A static and dynamic friction detection system for high-precision processing of semiconductor wafers

Abstract

The application discloses a static and dynamic friction detection system for high-precision processing of a semiconductor wafer, mainly comprising a reciprocating friction and wear detection device and a computer control system; when a fork pushes the wafer in the X direction, the deformation of a force transmission beam drives the internal iron core of a displacement sensor to slightly move, so that the size of the dynamic friction force is determined according to the voltage value collected by the computer control system; in the process, the static friction force can be effectively collected by detecting the strain gap deformation of the force transmission beam through the displacement sensor; meanwhile, when the wafer slightly moves in the Y direction, the size of the slight friction force is directly measured by a Y-direction strain force sensor. The combination of the two sensors can realize bidirectional force measurement, and can also realize the test of a wide friction force range and the full-coverage measurement of the static and dynamic friction forces in the same system. The application has the advantages of simple structure, low conversion and maintenance cost, and is suitable for large-scale application in the semiconductor processing and manufacturing industry and other material research institutions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-precision friction testing equipment, and relates to a static and dynamic friction detection system for a high-precision processing process of a semiconductor wafer, in particular to a side push static and dynamic friction detection system for a deep processing process of a semiconductor wafer. BACKGROUND

[0002] With the continuous development of semiconductor technology, the quality requirements for the wafer surface are also getting higher and higher. The friction and wear between the wafer and the wafer stage directly affect the surface quality and processing precision of the wafer during the deep processing of the semiconductor wafer. Therefore, through the detection of the friction between the wafer and the wafer stage, the appearance defects such as scratches, stains and cracks left on the wafer by the equipment during the processing process can be found in time, and the wafer bending and edge lifting phenomenon caused by thermal stress and mechanical stress can be found in time, thereby guiding the optimization and replacement of the grinding material and device, so as to ensure the stability of the wafer processing quality. At the same time, the friction data can also be used to provide a basis for the adjustment of wafer processing parameters, help material design and optimization of processing technology, and improve processing efficiency and wafer surface quality. During the wafer surface processing process, according to the working condition loading, a push force needs to be applied to the wafer laterally 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 the computer software. However, due to the small thickness of the wafer after deep processing, about 500-750 μm, and the small mass of the wafer, the friction and wear detection of the wafer material is multiplied. At present, due to the changes in international trade policy, some countries have issued export control policies in the field of semiconductor equipment, which has greatly affected the detection and analysis of domestic semiconductor materials. In order to improve the safety of the semiconductor industry chain, it is particularly urgent to increase the localization rate of semiconductor measurement equipment. At present, there is a lack of detection equipment for the friction performance of wafer materials on the domestic market. Therefore, it is necessary to develop a wafer material friction detection equipment. SUMMARY

[0003] Based on the above, the purpose of the present application is to provide a static and dynamic friction detection system for a high-precision processing process of a semiconductor wafer, which is used for friction and wear detection of semiconductor wafer materials during processing and movement, and simulates the reciprocating friction and wear detection of different regions on the wafer surface to provide a basis for the adjustment of wafer processing parameters, improve processing efficiency and wafer surface quality.

[0004] To achieve the purpose, the present application adopts the following technical scheme:

[0005] A static and dynamic friction detection system for a high-precision processing process of a semiconductor wafer, comprising a reciprocating friction and wear detection equipment and a computer control system.

[0006] The reciprocating friction and wear detection device takes the mounting base and the gantry as the main frame, the Y-direction electric translation table is arranged on the upper surface of the mounting base away from the gantry, the rotating platform with the self-locking nut is arranged on the Y-direction electric translation table, the lower sample table is arranged on the rotating platform, the top surface of the lower sample table is of the recessed structure, and the circular lower sample is arranged in the recessed structure of the lower sample table.

[0007] The X-direction electric translation table is horizontally arranged on the beam of the gantry, the Z-direction electric lifting table driven by the top stepping motor is arranged on the X-direction electric translation table, the high-precision friction force measuring device is arranged on the Z-direction electric lifting table, and the high-definition camera is arranged on the high-precision friction force measuring device.

[0008] The high-precision friction force measuring device comprises a two-dimensional piezoelectric ceramic translation table capable of being adjusted in the X and Z directions, the Y-shaped force transmission beam extending downward is arranged on one side of the two-dimensional piezoelectric ceramic translation table, the strain gaps are formed on the top of the two sides of the Y-shaped force transmission beam, and the high-precision displacement sensor is arranged on the two sides of the Y-shaped force transmission beam at the bottom of the two strain gaps. The bottom of the beam handle of the Y-shaped force transmission beam is connected with one end of the Y-direction strain type force sensor, the other end of the Y-direction strain type force sensor is connected with the side pushing wafer fork mechanism arranged horizontally, and the side pushing wafer fork mechanism is in abutment with the wafer.

[0009] The signal output end of the computer control system is electrically connected with the driving mechanisms of the Y-direction electric translation table, the Z-direction electric lifting table, the rotating platform, the X-direction electric translation table and the two-dimensional piezoelectric ceramic translation table respectively, and the signal input end of the computer control system is electrically connected with the high-precision displacement sensor and the Y-direction strain type force sensor respectively.

[0010] As a further improvement of the technical scheme of the application, the side pushing wafer fork mechanism comprises four forks, and each two forks are arranged in the circular arc structure matched with the outer periphery of the wafer.

[0011] Further, the X-direction electric translation table is driven through the transmission device, the transmission device comprises an X-direction servo motor, the main shaft of the X-direction servo motor is connected with the driving wheel, the driving wheel is connected with the driven wheel through the synchronous belt, and the driven wheel is connected with the screw rod of the X-direction electric translation table to realize transmission.

[0012] Further, the X-direction optical limit switch is arranged at the two ends of the X-direction electric translation table, the Y-direction optical limit switch is arranged at the two ends of the Y-direction electric translation table, and the X-direction optical limit switch and the Y-direction optical limit switch are electrically connected with the signal input end of the computer control system.

[0013] Further, the Y-direction electric translation table is driven by the Y-direction servo motor, and the Y-direction servo motor is connected with the translation table screw rod through the shaft coupling.

[0014] Further, the Z-direction electric lifting platform is driven by a stepping motor at the top thereof.

[0015] Further, the rotating platform is manually controlled to rotate. After the upper surface is installed with the lower sample, the disc can be manually rotated to select a test area. After being rotated to a suitable position, the rotating platform is locked by a nut.

[0016] Further, the circular lower sample is locked by bolts around the lower sample table after being installed in the lower sample table, and the bolts are made of flexible material.

[0017] Further, the installation base plate is provided with adjustable leveling feet at the bottom.

[0018] Further, the high-definition camera is installed on the same side of the Y-shaped force beam of the two-dimensional piezoelectric ceramic translation stage through a lens mounting frame.

[0019] By adopting the above technical scheme, the application has the following beneficial effects:

[0020] 1. The application is aimed at detecting the friction force between a wafer of different quality and a large-span equipment surface. A force transmission beam is combined with an inductive displacement sensor and a strain force sensor. When the wafer is moved in the X direction by a fork, the deformation of the force transmission beam drives the internal core of the displacement sensor to move slightly, so that the dynamic friction force is determined according to the voltage value collected by the computer control system. In this process, the strain gap deformation of the force transmission beam is detected by the displacement sensor to effectively collect the static friction force. At the same time, when the wafer is slightly moved in the Y direction, the size of the slight friction force is directly measured by the Y-direction strain force sensor. The combination of the two sensors can realize bidirectional force measurement, and can also realize the test of a wide range of friction forces and the full coverage measurement of dynamic and static friction forces in the same system.

[0021] 2. The application combines an optical lifting platform with a piezoelectric ceramic displacement platform to realize automatic adjustment of machine vision by combining a high-definition camera, which can accurately position the position of the wafer and realize high-precision control of the fork to avoid damage to the sample by moving parts.

[0022] 3. The force transmission beam structure is combined with elastic material to be sensitive to reaction, and is combined with a high-precision data acquisition device to realize simultaneous measurement of static and dynamic friction forces.

[0023] 4. The application has simple structure, low conversion and maintenance cost, and is suitable for large-scale application in the semiconductor processing and manufacturing industry and other material research institutions. DETAILED DESCRIPTION

[0024] Figure 1 The figure is a structural schematic diagram of the reciprocating friction and wear detection equipment in the application.

[0025] Figure 2 is a half sectional view; Figure 1

[0026] Figure 3 is a structural schematic view of a high-precision friction force measuring device in the application;

[0027] Figure 4 is a partial view of a transmission device in the application;

[0028] The figure mark: 1, installation bottom plate; 2, adjustable leveling foot; 3, gantry; 4, Y direction electric translation stage; 5, rotating platform; 6, lower sample table; 7, circular lower sample; 8, bolt; 9, wafer; 10, weight; 11, high-precision friction force measuring device: 11-1, shift fork, 11-2, Y direction strain type force sensor, 11-3, force transmission beam, 11-4, high-precision displacement sensor, 11-5, strain gap, 11-6, two-dimensional piezoelectric ceramic displacement table; 12, high-definition camera; 13, Z direction electric lifting platform; 14, stepping motor; 15, transmission device: 15-1, driving wheel, 15-2, synchronous belt, 15-3, driven wheel; 16, equipment shell; 17, Y direction servo motor; 18, shaft coupling; 19, Y direction optical limit switch; 20, X direction servo motor; 21, X direction electric translation stage; 22, X direction optical limit switch; 23, lens mounting frame. DETAILED DESCRIPTION

[0029] The structure and working process of the application will be described in detail below with reference to the drawings.

[0030] In the application, the computer control system adopts Advantech 610L, the X direction and Y direction electric translation stages are purchased from Shanghai Lianli Optical Fiber Laser Instrument Co., Ltd., the rotating platform 5 is purchased from Shanghai Lianli Optical Fiber Laser Instrument Co., Ltd., the Y direction strain type 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 Sensor Technology Co., Ltd., the two-dimensional piezoelectric ceramic displacement table 11-6 is purchased from Harbin Xinming Technology Co., Ltd., the high-definition camera 12 is purchased from Weite Vision Technology (Shenzhen) Co., Ltd., and the Z direction electric lifting platform 13 is purchased from Shanghai Lianli Optical Fiber Laser Instrument Co., Ltd.

[0031] With reference to Figures 1-4 , the application provides a static and dynamic friction detection system for a high-precision processing process of a semiconductor wafer, which comprises a reciprocating friction and wear detection device and a computer control system.

[0032] ​The reciprocating friction and wear detection device takes the installation base plate 1 and the gantry 3 as the main frame, the main frame is externally provided with a device shell 16, the bottom of the installation base plate 1 is provided with an adjustable leveling foot 2; the far end of the upper surface of the installation base plate 1 away from the gantry 3 is provided with a Y-direction electric translation stage 4, the Y-direction electric translation stage 4 is provided with a rotating platform 5 with a self-locking nut, the rotating platform 5 is provided with a lower sample stage 6, the top surface of the lower sample stage 6 is of a recessed structure, a circular lower test sample 7 is arranged in the recessed structure of the lower sample stage 6; the top surface of the circular lower test sample 7 is provided with a wafer 9 as an upper test sample, and the upper surface of the wafer 9 is provided with a force adding weight 10 for providing a positive pressure for wafer contact friction.

[0033] The X-direction electric translation stage 21 is horizontally installed on the beam of the gantry 3, the Z-direction electric lifting stage 13 driven by the stepping motor 14 is installed on the top of the X-direction electric translation stage 21, the high-precision friction force measuring device 11 is arranged on the Z-direction electric lifting stage 13, and the high-definition camera 12 is arranged on the high-precision friction force measuring device 11.

[0034] The high-precision friction force measuring device 11 comprises a two-dimensional piezoelectric ceramic translation stage 11-6 capable of performing micro-distance adjustment in the X and Z directions, the two-dimensional piezoelectric ceramic translation stage 11-6 is driven by voltage, the two-dimensional piezoelectric ceramic translation stage 11-6 is provided with a Y-shaped force transmission beam 11-3 extending downward on one side of the panel, strain gaps 11-5 are formed on the top of both sides of the Y-shaped force transmission beam 11-3, and high-precision displacement sensors 11-4 are arranged on both sides of the Y-shaped force transmission beam 11-3 at the bottom of the two strain gaps 11-5; the beam handle of the Y-shaped force transmission beam 11-3 is connected with one end of the Y-direction strain type force sensor 11-2, the other end of the Y-direction strain type force sensor 11-2 is connected with the side pushing wafer fork mechanism 11-1 arranged horizontally, and the side pushing wafer fork mechanism 11-1 is in abutment with the wafer 9. The high-definition camera 12 is installed on the same side of the Y-shaped force transmission beam 11-3 of the two-dimensional piezoelectric ceramic translation stage 11-6 through a lens mounting bracket 23.

[0035] Specifically, since the upper sample wafer 9 is mostly in the form of a 50mm disc, the side pushing wafer fork 11-1 mechanism is designed to include four forks, each two forks being in the form of a circular arc matching the outer periphery of the wafer 9, so as to realize the pushing and pulling movement of the wafer 9 on the circular lower sample 7, and the frictional force in the movement process is collected and recorded by the high-precision displacement sensor 11-4 and the Y-direction strain force sensor 11-2. The bottom of the four forks is a horizontal plane, and since the wafer 9 to be pushed is relatively thin, it needs to be accurately controlled when moving in the Z direction. Specifically, the coarse adjustment is completed by the Z-direction electric lifting platform 13 driven by the stepping motor 14, and 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 distance between the fork height and the circular lower sample 7 is ≤1mm, the electric lifting platform 13 stops working, and the two-dimensional piezoelectric ceramic translation stage 11-6 starts the fine adjustment mode to drive the fork to approach the lower sample 7 and the side of the upper sample wafer 9 with a small displacement, so as to realize the accurate positioning of the fork 11-1, which can not only push the wafer 9, but also ensure that the fork does not interfere with the circular lower sample 7.

[0036] Specifically, in order to coordinate the overall structure of the equipment and ensure the stability of the equipment operation, the X-direction electric translation stage 21 is driven by a transmission device 15, which includes an X-direction servo motor 20, the main shaft of the X-direction servo motor 20 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 screw rod of the X-direction electric translation stage 21 to realize transmission.

[0037] Specifically, in order to prevent the X and Y direction electric translation stages from colliding with the equipment shell 16 during movement, the X-direction optical limit switch 22 is arranged at both ends of the X-direction electric translation stage 21, and the Y-direction optical limit switch 19 is arranged at both ends of the Y-direction electric translation stage 4.

[0038] Specifically, the rotating platform 5 is manually driven to rotate, and after the circular lower sample 7 is installed, the disc can be manually rotated to select the test area, and after being rotated to the appropriate position, it is locked by the nut of the rotating platform. Specifically, in order to ensure the stability of the installation of the circular lower sample 7 during the rotation of the lower sample platform 6 and ensure the accuracy of the friction measurement, the circular lower sample 7 is locked by the bolts 8 around the lower sample platform 6 after being installed into the lower sample platform 6. In order to avoid scratching the circular lower sample 7, the bolts 8 are made of flexible material.

[0039] The computer control system signal output end is respectively connected with Y direction servo motor 17, X direction servo motor 20, stepping motor 14, rotating platform 5 drive mechanism, two-dimensional piezoelectric ceramic translation stage 11-6 drive mechanism, computer control system signal input end is respectively connected with high precision displacement sensor 11-4, Y direction strain type force sensor 11-2, X direction optical limit switch 22 and Y direction optical limit switch 19.

[0040] Referring to Figure 3 When the wafer with lighter mass or smaller contact surface friction with the generated displacement is in the test process, the fork pushing wafer 9 in X direction movement can be adjusted, the deformation of force transmission beam 11-3 drives the high precision displacement sensor 11-4 internal core micro motion, so as to determine the dynamic friction size according to the voltage value collected by computer control system, in this process, the deformation of strain gap 11-5 on the force transmission beam 11-3 can effectively collect the static friction by high precision displacement sensor 11-4 detection; at the same time, the wafer 9 in Y direction micro motion, the micro motion friction size is directly measured by Y direction strain type force sensor 11-2. The combination of two kinds of sensors can realize bidirectional force measurement, and also can realize the test of wider friction range and the measurement of static and dynamic friction.

Claims

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

2. The static and dynamic friction detection system for high precision processing of semiconductor wafers of claim 1, wherein, The X-direction electric translation stage (21) is driven by a transmission device (15), the transmission device (15) comprises an X-direction servo motor (20), the main shaft of the X-direction servo motor (20) is connected with a driving wheel (15-1), the driving wheel (15-1) is connected with a driven wheel (15-3) through a synchronous belt (15-2), and the driven wheel (15-3) is connected with the screw rod of the X-direction electric translation stage (21) to realize transmission.

3. A static and kinetic friction detection system for high precision processing of semiconductor wafers as claimed in claim 2, wherein The X-direction electric translation stage (21) is provided with X-direction optical limit switches (22) at both ends, the Y-direction electric translation stage (4) is provided with Y-direction optical limit switches (19) at both ends, and the X-direction optical limit switches (22) and the Y-direction optical limit switches (19) are electrically connected with the signal input end of the computer control system.

4. The static and dynamic friction detection system for high precision processing of semiconductor wafers of claim 3, wherein, The Y-direction electric translation stage (4) is driven by a Y-direction servo motor (17), and the Y-direction servo motor (17) is connected with the translation stage screw through a shaft coupling (18).

5. A static and kinetic friction detection system for high precision processing of semiconductor wafers as claimed in claim 4, wherein The Z-direction electric lifting stage (13) is driven by a stepping motor (14) at the top thereof.

6. A static and kinetic friction detection system for high precision processing of semiconductor wafers as defined in claim 5, wherein The rotating platform (5) is manually driven to rotate.

7. A static and dynamic friction detection system for high precision processing of semiconductor wafers according to any one of claims 1 to 6, characterized in that The circular lower sample (7) is locked after being loaded into the lower sample stage (6) through bolts (8) around the lower sample stage (6), and the bolts (8) are made of flexible material.

8. A static and dynamic friction detection system for high precision processing of semiconductor wafers according to any one of claims 1 to 6, characterized in that The adjustable leveling feet (2) are arranged at the bottom of the mounting bottom plate (1).

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

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