Method for cleaning inorganic coating of semiconductor substrate based on polishing mechanism

Abstract

The invention relates to the technical field of semiconductor manufacturing, and discloses a semiconductor substrate inorganic coating cleaning method based on a polishing mechanism, and the method comprises the steps: S1, preparing a working cleaning solution, accurately preparing a required chemical cleaning solution according to the conditions of a substrate inorganic coating and possibly contaminated impurities, and preparing ultrapure water; s2, preliminary washing: placing the semiconductor substrate with the inorganic coating taken down from the polishing mechanism on a washing rack of a cleaning machine, and slowly washing the surface of the substrate by using mild ultrapure water so as to wash away some large-particle impurities which are loosely attached and are easy to remove; according to the invention, the limiting piece is arranged, when the wafer moves to the bottom end of the gap space along with the supporting block, the supporting block for guiding above the gap limits the middle part of the bottom end of the wafer, and the side edge of the lower end of the wafer is in contact with the sealing ring I and the sealing ring II which are attached to support the side edge of the bottom end of the wafer; the gap is filled, and the situation of position deviation and collision when the wafer is placed is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a method for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism. Background Art

[0002] After the semiconductor substrate is polished, its inorganic coating usually needs to be cleaned. Because polishing fluid is used in the polishing process, the polishing fluid contains abrasive particles, chemical additives and other ingredients. These substances may remain on the surface of the substrate and the inorganic coating. Cleaning can remove the residual abrasive and impurities, making the surface of the inorganic coating smoother and smoother; removing chemical substances that may react with the coating can ensure the chemical stability of the inorganic coating; the cleaned inorganic coating can be better compatible with subsequent manufacturing processes.

[0003] In the prior art, in order to ensure that the wafer can be placed in the cleaning rack, the size of the cleaning rack must be larger than the size of the wafer. Therefore, there is a gap between the wafer and the cleaning rack. Therefore, during the process of placing the wafer into the cleaning rack and transferring the cleaning rack to the cleaning tank wafer, the wafer may be displaced and contact the cleaning rack due to the gap. Since the structure of the cleaning rack itself may have some sharp edges or uneven areas, when the wafer contacts it, since the wafer is usually thin and brittle, even a slight collision may cause edge cracks or scratches on the surface. Summary of the invention

[0004] Technical issues solved

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for cleaning inorganic coatings on semiconductor substrates based on a polishing mechanism, which can effectively solve the problem that the gap between the wafer and the cleaning rack used to position it during the cleaning process is easily damaged.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The present invention provides a method for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism, comprising:

[0008] S1. Preparation of cleaning solution. According to the inorganic coating of the substrate and possible impurities, accurately prepare the required chemical cleaning solution, and prepare ultrapure water;

[0009] S2. Preliminary rinsing: placing the semiconductor substrate with the inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinsing the substrate surface with mild ultrapure water to wash away some loosely attached and easily removable large particle impurities;

[0010] S3. Soaking in chemical solution: carefully place the substrate after preliminary rinsing into the prepared chemical cleaning solution, ensure that the substrate is completely immersed in the solution, and slowly shake the substrate so that the impurities on the substrate surface can fully contact with the chemical solution and react chemically. Take out the substrate and then immediately rinse it with a large amount of flowing ultrapure water. The purpose of ultrapure water rinsing is to remove the residual chemical cleaning solution on the substrate surface and the products generated by the reaction, ensure that the water after rinsing is close to neutral, and the water flowing down from the substrate surface is clear and free of impurities;

[0011] S4. Physical cleaning and ultrasonic cleaning: put the chemically cleaned substrate into the ultrasonic cleaning tank, turn on the ultrasonic cleaning machine, and clean the substrate under the action of ultrasound. Use the strong impact force generated by the cavitation bubble burst to shake off some tiny particles of impurities on the surface of the inorganic coating of the substrate that remain after chemical cleaning. During the cleaning process, pay attention to the power of the ultrasound to avoid excessive power to damage the substrate or coating;

[0012] S5. High-pressure jet cleaning: After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixture and use high-pressure jet cleaning equipment to jet clean the substrate with ultrapure water or a suitable chemical cleaning liquid. The jet can be sprayed at multiple angles and directions. The strong impact of the water flow further removes impurities and makes the substrate surface cleaner.

[0013] S6. Drying treatment After completing all the above cleaning steps, the substrate is placed in a dust-free, dry environment with a suitable temperature to dry naturally to avoid residual water stains on the surface of the substrate, which may affect the subsequent semiconductor manufacturing process;

[0014] The cleaning machine in S2 includes a cleaning tank, the inner wall of the cleaning tank is provided with a stirring member for stirring the cleaning liquid, a movable member is provided in the middle of the stirring member, a cleaning rack for placing wafers is provided inside the cleaning tank, a clamping plate that is engaged with the side wall of the cleaning tank is fixedly connected to the top of the cleaning rack, a partition plate for spacing the wafers is provided on the inner wall of the cleaning rack, a limiting member for supporting the side edge of the bottom end of the wafer is provided on the inner wall of the partition plate, a buffer member for supporting and guiding the bottom of the wafer is provided in the interval space between the partition plates, and the buffer member and the limiting member in a separated state can jointly support and limit the wafers placed in the cleaning rack at multiple angles;

[0015] Wherein, a movable part connected to the middle part of the stirring part is arranged on the inner wall of the cleaning tank, and the movable part adjusts the position of the limiting part and the partition plate as the stirring part moves to increase the contact area between the wafer and the cleaning liquid.

[0016] Furthermore, the buffer component includes a support block arranged in an arc shape to limit the middle part of the bottom end of the wafer, the bottom end of the support block is fixedly connected to a fixed plate, the side of the fixed plate is rotatably connected to a movable plate, a knob spring is arranged inside the movable plate, and the other end of the movable plate is slidably connected to a movable groove opened at the bottom end of the partition plate.

[0017] Furthermore, the side of the partition plate is symmetrically provided with a limiting groove for limiting the limiting member, the side of the limiting groove is provided with a side groove, and the inner wall of the side groove is provided with a stabilizing member.

[0018] Furthermore, the stabilizing member includes an arc-shaped abutment plate on the outer surface, the abutment plate is fixedly connected to a limiting block on one side close to the partition plate, the limiting block is externally sleeved with a leaf spring, and the leaf spring is embedded in the inner wall of a slide groove opened on the side of the cleaning rack.

[0019] Furthermore, the limiting member includes a fixing ring 1 that is slidably connected to the inner wall of the limiting groove and a fixing ring 2 that is fixedly connected to the inner wall of the limiting groove, the side of the fixing ring 1 close to the fixing ring 2 is connected to the fixing ring 2 through a cross-link rod that is rotatably connected thereto, a telescopic spring is elastically connected to the middle of the cross-link rod, the side of the fixing ring 1 away from the fixing ring 2 is fixedly connected to a sealing ring 1, a slot is provided at the other end of the sealing ring 1, one side of the fixing ring is fixedly connected to a cross-link rod, the side of the fixing ring 2 away from the fixing ring 1 is fixedly connected to a sealing ring 2, and a side of the sealing ring 2 is provided with a clamping block that interlocks with the clamping slot.

[0020] Furthermore, in the initial state, the telescopic spring remains contracted, and the lateral dimension of the cross-link is the smallest. At this time, the sides of the sealing ring 1 and the sealing ring 2 are in contact, and the clamping groove and the clamping block are not engaged.

[0021] Furthermore, the movable part includes a positioning shaft fixedly connected to the center of the stirring part, an elliptical ring is fixedly connected to the outer side of the positioning shaft, a positioning plate is slidably connected to the outer side of the elliptical ring, two positioning plates are symmetrically arranged with the center of the elliptical ring as the center, and a rotating wheel slidably connected to the side of the elliptical ring is provided on the side of the positioning plate, one of the sides of the positioning plate is provided with a push plate that fits against the side of the plate, and a connecting plate is fixedly connected to the bottom end of the positioning plate on the other side, and a sliding plate is fixedly connected to the other end of the connecting plate, the part of the positioning plate close to the elliptical ring passes through a positioning frame opened on the inner wall of the cleaning tank, and slot holes are opened at both ends of the positioning frame to limit the positioning plate, and the positioning plate is slidably connected to the groove opened on the inner wall of the cleaning tank.

[0022] Furthermore, a side of the push plate close to the abutment plate is configured as an inclined surface that gradually increases in size, and the push plate does not fit the abutment plate at its minimum size;

[0023] A top block is fixedly connected to the top of the slide plate, an upper surface of the top block is arranged in an arc shape, and a middle portion of the upper surface of the top block is fitted with the bottom end of the fixed plate.

[0024] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0025] The present invention is provided with a limiting piece. When the wafer is moved to the bottom end of the gap space along with the supporting block, in addition to the supporting block limiting the middle part of its bottom end, the side edge of the lower end of the wafer contacts the fitted sealing ring 1 and the sealing ring 2, supporting the side edge of the bottom end of the wafer, filling the gap to avoid position deviation and collision when the wafer is placed.

[0026] The present invention is provided with a buffer component, which can first limit the bottom end of the wafer and guide the downward movement of the wafer when the wafer is placed, so as to avoid collision with the inner wall of the cleaning rack during the downward movement. As the wafer is placed, the support block drives the fixed plate fixedly connected to it to move downward along the gap between the partition plates. The fixed plate moves and drives the movable plate to rotate. When the movable plate rotates, the long plate connected to the other end slides on the inner wall of the movable groove until the wafer is completely placed in, thereby ensuring the stability and safety of the wafer when it is placed.

[0027] The present invention is provided with a stabilizing member, and the stabilizing member is arranged on the side of the cleaning rack to exert an additional force on the wafer during the transfer process to prevent the wafer from moving, thereby ensuring that the wafer will not be damaged when the cleaning rack moves as a whole.

[0028] The present invention is provided with movable parts, and the support block, sealing ring 1 and sealing ring 2 for supporting and limiting the wafer are set in a separated state and are all set in an arc shape. During the cleaning process, the movable parts adjust the positions of the limiting parts and the partition plates along with the movement of the stirring parts, and the positions of the support block, sealing ring 1 and sealing ring 2 change, so that their original positioning positions can be cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of a cleaning method according to an embodiment of the present invention

[0031] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of a cleaning tank connection structure according to an embodiment of the present invention;

[0033] Figure 4 A schematic diagram of a connection structure of movable parts according to an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the structure of a cleaning rack according to an embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of a stabilizing member according to an embodiment of the present invention;

[0036] Figure 7 A schematic diagram of the structure of a buffer member according to an embodiment of the present invention;

[0037] Figure 8 Schematic diagram of the structure of the partition plate and the limit member according to an embodiment of the present invention.

[0038] The numbers in the figure represent: 1, cleaning tank; 11, channel; 2, cleaning rack; 21, card plate; 22, partition plate; 221, movable tank; 223, side tank; 226, limit tank; 23, buffer; 231, support block; 232, fixed plate; 233, movable plate; 234, knob spring; 24, slide; 25, stabilizer; 251, limit block; 252, leaf spring; 253, stop plate; 2 6. Limiting member; 261. Fixed ring 1; 262. Sealing ring 1; 263. Slot; 264. Fixed ring 2; 265. Sealing ring 2; 266. Block; 267. Telescopic spring; 268. Cross connecting rod; 3. Stirring member; 4. Movable member; 41. Positioning shaft; 42. Oval ring; 43. Positioning plate; 431. Push plate; 432. Connecting plate; 44. Positioning frame; 6. Slide plate; 61. Top block. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0040] The present invention will be further described below in conjunction with the embodiments.

[0041] Example:

[0042] See also Figure 1-Figure 8 The present invention provides a technical solution for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism, comprising:

[0043] S1. Preparation of cleaning solution. According to the inorganic coating of the substrate and possible impurities, accurately prepare the required chemical cleaning solution, and prepare ultrapure water;

[0044] S2. Preliminary rinsing: placing the semiconductor substrate with the inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinsing the substrate surface with mild ultrapure water to wash away some loosely attached and easily removable large particle impurities;

[0045] S3. Soaking in chemical solution: carefully place the substrate after preliminary rinsing into the prepared chemical cleaning solution, ensure that the substrate is completely immersed in the solution, and slowly shake the substrate so that the impurities on the substrate surface can fully contact with the chemical solution and react chemically. Take out the substrate and then immediately rinse it with a large amount of flowing ultrapure water. The purpose of ultrapure water rinsing is to remove the residual chemical cleaning solution on the substrate surface and the products generated by the reaction, ensure that the water after rinsing is close to neutral, and the water flowing down from the substrate surface is clear and free of impurities;

[0046] S4. Physical cleaning and ultrasonic cleaning: put the chemically cleaned substrate into the ultrasonic cleaning tank, turn on the ultrasonic cleaning machine, and clean the substrate under the action of ultrasound. Use the strong impact force generated by the cavitation bubble burst to shake off some tiny particles of impurities on the surface of the inorganic coating of the substrate that remain after chemical cleaning. During the cleaning process, pay attention to the power of the ultrasound to avoid excessive power to damage the substrate or coating;

[0047] S5. High-pressure jet cleaning: After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixture and use high-pressure jet cleaning equipment to jet clean the substrate with ultrapure water or a suitable chemical cleaning liquid. The jet can be sprayed at multiple angles and directions. The strong impact of the water flow further removes impurities and makes the substrate surface cleaner.

[0048] S6. Drying treatment After completing all the above cleaning steps, the substrate is placed in a dust-free, dry environment with a suitable temperature to dry naturally to avoid residual water stains on the surface of the substrate, which may affect the subsequent semiconductor manufacturing process;

[0049] refer to Figure 2 The cleaning rack 2 carrying the separated wafers is placed on the inner wall of the cleaning tank 1. The cleaning tank 1 is filled with pure water or cleaning liquid as needed. Figure 4 As shown, a clamping plate 21 is fixedly connected to the top of the cleaning rack 2 and is engaged with the outer wall of the top of the cleaning tank 1. A plurality of partition plates 22 are evenly arranged on the inner wall of the clamping plate 21. The gaps between the partition plates 22 are used to place wafers, and a buffer 23 is arranged inside the gaps.

[0050] refer to Figure 5 and Figure 7The buffer member 23 includes a support block 231 fixedly connected to the inner wall of the cleaning rack 2, a fixed plate 232 is fixedly connected to the bottom end of the support block 231, a movable plate 233 is rotatably connected to the side of the fixed plate 232, a knob spring 234 runs through the middle of one end of the movable plate 233, and the movable plate 233 is rotatably connected to the end away from the fixed plate 232 with a long plate, and the long plate is slidably connected to the movable groove 221 opened at the bottom end of the partition plate 22.

[0051] In the initial state, the movable plate 233 lifts the support block 231 to the upper end position of the gap between the partition plates 22. The top of the support block 231 is almost flush with the top of the partition plate 22. When placing the wafer, the bottom end of the wafer can be limited and supported first, and the wafer can be guided downward to avoid collision with the inner wall of the cleaning rack 2 during the downward movement. As the wafer is placed, the support block 231 drives the fixed plate 232 fixedly connected to it to move downward along the gap between the partition plates 22. The fixed plate 232 moves and drives the movable plate 233 to rotate. When the movable plate 233 rotates, the long plate connected to the other end slides on the inner wall of the movable groove 221 until the wafer is completely placed in. This ensures the stability and safety of the wafer when it is placed.

[0052] refer to Figure 2 , Figure 5 and Figure 8The partition plate 22 has a symmetrical side edge with a limiting groove 226 for limiting the limiting member 26. The limiting groove 226 has a side groove 223. The inner wall of the side groove 223 is provided with a stabilizing member 25. The limiting member 26 includes a fixing ring 1 261 slidably connected to the inner wall of the limiting groove 226 and a fixing ring 2 264 fixedly connected to the inner wall of the limiting groove 226. The inner wall of the limiting groove 226 is provided with an arc groove that slides with the fixing ring 1 261 and the fixing ring 2 264. The outer side of the limiting groove 226 is set as a semi-arc groove that is slidably sealed with the side of the sealing ring 1 262 and the clamping block 266. The side of the fixing ring 1 261 close to the fixing ring 264 is connected to the fixing ring 2 264 through a cross connecting rod 268 rotatably connected thereto. The middle part of the cross connecting rod 268 is elastically connected with a telescopic spring 267. The side of the fixing ring 1 261 away from the fixing ring 264 is fixedly connected with the sealing ring 1 262. The other end of the sealing ring 1 262 is provided with a clamping groove. 263, a cross connecting rod 268 is fixedly connected to the side of the fixing ring 1 261, a sealing ring 265 is fixedly connected to the side of the fixing ring 264 away from the fixing ring 1 261, and a clamping block 266 staggeredly engaged with the clamping groove 263 is provided on the side of the sealing ring 265. The sealing ring 1 262 and the sealing ring 265 are both set in an L shape, and the sides of the sealing ring 1 262 and the sealing ring 265 are both slidably sealed with the semi-arc groove; in the initial state, the telescopic spring 267 remains contracted, The cross-link 268 has the smallest lateral dimension. At this time, the sealing ring 1 262 is in contact with the side of the sealing ring 265, and the slot 263 is not in contact with the block 266. Therefore, when the wafer is moved to the bottom of the gap space with the support block 231, in addition to the support block 231 limiting the middle of its bottom end, the side of the lower end of the wafer is in contact with the sealing ring 1 262 and the sealing ring 2 265 that are in contact, supporting the side of the bottom end of the wafer, filling the gap and avoiding the position deviation and collision of the wafer when it is placed.

[0053] In the prior art, at the moment when the cleaning rack 2 enters the cleaning tank 1, the wafer may be impacted due to the resistance of the liquid or the impact force generated by the flow of liquid in the cleaning tank 1. Therefore, the present invention provides a stabilizing member 25 on the side of the cleaning rack 2 to apply additional force to the wafer during the transfer process to prevent it from moving, thereby ensuring that the wafer will not be damaged when the cleaning rack 2 moves as a whole.

[0054] refer to Figure 5 and Figure 6The stabilizing member 25 includes an arc-shaped abutment plate 253 on the outer surface, and the diameter of the arc gradually decreases from top to bottom. The abutment plate 253 is fixedly connected to a side of the partition plate 22 close to the limit block 251, and the limit block 251 is slidably connected to the inner wall of the side groove 223. The end of the limit block 251 close to the partition plate 22 is set to a trapezoid, and the minimum size of this end of the limit block 251 is equal to the size of the card block 266 in the contracted state. The limit block 251 can be inserted into the cross connecting rod 268. The outer sleeve of the limit block 251 is provided with a leaf spring 252, and the leaf spring 252 is embedded in the inner wall of the slide groove 24 opened on the side of the cleaning rack 2.

[0055] In the process of placing the cleaning rack 2 into the inner wall of the cleaning tank 1, the abutment plate 253, whose outer surface is set as an arc surface and whose size is slightly larger than the upper end size of the inner wall of the cleaning tank 1, first fits with the upper end of the inner wall of the cleaning tank 1, and the abutment plate 253 drives the limit block 251 to move toward the side groove 223 under the action of the extrusion force. At this time, the leaf spring 252 is elastically deformed, and the limit block 251 slides on the inner wall of the side groove 223 and is inserted into the contracted and closed cross link 268. A force is applied to the cross link 268 through the side of the limit block 251. The cross link 268 is opened by the support force of the inner wall. The clamping block 266 is elastically deformed, and the cross link 268 opens and its lateral size increases, thereby tightening the fixing ring 1 261 and the fixing ring 2 connected to the two ends of the cross link 268. 264 applies a force, and the top of the fixing ring 1 261 and the fixing ring 264 are both provided with a rectangular block that is slidably connected to the rectangular groove at the top of the inner wall of the limiting groove 226. The fixing ring 1 261 and the fixing ring 264 slide smoothly in opposite directions on the inner wall of the limiting groove 226. The fixing ring 1 261 drives the sealing ring 1 262 to slide toward the side close to the wafer, and the movement of the sealing ring 1 262 drives the card slot 263 to move. The card slot 263 moves and is engaged with the card block 266 opened on one side of the other sealing ring 265. At this time, the two are engaged and staggered and fit tightly. In the process of placing the cleaning rack 2 into the cleaning tank 1, the force on the side is evenly increased to further limit the bottom support member to prevent it from moving, thereby ensuring that the wafer will not be damaged when the cleaning rack 2 moves as a whole.

[0056] As the cleaning rack 2 is fully inserted, the side of the support plate 253 is no longer restricted by the top of the inner wall of the cleaning tank 1, and the leaf spring 252 elastically recovers to make the support plate 253 fit the inner wall of the cleaning tank 1. The telescopic spring 267 elastically recovers to restore the cross-link 268 to a contracted state. At this time, the sealing ring 265 and the sealing ring 1 262 are limited to the side of the wafer, but are not completely sealed and fitted, ensuring that the position of the wafer will not be offset due to the movement of the cleaning rack 2.

[0057] However, in the prior art, the positioning structure of the wafer is set at a fixed position. During the cleaning process, the positioning point at the fixed position may cause a cleaning dead corner in the cleaning area of ​​the wafer, resulting in incomplete cleaning. Therefore, the present invention sets the support block 231, sealing ring 1 262 and sealing ring 2 265 for supporting and limiting the wafer to a separated state, and all of them are set to an arc shape. During the cleaning process, the positions of the support block 231, sealing ring 1 262 and sealing ring 2 265 change, and their original positioning positions can be cleaned.

[0058] refer to Figure 5 , Figure 2 , Figure 3 and Figure 4 The inner wall of the cleaning tank 1 is provided with a movable part 4 connected to the middle of the stirring part 3. The movable part 4 adjusts the position of the limit part 26 and the partition plate 22 as the stirring part 3 moves to increase the contact area between the wafer and the cleaning liquid. The movable part 4 includes a positioning shaft 41 fixedly connected to the center of the stirring part 3, an elliptical ring 42 is fixedly connected to the outer side of the positioning shaft 41, and a positioning plate 43 is slidably connected to the outer side of the elliptical ring 42. Two positioning plates 43 are symmetrically arranged with the center of the elliptical ring 42 as the center. A rotating wheel slidably connected to the side of the elliptical ring 42 is opened on the side of the positioning plate 43. A push plate 431 that fits the side of the abutment plate 253 is arranged on the side of one of the positioning plates 43, and the other side A connecting plate 432 is fixedly connected to the bottom end of the positioning plate 43, and a slide plate 6 is fixedly connected to the other end of the connecting plate 432. A top block 61 is fixedly connected to the top of the slide plate 6. The upper surface of the top block 61 is set to an arc shape, and the middle part of the upper surface of the top block 61 is in contact with the bottom end of the fixed plate 232. The part of the positioning plate 43 close to the elliptical ring 42 passes through the positioning frame 44 opened on the inner wall of the cleaning tank 1. Slot holes for limiting the positioning plate 43 are opened at both ends of the positioning frame 44. The positioning plate 43 is slidably connected to the groove 11 opened on the inner wall of the cleaning tank 1. The side of the push plate 431 close to the abutment plate 253 is set to an inclined surface that changes from small to large, and the push plate 431 does not fit with the abutment plate 253 at its minimum size.

[0059] When the stirring member 3 is started to stir the cleaning liquid in the cleaning tank 1, the stirring member 3 rotates to drive the positioning shaft 41 to rotate, and the rotation of the positioning shaft 41 drives the elliptical ring 42 to rotate. The rotation of the elliptical ring 42 drives the positioning plate 43, which is limited by the slot hole of the positioning frame 44 and can only move horizontally, to slide. The positioning plate 43 slides on the inner wall of the groove 11. Since the positioning plates 43 are symmetrically distributed with the center of the positioning shaft 41 as the center, the two positioning plates 43 slidably connected to the elliptical ring 42 move in opposite directions respectively, and one of the positioning plates 43 drives the push plate 431 to move, and the push plate 431 moves from not contacting the surface of the abutment plate 253 to contacting the surface of the abutment plate 253. The sealing ring 265 and the sealing ring 1 262 are in close contact with each other to position the side of the bottom end of the wafer. However, the other positioning plate 43 drives the connecting plate 432 to move, and the movement of the connecting plate 432 drives the sliding plate 6 to move. The movement of the sliding plate 6 drives the supporting block 231 that supports the middle part of the bottom end of the wafer to no longer be in close contact with the bottom end of the wafer. With the movement of the top block 61, the fixing plate 232 drives the supporting block 231 to move downward by a certain space. At this time, there is a gap between the bottom end of the wafer and the supporting block 231. The cleaning liquid passes through the gap to rinse and clean the position of the wafer originally limited by the supporting block 231, avoiding the cleaning dead corner at this place, and also through the reinforced The side limiter prevents the wafer from shifting during the cleaning process. The positioning shaft 41 rotates one circle to drive the positioning plate 43 to move back and forth once; when one of the positioning plates 43 drives the connecting plate 432 to move, the other positioning plate 43 drives the connecting plate 432 to move, and the movement of the connecting plate 432 drives the slide plate 6 to move. The movement of the slide plate 6 drives the support block 231 that supports the middle part of the bottom end of the wafer to fit tightly to the bottom end of the wafer again. With the movement of the top block 61, the fixed plate 232 drives the support block 231 to move upward by a certain space. At this time, the bottom end of the wafer is tightly connected to the support block 231, driving 253 to move from a position that does not fit with the surface of the abutment plate to a position that fits with the surface of the abutment plate 253. At this time, the sealing ring 265 and the sealing ring 1 262 fit tightly together to position the side of the bottom end of the wafer. However, at this time, the other positioning plate 43 drives the push plate 431 to move, and the push plate 431 moves from fitting with the surface of the abutment plate 253 to fitting with the surface of the non-abutment plate 253. At this time, the sealing ring 265 and the sealing ring 1 262 are no longer tightly fitted, and the cleaning liquid will pass through the gap to rinse and clean the position of the wafer originally limited by the sealing ring 265 and the sealing ring 1 262, avoiding the cleaning dead corner at this location, and also preventing the wafer from shifting during the cleaning process through the reinforced bottom limit. With the rotation of the stirring member 3, multiple position changes are achieved to improve the cleaning quality.

[0060] At the same time, during the actual polishing process, polishing pads and polishing liquid are used, and material particles of the polishing pads may remain on the wafer surface. At the same time, materials removed from the wafer surface may remain on the wafer surface in the form of debris. The fixed-position positioning structure in the prior art fills the gap between the wafer and the positioning groove, and at the same time, the debris that should have flowed out along the gap is blocked in the gap on the wafer surface of the positioning structure, which reduces the cleaning quality and easily increases the collision between the debris and the wafer during the subsequent transfer process. It also leaves scratches on the wafer surface and destroys the microstructure of the wafer surface. For high-precision semiconductor wafers, this may affect the performance and reliability of the chip. In integrated circuit manufacturing, tiny scratches may cause circuit short circuits or abnormal signal transmission. The repeated friction of debris in the gap between the fixture and the wafer will also accelerate the wear of the positioning. Therefore, the arc size formed by the support block 231, sealing ring 1 262 and sealing ring 265 provided in the present invention is smaller than half the arc of the wafer. When there is a gap between the support block 231 and the wafer, the cleaning liquid can easily push the debris out from the inner wall of the support block 231. At the same time, when the groove 263 opened on one side of the sealing ring 1 262 and the block 266 opened on one side of the sealing ring 265 are not completely tightly fitted between the sealing ring 1 262 and the sealing ring 265, the debris can easily slide out from the gap in the groove 263 along the arc surface under the impact force of gravity and the stirring liquid during the movement. Therefore, when cleaning the dead corners of the wafer surface, the debris can also be cleaned out of the positioning structure.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning an inorganic coating on a semiconductor substrate based on a polishing mechanism, characterized in that: include: S1. Preparation of cleaning solution. According to the inorganic coating of the substrate and possible impurities, accurately prepare the required chemical cleaning solution, and prepare ultrapure water; S2. Preliminary rinsing: placing the semiconductor substrate with the inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinsing the substrate surface with mild ultrapure water to wash away some loosely attached and easily removable large particle impurities; S3. Soaking in chemical solution: carefully place the substrate after preliminary rinsing into the prepared chemical cleaning solution, ensure that the substrate is completely immersed in the solution, and slowly shake the substrate so that the impurities on the substrate surface can fully contact with the chemical solution and react chemically. Take out the substrate and then immediately rinse it with a large amount of flowing ultrapure water. The purpose of ultrapure water rinsing is to remove the residual chemical cleaning solution on the substrate surface and the products generated by the reaction, ensure that the water after rinsing is close to neutral, and the water flowing down from the substrate surface is clear and free of impurities; S4. Physical cleaning and ultrasonic cleaning: put the chemically cleaned substrate into the ultrasonic cleaning tank, turn on the ultrasonic cleaning machine, and clean the substrate under the action of ultrasound. Use the strong impact force generated by the cavitation bubble burst to shake off some tiny particles of impurities on the surface of the inorganic coating of the substrate that remain after chemical cleaning. During the cleaning process, pay attention to the power of the ultrasound to avoid excessive power to damage the substrate or coating; S5. High-pressure jet cleaning: After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixture and use high-pressure jet cleaning equipment to jet clean the substrate with ultrapure water or a suitable chemical cleaning liquid. The jet can be sprayed at multiple angles and directions. The strong impact of the water flow further removes impurities and makes the substrate surface cleaner. S6. Drying treatment After completing all the above cleaning steps, the substrate is placed in a dust-free, dry environment with a suitable temperature to dry naturally to avoid residual water stains on the surface of the substrate, which may affect the subsequent semiconductor manufacturing process; The cleaning machine in S2 comprises a cleaning tank (1), the inner wall of the cleaning tank (1) is provided with a stirring member (3) for stirring the cleaning liquid, a movable member (4) is provided in the middle of the stirring member (3), a cleaning rack (2) for placing wafers is provided inside the cleaning tank (1), a clamping plate (21) which is fixedly connected to the top of the cleaning rack (2) and is engaged with the side wall of the cleaning tank (1), a partition plate (22) for spacing the wafers is provided on the inner wall of the cleaning rack (2), a limiting member (26) for supporting the side edge of the bottom end of the wafer is provided on the inner wall of the partition plate (22), a buffer member (23) for supporting and guiding the bottom of the wafer is provided in the space between the partition plates (22), and the buffer member (23) and the limiting member (26) in a separated state can jointly support and limit the wafers placed in the cleaning rack (2) at multiple angles; The inner wall of the cleaning tank (1) is provided with a movable part (4) connected to the middle of the stirring part (3); the movable part (4) adjusts the position of the limit part (26) and the partition plate (22) as the stirring part (3) moves, thereby increasing the contact area between the wafer and the cleaning liquid.

2. A method for cleaning inorganic coatings on semiconductor substrates based on a polishing mechanism according to claim 1, characterized in that: The buffer member (23) comprises a support block (231) arranged in an arc shape to limit the middle part of the bottom end of the wafer, the bottom end of the support block (231) is fixedly connected to a fixed plate (232), the side of the fixed plate (232) is rotatably connected to a movable plate (233), a knob spring (234) is arranged inside the movable plate (233), and the other end of the movable plate (233) is slidably connected to a movable groove (221) opened at the bottom end of the partition plate (22).

3. The method for cleaning inorganic coating of semiconductor substrate based on polishing mechanism according to claim 1, characterized in that: The partition plate (22) is symmetrically provided with a limiting groove (226) on the side for limiting the limiting member (26), a side groove (223) is provided on the side of the limiting groove (226), and a stabilizing member (25) is provided on the inner wall of the side groove (223).

4. A method for cleaning inorganic coatings on semiconductor substrates based on a polishing mechanism according to claim 3, characterized in that: The stabilizing member (25) comprises an arc-shaped abutment plate (253) on the outer surface thereof; the abutment plate (253) is fixedly connected to a limiting block (251) on one side close to the partition plate (22); a leaf spring (252) is sleeved on the outer side of the limiting block (251); and the leaf spring (252) is embedded in the inner wall of a slide groove (24) provided on the side of the cleaning rack (2).

5. The method for cleaning inorganic coating of semiconductor substrate based on polishing mechanism according to claim 3, characterized in that: The limiting member (26) comprises a fixing ring 1 (261) slidably connected to the inner wall of the limiting groove (226) and a fixing ring 2 (264) fixedly connected to the inner wall of the limiting groove (226); a side of the fixing ring 1 (261) close to the fixing ring 2 (264) is connected to the fixing ring 2 (264) via a cross connecting rod (268) rotatably connected thereto; a telescopic spring (267) is elastically connected to the middle part of the cross connecting rod (268); A sealing ring 1 (262) is fixedly connected to the side away from the fixing ring 2 (264), and a clamping groove (263) is provided at the other end of the sealing ring 1 (262). A cross connecting rod (268) is fixedly connected to the side of the fixing ring 1 (261). A sealing ring 2 (265) is fixedly connected to the side of the fixing ring 2 (264) away from the fixing ring 1 (261), and a clamping block (266) that interlocks with the clamping groove (263) is provided on the side of the sealing ring 2 (265).

6. The method for cleaning inorganic coating of semiconductor substrate based on polishing mechanism according to claim 5, characterized in that: In the initial state, the telescopic spring (267) remains contracted, and the cross link (268) has the smallest lateral dimension. At this time, the sealing ring 1 (262) and the sealing ring 2 (265) are in contact with each other, and the clamping groove (263) and the clamping block (266) are not engaged.

7. The method for cleaning inorganic coating of semiconductor substrate based on polishing mechanism according to claim 1, characterized in that: The movable member (4) comprises a positioning shaft (41) fixedly connected to the center of the stirring member (3); an elliptical ring (42) is fixedly connected to the outer side of the positioning shaft (41); a positioning plate (43) is slidably connected to the outer side of the elliptical ring (42); two positioning plates (43) are symmetrically arranged with the center of the elliptical ring (42) as the center; a rotating wheel slidably connected to the side of the elliptical ring (42) is provided on the side of the positioning plate (43); a counter plate (253) is provided on the side of one of the positioning plates (43) A push plate (431) is fitted on the side, and a connecting plate (432) is fixedly connected to the bottom end of the positioning plate (43) on the other side, and a sliding plate (6) is fixedly connected to the other end of the connecting plate (432). The part of the positioning plate (43) close to the elliptical ring (42) passes through a positioning frame (44) provided on the inner wall of the cleaning tank (1). Slot holes for limiting the positioning plate (43) are provided at both ends of the positioning frame (44), and the positioning plate (43) is slidably connected to a groove (11) provided on the inner wall of the cleaning tank (1).

8. A method for cleaning inorganic coatings on semiconductor substrates based on a polishing mechanism according to claim 7, characterized in that: The side of the push plate (431) close to the abutment plate (253) is configured as an inclined surface that gradually increases in size, and the push plate (431) does not fit the abutment plate (253) at its smallest size; A top block (61) is fixedly connected to the top of the slide plate (6); the upper surface of the top block (61) is arranged in an arc shape; the middle portion of the upper surface of the top block (61) is in contact with the bottom end of the fixed plate (232).

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