Wafer cleaning device and method based on megasonic waves

Abstract

The invention discloses a wafer cleaning device and method based on megasonic, and relates to the technical field of wafer preprocessing, the wafer cleaning device comprises a cleaning box, the top of the cleaning box is provided with a transportation track, a megasonic generator is installed in the cleaning box, and a wafer transportation frame is slidably arranged on the inner side of the transportation track; a plurality of movable wafer bodies are clamped at the bottom of the wafer transportation frame at the same time, a detection camera is installed on the transportation track and used for collecting photolithographic surface bevel angle photos of the wafer bodies, and humidity data of the wafer bodies are recognized based on the photolithographic surface bevel angle photos; as the symmetrical air-drying mechanism can apply symmetrical wind power to the surface of the wafer body, when the wafer body is subjected to large wind power, acting force on the two sides of the wafer body can offset each other, it is guaranteed that the wafer body cannot deform, the safety of the wafer body is guaranteed, and the wafer body can be dried while the air-drying efficiency of the wafer body is improved. And the wafer body is not easy to crack.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer pre-processing, and in particular to a wafer cleaning device and a cleaning method based on megasonic waves. Background Art

[0002] Wafer refers to the silicon wafer used to make silicon semiconductor circuits. Its original material is silicon. High-purity polysilicon is dissolved and mixed with silicon crystal seeds, and then slowly pulled out to form cylindrical single crystal silicon. After grinding, polishing and slicing, the silicon crystal rod forms a silicon wafer, that is, a wafer. The cleanliness of the wafer surface directly affects the yield of the chip, so the wafer needs to be specially cleaned before photolithography; Existing wafer cleaning devices, such as the wafer cleaning device disclosed in Chinese patent application publication number CN111312631A and the device for cleaning wafers and the method for cleaning wafers disclosed in Chinese patent application publication number CN118800681A, often require clamping operations on the sides of the wafer when cleaning the wafer, causing the photolithography surface of the wafer to be impacted by the outside, thereby creating a risk of reducing the chip yield of wafer production and poor safety. Summary of the invention

[0003] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a wafer cleaning device and a cleaning method based on megasonic waves, so as to solve the problem in the prior art that the wafer cleaning device needs to clamp the side of the wafer when cleaning the wafer, resulting in the photolithography surface of the wafer being subjected to external collision, thereby creating a risk of reducing the chip yield of the wafer production.

[0004] The purpose of the present invention can be achieved through the following technical solutions: The first aspect of the present invention is to provide a wafer cleaning device based on megasonic waves, including a cleaning box, a transport track is arranged on the top, a megasonic wave generator is installed inside the cleaning box, a wafer transport rack is slidably arranged on the inner side of the transport track, and the bottom of the wafer transport rack clamps a plurality of movable wafer bodies at the same time. A detection camera is installed on the transport track, and the detection camera is used to collect oblique-angle photos of the photoetching surface of the wafer body, and the moisture data of the wafer body is identified based on the oblique-angle photos of the photoetching surface. A symmetrical air-drying mechanism is arranged on one side of the cleaning box, and the wafer transport rack staggers the clamped plurality of wafer bodies on the top surface of the symmetrical air-drying mechanism. The symmetrical air-drying mechanism applies symmetrical blowing to the surface of the wafer body while rotating the wafer body along a vertical plane, and the time for the symmetrical air-drying mechanism to apply symmetrical blowing to the surface of the wafer body is determined based on the moisture data.

[0005] As a further solution of the present invention: the wafer transport rack comprises a mobile rack, a lifting platform is installed on the bottom surface of the mobile rack, and a plurality of clamping mechanisms are installed on the bottom surface of the lifting platform.

[0006] As a further solution of the present invention: the mobile frame includes a rectangular frame, and track sliders matching the transport track are fixedly connected at both ends of the rectangular frame near the transport track, and vertically arranged hydraulic cylinders are fixedly connected at the four corners of the top surface of the rectangular frame, and a telescopic rod is connected to the bottom end of the hydraulic cylinder.

[0007] As a further solution of the present invention: the lifting platform includes a rectangular platform, and several groups of mounting seats are installed on the bottom surface of the rectangular platform. Each group of mounting seats is directly installed with a threaded rod through a bearing, and a movable seat is nested on the side of the threaded rod. The end of the telescopic rod away from the hydraulic cylinder is fixedly connected to the top surface of the rectangular platform.

[0008] As a further solution of the present invention: the clamping mechanism includes an arc frame, a hydraulic cavity is opened inside the arc frame, movable arc arms are inserted at both ends of the arc frame, one end of the arc arm away from the arc frame is fixedly connected to a movable pulley seat, and at least one fixed pulley is installed on the bottom surface of the arc frame.

[0009] As a further solution of the present invention: the axle of the fixed pulley and the axle of the movable pulley seat are on the same circle.

[0010] As a further solution of the present invention: the fixed pulley and the pulleys in the movable pulley seat are both made of rubber.

[0011] As a further solution of the present invention: the symmetrical air-drying mechanism includes an air-drying table, the top surface of the air-drying table is provided with an air-drying groove, the inner bottom surface of the air-drying groove is fixedly connected with a plurality of support seats, and a driving pulley is installed at the center position of the top surface of the support seat.

[0012] As a further solution of the present invention: rotating arms are installed at the center positions of both sides of the support seat, a ventilation groove is opened inside the rotating arms, a plurality of ventilation holes are evenly opened on one side of the rotating arms, and the plurality of ventilation holes are connected to the ventilation groove; a blower is arranged inside the air drying table, and the output end of the blower is connected to the ventilation groove.

[0013] As a further solution of the present invention: the moisture data is the specific area fraction of water stains on the wafer body.

[0014] A second aspect of the present invention is to provide a wafer cleaning method based on megasonic waves, which is implemented based on the above-mentioned wafer cleaning device based on megasonic waves, and comprises the following steps: S1: The wafer transport rack transports a group of wafer bodies to the inside of the cleaning box, and completely immerses the wafer bodies in the cleaning liquid inside the cleaning box; S2: Turn on the megasonic wave generator installed inside the cleaning box to perform megasonic wave cleaning on the wafer body inside the cleaning box; S3: The wafer transport rack takes out the cleaned wafer body from the inside of the cleaning box and transports it to the top of the symmetrical air-drying mechanism through the transport track; S4: The wafer transport rack adjusts a group of wafer bodies on the bottom surface from an overlapping state to a staggered separation state, so that the gap between the group of wafer bodies is increased; S5: using a detection camera to collect oblique angle photos of the photolithography surface of the wafer body, and identifying moisture data of the wafer body based on the oblique angle photos of the photolithography surface; S6: The wafer transport rack transports the wafer bodies in the staggered and separated state to the top surface of the symmetrical air-drying mechanism, and the symmetrical air-drying mechanism applies symmetrical blowing to the side surfaces of the wafer bodies. The symmetrical air-drying mechanism simultaneously rotates the wafer bodies in the vertical direction, and determines the time for the symmetrical air-drying mechanism to apply symmetrical blowing to the side surfaces of the wafer bodies based on the moisture data; S7: The wafer transport rack adjusts the wafer bodies in the staggered and separated state to an overlapping state, and then transports the wafer bodies in the overlapping state into a packing box.

[0015] 1. In the present invention, the wafer transport rack can stagger and confine several wafer bodies clamped on the top surface of the symmetrical air-drying mechanism, which will greatly increase the gap between the wafer bodies and facilitate the symmetrical air-drying mechanism to air-dry the surface of the wafer body. Since the symmetrical air-drying mechanism will exert symmetrical wind force on the surface of the wafer body, when the wafer body is subjected to a large wind force, the forces on both sides of the wafer body will offset each other, ensuring that the wafer body will not be deformed, ensuring the safety of the wafer body, and improving the air-drying efficiency of the wafer body while preventing the wafer body from being broken.

[0016] 2. In the present invention, when the clamping mechanism needs to release the wafer body, the oil cylinder arranged in the connecting block is opened, and the oil cylinder can absorb the hydraulic oil in the hydraulic cavity through the connecting block, so that the arc-shaped arm can automatically shrink, so that the wafer body clamped on the clamping mechanism can be freely detached. When the clamping mechanism needs to clamp the wafer body, the operation is reversed to automatically unfold the arc-shaped arm. The wheel surfaces of the fixed pulley and the movable pulley seat are both concave surfaces, which fit the arc-shaped end face of the wafer body. During the whole process of transporting the wafer body by the clamping mechanism, the clamping mechanism only contacts the end face of the wafer body instead of the side face, which ensures that the side face of the wafer body will not be touched by external machinery, thereby improving the protection effect of the wafer body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] Figure 1 It is a structural schematic diagram of the left side of the wafer cleaning device based on megasonic waves of the present invention; Figure 2 It is a structural schematic diagram of the right side of the wafer cleaning device based on megasonic waves of the present invention; Figure 3 It is a structural schematic diagram of the wafer transport rack in the present invention; Figure 4 It is a structural schematic diagram of the mobile frame and the lifting platform in the present invention; Figure 5 It is a structural schematic diagram of the clamping mechanism in the present invention in a released clamping state; Figure 6 It is a structural schematic diagram of the clamping state of the clamping mechanism in the present invention; Figure 7 It is a schematic diagram of the internal structure of the clamping mechanism in the present invention; Figure 8 It is a structural schematic diagram of the symmetrical air-drying mechanism in the present invention.

[0019] Description of the drawings: 1. Cleaning box; 2. Transport track; 21. Column; 3. Wafer transport rack; 31. Mobile rack; 311. Rectangular frame; 312. Track slider; 313. Hydraulic cylinder; 314. Telescopic rod; 32. Lifting platform; 321. Rectangular table; 322. Mounting seat; 323. Threaded rod; 324. Mobile seat; 33. Clamping mechanism; 331. Arc rack; 332. Connecting block; 333. Fixed pulley; 334. Arc arm; 335. Movable pulley seat; 336. Hydraulic chamber; 4. Symmetrical air-drying mechanism; 41. Air-drying table; 42. Air-drying tank; 43. Support seat; 44. Driving pulley; 45. Rotating arm; 5. Wafer body. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1

[0022] like Figure 1-Figure 8As shown, the present invention discloses a wafer cleaning device based on megasonic waves, comprising a cleaning box 1, a transport track 2 is arranged on the top of which, and a megasonic wave generator is installed inside the cleaning box 1; it should be noted that four vertically arranged columns 21 are fixedly connected to the top surface of the cleaning box 1, and the transport track 2 is horizontally installed on the four vertically arranged columns 21. The specifications and length of the transport track 2 are adaptively selected by those skilled in the art according to the pretreatment site conditions of the wafer body 5. The transport track 2 can also be arc-shaped to ensure that the transport track 2 can normally drive the wafer transport rack 3. Therefore, the driving mode of the transport track 2 is not limited to electric control, pneumatic control or other mechanical driving methods, such as driving the wafer transport rack 3 by a chain. The megasonic generator is a device specially used to generate ultrasonic waves. The frequency of the megasonic generator is between 1 GHz and 1 THz. The specific frequency is adaptively selected by the technicians in this field according to the cleaning time and the cleaning temperature of the wafer body 5. The model of the megasonic generator and the number and installation position of the megasonic generator in the cleaning box 1 are adaptively selected by the technicians in this field. Theoretically, the megasonic generator can be installed at any position in the cleaning box 1. A wafer transport rack 3 is slidably arranged on the inner side of the transport track 2. The bottom of the wafer transport rack 3 clamps a plurality of movable wafer bodies 5 at the same time. It should be noted that the bottom of a wafer transport rack 3 can clamp a plurality of wafer bodies 5 at the same time. The wafer body 5, multiple wafer bodies 5 are in a vertically overlapping state, ensuring the cleaning efficiency of the cleaning box 1 on the wafer body 5; a symmetrical air-drying mechanism 4 is arranged on one side of the cleaning box 1, and the wafer transport rack 3 staggers the clamped multiple wafer bodies 5 on the top surface of the symmetrical air-drying mechanism 4, and the symmetrical air-drying mechanism 4 applies symmetrical blowing to the surface of the wafer body 5 while rotating the wafer body 5 along the vertical plane. It should be noted that the wafer transport rack 3 can stagger the clamped multiple wafer bodies 5 on the top surface of the symmetrical air-drying mechanism 4, which will greatly increase the gap between the wafer bodies 5, making it easier for the symmetrical air-drying mechanism 4 to air-dry the surface of the wafer body 5, and a blower should be arranged inside the symmetrical air-drying mechanism 4. The blower can apply wind force to the surface of the wafer body 5. It should also be noted that a nitrogen bottle is arranged inside the symmetrical air-drying mechanism 4, and the output end of the nitrogen bottle is connected to the output end of the blower to ensure that the wind applied by the blower to the surface of the wafer body 5 is nitrogen. Nitrogen, as an inert gas, can improve the protection effect of the wafer body 5 while air-drying the wafer body 5. Since the symmetrical air-drying mechanism 4 will apply symmetrical wind force to the surface of the wafer body 5, when the wafer body 5 is subjected to a large wind force, the forces on both sides of the wafer body 5 will offset each other, ensuring that the wafer body 5 will not be deformed, ensuring the safety of the wafer body 5, and improving the air-drying efficiency of the wafer body 5. The wafer body 5 is not easy to break.

[0023] Example 2

[0024] like Figures 1 to 8 As shown, the wafer transport rack 3 includes a moving rack 31, a lifting platform 32 is installed on the bottom surface of the moving rack 31, and a plurality of clamping mechanisms 33 are installed on the bottom surface of the lifting platform 32. The moving rack 31 includes a rectangular frame 311, and track sliders 312 matching the transport rail 2 are fixedly connected at both ends of the rectangular frame 311 near the transport rail 2, and vertically arranged hydraulic cylinders 313 are fixedly connected at the four corners of the top surface of the rectangular frame 311, and a telescopic rod 314 is connected to the bottom end of the hydraulic cylinder 313. It should be noted that since the track sliders 312 matching the transport rail 2 are fixedly connected at both ends of the rectangular frame 311 near the transport rail 2, the rectangular frame 311 can slide horizontally on the inner side of the transport rail 2 through the cooperation of the track sliders 312 and the transport rail 2. It should also be noted that the transport rail 2 can normally drive the wafer transport rack 3, so the driving method of the transport rail 2 is not limited to electric control, pneumatic control or other mechanical methods. The wafer transport rack 3 can be driven by a chain, for example, or by a lead screw nut. The specific driving method is adaptively selected by technicians in this field according to the actual situation of the transport track 2; the telescopic rod 314 can be composed of multiple hollow tubes that are mutually socketed. The main purpose is to control the height of the lifting platform 32 through the hydraulic cylinder 313 and the telescopic rod 314, so as to ensure that the lifting platform 32 can completely immerse the wafer body 5 in the cleaning liquid inside the cleaning box 1. The cleaning liquid inside the cleaning box 1 can be deionized water. It is adaptively selected by technicians in this field according to the needs of the wafer body 5. The number of clamping mechanisms 33 is consistent with the number of wafer bodies 5, that is, one clamping mechanism 33 clamps a wafer body 5, and the clamping mechanism 33 can limit the wafer body 5 to the bottom surface of the lifting platform 32 in an equidistant and overlapping manner, so that the lifting platform 32 can drive the wafer body 5 through the clamping mechanism 33 to realize the transportation of the wafer body 5.

[0025] The lifting platform 32 includes a rectangular platform 321, and a plurality of mounting seats 322 are installed on the bottom surface of the rectangular platform 321. Each mounting seat 322 is directly installed with a threaded rod 323 through a bearing. A movable seat 324 is embedded on the side of the threaded rod 323. The end of the telescopic rod 314 away from the hydraulic cylinder 313 is fixedly connected to the top surface of the rectangular platform 321. It should be noted that the mounting seats 322 are symmetrically arranged on the bottom surface of the rectangular platform 321. The two mounting seats 322 are connected to the threaded rod 323 through a bearing. The threaded rod 323 on the bottom surface of the rectangular platform 321 and the movable seat 324 on the side thereof can be alternately divided into two groups, and then two groups of driving devices are arranged inside the rectangular platform 321. The mechanism drives the moving seats 324 on the sides of the two groups of threaded rods 323 to the two sides of the bottom surface of the rectangular platform 321 respectively. The moving seats 324 of the same group can be fixedly connected by long rods to ensure that the moving seats 324 of the same group can move synchronously. Then, a horizontal linear driving mechanism is set inside the rectangular platform 321. The horizontal linear driving mechanism can be an electric push rod, a hydraulic push rod or a pneumatic push rod. The long rod is pushed by the output end of the horizontal linear driving mechanism to realize the movement of the moving seats 324 of the same group. The bottom surface of the moving seat 324 is fixedly connected to the top of the clamping mechanism 33, so the moving moving seat 324 can drive the clamping mechanism 33 to move synchronously. When the wafer transport rack 3 needs to transport the wafer body 5 to the inside of the cleaning box 1 for megasonic cleaning, it is necessary to overlap multiple wafer bodies 5. Therefore, the two groups of movable seats 324 can be adjusted to the same straight line through the horizontal linear drive mechanism, so that the wafer bodies 5 corresponding to the two groups of movable seats 324 are also on the same straight line, that is, overlapped. At this time, when the lifting platform 32 moves downward, the clamping mechanism 33 can be used to drive the wafer body 5 to move downward. By controlling the height of the lifting platform 32 moving downward, the wafer body 5 can be completely immersed in the cleaning liquid inside the cleaning box 1. When the wafer transport rack 3 needs to transport the wafer body 5 to the top of the symmetrical air-drying mechanism 4 for air-drying operation, the multiple wafer bodies 5 need to be staggered and crossed with each other. Therefore, the two groups of movable seats 324 can be adjusted to the two sides of the bottom surface of the rectangular table 321 through the horizontal linear drive mechanism. At this time, the positions of the multiple wafer bodies 5 will be staggered and crossed with each other, so that the gap between the multiple wafer bodies 5 will be greatly increased, and then the symmetrical air-drying mechanism 4 can be used to perform air-drying operation on the wafer body 5.

[0026] The clamping mechanism 33 includes an arc frame 331, and a hydraulic chamber 336 is provided inside the arc frame 331. Movable arc arms 334 are inserted at both ends of the arc frame 331. One end of the arc arm 334 away from the arc frame 331 is fixedly connected to a movable pulley seat 335. At least one fixed pulley 333 is installed on the bottom surface of the arc frame 331. The axle of the fixed pulley 333 and the axle of the movable pulley seat 335 are on the same circle. The pulleys in the fixed pulley 333 and the movable pulley seat 335 are both made of rubber. It should be noted that when the clamping mechanism 33 needs to release the wafer body 5, the oil cylinder arranged in the connecting block 332 is opened, and the oil cylinder can absorb the hydraulic oil in the hydraulic chamber 336 through the connecting block 332, so that the arc arm 334 automatically contracts, so that the wafer body 5 clamped by the clamping mechanism 33 The wafer body 5 will be free to detach, and in the process of automatic detachment of the wafer body 5, the clamping mechanism 33 only contacts the end face of the wafer body 5 instead of the side face, which ensures that the side face of the wafer body 5 will not be touched by external machinery, thereby improving the protection effect of the wafer body 5. When the clamping mechanism 33 needs to clamp the wafer body 5, the reverse operation is performed to automatically unfold the arc arm 334. It should be noted that the arc arm 334 needs to cover a length exceeding half the circumference of the wafer body 5 to ensure that the wafer body 5 is fixed on the inner side of the clamping mechanism 33. The wheel surfaces of the fixed pulley 333 and the movable pulley seat 335 are both concave surfaces, which fit the arc end face of the wafer body 5. In the whole process of transporting the wafer body 5 by the clamping mechanism 33, the clamping mechanism 33 will not touch the side face of the wafer body 5.

[0027] Example 3

[0028] A detection camera (not shown in the accompanying drawings) is installed on the transport track 2. The detection camera is used to collect photos of the bevel angle of the photoetching surface of the wafer body 5, and identify the moisture data of the wafer body 5 based on the photos of the bevel angle of the photoetching surface. The moisture data is the specific area fraction of water stains on the wafer body 5. It should be noted that the detection camera is adaptively installed by technical personnel in this field according to the transport track 2 and the photos of the bevel angle of the photoetching surface that need to be taken. In order to clearly take photos of the bevel angle of the photoetching surface of each wafer body 5, the detection camera needs to be movably installed on the transport track 2 and can be moved laterally along the mobile frame 31 to ensure that the detection camera can take photos of the bevel angle of the photoetching surface of each wafer body 5 and label the wafer bodies 5. The technical personnel in this field pre-photograph the wafer body 5 with the detection camera, and select the shooting position and shooting times of the detection camera according to the number of clear and complete photos of the bevel angle of the photoetching surface in the photos taken; For example, when the number of clear and complete photos of the lithography surface bevel in the photos taken by the detection camera is 5, the first shot can be taken at the wafer body 5 labeled 3, and the second shot can be taken at the wafer body 5 labeled 7, until the photos of the lithography surface bevel of all wafer bodies 5 are collected.

[0029] Then, the bevel angle photograph of the lithographic surface of the wafer body 5 is gray-scaled to obtain a gray-scale image of the bevel angle of the lithographic surface; Extracting a characteristic region in the grayscale image of the bevel angle of the lithography surface, where the characteristic region is the region of the lithography surface in the grayscale image of the bevel angle of the lithography surface; The characteristic area is divided into n pixels, and the technicians in this field collect the grayscale values ​​of n pixels of the characteristic area without water stains in advance. , ,…… ,Will , ,…… As a contrasting gray value; Collect the grayscale value of the characteristic area corresponding to the wafer body 5 , ,…… ; The gray value variance σ of the characteristic area corresponding to the wafer body 5 is calculated, and the calculation formula of σ is: ; When there is no water stain on the photoetching surface of the wafer body 5, , at this time, the gray value variance σ=0. ​​When the photolithography surface of the wafer body 5 is covered with water stains, the gray value variance σ of the characteristic area corresponding to the wafer body 5 will reach the maximum value. Therefore, the gray value variance σ is proportional to the specific area fraction S of the water stains on the wafer body 5. A mathematical relationship between the specific area fraction S and the gray value variance σ is fitted by a technician in this field using a computer. After the detection camera collects the grayscale image of the bevel angle of the lithographic surface of the wafer body 5, the grayscale value variance σ of the characteristic area of ​​the bevel angle grayscale image of the lithographic surface is calculated, and the specific area fraction S corresponding to the grayscale value variance σ is calculated according to the mathematical relationship; A fractional threshold of the specific area fraction S is preset by technical personnel in this field. When the specific area fraction S is greater than or equal to the fractional threshold, the symmetrical air-drying mechanism 4 adopts a long-time working mode. When the specific area fraction S is less than the fractional threshold, the symmetrical air-drying mechanism 4 adopts a short-time working mode. It should also be noted that the long-time working mode and the short-time working mode of the symmetrical air-drying mechanism 4 are adaptively selected by technical personnel in this field according to the air-drying conditions of the water stains on the photoetching surface of the wafer body 5 to ensure that the water stains on the photoetching surface of the wafer body 5 can be completely air-dried.

[0030] The symmetrical air-drying mechanism 4 comprises an air-drying table 41 , the top surface of which is provided with an air-drying groove 42 , the inner bottom surface of the air-drying groove 42 is fixedly connected with a plurality of support seats 43 , and a driving pulley 44 is installed at the center position of the top surface of the support seat 43 .

[0031] A rotating arm 45 is installed at the center position of both sides of the support seat 43, and a ventilation groove is opened inside the rotating arm 45. A plurality of ventilation holes are evenly opened on one side of the rotating arm 45, and the plurality of ventilation holes are connected to the ventilation groove. A blower is arranged inside the air drying station 41, and the output end of the blower is connected to the ventilation groove. When the photoetching surface of the wafer body 5 is air-dried, a detection camera is first used to collect an angled photo of the photoetching surface of the wafer body 5, and then the angled photo of the photoetching surface is grayed to obtain an angled grayscale image of the photoetching surface, and a feature area in the angled grayscale image of the photoetching surface is extracted, and the grayscale value variance σ of the feature area is calculated, and then the mathematical relationship is used to calculate Calculate the specific area fraction S corresponding to the gray value variance σ, and compare the specific area fraction S with the score threshold. If the specific area fraction S is greater than or equal to the score threshold, the symmetrical air-drying mechanism 4 adopts a long-time working mode. If the specific area fraction S is less than the score threshold, the symmetrical air-drying mechanism 4 adopts a short-time working mode. When the symmetrical air-drying mechanism 4 is working, the wind force delivered by the blower can be delivered to the side of the wafer body 5 through the ventilation holes and the ventilation slots to air-dry the side of the wafer body 5. Since the air-drying time of the symmetrical air-drying mechanism 4 is adjusted by the specific area fraction S, the symmetrical air-drying mechanism 4 can accurately air-dry the water stains on the photoetching surface of the wafer body 5.

[0032] Example 4

[0033] Different from the third embodiment, a convolutional neural network (CNN) is used to identify the level of the specific area fraction S of the water stain on the wafer body 5. For example, the level of the specific area fraction S of the water stain on the wafer body 5 is divided into five levels, namely: Level 1: 0% ≦ S < 20%, Level 2: 20% ≦ S < 40%, Level 3: 40% ≦ S < 60%, Level 4: 60% ≦ S < 80% and Level 5: S ≥ 80%; The method for using a convolutional neural network to identify the level of the specific area fraction S of water stains on the wafer body 5 includes the following steps: First, a historical training data set is collected. The historical training data set is a large number of bevel photos of the photoetching surface of the wafer body 5. The bevel photos of the photoetching surface of the wafer body 5 are collected by a person skilled in the art in the process of using a wafer cleaning device based on megasonic waves. Specifically, the bevel photos of the photoetching surface of the wafer body 5 are collected by a detection camera. In addition, it should be noted that the bevel photos of the photoetching surface of the wafer body 5 should contain different amounts of water stains as much as possible to improve the accuracy of the convolutional neural network training; Then, a person skilled in the art will grade the bevel photos of the lithographic surface of the wafer body 5 according to the size of the specific area fraction S of the water stains on the wafer body 5, which can be specifically divided into five grades; The bevel photos of the lithographic surface are then preprocessed, including image size adjustment, grayscale conversion, and normalization operations.

[0034] Select the VGGNet or ResNet convolutional neural network architecture, and then train the convolutional neural network model for identifying the level of the specific area fraction S of water stains on the wafer body 5, and update the parameters of the model through the back propagation algorithm so that the model gradually learns the mapping relationship between the specific area fraction S of water stains and the five levels. During the training process, the performance of the model is regularly evaluated on the validation set, and the accuracy, recall rate and other indicators are observed to prevent the model from overfitting.

[0035] When the training of the convolutional neural network model for identifying the level of the specific area fraction S of the water stains on the photoetching surface of the wafer body 5 is completed, the detection camera can be used to collect the bevel photo of the photoetching surface of the wafer body 5, and then the convolutional neural network model can be used to identify the level of the specific area fraction S corresponding to the bevel photo of the photoetching surface. Since the level of the specific area fraction S is divided into five levels, the air-drying time of the symmetrical air-drying mechanism 4 can also be divided into five levels. The technical personnel in this field shall make adaptive adjustments according to the working efficiency of the symmetrical air-drying mechanism 4 to ensure that the symmetrical air-drying mechanism 4 can completely air-dry the water stains on the photoetching surface of the wafer body 5; It should be noted that, since the symmetrical air-drying mechanism 4 adopts the same working mode, the level of the air-drying time of the symmetrical air-drying mechanism 4 can be determined according to the maximum level of the specific area fraction S corresponding to the bevel angle photograph of the etched surface; The rotating arms 45 on the symmetrical air-drying mechanism 4 may also be numbered, the numbers corresponding to the numbers of the wafer bodies 5, and electromagnetic valves are arranged inside the ventilation slots corresponding to the rotating arms 45, and the air-drying time of different rotating arms 45 for different wafer bodies 5 is controlled according to the electromagnetic valves; For example, the detection camera captures a photo of the beveled surface of the wafer body 5 labeled j, and recognizes through the convolutional neural network model that the level of the specific area fraction S of the beveled surface of the wafer body 5 labeled j is the third level, then the air-drying time of the rotating arm 45 No. j should also be the third level, so that the air-drying time of different wafer bodies 5 can be accurately controlled.

[0036] Example 5

[0037] like Figure 1-Figure 8 As shown, the present invention discloses a wafer cleaning method based on megasonic waves, and the wafer cleaning method is implemented based on the above-mentioned wafer cleaning device based on megasonic waves, and comprises the following steps: S1: The wafer transport rack 3 transports a group of wafer bodies 5 to the interior of the cleaning box 1, and makes the wafer bodies 5 completely immersed in the cleaning liquid inside the cleaning box 1. Four vertically arranged columns 21 are fixedly connected to the top surface of the cleaning box 1, and the transport track 2 is horizontally installed on the four vertically arranged columns 21. The specifications and length of the transport track 2 are adaptively selected by technical personnel in this field according to the pre-treatment site conditions of the wafer bodies 5. The transport track 2 can also be arc-shaped to ensure that the transport track 2 can normally drive the wafer transport rack 3. Therefore, the driving method of the transport track 2 is not limited to electric control, pneumatic control or other mechanical methods. For example, the wafer transport rack 3 is driven by a chain. Since the two ends of the rectangular frame 311 are fixedly connected with a track slider 312 matching the transport track 2, the rectangular frame 311 can slide horizontally on the inner side of the transport track 2 through the cooperation of the track slider 312 and the transport track 2. In addition, it should be noted that the transport track 2 can normally drive the wafer transport rack 3. Therefore, the driving mode of the transport track 2 is not limited to electric control, pneumatic control or other mechanical driving modes. For example, the wafer transport rack 3 can be driven by a chain, or the wafer transport rack 3 can be driven by a lead screw nut. The specific driving mode is adaptively selected by technicians in this field according to the actual situation of the transport track 2. The telescopic rod 314 can be composed of multiple hollow tubes that are mutually sleeved. The main purpose is to control the height of the lifting platform 32 through the hydraulic cylinder 313 and the telescopic rod 314 to ensure that the lifting platform 32 can completely immerse the wafer body 5 in the cleaning liquid inside the cleaning box 1. The cleaning liquid inside the cleaning box 1 can be deionized water. It is adaptively selected by technicians in this field according to the needs of the wafer body 5. The number of clamping mechanisms 33 is consistent with the number of wafer bodies 5, that is, one clamping mechanism 33 clamps a wafer body 5. The clamping mechanism 33 can limit the wafer body 5 to the bottom surface of the lifting platform 32 in an equidistant and overlapping manner, so that the lifting platform 32 can drive the wafer body 5 through the clamping mechanism 33 to realize the transportation of the wafer body 5. S2: Turn on the megasonic generator installed inside the cleaning box 1, and perform megasonic cleaning on the wafer body 5 inside the cleaning box 1. The megasonic generator is a device specially used to generate ultrasonic waves. The frequency of the megasonic generator is between 1 GHz and 1 THz. The specific frequency is adaptively selected by a technician in this field according to the cleaning time and the cleaning temperature of the wafer body 5. The model of the megasonic generator, the number of megasonic generators set inside the cleaning box 1, and the installation position are adaptively selected by a technician in this field. In theory, the megasonic generator can be installed at any position inside the cleaning box 1. S3: The wafer transport rack 3 takes out the cleaned wafer body 5 from the inside of the cleaning box 1 and transports it to the top of the symmetrical air-drying mechanism 4 through the transport track 2; S4: The wafer transport rack 3 adjusts a group of wafer bodies 5 on the bottom surface from an overlapping state to a staggered separation state, so that the gap between the group of wafer bodies 5 is increased. When the wafer transport rack 3 needs to transport the wafer bodies 5 to the top of the symmetrical air-drying mechanism 4 for air-drying operation, the multiple wafer bodies 5 need to be staggered and crossed with each other. Therefore, the two groups of movable seats 324 can be adjusted to the two sides of the bottom surface of the rectangular table 321 through the horizontal linear driving mechanism. At this time, the positions of the multiple wafer bodies 5 will be staggered and crossed with each other, so that the gap between the multiple wafer bodies 5 will be greatly increased, and then the symmetrical air-drying mechanism 4 can be used to perform air-drying operation on the wafer bodies 5; S5: Use the detection camera to collect the oblique angle photos of the photolithography surface of the wafer body 5, and identify the moisture data of the wafer body 5 based on the oblique angle photos of the photolithography surface. The moisture data is the specific area fraction of the water stains on the wafer body 5. The specific area fraction S is determined as follows: A detection camera (not shown in the accompanying drawings) is installed on the transport track 2. The detection camera is used to collect photos of the bevel angle of the photoetching surface of the wafer body 5, and identify the moisture data of the wafer body 5 based on the photos of the bevel angle of the photoetching surface. The moisture data is the specific area fraction of water stains on the wafer body 5. It should be noted that the detection camera is adaptively installed by technical personnel in this field according to the transport track 2 and the photos of the bevel angle of the photoetching surface that need to be taken. In order to clearly take photos of the bevel angle of the photoetching surface of each wafer body 5, the detection camera needs to be movably installed on the transport track 2 and can be moved laterally along the mobile frame 31 to ensure that the detection camera can take photos of the bevel angle of the photoetching surface of each wafer body 5 and label the wafer bodies 5. The technical personnel in this field pre-photograph the wafer body 5 with the detection camera, and select the shooting position and shooting times of the detection camera according to the number of clear and complete photos of the bevel angle of the photoetching surface in the photos taken; For example, when the number of clear and complete photos of the lithography surface bevel in the photos taken by the detection camera is 5, the first shot can be taken at the wafer body 5 labeled 3, and the second shot can be taken at the wafer body 5 labeled 7, until the photos of the lithography surface bevel of all wafer bodies 5 are collected.

[0038] Then, the bevel angle photograph of the lithographic surface of the wafer body 5 is gray-scaled to obtain a gray-scale image of the bevel angle of the lithographic surface; Extracting a characteristic region in the grayscale image of the bevel angle of the lithography surface, where the characteristic region is the region of the lithography surface in the grayscale image of the bevel angle of the lithography surface; The characteristic area is divided into n pixels, and the technicians in this field collect the grayscale values ​​of n pixels of the characteristic area without water stains in advance. , ,…… ,Will , ,…… As a contrasting gray value; Collect the grayscale value of the characteristic area corresponding to the wafer body 5 , ,…… ; The gray value variance σ of the characteristic area corresponding to the wafer body 5 is calculated, and the calculation formula of σ is: ; When there is no water stain on the photoetching surface of the wafer body 5, , at this time, the gray value variance σ=0. ​​When the photolithography surface of the wafer body 5 is covered with water stains, the gray value variance σ of the characteristic area corresponding to the wafer body 5 will reach the maximum value. Therefore, the gray value variance σ is proportional to the specific area fraction S of the water stains on the wafer body 5. A mathematical relationship between the specific area fraction S and the gray value variance σ is fitted by a technician in this field using a computer. After the detection camera collects the grayscale image of the bevel angle of the lithographic surface of the wafer body 5, the grayscale value variance σ of the characteristic area of ​​the bevel angle grayscale image of the lithographic surface is calculated, and the specific area fraction S corresponding to the grayscale value variance σ is calculated according to the mathematical relationship; S6: The wafer transport rack 3 transports the wafer bodies 5 in the staggered and separated state to the top surface of the symmetrical air-drying mechanism 4. The symmetrical air-drying mechanism 4 applies symmetrical blowing to the side surfaces of the wafer bodies 5. The symmetrical air-drying mechanism 4 simultaneously rotates the wafer bodies 5 in the vertical direction. Since the symmetrical air-drying mechanism 4 applies symmetrical wind force to the surface of the wafer bodies 5, the air-drying time is determined by the humidity data. Specifically, a detection camera is used to collect an angled photo of the photolithography surface of the wafer bodies 5, and then the angled photo of the photolithography surface is grayed to obtain an angled grayscale image of the photolithography surface, and the feature area in the angled grayscale image of the photolithography surface is extracted, and the grayscale value variance σ of the feature area is calculated, and then the digital The specific area fraction S corresponding to the gray value variance σ is calculated by using a mathematical relationship, and the specific area fraction S is compared with the score threshold. If the specific area fraction S is greater than or equal to the score threshold, the symmetrical air-drying mechanism 4 adopts a long-time working mode. If the specific area fraction S is less than the score threshold, the symmetrical air-drying mechanism 4 adopts a short-time working mode. When the symmetrical air-drying mechanism 4 is working, the wind force delivered by the blower can be delivered to the side of the wafer body 5 through the ventilation holes and the ventilation slots to air-dry the side of the wafer body 5. Since the air-drying time of the symmetrical air-drying mechanism 4 is adjusted by the specific area fraction S, the symmetrical air-drying mechanism 4 can accurately air-dry the water stains on the photoetching surface of the wafer body 5. Therefore, when the wafer body 5 is subjected to a strong wind force, the forces on both sides of the wafer body 5 will offset each other, ensuring that the wafer body 5 will not be deformed, ensuring the safety of the wafer body 5, and improving the air drying efficiency of the wafer body 5 while preventing the wafer body 5 from being broken; S6: The wafer transport rack 3 adjusts the wafer bodies 5 in the staggered and separated state to an overlapping state, and then transports the wafer bodies 5 in the overlapping state to a packing box, thereby achieving cleaning and packing of the wafer bodies 5.

[0039] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A wafer cleaning device based on megasonic waves, characterized in that: include: A cleaning box (1) is provided with a transport track (2) on the top, and a megasonic generator is installed inside the cleaning box (1); A wafer transport rack (3) which is slidably arranged on the inner side of the transport track (2), and the bottom of the wafer transport rack (3) simultaneously clamps a plurality of movable wafer bodies (5); A detection camera, which is installed on the transport track (2), and is used to collect oblique-angle photos of the photoetching surface of the wafer body (5), and identify moisture data of the wafer body (5) based on the oblique-angle photos of the photoetching surface; A symmetrical air-drying mechanism (4) is arranged on one side of a cleaning box (1); a wafer transport rack (3) staggers a plurality of wafer bodies (5) held thereon to be confined on the top surface of the symmetrical air-drying mechanism (4); the symmetrical air-drying mechanism (4) applies symmetrical blowing to the surface of the wafer body (5) while rotating the wafer body (5) along a vertical plane; and the time for the symmetrical air-drying mechanism (4) to apply symmetrical blowing to the surface of the wafer body (5) is determined based on moisture data.

2. The wafer cleaning device based on megasonic waves according to claim 1, characterized in that: The wafer transport rack (3) comprises a moving rack (31), a lifting platform (32) is installed on the bottom surface of the moving rack (31), and a plurality of clamping mechanisms (33) are installed on the bottom surface of the lifting platform (32).

3. The wafer cleaning device based on megasonic waves according to claim 2, characterized in that: The mobile frame (31) comprises a rectangular frame (311), and track sliders (312) matching the transport track (2) are fixedly connected at both ends of the rectangular frame (311) near the transport track (2), and vertically arranged hydraulic cylinders (313) are fixedly connected at the four corners of the top surface of the rectangular frame (311), and the bottom end of the hydraulic cylinder (313) is connected to a telescopic rod (314).

4. The wafer cleaning device based on megasonic waves according to claim 3, characterized in that: The lifting platform (32) comprises a rectangular platform (321), a plurality of groups of mounting seats (322) are installed on the bottom surface of the rectangular platform (321), each group of mounting seats (322) is directly installed with a threaded rod (323) through a bearing, a movable seat (324) is embedded on the side of the threaded rod (323), and one end of the telescopic rod (314) away from the hydraulic cylinder (313) is fixedly connected to the top surface of the rectangular platform (321).

5. The wafer cleaning device based on megasonic waves according to claim 4, characterized in that: The clamping mechanism (33) comprises an arc frame (331), a hydraulic chamber (336) is provided inside the arc frame (331), movable arc arms (334) are inserted at both ends of the arc frame (331), one end of the arc arm (334) away from the arc frame (331) is fixedly connected to a movable pulley seat (335), and at least one fixed pulley (333) is installed on the bottom surface of the arc frame (331).

6. The wafer cleaning device based on megasonic waves according to claim 5, characterized in that: The axle of the fixed pulley (333) and the axle of the movable pulley seat (335) are on the same circle.

7. The wafer cleaning device based on megasonic waves according to claim 5, characterized in that: The fixed pulley (333) and the pulleys in the movable pulley seat (335) are both made of rubber.

8. The wafer cleaning device based on megasonic waves according to claim 1, characterized in that: The symmetrical air-drying mechanism (4) comprises an air-drying table (41), the top surface of the air-drying table (41) is provided with an air-drying groove (42), the inner bottom surface of the air-drying groove (42) is fixedly connected to a plurality of support seats (43), and a driving pulley (44) is installed at the center position of the top surface of the support seat (43).

9. The wafer cleaning device based on megasonic waves according to claim 8, characterized in that: Rotating arms (45) are installed at the center positions of both sides of the support seat (43), a ventilation slot is provided inside the rotating arm (45), a plurality of ventilation holes are evenly provided on one side of the rotating arm (45), and the plurality of ventilation holes are connected to the ventilation slot. A blower is provided inside the air drying table (41), and an output end of the blower is connected to the ventilation slot.

10. The wafer cleaning device based on megasonic waves according to claim 1, characterized in that: The moisture data is the specific area fraction of water stains on the wafer body (5).

11. A wafer cleaning method based on megasonic waves, characterized in that: The wafer cleaning method is implemented based on the wafer cleaning device based on megasonic waves according to any one of claims 1 to 10, and comprises the following steps: S1: The wafer transport rack (3) transports a group of wafer bodies (5) to the inside of the cleaning box (1), and completely immerses the wafer bodies (5) in the cleaning liquid inside the cleaning box (1); S2: turning on the megasonic wave generator installed inside the cleaning box (1) to perform megasonic wave cleaning on the wafer body (5) inside the cleaning box (1); S3: The wafer transport rack (3) takes out the cleaned wafer body (5) from the inside of the cleaning box (1) and transports it to the top of the symmetrical air-drying mechanism (4) via the transport track (2); S4: the wafer transport rack (3) adjusts a group of wafer bodies (5) on the bottom surface from an overlapping state to a staggered separated state, thereby increasing the gap between the group of wafer bodies (5); S5: using a detection camera to collect oblique angle photos of the photolithography surface of the wafer body (5), and identifying moisture data of the wafer body (5) based on the oblique angle photos of the photolithography surface; S6: the wafer transport rack (3) transports the wafer bodies (5) in the staggered and separated state to the top surface of the symmetrical air-drying mechanism (4), the symmetrical air-drying mechanism (4) applies symmetrical blowing to the side surfaces of the wafer bodies (5), and the symmetrical air-drying mechanism (4) simultaneously rotates the wafer bodies (5) in the vertical direction, and the time for the symmetrical air-drying mechanism (4) to apply symmetrical blowing to the side surfaces of the wafer bodies (5) is determined based on the moisture data; S7: The wafer transport rack (3) adjusts the wafer bodies (5) in the staggered and separated state to an overlapping state, and then transports the wafer bodies (5) in the overlapping state into a packing box.

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