Static and dynamic friction detection system for high-precision processing process of semiconductor wafer

Abstract

The invention discloses a static and dynamic friction detection system for a high-precision processing process of a semiconductor wafer. The static and dynamic friction detection system mainly comprises reciprocating friction wear detection equipment and a computer control system, when the shifting fork pushes the wafer to move in the X direction, an iron core in the displacement sensor is driven to slightly move through deformation of the force transmission beam, so that the dynamic friction force is determined according to a voltage value acquired by a computer control system, and in the process, static friction force can be effectively acquired by detecting strain gap deformation on the force transmission beam through the displacement sensor; meanwhile, when the wafer performs micro motion in the Y direction, the micro motion friction force is directly measured by the Y-direction strain type force sensor. The two sensors are combined, so that bidirectional force measurement can be realized, and meanwhile, wide friction force range test and same-system full-coverage measurement of dynamic and static friction force can be realized. The device is simple in structure, low in conversion and maintenance cost and suitable for large-scale application in the semiconductor processing and manufacturing industry and other material research and development mechanisms.

Description

Technical Field

[0001] The invention relates to the field of high-precision friction testing equipment, in particular to a static and dynamic friction detection system for high-precision processing of semiconductor wafers, and in particular to a side-pushing static and dynamic friction detection system for deep processing of semiconductor wafers. Background Art

[0002] With the continuous development of semiconductor technology, the quality requirements for the wafer surface are getting higher and higher. During the deep processing of semiconductor wafers, the friction and wear between the wafer and the stage directly affect the surface quality and processing accuracy of the wafer. Therefore, by detecting the friction between the wafer and the stage, it is possible to timely discover the appearance defects such as scratches, stains, cracks, etc. left by the equipment on the wafer during the processing, as well as the phenomenon of wafer bending and warping caused by thermal stress and mechanical stress, and then guide the optimization and replacement of grinding materials and devices, so as to ensure the stability of wafer processing quality. At the same time, friction data can also provide a basis for the adjustment of wafer processing parameters, help material design and optimize processing technology, and improve processing efficiency and wafer surface quality. During the wafer surface processing, according to the working condition loading, it is necessary to apply thrust to the side of the wafer to guide the wafer to move in the planned direction, so as to test the static and dynamic friction of the wafer, and calculate the friction coefficient through computer software. However, due to the small thickness of the wafer after deep processing, about 500-750μm, and its small mass, the difficulty of friction and wear detection of wafer materials has doubled. At present, due to changes in international trade policies, some countries have issued export control policies for the semiconductor equipment field, which has greatly affected the detection and analysis of domestic semiconductor materials. In order to improve the security of the semiconductor industry chain, the localization rate of semiconductor measurement equipment is particularly urgent. At the same time, there is a lack of testing equipment for the friction performance of wafer materials in the domestic market. Therefore, it is very necessary to develop a device for wafer material friction testing. Summary of the invention

[0003] Based on the above, the purpose of the present invention is to provide a static and dynamic friction detection system for high-precision processing of semiconductor wafers, which is used for friction and wear detection of semiconductor wafer materials during processing and sample transfer, and at the same time simulates reciprocating friction and wear detection to achieve balanced loading of different areas on the upper surface of the wafer, thereby providing a basis for adjusting wafer processing parameters and improving processing efficiency and wafer surface quality.

[0004] To achieve its purpose, the present invention adopts the following technical solutions: A static and dynamic friction detection system for high-precision processing of semiconductor wafers, including a reciprocating friction and wear detection device and a computer control system; The reciprocating friction and wear detection equipment uses a mounting base plate and a gantry as a main frame, a Y-axis electric translation stage is provided on the upper surface of the mounting base plate at one end away from the gantry, a rotating platform with a self-locking nut is provided on the Y-axis electric translation stage, a lower sample stage is provided on the rotating platform, the top surface of the lower sample stage is a recessed structure, and a circular lower sample is loaded into the recessed structure of the lower sample stage; a wafer as an upper sample is provided on the top surface of the circular lower sample, and a force weight is provided on the upper surface of the wafer to provide positive pressure for wafer contact friction; An X-axis electric translation platform is horizontally installed on the gantry crossbeam, a Z-axis electric lifting platform driven by a top stepper motor is installed on the X-axis electric translation platform, a high-precision friction force measuring device is provided on the Z-axis electric lifting platform, and a high-definition camera is provided on the high-precision friction force measuring device; The high-precision friction force measurement device comprises a two-dimensional piezoelectric ceramic translation stage that can be adjusted in micro-distance in the X and Z directions. A Y-shaped force transmission beam extending downward is provided on one side of the panel of the two-dimensional piezoelectric ceramic translation stage. Strain gaps are provided on both sides of the top of the Y-shaped force transmission beam. High-precision displacement sensors are installed on both sides of the Y-shaped force transmission beam at the bottom of the two strain gaps. The bottom of the Y-shaped force transmission beam handle is connected to one end of the Y-direction strain force sensor, and the other end of the Y-direction strain force sensor is connected to a horizontally arranged side-pushing wafer fork mechanism, and the side-pushing wafer fork mechanism is in contact with the wafer. The signal output end of the computer control system is electrically connected to the driving mechanisms of the Y-axis electric translation stage, the Z-axis electric lifting stage, the rotating platform, the X-axis electric translation stage, and the two-dimensional piezoelectric ceramic translation stage, and the signal input end of the computer control system is electrically connected to the high-precision displacement sensor and the Y-axis strain force sensor.

[0005] As a further improvement of the technical solution of the present invention, the fork mechanism for side-pushing the wafer includes four forks, and an arc structure matching the outer circumference of the wafer is formed between every two forks.

[0006] Furthermore, the X-axis electric translation stage is driven by a transmission device, which includes an X-axis servo motor, a main shaft of the X-axis servo motor is connected to a driving wheel, the driving wheel is connected to a driven wheel through a synchronous belt, and the driven wheel is connected to a lead screw of the X-axis electric translation stage to realize transmission.

[0007] Furthermore, X-axis optical limit switches are provided at both ends of the X-axis electric translation stage, and Y-axis optical limit switches are provided at both ends of the Y-axis electric translation stage. Both the X-axis optical limit switch and the Y-axis optical limit switch are electrically connected to the signal input end of the computer control system.

[0008] Furthermore, the Y-axis electric translation stage is driven by a Y-axis servo motor, and the Y-axis servo motor is connected to the translation stage lead screw via a coupling.

[0009] Furthermore, the Z-axis electric lifting platform is driven by a stepping motor on its top.

[0010] Furthermore, the rotating platform is rotated by manual control. After the lower sample is installed on the upper surface, the disc can be manually rotated to select the test area, and after rotating to a suitable position, it can be locked by the nut provided by the rotating platform.

[0011] Furthermore, after the circular lower sample is loaded into the lower sample stage, it is locked by bolts around the lower sample stage, and the bolts are made of flexible material.

[0012] Furthermore, the bottom of the mounting base plate is provided with leveling feet.

[0013] Furthermore, the high-definition camera is mounted on the same side of the Y-shaped force measuring beam of the two-dimensional piezoelectric ceramic translation stage through a lens mounting frame.

[0014] By adopting the above technical solution, the beneficial effects achieved by the present invention are as follows: 1. The present invention aims at detecting the friction force between wafers of different qualities and the equipment surface over a large span. It proposes to use a force transmission beam in combination with an inductive displacement sensor and a strain force sensor. When the shift fork pushes the wafer to move in the X direction, the deformation of the force transmission beam drives the internal iron core of the displacement sensor to slightly move, so as to determine the magnitude of the dynamic friction force according to the voltage value collected by the computer control system. In this process, the static friction force can be effectively collected by detecting the strain gap deformation on the force transmission beam through the displacement sensor; at the same time, when the wafer slightly moves in the Y direction, the magnitude of the micro-motion friction force is directly measured by the Y-direction strain force sensor. The combination of the two sensors can realize bidirectional force measurement, as well as the test of a wider friction range and the full coverage measurement of dynamic and static friction forces in the same system.

[0015] 2. The present invention adopts an optical lifting platform with a piezoelectric ceramic displacement platform, and combines a high-definition camera to realize automatic machine vision adjustment, which can accurately locate the position of the wafer, realize high-precision control of the fork, and avoid damage to the sample by moving parts.

[0016] 3. The force transmission beam structure of the present invention is sensitive when used with elastic materials and can realize simultaneous measurement of static and dynamic friction forces when used with a high-precision data acquisition device.

[0017] 4. The present invention has a simple structure, low conversion and maintenance costs, and is suitable for large-scale application in the semiconductor processing and manufacturing industry and other material research and development institutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the reciprocating friction and wear detection device in the present invention; Figure 2 for Figure 1 A half-section view of Figure 3 It is a structural schematic diagram of the high-precision friction force measurement device in the present invention; Figure 4 It is a partial view of the transmission device in the present invention; Figure numerals: 1, mounting base; 2, adjustable leveling feet; 3, gantry; 4, Y-axis electric translation stage; 5, rotating platform; 6, lower sample stage; 7, circular lower sample; 8, bolts; 9, wafer; 10, weights; 11, high-precision friction force measurement device: 11-1, shift fork, 11-2, Y-axis strain force sensor, 11-3, force transmission beam, 11-4, high-precision displacement sensor, 11-5, strain gap, 11-6, two 1. piezoelectric ceramic translation stage; 12. high-definition camera; 13. Z-axis electric lifting platform; 14. stepping motor; 15. transmission device: 15-1. driving wheel; 15-2. synchronous belt; 15-3. driven wheel; 16. equipment housing; 17. Y-axis servo motor; 18. coupling; 19. Y-axis optical limit switch; 20. X-axis servo motor; 21. X-axis electric translation stage; 22. X-axis optical limit switch; 23. lens mounting bracket. DETAILED DESCRIPTION

[0019] The structure and working process of the present invention are described in detail below with reference to the accompanying drawings.

[0020] In the present invention, the computer control system adopts Advantech 610L, the X-axis and Y-axis electric translation stages are purchased from Shanghai Lianyi Fiber Laser Equipment Co., Ltd., the rotating platform 5 is purchased from Shanghai Lianyi Fiber Laser Equipment Co., Ltd., the Y-axis strain force sensor 11-2 is purchased from Bengbu Sensor System Engineering Co., Ltd., the high-precision displacement sensor 11-4 is purchased from Beijing Jinghaiquan Sensing Technology Co., Ltd., the two-dimensional piezoelectric ceramic displacement stage 11-6 is purchased from Harbin Xinmingtian Technology Co., Ltd., the high-definition camera 12 is purchased from Micro Vision Technology (Shenzhen) Co., Ltd., and the Z-axis electric lifting platform 13 is purchased from Shanghai Lianyi Fiber Laser Equipment Co., Ltd.

[0021] Reference Figure 1-4 The present invention provides a static and dynamic friction detection system for high-precision processing of semiconductor wafers, including a reciprocating friction and wear detection device and a computer control system.

[0022] The reciprocating friction and wear detection equipment uses a mounting base plate 1 and a gantry 3 as a main frame, an equipment housing 16 is provided on the outside of the main frame, and an adjustable leveling foot 2 is provided at the bottom of the mounting base plate 1; a Y-axis electric translation stage 4 is provided at one end of the upper surface of the mounting base plate 1 away from the gantry 3, a rotating platform 5 with a self-locking nut is provided on the Y-axis electric translation stage 4, a lower sample stage 6 is provided on the rotating platform 5, the top surface of the lower sample stage 6 is a recessed structure, and a circular lower sample 7 is loaded into the recessed structure of the lower sample stage 6; a wafer 9 serving as an upper sample is provided on the top surface of the circular lower sample 7, and a force-added weight 10 is provided on the upper surface of the wafer 9 to provide positive pressure for wafer contact friction.

[0023] An X-axis electric translation platform 21 is horizontally installed on the crossbeam of the gantry 3, and a Z-axis electric lifting platform 13 driven by a stepper motor 14 is installed on the top of the X-axis electric translation platform 21. A high-precision friction force measuring device 11 is provided on the Z-axis electric lifting platform 13, and a high-definition camera 12 is provided on the high-precision friction force measuring device 11.

[0024] The high-precision friction force measuring device 11 includes a two-dimensional piezoelectric ceramic translation stage 11-6 that can be adjusted in micro-distance in the X and Z directions. The two-dimensional piezoelectric ceramic translation stage 11-6 is driven by voltage. A Y-shaped force transmission beam 11-3 extending downward is provided on one side of the panel of the two-dimensional piezoelectric ceramic translation stage 11-6. Strain gaps 11-5 are opened on both sides of the top of the Y-shaped force transmission beam 11-3. High-precision displacement sensors 11-4 are installed on both sides of the Y-shaped force transmission beam 11-3 at the bottom of the two strain gaps 11-5. The bottom of the handle of the Y-shaped force transmission beam 11-3 is connected to one end of the Y-direction strain type force sensor 11-2, and the other end of the Y-direction strain type force sensor 11-2 is connected to the horizontally arranged side-pushing wafer fork 11-1 mechanism, and the side-pushing wafer fork 11-1 mechanism is in contact with the wafer 9. The high-definition camera 12 is installed on the same side of the Y-shaped force measuring beam 11-3 of the two-dimensional piezoelectric ceramic translation stage 11-6 through a lens mounting frame 23.

[0025] Specifically, since the upper sample wafer 9 is mostly in the shape of a 50 mm disc, the side-pushing wafer fork 11-1 mechanism is designed to include four forks, and an arc structure that matches the outer periphery of the wafer 9 is formed between every two forks, which can realize the push-pull movement of the wafer 9 on the circular lower sample 7. The friction force during the movement is collected and recorded by the high-precision displacement sensor 11-4 and the Y-axis strain force sensor 11-2. The bottom of the four forks is a horizontal plane. Since the pushed wafer 9 is relatively thin, precise control is required when moving in the Z direction, which is specifically controlled in two steps: coarse adjustment is completed by the stepper motor 14 driving the Z-axis electric lifting platform 13. When the high-definition camera 12 detects that the distance between the fork and the circular lower sample 7 is large, the electric lifting platform 13 works to drive the fork to move downward. When the high-definition camera detects that the height of the fork is ≤1mm away from the circular lower sample 7, the electric lifting platform 13 stops working, and the two-dimensional piezoelectric ceramic translation stage 11-6 starts the fine adjustment mode, driving the fork to approach the lower sample 7 and the side of the upper sample wafer 9 with a smaller displacement, so as to realize the precise positioning of the fork 11-1, which can not only ensure the pushing of the wafer 9, but also ensure that the fork does not interfere with the circular lower sample 7.

[0026] Specifically, in order to coordinate the overall structure of the equipment and ensure the smooth operation of the equipment, the X-axis electric translation stage 21 is driven by a transmission device 15, which includes an X-axis servo motor 20, the main shaft of which is connected to a driving wheel 15-1, the driving wheel 15-1 is connected to a driven wheel 15-3 through a synchronous belt 15-2, and the driven wheel 15-3 is connected to the lead screw of the X-axis electric translation stage 21 to achieve transmission. The Y-axis electric translation stage 4 is driven by a Y-axis servo motor 17, and the Y-axis servo motor 17 is connected to the translation stage lead screw through a coupling 18.

[0027] Specifically, to prevent the X- and Y-axis electric translation stages from colliding with the device housing 16 during movement, the present invention provides X-axis optical limit switches 22 at both ends of the X-axis electric translation stage 21 and Y-axis optical limit switches 19 at both ends of the Y-axis electric translation stage 4.

[0028] Specifically, the rotating platform 5 is driven to rotate manually. After the circular lower sample 7 is installed, the disc can be manually rotated to select the test area. After rotating to a suitable position, it is locked by the nut provided on the rotating platform. Specifically, in order to ensure the installation stability of the circular lower sample 7 during the rotation of the lower sample stage 6 and to ensure the accuracy of the friction measurement, the circular lower sample 7 is locked by the bolts 8 around the lower sample stage 6 after being loaded into the lower sample stage 6. In order to avoid scratching the circular lower sample 7, the bolts 8 are made of flexible material.

[0029] The signal output end of the computer control system is electrically connected to the Y-axis servo motor 17, the X-axis servo motor 20, the stepper motor 14, the rotating platform 5 driving mechanism, and the driving mechanism of the two-dimensional piezoelectric ceramic translation stage 11-6, and the signal input end of the computer control system is electrically connected to the high-precision displacement sensor 11-4, the Y-axis strain force sensor 11-2, the X-axis optical limit switch 22 and the Y-axis optical limit switch 19.

[0030] Reference Figure 3 When the wafer with a light mass or a small friction force on the contact surface of the generated displacement is tested, the shift fork can be adjusted to push the wafer 9 to move in the X direction, and the deformation of the force transmission beam 11-3 drives the internal iron core of the high-precision displacement sensor 11-4 to slightly move, so as to determine the magnitude of the dynamic friction force according to the voltage value collected by the computer control system. In this process, the static friction force can be effectively collected by detecting the deformation of the strain gap 11-5 on the force transmission beam 11-3 through the high-precision displacement sensor 11-4; at the same time, when the wafer 9 slightly moves in the Y direction, the magnitude of the micro-motion friction force is directly measured by the Y-direction strain force sensor 11-2. The combination of the two sensors can realize bidirectional force measurement, as well as the test of a wider friction range and the measurement of dynamic and static friction.

Claims

1. A static and dynamic friction detection system for high-precision processing of semiconductor wafers, characterized in that: Includes reciprocating friction and wear detection equipment and computer control system; The reciprocating friction and wear detection equipment uses a mounting base plate (1) and a gantry (3) as a main frame, a Y-axis electric translation stage (4) is provided at one end of the upper surface of the mounting base plate (1) away from the gantry (3), a rotating platform (5) with a self-locking nut is provided on the Y-axis electric translation stage (4), a lower sample stage (6) is provided on the rotating platform (5), the top surface of the lower sample stage (6) is a recessed structure, and a circular lower sample (7) is loaded into the recessed structure of the lower sample stage (6); a wafer (9) as an upper sample is provided on the top surface of the circular lower sample (7), and a force weight (10) for providing positive pressure for wafer contact friction is provided on the upper surface of the wafer (9); An X-axis electric translation platform (21) is horizontally mounted on the crossbeam of the gantry (3); a Z-axis electric lifting platform (13) driven by a top stepping motor (14) is mounted on the X-axis electric translation platform (21); a high-precision friction force measuring device (11) is mounted on the Z-axis electric lifting platform (13); and a high-definition camera (12) is mounted on the high-precision friction force measuring device (11); The high-precision friction force measurement device (11) comprises a two-dimensional piezoelectric ceramic translation stage (11-6) capable of performing micro-adjustment in the X and Z directions; a Y-shaped force transmission beam (11-3) extending downward is provided on one side of a panel of the two-dimensional piezoelectric ceramic translation stage (11-6); strain gaps (11-5) are provided on both sides of the top of the Y-shaped force transmission beam (11-3); high-precision displacement sensors (11-4) are installed on both sides of the Y-shaped force transmission beam (11-3) at the bottom of the two strain gaps (11-5); the bottom of the handle of the Y-shaped force transmission beam (11-3) is connected to one end of a Y-direction strain-type force sensor (11-2); the other end of the Y-direction strain-type force sensor (11-2) is connected to a horizontally arranged side-pushing wafer fork (11-1) mechanism; the side-pushing wafer fork (11-1) mechanism is in contact with a wafer (9); The signal output end of the computer control system is electrically connected to the drive mechanisms of the Y-axis electric translation stage (4), the Z-axis electric lifting stage (13), the rotating platform (5), the X-axis electric translation stage (21), and the two-dimensional piezoelectric ceramic translation stage (11-6), respectively, and the signal input end of the computer control system is electrically connected to the high-precision displacement sensor (11-4) and the Y-axis strain force sensor (11-2), respectively.

2. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as claimed in claim 1, characterized in that: The side-pushing wafer shift fork (11-1) mechanism comprises four shift forks, and between every two shift forks there is an arc structure that matches the outer circumference of the wafer (9).

3. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as claimed in claim 2, characterized in that: The X-axis electric translation stage (21) is driven by a transmission device (15), the transmission device (15) comprising an X-axis servo motor (20), the main shaft of the X-axis servo motor (20) being connected to a driving wheel (15-1), the driving wheel (15-1) being connected to a driven wheel (15-3) via a synchronous belt (15-2), and the driven wheel (15-3) being connected to a lead screw of the X-axis electric translation stage (21) to achieve transmission.

4. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as claimed in claim 3, characterized in that: X-direction optical limit switches (22) are provided at both ends of the X-direction electric translation stage (21), and Y-direction optical limit switches (19) are provided at both ends of the Y-direction electric translation stage (4). Both the X-direction optical limit switch (22) and the Y-direction optical limit switch (19) are electrically connected to a signal input end of a computer control system.

5. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as claimed in claim 4, characterized in that: The Y-axis electric translation stage (4) is driven by a Y-axis servo motor (17), and the Y-axis servo motor (17) is connected to the translation stage lead screw via a coupling (18).

6. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as claimed in claim 5, characterized in that: The Z-axis electric lifting platform (13) is driven by a stepping motor (14) on the top thereof.

7. A static and dynamic friction detection system for high-precision semiconductor wafer processing as claimed in claim 6, characterized in that: The rotating platform (5) is rotated by manual drive.

8. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as described in any one of claims 1 to 7, characterized in that: After the circular lower sample (7) is loaded into the lower sample platform (6), it is locked by bolts (8) around the lower sample platform (6), and the bolts (8) are made of a flexible material.

9. A static and dynamic friction detection system for high-precision processing of semiconductor wafers as described in any one of claims 1 to 7, characterized in that: The bottom of the installation base plate (1) is provided with a leveling foot (2).

10. A static and dynamic friction detection system for high-precision processing of semiconductor wafers according to any one of claims 1 to 7, characterized in that: The high-definition camera (12) is mounted on the same side of the Y-shaped force measuring beam (11-3) of the two-dimensional piezoelectric ceramic translation stage (11-6) via a lens mounting frame (23).

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