A wafer defect detection and position correction device and method for a chip etching machine

Abstract

A wafer defect detection and position correction device and method for a chip etching machine disclosed by the present invention include a base, a wafer correction module, a rotating lifting table module, and a machine vision module. The wafer correction module is installed at one end of the base, the rotating lifting table module is installed at the other end of the base, the machine vision module is installed on the side wall of the base, and the machine vision module is arranged adjacent to the rotating lifting table module. The present invention belongs to the technical field of chip processing, and specifically is a wafer defect detection and position correction device for a chip etching machine integrating machine vision and mechatronics. Machine vision uses optical devices for non-contact perception, featuring high efficiency and high automation. A wafer defect detection and position correction device for a chip etching machine that uses a machine vision system to identify and position the wafer and perform defect detection, ensuring that the wafer has no obvious defects when entering the etching process and can be smoothly transferred to the correct position in the reaction chamber by a manipulator.

Description

Technical Field

[0001] The present invention belongs to the technical field of chip processing, and particularly relates to a wafer defect detection and position correction device and method for a chip etching machine. Background Art

[0002] A wafer refers to a silicon wafer used for processing semiconductor chips, and its overall shape is circular, so it is called a wafer. The etching machine transports the wafer into the reaction chamber of the machine tool through a manipulator for etching processing. If the position of the wafer is deviated when the manipulator picks up the wafer, it may cause the wafer to be in an incorrect position in the reaction chamber, resulting in etching failure; in addition, during the production process of the previous process, the wafer may have defects such as cracks, scratches, fingerprints, dust, stains, and chipping and warping at the edge of the wafer. Allowing it to enter the subsequent production process will cause greater economic losses.

[0003] To ensure that the wafer can be smoothly grasped by the manipulator and ensure the correct position of the wafer in the reaction chamber, a wafer position correction device is usually set at the initial stage of wafer transfer. Usually, an optoelectronic sensor is used for edge detection in combination with a rotary table.

[0004] CN213022913U discloses a wafer position detection and alignment device. This device has a movable rotary turntable, and there are four groups of evenly distributed positioning devices and wafer limit sleeves on the turntable. The positioning device consists of three positioning rods. A microscope and three laser lights are mounted above the turntable of this device, and the laser lights are vertically directed at the turntable. The positioning principle is to move and position a set of positioning devices to the position of the three laser beams above by rotating and moving the pose of the turntable, so as to achieve three-point positioning;

[0005] CN213878041U discloses a new type of wafer edge inspection device. There is a rotary stage on the inspection machine frame of this device, and there is an edge and corner finder on the rotary stage. The edge and corner finder is used to limit the wafer, and the pose of the wafer is adjusted through the turning screw and turning handle on the edge and corner finder, so that the staff can perform edge inspection through a magnifying glass with a light source on the upper edge;

[0006] CN113884506A discloses a silicon wafer edge and surface automatic vision detection system and detection method. This system clamps the camera through two U-shaped frames, drives the camera to make an inclined movement through an electric push rod, drives the camera to rotate through a first motor, drives the camera to translate through a translation mechanism, and drives the translation mechanism and the camera to make a lifting movement through a second motor. The above movement mechanisms act on the camera to perform mobile detection on the conveyor belt;

[0007] CN113871314A discloses a wafer edge topography inspection system and its inspection method. In this system, the wafer is placed on a turntable in a circular groove of a placement plate, and a vacuum pump is used to evacuate the air to fix the wafer. The second motor drives the turntable to rotate, thereby driving the wafer to rotate. Then, the third motor is started to drive the connecting plate loaded with the inspector to move to the wafer workpiece, and the inspector is used to inspect the edge topography of the wafer.

[0008] Currently, the following problems generally exist in the wafer positioning and defect detection of chip etching machines: (1) The processes of wafer positioning and defect detection are complex and inefficient. (2) There is a lack of wafer defect detection function or the defect detection items are single, making it difficult to solve various possible problems and resulting in poor flexibility. (3) Wafer positioning and detection are two separate systems, occupying a large amount of space and affecting the compactness of the machine tool. (4) For wafers made of semi-transparent materials such as silicon carbide, the positioning accuracy is relatively low when using the photoelectric sensor edge patrol method, and it cannot even be achieved when the transparency is relatively high. Summary of the Invention

[0009] In view of the above situation, to overcome the defects of the prior art, the present invention provides a chip etching machine wafer defect detection and position correction device and its method, which is a chip etching machine wafer defect detection and position correction device integrating machine vision and mechatronics. Machine vision uses optical devices for non-contact sensing, featuring high efficiency and high automation. The machine vision system is used to identify and position the wafer and perform defect detection, ensuring that the wafer has no obvious defects when entering the etching process and can be smoothly transferred to the correct position in the reaction chamber by the manipulator.

[0010] The technical solution adopted by the present invention is as follows: A chip etching machine wafer defect detection and position correction device includes a base, a wafer correction module, a rotary lifting table module, and a machine vision module. The wafer correction module is installed at one end of the base, the rotary lifting table module is installed at the other end of the base, the machine vision module is installed on the side wall of the base, and the machine vision module is arranged adjacent to the rotary lifting table module. The wafer correction module includes a correction base, a U-shaped pulley, a correction stepping motor, a sliding plate, a correction vacuum generator, a guide rail slider, a belt clamp, a shuttle, a slide rail, and a belt tension pulley. The correction base is provided on the base, the correction stepping motor is provided on one side of the upper part of the correction base, the belt tension pulley is provided on the side of the upper part of the correction base away from the correction stepping motor, the U-shaped pulley is provided at the output end of the correction stepping motor, the slide rail is provided on the correction base, the guide rail slider is provided on the slide rail, the sliding plate is slidably provided on the guide rail slider, the correction vacuum generator is provided on one side of the upper part of the sliding plate, the shuttle is provided on the other side of the upper part of the sliding plate, the correction vacuum generator and the shuttle are arranged opposite to each other, and the belt clamp is provided in the middle of the sliding plate.

[0011] Further, the rotary lifting table module includes a lower mounting plate, a positioning pin, an upper mounting plate, a double-column and double-shaft micro cylinder, a vacuum generator for the lifting module, a stepping motor for the lifting module, a coupling, a nozzle mounting seat, and a nozzle. The lower mounting plate is provided at one end of the base. The positioning pin is provided in the middle of the upper part of the lower mounting plate, and the positioning pin is nested and welded with the lower mounting plate. The double-column and double-shaft micro cylinder is provided on the side wall of the lower mounting plate. The upper mounting plate is provided above the double-column and double-shaft micro cylinder. The vacuum generator for the lifting module is provided on the side wall of the lower mounting plate. The stepping motor for the lifting module is provided on the side wall of the lower mounting plate away from the positioning pin. The coupling is provided at the output end of the stepping motor for the lifting module. The nozzle mounting seat is provided above the coupling. The nozzle is provided above the nozzle mounting seat, and the nozzle mounting seat is communicated with the vacuum generator for the lifting module.

[0012] Further, the machine vision module includes a mounting bracket, an industrial camera, and a coaxial light source. The mounting bracket is provided on the side wall of the base. The industrial camera is provided above the mounting bracket. The coaxial light source is provided on the side wall of the mounting bracket, and a lens is installed on the industrial camera.

[0013] Further, the groove of the shuttle should be coaxial with the outer contour of the nozzle, and the lens is provided directly above the nozzle.

[0014] Further, the limit pin column includes a pin and a pin base. One end of the pin is installed on the upper mounting plate, and the pin is threadedly connected with the upper mounting plate. The pin base is integrally nested and welded with the lower mounting plate.

[0015] Further, two magnetic switches are provided on the side wall of the vacuum generator for the lifting module.

[0016] Preferably, the industrial camera model is MV-CS016-10GM of Hikvision.

[0017] The present invention further includes a method for using a chip etching machine wafer defect detection and position correction device, including the following steps:

[0018] Step S1: Calibrate the wafer correction module, the rotary lifting table module, and the machine vision module to obtain the scale relationship between the image coordinate system of the wafer image in the standard position and the world coordinate system where the wafer actually is, and determine the correct position of the wafer;

[0019] Step S2: The wafer correction module transfers the wafer to the rotary lifting table module;

[0020] Step S3: The machine vision module captures the wafer image, identifies and locates the outer contour of the wafer, determines whether there are defects such as cracks, scratches, fingerprints, dust, and stains on the surface image of the wafer within the contour, and determines whether there are defects such as chipping and warping at the edge of the wafer. If any of the above defects exist, an alarm is given and waiting for the staff to handle. If none of the above defects exist, the center coordinates of the wafer in the image are obtained, and the offset and offset angle parameters of this coordinate relative to the correct position are calculated;

[0021] Step S4: The rotation and lifting table module rotates the wafer according to the offset angle to correct the angle offset, and then converts the pixel offset of the wafer with the calibrated scale to obtain the actual wafer offset. The wafer correction module moves according to the actual offset to correct the position offset;

[0022] Step S5: The rotation and lifting table module drives the corrected wafer to rotate one week. During this period, the machine vision module captures an image every 30° rotation of the wafer and repeats the content of the steps to obtain the offset between the corrected wafer position and the standard position. If the offset distance is outside the error allowable range, the content of Step S4 is repeated. If the offset distance is within the error allowable range, the wafer defect detection and position correction are ended;

[0023] Step S6: After the wafer defect detection and position correction are ended, the wafer correction module retreats to the right limit and sends a "Ready" signal to the etcher, waiting for the handling robot to pick up the wafer.

[0024] After adopting the above structure, the beneficial effects of the present invention are as follows: The present invention relates to a wafer defect detection and position correction device and method for a chip etcher. The correction uses a machine vision system to identify and locate the wafer, which can quickly correct the wafer position according to the processing requirements, ensuring the correct position when the robot smoothly grabs the wafer and the wafer is transported into the reaction chamber; it can detect defects such as surface cracks, scratches, fingerprints, dust, stains on the wafer during the previous production process, and chipping and warping at the edge of the wafer, with the characteristics of simple structure, convenient operation, labor-saving and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification, together with the embodiments of the present invention, to explain the present invention, and do not constitute a limitation to the present invention.

[0026] Figure 1 It is a schematic diagram of the overall structure of a wafer defect detection and position correction device for a chip etcher of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the wafer correction module of a wafer defect detection and position correction device for a chip etcher of the present invention;

[0028] Figure 3Schematic structural diagram of the rotation and lifting module of a wafer defect detection and position correction device for a chip etching machine according to the present invention;

[0029] Figure 4 Schematic structural diagram of the machine vision module of a wafer defect detection and position correction device for a chip etching machine according to the present invention.

[0030] In the drawings: 1, base; 2, wafer correction module; 3, rotation and lifting table module; 4, machine vision module; 5, correction base; 6, U-shaped pulley; 7, correction stepper motor; 8, cross slide; 9, correction vacuum generator; 10, guide rail slider; 11, belt fixture; 12, shuttle; 13, slide rail; 14, belt tensioning pulley; 15, lower mounting plate; 16, positioning pin; 17, upper mounting plate; 18, double-column and double-shaft micro cylinder; 19, lifting module vacuum generator; 20, lifting module stepper motor; 21, coupling; 22, nozzle mounting seat; 23, nozzle; 24, mounting bracket; 25, industrial camera; 26, coaxial light source; 27, lens; 28, pin; 29, pin base; 30, magnetic switch. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0033] As Figure 1 shown, a wafer defect detection and position correction device for a chip etching machine includes a base 1, a wafer correction module 2, a rotation and lifting table module 3, and a machine vision module 4. The wafer correction module 2 is installed at one end of the base 1, the rotation and lifting table module 3 is installed at the other end of the base 1, the machine vision module 4 is installed on the side wall of the base 1, and the machine vision module 4 is arranged adjacent to the rotation and lifting table module 3.

[0034] AsFigure 2 As shown, the wafer alignment module 2 is installed at the rear end of the base 1 and is used to align the groove on the shuttle 12 of the wafer that is connected to the alignment vacuum generator 9. The alignment vacuum generator 9 and the shuttle 12 are both installed on the cross slide 8. The cross slide 8 is matched with the guide rail slider 10, and a belt clamp 11 is installed on the guide rail slider 10. The belt clamp 11 is used to clamp the belt on which the U-shaped pulley 6 and the belt tensioning pulley 14 are installed. The alignment stepper motor 7 can drive the guide rail slider 10 to reciprocate along the guide rail direction through the belt.

[0035] As Figure 3 shown, the lower mounting plate 15 of the rotary lifting table module 3 is installed at the front end of the base 1. There is a positioning pin 16 nested and welded on the lower mounting plate 15. A double-column and double-shaft micro cylinder 18 is installed at the left end, and a lifting module vacuum generator 19 is installed at the rear end. The double-column and double-shaft micro cylinder 18 pushes the upper mounting plate 17 to move up and down. The end of the upper mounting plate 17 is equipped with a lifting module stepper motor 20. A nozzle mounting seat 22 is clamped on the optical axis of the lifting module stepper motor 20 through a coupling 21. The nozzle mounting seat 22 is connected to the lifting module vacuum generator 19, and a matching nozzle 23 is installed at the top of the nozzle mounting seat 22.

[0036] As Figure 4 shown, the mounting bracket 24 of the machine vision module 4 is installed on the left side of the base 1. An industrial camera 25 and a coaxial light source 26 are installed on the mounting bracket 24. A lens 27 is installed on the industrial camera 25.

[0037] Among them, the groove of the shuttle 12 should be coaxial with the outer contour of the nozzle 23. The lens 27 is arranged directly above the nozzle 23. The positioning pin 16 includes a pin 28 and a pin base 29. One end of the pin 28 is installed on the upper mounting plate 17, and the pin 28 is threadedly connected to the upper mounting plate 17. The pin 28 base 1 is integrally nested and welded with the lower mounting plate 15. Two magnetic switches 30 are provided on the side wall of the lifting module vacuum generator 19.

[0038] During specific use, calibrate the wafer alignment module 2, the rotary lifting table module 3, and the machine vision module 4 to obtain the scale relationship between the image coordinate system of the wafer image in the standard position and the world coordinate system where the wafer actually is, and determine the correct position of the wafer. The wafer alignment module 2 transfers the wafer to the rotary lifting table module 3. The machine vision module 4 captures the wafer image, identifies and locates the outer contour of the wafer, and judges whether there are defects such as cracks, scratches, fingerprints, dust, and stains on the wafer surface image within the contour and whether there are defects such as chipping and warping at the wafer edge. If any of the above defects exist, an alarm is given and waiting for the staff to handle. If none of the above defects exist, the coordinates of the wafer center in the image are obtained, the offset and offset angle parameters of this coordinate relative to the correct position are calculated. The rotary lifting table module 3 rotates the wafer according to the offset angle to correct the angle offset, and then converts the pixel offset of the wafer with the calibrated scale to obtain the actual wafer offset. The wafer alignment module 2 moves according to the actual offset to correct the position offset. The rotary lifting table module 3 drives the corrected wafer to rotate one week. During this period, the machine vision module 4 captures an image every 30° of wafer rotation and repeats the content of the steps to obtain the offset between the corrected wafer position and the standard position. If the offset distance is outside the error tolerance range, repeat the content of step S4. If the offset distance is within the error tolerance range, the wafer defect detection and position correction end. After the wafer defect detection and position correction end, the wafer alignment module 2 retreats to the right limit and sends a "Ready" signal to the etching machine, waiting for the handling robot to pick up the wafer.

[0039] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. In general, if those of ordinary skill in the art are inspired by it and design similar structural methods and embodiments without creative efforts without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A wafer defect detection and position correction device for a chip etching machine, characterized in that: It includes a base, a wafer alignment module, a rotary lifting table module and a machine vision module. The wafer alignment module is installed at one end of the base, the rotary lifting table module is installed at the other end of the base, the machine vision module is installed on the side wall of the base, and the machine vision module is arranged adjacent to the rotary lifting table module. The wafer alignment module includes an alignment base, a U-shaped pulley, an alignment stepping motor, a sliding plate, an alignment vacuum generator, a guide rail slider, a belt clamp, a shuttle, a slide rail and a belt tensioning pulley. The alignment base is arranged on the base, the alignment stepping motor is arranged on one side of the upper part of the alignment base, the belt tensioning pulley is arranged on the upper part of the alignment base away from the alignment stepping motor, the U-shaped pulley is arranged at the output end of the alignment stepping motor, the slide rail is arranged on the alignment base, the guide rail slider is arranged on the slide rail, the sliding plate is slidably arranged on the guide rail slider, the alignment vacuum generator is arranged on one side of the upper part of the sliding plate, the shuttle is arranged on the other side of the upper part of the sliding plate, the alignment vacuum generator and the shuttle are arranged oppositely, and the belt clamp is arranged at the middle of the sliding plate; The rotary lifting table module includes a lower mounting plate, a positioning pin, an upper mounting plate, a double-column double-shaft micro cylinder, a lifting module vacuum generator, a lifting module stepping motor, a coupling, a nozzle mounting seat and a nozzle. The lower mounting plate is arranged at one end of the base, the positioning pin is arranged at the middle of the upper part of the lower mounting plate, the positioning pin is nested and welded with the lower mounting plate, the double-column double-shaft micro cylinder is arranged on the side wall of the lower mounting plate, the upper mounting plate is arranged above the double-column double-shaft micro cylinder, the lifting module vacuum generator is arranged on the side wall of the lower mounting plate, the lifting module stepping motor is arranged on the side wall of the lower mounting plate away from the positioning pin, the coupling is arranged at the output end of the lifting module stepping motor, the nozzle mounting seat is arranged above the coupling, the nozzle is arranged above the nozzle mounting seat, and the nozzle mounting seat is communicated with the lifting module vacuum generator; The machine vision module includes a mounting bracket, an industrial camera and a coaxial light source. The mounting bracket is arranged on the side wall of the base, the industrial camera is arranged on the upper part of the mounting bracket, the coaxial light source is arranged on the side wall of the mounting bracket, and a lens is installed on the industrial camera.

2. The wafer defect detection and position correction device for a chip etching machine according to claim 1, wherein: The groove of the shuttle should be coaxial with the outer contour of the nozzle, and the lens is arranged directly above the nozzle.

3. The wafer defect detection and position correction device for a chip etching machine according to claim 1, characterized in that: The positioning pin includes a pin and a pin base. One end of the pin is installed on the upper mounting plate, the pin is threadedly connected with the upper mounting plate, and the pin base is integrally nested and welded with the lower mounting plate.

4. A wafer defect detection and position correction device for a chip etching machine according to claim 1, characterized in that: Two magnetic switches are arranged on the side wall of the lifting module vacuum generator.

5. The usage method of a wafer defect detection and position correction device for a chip etching machine according to any one of claims 1-4, characterized in that: It includes the following steps: Step S1: Calibrate the wafer alignment module, the rotary lifting table module and the machine vision module to obtain the scale relationship between the image coordinate system of the wafer image in the standard position and the world coordinate system where the wafer actually is, and determine the correct position of the wafer; Step S2: The wafer alignment module transfers the wafer to the rotary lifting table module; Step S3: The machine vision module captures the wafer image, identifies and locates the outer contour of the wafer, judges whether there are defects such as cracks, scratches, fingerprints, dust, and stains on the wafer surface image within the contour, and judges whether there are defects such as chipping and warping at the wafer edge image. If any of the above defects exist, an alarm is given and waiting for the staff to handle. If none of the above defects exist, the coordinates of the wafer center in the image are obtained, and the offset and offset angle parameters of this coordinate relative to the correct position are calculated; Step S4: The rotation and lifting table module rotates the wafer according to the offset angle to correct the angle offset, then converts the pixel offset of the wafer with the calibrated scale to obtain the actual wafer offset, and the wafer correction module moves according to the actual offset to correct the position offset; Step S5: The rotation and lifting table module drives the corrected wafer to rotate one week. During this period, the machine vision module grabs an image every 30° of wafer rotation and repeats the content of the steps to obtain the offset between the corrected wafer position and the standard position. If the offset distance is outside the error tolerance range, repeat the content of Step S4. If the offset distance is within the error tolerance range, the wafer defect detection and position correction are completed; Step S6: After the wafer defect detection and position correction are completed, the wafer correction module retreats to the right limit and sends a "Ready" signal to the etcher, waiting for the handling robot to pick up the wafer.

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