moving mechanism.

[0009] Furthermore, a target plate is connected to the scanning flipping part, and the back side of the target plate is fixedly connected to the target plate.

[0010] Furthermore, the center of gravity of the target plate and all the target plates on it corresponds to the rotation axis of the scanning flipping part.

[0011] Furthermore, the target disk is an electrostatic chuck.

[0012] Furthermore, the scanning flipping unit is rotatably connected to the scanning moving mechanism via a scanning extension arm. The length direction of the scanning extension arm is consistent with the rotation axis direction of the scanning flipping unit, and the length direction of the scanning extension arm is perpendicular to the scanning moving direction of the scanning moving mechanism.

[0013] Furthermore, the scanning moving mechanism includes a scanning rear arm and a scanning front arm that are rotatably connected. The scanning rear arm is rotatably connected to the scanning connecting seat, and the end of the scanning front arm away from the scanning rear arm is rotatably connected to the scanning extension arm.

[0014] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0015] This invention relates to a multi-target scanning robot for ion implantation, which has multiple target disks, enabling simultaneous holding of multiple wafers for scanning and implantation. The ion implantation scanning process requires a certain overscan to ensure the integrity of the entire wafer implantation. For a scheme that scans multiple wafers simultaneously, only one overscan distance is needed, thus effectively shortening the average processing time per wafer. Simultaneously, because the scanning distance is relatively longer each time, the time interval between each point on the wafer contacting the ion beam also increases, resulting in more self-healing time and more cooling time. Consequently, lattice damage is reduced, and wafer temperature is controlled lower, helping to ensure the quality of ion implantation and the smooth progress of the process. This solution can be implemented without changing the entire 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. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the scanning robot according to the first embodiment of this utility model.

[0017] Figure 2 This is a schematic diagram of the structure of the scanning robot according to the second embodiment of this utility model.

[0018] Figure 3 This is a schematic diagram of the structure of the scanning robot according to the third embodiment of this utility model.

[0019] Figure 4 This is a schematic diagram of the scanning process and movement distance of the existing single-chip injection method.

[0020] Figure 5 This is a schematic diagram illustrating the process and movement distance of simultaneously implanting two wafers according to this utility model.

[0021] Explanation of reference numerals in the attached figures:

[0022] 11. Scanning connector; 12. Scanning moving mechanism; 121. Scanning rear arm; 122. Scanning forearm; 13. Scanning flipping part; 14. Target disk; 15. Target disk fixing plate; 16. Scanning extension arm; 2. Ion beam. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] It should also be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0025] It should be noted that the concepts of "first" and "second" mentioned in this utility model are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0026] 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".

[0027] This utility model discloses a multi-target disk scanning robot for ion implantation, belonging to the field of semiconductor manufacturing technology, and particularly suitable for high-current ion implantation equipment. It includes a scanning connector, a scanning moving mechanism, and a scanning flipping unit connected sequentially. 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, with the two or more target disks 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 also have some limitations. These 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, resulting in 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.

[0028] Please see Figure 1 The present invention provides a multi-target disk scanning robot for ion implantation, comprising a scanning connection base 11, a scanning movement mechanism 12, and a scanning flipping unit 13 connected in sequence, thereby forming a controllable robotic arm structure. The scanning connection base 11 is used to connect to an ion implantation device. The scanning movement mechanism 12 is used to reciprocate the wafer during the ion implantation scanning process 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 a desired 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 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 2 can completely cover multiple wafers located on the scanning robot.

[0029] In a preferred embodiment, the scanning robot has three or four target disks arranged in a relatively aligned or staggered pattern. It is understood that, to a certain extent, the more wafers undergoing ion implantation simultaneously, the better the implantation efficiency; however, too many should be avoided to prevent excessive impact on wafer transport and equipment stability. Holding three or four wafers simultaneously is preferable.

[0030] like Figure 1As 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.

[0031] like Figure 2 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 2 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).

[0032] like Figure 3 As 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).

[0033] 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.

[0034] 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 1A 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 2 from directly irradiating the scanning flipping section 13. All surfaces on the scanning robot that will directly contact the ion beam 2 have special treatments, such as having a graphite layer on the surface, 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.

[0035] Preferably, the center of gravity of the target plate fixing plate 15 and all the target plates 14 thereon 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 of the above structure onto the plane where the target plates 14 are located overlap. This structure is more balanced and helps to ensure the stability of the flipping and other operating processes.

[0036] 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.

[0037] 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 2.

[0038] 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 2. Furthermore, this scanning movement mechanism 12 has the advantage of more flexible operation. In the illustrated embodiment, during scanning, the scanning movement mechanism 12 mainly drives the wafer to move and scan in the vertical direction; as needed, this structure can also perform other actions. It is conceivable that in other feasible embodiments, the scanning movement mechanism can be a telescopic mechanism, such as other forms of electrically operated telescopic rods, which can also achieve the required movement process.

[0039] The main concept, working principle and beneficial technical effects of this utility model are as follows.

[0040] The present invention mainly includes the following steps in the ion implantation process.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] Step four: After completing the ion implantation required for the process (usually after repeated scanning to reach the required implantation dose, and in this solution, all wafers held on the scanning robot have completed ion implantation), the scanning robot returns to its initial flat position and waits for the wafers on it to be removed.

[0045] 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.

[0046] As a preferred application of this utility model, the ion beam 2 is a strip beam, and the length of the cross-sectional shape of the ion beam 2 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.

[0047] Please see Figure 4 , Figure 5 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 4 When 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.

[0048] Furthermore, during the overall operation of the ion implantation equipment, 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.

[0049] 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.

[0050] Furthermore, when using this method, the number of wafers to be processed each time is generally an integer multiple of the number of target disks, or one or more baffles are placed simultaneously. These baffles are, for example, sheets of the same size as the wafers, made of materials such as silicon or graphite, or the same as or similar to the wafers, thus allowing them to contact the ion beam without causing contamination. For cases requiring ion implantation of fewer wafers than the number of target disks, in step one, baffles are used as substitutes for wafers and transported and placed on the target disks, ensuring that each target disk contains either a wafer or a baffle to prevent direct ion beam irradiation. After implantation is complete, the baffles are returned, awaiting the next application.

[0051] 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 2 , Figure 3 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.

[0052] In summary, the multi-target scanning robot for ion implantation of this invention has multiple target disks, enabling simultaneous holding of multiple wafers for scanning and implantation. The scanning process of ion implantation requires a certain amount of overscanning to ensure the integrity of the entire implantation process. For the scheme of scanning multiple wafers simultaneously, only one overscan distance is needed, thus effectively shortening the average processing time per wafer. Simultaneously, because the scanning distance is relatively longer each time, the time interval between each point on the wafer contacting the ion beam also increases, resulting in more self-healing time and more cooling time. Consequently, lattice damage is lower, and wafer temperature is controlled lower, helping to ensure the quality of ion implantation and the smooth progress of the process. This solution can be implemented without changing the entire beam system, can be modified based on existing microcontrollers, is easy to implement, and will not affect the process results or the safe and reliable operation of the equipment, thus possessing extremely high application value.

[0053] 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. A multi-target disk scanning robot for ion implantation, characterized in that, It includes a scanning connector (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), and two or more target disks (14) are arranged on the scanning flipping part (13), and 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 multi-target disk scanning robot for ion implantation according to claim 1, 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).

3. The multi-target disk scanning robot for ion implantation according to claim 1, characterized in that, The target disks (14) are three adjacent disks, and the three target disks (14) are arranged in a triangle.

4. The multi-target disk scanning robot for ion implantation according to claim 1, characterized in that, The target disks (14) are four adjacent ones, and the four target disks (14) are arranged in a quadrilateral shape.

5. The multi-target disk scanning robot for ion implantation according to claim 4, 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).

6. The multi-target disk scanning robot for ion implantation according to any one of claims 1-5, characterized in that, The target plate fixing plate (15) is connected to the scanning flipping part (13), and the back side of the target plate (14) is fixedly connected to the target plate fixing plate (15).

7. The multi-target disk scanning robot for ion implantation according to claim 6, characterized in that, The center of gravity of the target plate (15) and all the target plates (14) on it corresponds to the rotation axis of the scanning flipping part (13).

8. The multi-target disk scanning robot for ion implantation according to any one of claims 1-5, characterized in that, The target disk (14) is an electrostatic chuck.

9. The multi-target disk scanning robot for ion implantation according to any one of claims 1-5, characterized in that, The scanning flipping part (13) is rotatably connected to the scanning moving mechanism (12) via the scanning extension arm (16). The length direction of the scanning extension arm (16) is consistent with the rotation axis direction of the scanning flipping part (13), and the length direction of the scanning extension arm (16) is perpendicular to the scanning moving direction of the scanning moving mechanism (12).

10. The multi-target disk scanning robot for ion implantation according to claim 9, characterized in that, The scanning moving 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 connecting 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).

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