Wafer edge chamfer cutting and cleaning method and cutting and cleaning device

Abstract

A wafer cutting and cleaning device comprises a body (10), a cutting station (20), a rotating mechanism (30), a movable frame (40), an etching system (50), a water jet system (60), and an air knife system (70). The wafer edge chamfering method comprises the following steps: firstly, fixing the wafer on a processing position, starting the processing position rotating mechanism to rotate the wafer; moving the etching liquid nozzle to the vicinity of the wafer edge, and spraying the etching liquid to the wafer edge; moving the high-pressure water nozzle to the vicinity of the wafer edge previously sprayed with the etching liquid, starting the high-pressure water jet, and spraying and cutting the etched position of the wafer at a predetermined angle; then starting the high-pressure air knife installed with the high-pressure water nozzle, and further spraying and cutting the surface cut by the water jet at a predetermined angle; and sending the wafer to the cleaning station for subsequent cleaning. The present invention can ensure the accuracy of the cutting angle during the chamfering process, and can effectively protect the integrity of the wafer and the integrity of the internal structure.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and in particular to a method and equipment for cleaning wafer edge chamfering and cutting. Background Art

[0002] Wafer chamfering is a common technique used today. Its primary purpose is, first, to prevent wafer edge cracking. During manufacturing and use, wafers are often impacted by robotic grippers, causing cracks along the wafer edge and creating stress concentration areas. These stress concentration areas cause the wafer to continuously release contaminants during use, thereby affecting product yield. Second, they prevent the concentration of thermal stress. During use, wafers undergo numerous high-temperature processes, such as oxidation and diffusion. When the thermal stress generated during these processes exceeds the strength of the silicon lattice, dislocations and stacking faults can occur. Rounding the wafer edge can prevent these defects. Third, it increases the flatness of the epitaxial layer and photoresist layer at the wafer edge. During the epitaxial growth process, sharp corners grow faster than flat surfaces. Therefore, wafers that are not rounded are more likely to have protrusions at the edge. Similarly, when applying photoresist using a spin coater, the photoresist solution can accumulate at the wafer edge. These uneven edges can affect the focus accuracy of the mask.

[0003] Current methods for creating chamfered or angled wafer edges include mechanical grinding, laser cutting, and etching. While mechanical grinding and laser cutting are convenient and economical, they also present challenges such as proneness to chipping, poor uniformity, and contamination. Etching alone, on the other hand, suffers from poor control accuracy and the tendency to corrode surrounding wafers. Summary of the Invention

[0004] The present invention adopts a method of combining etching and cutting, and particularly adopts a water or wind cutting method which is less harmful to the wafer, thereby avoiding the technical problem of easily damaging the wafer in the prior art.

[0005] The cutting and cleaning equipment designed by the present invention to solve the above-mentioned technical problems includes a body, a cutting station arranged in the body, a rotating mechanism for driving the cutting station, and a movable frame arranged above the cutting station. The body is also provided with an etching system, a water jet system and an air knife system. The etching liquid nozzle in the etching system, the high-pressure water jet nozzle in the water jet system and the high-pressure air knife nozzle in the air knife system are installed on the movable frame. The cutting and cleaning device also includes a control system for controlling the above-mentioned systems and the rotating mechanism.

[0006] A further improvement of the present invention is that the etching system further includes an etching liquid tank, an etching liquid pipeline for conveying etching liquid to the etching liquid nozzle, and an etching liquid volume adjustment mechanism for controlling the opening of the etching liquid nozzle. The water jet system further includes a water tank, a booster pump, a high-pressure water pipeline for conveying high-pressure water to the high-pressure water jet nozzle, and a first angle adjuster provided on the high-pressure water jet nozzle. The air knife system further includes a booster pump connected to an air source, a high-pressure air pipeline for conveying high-pressure air to the high-pressure air knife nozzle, and a second angle adjuster provided on the high-pressure air knife nozzle.

[0007] To ensure precise cutting angles, the first and second angle adjusters of the present invention are both servo motors, which control the rotation angles of the high-pressure water jet nozzle and high-pressure air jet nozzle via a reduction system. The servo motors are controlled by the control system. Alternatively, the first angle adjuster is a contour adjuster, comprising a contour plate, a first mold roller fixed to the high-pressure water jet nozzle that contacts the contoured edge of the contour plate, and a first elastic member for supporting the high-pressure water jet nozzle. The second angle adjuster is a contour adjuster, comprising a contour plate, a second mold roller fixed to the high-pressure air jet nozzle that contacts the contoured edge of the contour plate, and a second elastic member for supporting the high-pressure air jet nozzle. Both the first and second elastic members are rubber piles.

[0008] The method for performing wafer chamfering processing using the cutting and cleaning equipment is as follows:

[0009] a. First, fix the wafer on the processing position and start the processing position rotation mechanism to rotate the wafer. The rotation speed of the rotation mechanism decreases as the etching liquid nozzle gradually moves toward the edge;

[0010] b. Move the etching liquid nozzle to the edge of the wafer and spray the etching liquid toward the edge of the wafer. The amount of etching liquid sprayed increases as the nozzle moves toward the edge.

[0011] c. After the etching liquid has remained on the wafer surface for a period of time, the high-pressure water nozzle is moved to the edge of the wafer that was previously sprayed with the etching liquid. The high-pressure water jet is turned on and sprayed at a predetermined angle to cut the etched area of ​​the wafer. The pressure of the high-pressure water jet gradually increases as it moves toward the edge.

[0012] d. After step C is completed, the high-pressure air knife installed together with the high-pressure water nozzle is started, and the water jet-cut surface is further sprayed and trimmed according to a predetermined angle. The high-pressure air knife gradually increases as it moves toward the edge;

[0013] e. Send the wafer to the cleaning station for post-cleaning.

[0014] The present invention adopts the above technical solution, which can ensure the accuracy of the cutting angle during the chamfering process and effectively protect the integrity of the chip and the integrity of the internal structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the wafer chamfering cutting process of the present invention;

[0016] Figure 2 is a schematic diagram of a mobile frame of a cutting and cleaning device of the present invention;

[0017] Figure 3 is a schematic cross-sectional view of an etching liquid nozzle of the present invention;

[0018] Figure 4 It is a working schematic diagram of the first and second angle adjusters of the present invention. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are described with reference to the above drawings.

[0020] Depend on Figure 1It can be seen that the cutting and cleaning device in the present invention includes a body 10, a cutting station 20 arranged in the body, a rotating mechanism 30 for driving the cutting station 20, and a movable frame 40 arranged above the cutting station. The body is also provided with an etching system 50, a water jet system 60 and an air knife system 70. The etching liquid nozzle 51 in the etching system 50, the high-pressure water jet nozzle 61 in the water jet system 60 and the high-pressure air knife nozzle 71 in the air knife system 70 are installed in the movable frame 40. The cutting and cleaning device also includes a control system 80 for controlling the above-mentioned systems and the rotating mechanism. The method for using the device to perform chamfer cutting and cleaning of wafers includes the following steps: a. first, fix wafer A on the processing position and start the processing position rotation mechanism to rotate the wafer; b. move the etching liquid nozzle to the edge of the wafer and spray the etching liquid to the edge of the wafer; c. after the etching liquid stays on the wafer surface for a period of time, move the high-pressure water nozzle to the edge of the wafer previously sprayed with the etching liquid, start the high-pressure water jet, and spray and cut the etched position of the wafer at a predetermined angle; d. after step C is completed, start the high-pressure air knife installed together with the high-pressure water nozzle, and further spray and cut the surface cut by the water jet at a predetermined angle; e. send the wafer to the cleaning station for post-cleaning. This combination of processing mainly involves softening the wafer when the etching liquid is sprayed on the designated area of ​​the wafer for etching. In this softened state, water jet and air knife cutting are performed. This can avoid the problem of long-term wafer etching possibly damaging the surrounding tissue. The wafer itself can fully withstand the softened tissue and will not cause physical damage to it by relatively soft media such as air and water knives, thereby ensuring the safety of the wafer itself. Since the cutting is performed by angle adjustment, accurate chamfer cutting is also guaranteed.

[0021] Depend on Figures 1 to 3As can be seen, the etching system 50 of the present invention also includes an etching liquid tank 52, an etching liquid pipeline 53 for transporting etching liquid to the etching liquid nozzle 51, and an etching liquid amount adjustment mechanism 54 for controlling the opening size of the etching liquid nozzle 51. The water jet system 60 also includes a water tank 62, a booster pump 63, a high-pressure water pipeline 64 for transporting high-pressure water to the high-pressure water jet nozzle 61, and a first angle adjuster 65 provided on the high-pressure water jet nozzle 61. The air knife system 70 also includes a booster pump 62 connected to an air source, a high-pressure air pipeline 73 for transporting high-pressure air to the high-pressure air knife nozzle 71, and a second angle adjuster 74 provided on the high-pressure air knife nozzle 71. In the present invention, the movable frame is a fan-shaped structure, wherein the etching liquid nozzle 51, the high-pressure water jet nozzle 61, and the high-pressure air knife nozzle 71 are all installed in the same circular position of the movable frame, in the opposite direction of the wafer rotation. When the etching liquid is sprayed to the edge of the wafer, etching is carried out. Since the water jet and air knife are separated from the etching liquid nozzle by a distance, a certain amount of time is given to the etching to ensure that the etched area of ​​the wafer is softened. This distance is set by the corrosion rate of the etching liquid, which can ensure softening without excessive erosion. The angles of the air knife and water knife are controlled by the adjustment device to achieve the required angle and shape. By cutting the wafer with air and water jets, the cooling and preliminary cleaning effects can be further achieved.

[0022] In the present invention, the first angle adjuster 65 and the second angle adjuster 74 are both servo motors, which control the rotation angles of the high-pressure water jet nozzle 61 and the high-pressure air knife nozzle 71 through a reduction system. The servo motors are controlled by the control system 80 (not shown in the figure).

[0023] Depend on Figure 4As can be seen, the first angle adjuster 65 in the present invention is a contour adjuster, comprising a contour plate 651, a first die-rest roller 652 fixed to the high-pressure water jet nozzle 61 abutting the contoured edge of the contour plate 651, and a first elastic member 653 for abutting the high-pressure water jet nozzle 61. The second angle adjuster 74 is a contour adjuster, comprising a contour plate 741, a second die-rest roller 742 fixed to the high-pressure air knife nozzle 71 abutting the contoured edge of the contour plate 741, and a second elastic member 743 for abutting the high-pressure air knife nozzle 71. The first elastic member 653 and the second elastic member 743 are both rubber piles. The contour adjustment structure in this solution is relatively simple. As the nozzle moves toward the edge of the wafer, the trajectory of the mold roller changes under the control of the contour plate, thereby changing the angle of the controlled nozzle. If the shape of the wafer chamfer is different, the contour plate can be directly replaced. The reliability is relatively high and the precision is relatively accurate. The elastic component 743 in the present invention can ensure the accuracy of the angle adjustment during the contouring action to prevent jumping, and the rubber pile is used as the elastic recovery element, mainly to avoid the possibility of up and down jumping caused by ordinary spring elements, which affects the error of the cutting angle. The rubber pile is not very sensitive to rebound during the compression process and can absorb a certain amount of compression force to a certain extent, thereby preventing up and down jumping.

[0024] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A wafer edge chamfering and cleaning method, characterized in that: The method comprises the following steps: a. First, fix the wafer in the processing position and start the processing position rotation mechanism to rotate the wafer. The rotation mechanism gradually decreases as the etching liquid nozzle moves toward the edge. In step b, the amount of etching liquid sprayed increases as the nozzle moves toward the edge. b. Move the etching liquid nozzle to the edge of the wafer and spray the etching liquid toward the edge of the wafer; c. After the etching liquid has remained on the wafer surface for a period of time, the high-pressure water nozzle is moved to the edge of the wafer that was previously sprayed with the etching liquid, and the high-pressure water jet is turned on to spray and cut the etched area of ​​the wafer at a predetermined angle; d. After step C is completed, start the high-pressure air knife installed together with the high-pressure water nozzle, and further spray and cut the water jet-cut surface according to a predetermined angle; e. Send the wafer to the cleaning station for post-cleaning.

2. The wafer edge chamfering and cleaning method according to claim 1, wherein: The high-pressure water jet and high-pressure air knife in steps c and d gradually increase in size as they move toward the edge.

3. A cutting cleaning device for implementing the cleaning method according to claim 1 or 2, characterized in that: The cutting and cleaning device comprises a body (10), a cutting station (20) arranged in the body, a rotating mechanism (30) for driving the cutting station (20), and a movable frame (40) arranged above the cutting station. The body is also provided with an etching system (50), a water knife system (60) and an air knife system (70). The etching liquid nozzle (51) in the etching system (50), the high-pressure water knife nozzle (61) in the water knife system (60) and the high-pressure air knife nozzle (71) in the air knife system (70) are installed on the movable frame (40). The cutting and cleaning device also comprises a control system (80) for controlling the above-mentioned systems and the rotating mechanism.

4. The cutting and cleaning device according to claim 3, characterized in that: The etching system (50) further comprises an etching liquid tank (52), an etching liquid pipeline (53) for conveying the etching liquid to the etching liquid nozzle (51), and an etching liquid amount adjustment mechanism (54) for controlling the opening size of the etching liquid nozzle (51).

5. The cutting and cleaning device according to claim 3, characterized in that: The water knife system (60) further comprises a water tank (62), a booster water pump (63), a high-pressure water pipe (64) for conveying high-pressure water to the high-pressure water knife nozzle (61), and a first angle adjuster (65) arranged on the high-pressure water knife nozzle (61); the air knife system (70) further comprises a booster air pump (62) connected to an air source, a high-pressure air pipe (73) for conveying high-pressure air to the high-pressure air knife nozzle (71), and a second angle adjuster (74) arranged on the high-pressure air knife nozzle (71).

6. The cutting and cleaning device according to claim 5, characterized in that: The first angle adjuster (65) and the second angle adjuster (74) are both servo motors, which control the rotation angles of the high-pressure water knife nozzle (61) and the high-pressure air knife nozzle (71) through a deceleration system, and the servo motors are controlled by the control system (80).

7. The cutting and cleaning device according to claim 5, characterized in that: The first angle adjuster (65) is a contour adjuster, comprising a contour plate (651), a first mold roller (652) fixed on the high-pressure water jet nozzle (61) abutting against the contour edge of the contour plate (651), and a first elastic member (653) for abutting against the high-pressure water jet nozzle (61).

8. The cutting and cleaning device according to claim 5, characterized in that: The second angle adjuster (74) is a contour adjuster, comprising a contour plate (741), a second mold roller (742) fixed on the high-pressure air knife nozzle (71) abutting against the contour edge of the contour plate (741), and a second elastic member (743) for abutting against the high-pressure air knife nozzle (71).

9. The cutting and cleaning device according to claim 7, characterized in that: The first elastic member (653) is a rubber pile.

10. The cutting and cleaning device according to claim 8, characterized in that: The second elastic member (743) is a rubber pile.

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