A cleaning method for inorganic coatings on semiconductor substrates based on a polishing mechanism

Abstract

The present invention relates to the technical field of semiconductor manufacturing, and discloses a method for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism, including S1. Preparation work, cleaning solution preparation. According to the situation of the inorganic coating of the substrate and the possible contaminants, accurately prepare the required chemical cleaning solution, and at the same time prepare ultrapure water; S2. Preliminary rinsing. Place the semiconductor substrate with the inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinse the surface of the substrate with mild ultrapure water. The purpose is to wash away some large particulate impurities that are loosely attached and easily removed. The invention is provided with a limiting member. When the wafer moves to the bottom end of the gap space along with the support block, in addition to the support block that guides above the gap limiting the middle of its bottom end, the lower side edges of the wafer contact the fitting sealing ring 1 and sealing ring 2, supporting the lower side edges of the wafer, playing a role in filling the gap to avoid the situation of position deviation and collision when the wafer is placed.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly relates 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, it is usually necessary to clean its inorganic coating. Because polishing fluid is used during the polishing process, and the polishing fluid contains components such as abrasive particles and chemical additives. These substances may remain on the surface of the substrate and the inorganic coating. Cleaning can remove the residual abrasives and impurities, making the surface of the inorganic coating smoother and more even; remove chemical substances that may react with the coating to ensure the chemical stability of the inorganic coating; and 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 is larger than that of the wafer. Therefore, there is a gap between the wafer and the cleaning rack. Therefore, during the process of placing the wafer in the cleaning rack and transferring the cleaning rack to the cleaning tank where the wafer is located, the wafer may be displaced and come into contact with the cleaning rack due to the existence of the gap. Since the structure of the cleaning rack itself may have some sharp corners or uneven places, when the wafer comes into contact with it, because the wafer is usually thin and brittle, even a slight collision may cause edge cracking or surface scratching. Summary of the Invention

[0004] Technical Problems to be Solved

[0005] In view of the above-mentioned drawbacks of the prior art, the present invention provides a method for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism, which can effectively solve the problem that the wafer is easily damaged due to the gap between the wafer and the cleaning rack for positioning it during the cleaning process in the prior art.

[0006] To achieve the above object, the present invention is realized 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, including:

[0008] S1. Preparation work, preparation of cleaning solution. According to the situation of the inorganic coating of the substrate and the possible contaminated impurities, accurately prepare the required chemical cleaning solution, and at the same time prepare ultrapure water;

[0009] S2. Preliminary rinsing. Place the semiconductor substrate with an inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinse the surface of the substrate with mild ultrapure water. The purpose is to wash away some large particle impurities that are loosely attached and easy to remove;

[0010] S3. Chemical solution immersion: Carefully place the substrate after preliminary rinsing into the prepared chemical cleaning solution, ensuring that the substrate is completely immersed in the solution. Slowly shake the substrate to allow the impurities on the substrate surface to fully contact the chemical solution and undergo chemical reactions. Then take out the substrate and immediately rinse it thoroughly with a large amount of flowing ultrapure water. The purpose of rinsing with ultrapure water is to remove the residual chemical cleaning solution and reaction products on the substrate surface, ensuring that the rinsed water is close to neutral and the water flowing down from the substrate surface is clear without impurity residues.

[0011] S4. Physical cleaning - Ultrasonic cleaning: Place the substrate after chemical cleaning into the ultrasonic cleaning tank, turn on the ultrasonic cleaner, and let the substrate be cleaned under the action of ultrasonic waves. Use the powerful impact force generated by the collapse of cavitation bubbles to shake off some of the tiny particle impurities remaining on the surface of the inorganic coating of the substrate after chemical cleaning. Pay attention to the power of the ultrasonic waves during the cleaning process to avoid damaging the substrate or the coating due to excessive power.

[0012] S5. High - pressure jet cleaning: After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixing device, and use high - pressure jet cleaning equipment to spray - clean the substrate from multiple angles and directions with ultrapure water or a suitable chemical cleaning solution. Further remove impurities through the powerful water flow impact force to make the substrate surface cleaner.

[0013] S6. Drying treatment: After completing all the above cleaning steps, place the substrate in a dust - free, dry and properly - temperatured environment to air - dry naturally, avoiding water stains remaining on the substrate surface, which may affect the subsequent semiconductor manufacturing process.

[0014] Among them, the cleaning machine described in S2 includes a cleaning tank. The inner wall of the cleaning tank is provided with a stirring member for agitating the cleaning solution. An active member is provided in the middle of the stirring member. A cleaning rack for placing wafers is provided inside the cleaning tank. The top end of the cleaning rack is fixedly connected with a clamping plate that is snap - fitted with the side wall of the cleaning tank. The inner wall of the cleaning rack is provided with a partition plate for spacing the wafers. The inner wall of the partition plate is provided with a limiting member for supporting the side of the bottom end of the wafer. A buffer member for supporting and guiding the bottom of the wafer is provided in the spaced space between the partition plates. The buffer member and the limiting member in the separated state can jointly support and limit the wafer placed in the cleaning rack from multiple angles.

[0015] Among them, the inner wall of the cleaning tank is provided with an active member connected to the middle of the stirring member. The active member moves with the stirring member to adjust the positions of the limiting member and the buffer member, increasing the contact area between the wafer and the cleaning solution.

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

[0017] Further, limiting grooves for limiting the limiting member are symmetrically opened on the side of the partition plate. Side grooves are opened on the side of the limiting grooves. A stabilizing member is arranged on the inner wall of the side grooves.

[0018] Further, the stabilizing member includes a pressing plate with an arc-shaped outer surface. A limiting block is fixedly connected to the side of the pressing plate close to the partition plate. A leaf spring is sleeved outside the limiting block. The leaf spring is embedded in the inner wall of a sliding groove opened on the side of the cleaning rack.

[0019] Further, the limiting member includes a first fixing ring slidably connected to the inner wall of the limiting groove and a second fixing ring fixedly connected to the inner wall of the limiting groove. One side of the first fixing ring close to the second fixing ring is connected to the second fixing ring through a cross connecting rod rotatably connected thereto. A telescopic spring is elastically connected to the middle of the cross connecting rod. A first sealing ring is fixedly connected to the side of the first fixing ring far from the second fixing ring. A card slot is opened at the other end of the first sealing ring. A cross connecting rod is fixedly connected to the side of the first fixing ring. A second sealing ring is fixedly connected to the side of the second fixing ring far from the first fixing ring. A block is opened on the side of the second sealing ring and is staggeredly engaged with the card slot.

[0020] Further, in the initial state, the telescopic spring remains contracted, the transverse dimension of the cross connecting rod is the smallest. At this time, the sides of the first sealing ring and the second sealing ring are in contact, and the card slot and the block are not engaged.

[0021] Further, the movable member includes a positioning shaft fixedly connected to the center of the stirring member. An elliptical ring is fixedly connected to the outside of the positioning shaft. A positioning plate is slidably connected to the outside of the elliptical ring. Two positioning plates are symmetrically arranged with the center of the elliptical ring as the center. A runner slidably connected to the side of the elliptical ring is opened on the side of the positioning plate. A pushing plate that fits the side of the pressing plate is arranged on the side of one of the positioning plates. A connecting plate is fixedly connected to the bottom end of the other positioning plate. 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 penetrates through a positioning frame opened on the inner wall of the cleaning tank. Slot holes for limiting the positioning plate are opened at both ends of the positioning frame. The positioning plate is slidably connected to a channel opened on the inner wall of the cleaning tank.

[0022] Further, the side of the pushing plate close to the pressing plate is set as an inclined surface that becomes larger from small. The smallest dimension of the pushing plate does not fit the pressing plate.

[0023] A top block is fixedly connected to the top end of the skateboard. The upper surface of the top block is arc-shaped, and the middle part of the upper surface of the top block fits against the bottom end of the fixing plate.

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

[0025] The present invention is provided with a limiting member. When the wafer is moved to the bottom end of the gap space along with the support block, in addition to the support block limiting the middle part of its bottom end, the lower side edges of the wafer contact the sealing ring one and the sealing ring two in contact, supporting the lower side edges of the wafer bottom end, filling the gap to avoid the situation of position deviation and collision when the wafer is placed.

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

[0027] The present invention is provided with a stabilizing member. A stabilizing member is provided on the side of the cleaning rack to apply an additional force to the wafer during the transfer process to prevent it from moving and ensure that the wafer will not be damaged when the entire cleaning rack moves.

[0028] The present invention is provided with a movable member. The support block, the sealing ring one, and the sealing ring two that support and limit the wafer are set in a separated state and are all arc-shaped. During the cleaning process, the movable member moves along with the stirring member to adjust the positions of the limiting member and the partition plate. The positions of the support block, the sealing ring one, and the sealing ring two change, and their original positioning positions can be cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is a schematic flowchart of the cleaning method according to an embodiment of the present invention;

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

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

[0033] Figure 4 Schematic diagram of the moving part connection structure according to an embodiment of the present invention;

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

[0035] Figure 6 Schematic diagram of the stabilizing part structure according to an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the buffer part structure according to an embodiment of the present invention;

[0037] Figure 8 Schematic diagram of the partition board and the limiting part structure according to an embodiment of the present invention.

[0038] The reference numerals in the figure respectively represent: 1, cleaning tank; 11, channel; 2, cleaning rack; 21, clamping plate; 22, partition board; 221, moving slot; 223, side slot; 226, limiting slot; 23, buffer part; 231, supporting block; 232, fixing plate; 233, moving plate; 234, knob spring; 24, sliding slot; 25, stabilizing part; 251, limiting block; 252, leaf spring; 253, abutting plate; 26, limiting part; 261, first fixing ring; 262, first sealing ring; 263, clamping slot; 264, second fixing ring; 265, second sealing ring; 266, clamping block; 267, telescopic spring; 268, cross link; 3, stirring part; 4, moving part; 41, positioning shaft; 42, elliptical ring; 43, positioning plate; 431, pushing plate; 432, connecting plate; 44, positioning frame; 6, sliding plate; 61, top block. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] The present invention will be further described below with reference to the embodiments.

[0041] Embodiment:

[0042] Please refer to Figures 1 - 8 , the present invention provides a technical solution for a semiconductor substrate inorganic coating cleaning method based on a polishing mechanism, including:

[0043] S1. Preparation, cleaning solution preparation. According to the inorganic coating on the substrate and the possible contaminants, accurately prepare the required chemical cleaning solution, and at the same time prepare ultrapure water.

[0044] S2. Preliminary rinsing. Place the semiconductor substrate with an inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinse the surface of the substrate with mild ultrapure water. The purpose is to wash away some large particle impurities that are loosely attached and easy to remove.

[0045] S3. Chemical solution immersion. Carefully place the preliminarily rinsed substrate into the prepared chemical cleaning solution, ensure that the substrate is completely immersed in the solution, slowly shake the substrate so that the impurities on the surface of the substrate can fully contact the chemical solution and undergo a chemical reaction. Then take out the substrate and immediately rinse the substrate thoroughly with a large amount of flowing ultrapure water. The purpose of rinsing with ultrapure water is to remove the residual chemical cleaning solution and the reaction products on the surface of the substrate, ensure that the rinsed water is close to neutral, and the water flowing down from the surface of the substrate is clear without impurity residues.

[0046] S4. Physical cleaning, ultrasonic cleaning. Place the substrate after chemical cleaning into the ultrasonic cleaning tank, turn on the ultrasonic cleaning machine, and let the substrate be cleaned under the action of ultrasonic waves. Utilize the powerful impact force generated by the collapse of cavitation bubbles to shake off some tiny particle impurities that still remain on the surface of the inorganic coating of the substrate after chemical cleaning. During the cleaning process, pay attention to the power of the ultrasonic waves to avoid damaging the substrate or the coating due to too high power.

[0047] S5. High-pressure jet cleaning. After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixing device, and use high-pressure jet cleaning equipment to jet-clean the substrate from multiple angles and directions with ultrapure water or a suitable chemical cleaning solution. Further remove impurities through the powerful water flow impact force to make the surface of the substrate cleaner.

[0048] S6. Drying treatment. After completing all the above cleaning steps, place the substrate in a dust-free, dry and properly temperature-controlled environment to air-dry naturally, and avoid water stains remaining on the surface of the substrate, which may affect the subsequent semiconductor manufacturing process.

[0049] Reference Figure 2 , the rinsing rack 2 carrying spaced wafers is placed on the inner wall of the cleaning tank 1. The cleaning tank 1 contains pure water or cleaning solution as required, reference Figure 4 As shown, a clamping plate 21 fixedly connected to the top end of the rinsing rack 2 is engaged with the outer wall of the top end 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 member 23 is arranged inside the gaps.

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

[0051] In the initial state, the movable plate 233 raises the support block 231 to the upper position of the gap between the partition plates 22. The top end of the support block 231 is almost flush with the top end of the partition plate 22. When placing the wafer, it can first limit and support the bottom end of the wafer and guide the downward movement of the wafer to avoid collision with the inner wall of the cleaning rack 2 during its downward movement. As the wafer is placed, the support block 231 drives the fixing plate 232 fixedly connected to it to move downward along the gap between the partition plates 22. While the fixing plate 232 moves, it drives the movable plate 233 to rotate. While the movable plate 233 rotates, the long plate rotatably connected to the other end slides on the inner wall of the movable slot 221 until the wafer is completely placed, ensuring the stability and safety when the wafer is placed.

[0052] Reference Figure 2 , Figure 5 and Figure 8, the partition plate 22 is symmetrically provided with limiting grooves 226 on the sides of the partition plate 22 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. The limiting member 26 includes a first fixed ring 261 slidably connected to the inner wall of the limiting groove 226 and a second fixed ring 264 fixedly connected to the inner wall of the limiting groove 226. The inner wall of the limiting groove 226 is set as an arc groove for sliding with the first fixed ring 261 and the second fixed ring 264. The outside of the limiting groove 226 is set as a semi-arc groove for sliding and sealing with the sides of the first sealing ring 262 and the clamping block 266. One side of the first fixed ring 261 close to the second fixed ring 264 is connected to the second fixed ring 264 through a cross link 268 rotatably connected thereto. A telescopic spring 267 is elastically connected to the middle of the cross link 268. One side of the first fixed ring 261 away from the second fixed ring 264 is fixedly connected with a first sealing ring 262. A clamping groove 263 is opened at the other end of the first sealing ring 262. A cross link 268 is fixedly connected to the side of the first fixed ring 261. One side of the second fixed ring 264 away from the first fixed ring 261 is fixedly connected with a second sealing ring 265. A clamping block 266 is provided on the side of the second sealing ring 265 for staggered engagement with the clamping groove 263. Both the first sealing ring 262 and the second sealing ring 265 are set as L-shaped, and the sides of the first sealing ring 262 and the second sealing ring 265 are both in sliding seal with the semi-arc groove; in the initial state, the telescopic spring 267 remains contracted, and the transverse dimension of the cross link 268 is the smallest. At this time, the sides of the first sealing ring 262 and the second sealing ring 265 are in contact, and the clamping groove 263 and the clamping block 266 are not engaged. Therefore, when the wafer is moved to the bottom of the gap space along with the support block 231, in addition to the support block 231 limiting the middle of its bottom end, the lower side of the wafer contacts the first sealing ring 262 and the second sealing ring 265 in contact, supporting the lower side of the wafer bottom end, filling the gap and avoiding the situation of the wafer being displaced and collided when 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 liquid flow in the cleaning tank 1. Therefore, in the present invention, a stabilizing member 25 is provided on the side of the cleaning rack 2 to apply an additional force to the wafer during the transfer process to prevent it from moving and ensure that the wafer will not be damaged when the cleaning rack 2 moves as a whole.

[0054] Reference Figure 5 and Figure 6, the stabilizer 25 includes a pressing plate 253 with an arc-shaped outer surface, and the diameter of the arc gradually decreases from top to bottom. A limiting block 251 is fixedly connected to the side of the pressing plate 253 close to the partition plate 22. The limiting block 251 is slidably connected to the inner wall of the side groove 223. One end of the limiting block 251 close to the partition plate 22 is trapezoidal, and the minimum dimension of this end of the limiting block 251 is equal to the dimension of the block 266 in the contracted state. The limiting block 251 can be inserted into the cross-link 268. A leaf spring 252 is sleeved outside the limiting block 251, and the leaf spring 252 is embedded in the inner wall of the chute 24 opened on the side of the cleaning rack 2.

[0055] During the process of placing the cleaning rack 2 into the inner wall of the cleaning tank 1, the pressing plate 253 with an arc-shaped outer surface and a size slightly larger than the upper end dimension of the inner wall of the cleaning tank 1 first fits with the upper end of the inner wall of the cleaning tank 1. Under the action of the extrusion force, the pressing plate 253 drives the limiting block 251 to move towards the side groove 223. At this time, the leaf spring 252 undergoes elastic deformation, and the limiting block 251 slides on the inner wall of the side groove 223 and is inserted into the contracted and closed cross-link 268. By applying a force to the cross-link 268 through the side of the limiting block 251, the cross-link 268 is opened under the action of the inner wall support force, and the block 266 undergoes elastic deformation and the transverse dimension of the opened cross-link 268 increases. Thus, a force is applied to the fixing ring one 261 and the fixing ring two 264 connected to both ends of the cross-link 268. Rectangular blocks that are slidably connected to the rectangular grooves at the top of the inner wall of the limiting groove 226 are provided at the tops of both the fixing ring one 261 and the fixing ring two 264. The fixing ring one 261 and the fixing ring two 264 slide smoothly and reversely on the inner wall of the limiting groove 226. The fixing ring one 261 drives the sealing ring one 262 to slide towards the side close to the wafer. The movement of the sealing ring one 262 drives the movement of the card slot 263, and the movement of the card slot 263 is engaged with the block 266 provided on one side of the other sealing ring two 265. At this time, the two are engaged and staggered and closely fit. During the process of placing the cleaning rack 2 into the cleaning tank 1, the force on the side increases evenly to further limit the bottom support member and prevent it from moving, ensuring that the wafer will not be damaged when the entire cleaning rack 2 moves.

[0056] As the cleaning rack 2 is completely placed in, the side of the pressing plate 253 is no longer restricted by the upper end of the inner wall of the cleaning tank 1. The elastic deformation of the leaf spring 252 is restored, causing the pressing plate 253 to fit with the inner wall of the cleaning tank 1. The elastic deformation of the telescopic spring 267 is restored, and the cross-link 268 is restored to the contracted state. At this time, the sealing ring two 265 and the sealing ring one 262 limit the side of the wafer but do not completely seal and fit, ensuring that the position of the wafer will not shift due to the movement of the cleaning rack 2.

[0057] However, in the prior art, the positioning structure for the wafer is set at a fixed position. During the cleaning process, the positioning points at the fixed position will cause cleaning dead spots in the cleaning area of the wafer, resulting in incomplete cleaning. Therefore, in the present invention, the support block 231, the first sealing ring 262, and the second sealing ring 265 for supporting and limiting the wafer are set in a separated state and are all arc-shaped. During the cleaning process, the positions of the support block 231, the first sealing ring 262, and the second sealing ring 265 change, and the original positioning positions can be cleaned.

[0058] Reference Figure 5 , Figure 2 , Figure 3 and Figure 4 , an active member 4 connected to the middle of the stirring member 3 is provided on the inner wall of the cleaning tank 1. The active member 4 moves with the stirring member 3 to adjust the positions of the limiting member 26 and the buffer member 23, increasing the contact area between the wafer and the cleaning liquid. The active member 4 includes a positioning shaft 41 fixedly connected to the center of the stirring member 3. An elliptical ring 42 is fixedly connected to the outside of the positioning shaft 41. A positioning plate 43 is slidably connected to the outside of the elliptical ring 42. There are two positioning plates 43 symmetrically arranged with the center of the elliptical ring 42 as the center. A runner slidably connected to the side of the elliptical ring 42 is provided on the side of the positioning plate 43. A push plate 431 that fits against the side of the abutting plate 253 is provided on the side of one of the positioning plates 43. A connecting plate 432 is fixedly connected to the bottom end of the other positioning plate 43. The other end of the connecting plate 432 is fixedly connected to a sliding plate 6. A top block 61 is fixedly connected to the top end of the sliding plate 6. The upper surface of the top block 61 is arc-shaped. The middle of the upper surface of the top block 61 fits against the bottom end of the fixing plate 232. The part of the positioning plate 43 close to the elliptical ring 42 passes through a 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 a channel 11 opened on the inner wall of the cleaning tank 1. The side of the push plate 431 close to the abutting plate 253 is provided with an inclined surface that becomes larger from small. The smallest dimension of the push plate 431 does not fit against the abutting plate 253.

[0059] When the stirring member 3 starts to stir the cleaning liquid in the cleaning tank 1, the rotation of the stirring member 3 drives the rotation of the positioning shaft 41. The rotation of the positioning shaft 41 drives the rotation of the elliptical ring 42. While the elliptical ring 42 rotates, it drives the sliding of the positioning plate 43 that is restricted by the slot holes of the positioning frame 44 and can only perform lateral displacement. The positioning plate 43 slides on the inner wall of the channel 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. One of the positioning plates 43 drives the movement of the push plate 431. The push plate 431 moves from a position where it does not fit the surface of the abutting plate 253 to a position where it fits the surface of the abutting plate 253. At this time, the second sealing ring 265 and the first sealing ring 262 are closely attached to position the side of the bottom end of the wafer. However, at this time, the other positioning plate 43 drives the movement of the connecting plate 432. The movement of the connecting plate 432 drives the movement of the sliding plate 6. The movement of the sliding plate 6 drives the support block 231 that supports the middle part of the bottom end of the wafer to no longer closely fit the bottom end of the wafer. As the top block 61 moves, the fixing plate 232 drives the support 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 support block 231. The cleaning liquid flushes and cleans the position of the wafer that was originally limited by the support block 231 through the gap, avoiding the cleaning dead angle at this place. At the same time, it also avoids the offset of the wafer during the cleaning process through the reinforced side limit. The rotation of the positioning shaft 41 drives the positioning plate 43 to perform a reciprocating movement once; when one of the positioning plates 43 drives the movement of the connecting plate 432, the other positioning plate 43 drives the movement of the connecting plate 432. The movement of the connecting plate 432 drives the movement of the sliding plate 6. The movement of the sliding plate 6 drives the support block 231 that supports the middle part of the bottom end of the wafer to closely fit the bottom end of the wafer again. As the top block 61 moves, the fixing plate 232 drives the support block 231 to move upward by a certain space. At this time, the bottom end of the wafer is close to the support block 231. The driving 253 moves from a position where it does not fit the surface of the abutting plate to a position where it fits the surface of the abutting plate 253. At this time, the second sealing ring 265 and the first sealing ring 262 are closely attached to position the side of the bottom end of the wafer. However, at this time, the other positioning plate 43 drives the movement of the push plate 431. The push plate 431 moves from a position where it fits the surface of the abutting plate 253 to a position where it does not fit the surface of the abutting plate 253. At this time, the second sealing ring 265 and the first sealing ring 262 are no longer closely attached. The cleaning liquid will flush and clean the position of the wafer that was originally limited by the second sealing ring 265 and the first sealing ring 262 through the gap, avoiding the cleaning dead angle at this place. At the same time, it also avoids the offset of the wafer during the cleaning process through the reinforced bottom limit. With the rotation of the stirring member 3, multiple position changes are realized, improving the cleaning quality.

[0060] During the actual polishing process, a polishing pad and polishing liquid are used. The material particles of the polishing pad may remain on the surface of the wafer. At the same time, the material removed from the wafer surface may remain on the wafer surface in the form of debris. In the prior art, while the positioning structure at a fixed position fills the gap between the wafer and the positioning groove, it will also block debris that should flow out along the gap in the gap between the positioning structure and the wafer surface. This reduces the cleaning quality and is also likely to increase the collision between debris and the wafer during subsequent transfer. Moreover, it will leave scratches on the wafer surface and damage the microscopic structure of the wafer surface. For high-precision semiconductor wafers, this may affect the performance and reliability of the chip. In integrated circuit manufacturing, a tiny scratch may cause a short circuit in the circuit or abnormal signal transmission. The debris repeatedly rubs in the gap between the fixture and the wafer, which will also accelerate the wear of the positioning. Therefore, the arc formed by the support block 231, the first sealing ring 262, and the second sealing ring 265 in the present invention has an arc size less than half 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 first sealing ring 262 and the second sealing ring 265 are not completely tightly fitted, the clamping groove 263 opened on one side of the first sealing ring 262 and the clamping block 266 opened on one side of the second sealing ring 265 enable the debris to easily slide out from the gap of the clamping groove 263 along the arc surface under the action of gravity and the impact force of the agitated liquid during the moving process. Therefore, when cleaning the dead corners on the wafer surface, the debris can also be cleaned out from 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cleaning method for an inorganic coating on a semiconductor substrate based on a polishing mechanism, characterized in that, Including: S1. Preparation work, cleaning solution preparation. According to the inorganic coating of the substrate and the possible contaminated impurities, accurately prepare the required chemical cleaning solution, and at the same time prepare ultrapure water. S2. Preliminary rinsing. Place the semiconductor substrate with an inorganic coating removed from the polishing mechanism on the rinsing rack of the cleaning machine, and slowly rinse the surface of the substrate with mild ultrapure water. The purpose is to wash away some large particle impurities that are loosely attached and easily removed. S3. Chemical solution immersion. Carefully place the preliminarily rinsed substrate into the prepared chemical cleaning solution, ensure that the substrate is completely immersed in the solution, slowly shake the substrate to make the impurities on the substrate surface fully contact with the chemical solution and undergo chemical reactions. Then immediately rinse the substrate thoroughly with a large amount of flowing ultrapure water. The purpose of rinsing with ultrapure water is to remove the residual chemical cleaning solution and reaction products on the substrate surface, ensure that the rinsed water is close to neutral, and the water flowing down from the substrate surface is clear without impurity residue. S4. Physical cleaning, ultrasonic cleaning. Place the substrate after chemical cleaning into the ultrasonic cleaning tank, turn on the ultrasonic cleaning machine, and let the substrate be cleaned under the action of ultrasonic waves. Use the powerful impact force generated by the collapse of cavitation bubbles to shake off some tiny particle impurities that still remain on the surface of the inorganic coating of the substrate after chemical cleaning. During the cleaning process, pay attention to the power of the ultrasonic waves to avoid damaging the substrate or the coating due to too high power. S5. High-pressure jet cleaning. After taking out the substrate from the ultrasonic cleaning tank, place it on a suitable fixing device, and use high-pressure jet cleaning equipment to spray and clean the substrate from multiple angles and directions with ultrapure water or a suitable chemical cleaning solution. Further remove impurities through the powerful water flow impact force to make the substrate surface cleaner. S6. Drying treatment. After completing all the above cleaning steps, place the substrate in a dust-free, dry and temperature-appropriate environment to dry naturally, avoiding water stains remaining on the substrate surface and affecting the subsequent semiconductor manufacturing process. Among them, the cleaning machine described in S2 includes a cleaning tank (1). The inner wall of the cleaning tank (1) is provided with a stirring member (3) for stirring the cleaning solution. An active member (4) is arranged in the middle of the stirring member (3). A cleaning rack (2) for placing wafers is arranged inside the cleaning tank (1). The top end of the cleaning rack (2) is fixedly connected with a clamping plate (21) that is snap-fitted with the side wall of the cleaning tank (1). The inner wall of the cleaning rack (2) is provided with a partition plate (22) for spacing the wafers. The inner wall of the partition plate (22) is provided with a limiting member (26) for supporting the side of the bottom end of the wafer. A buffer member (23) for supporting and guiding the bottom of the wafer is arranged in the spaced space between the partition plates (22). The separated buffer member (23) and limiting member (26) can jointly support and limit the wafer placed in the cleaning rack (2) from multiple angles. Among them, the inner wall of the cleaning tank (1) is provided with an active member (4) connected to the middle of the stirring member (3). The active member (4) moves with the stirring member (3) to adjust the positions of the limiting member (26) and the buffer member (23), increasing the contact area between the wafer and the cleaning solution.

2. The inorganic coating cleaning method for semiconductor substrates based on a polishing mechanism according to claim 1, wherein: The buffer member (23) includes a support block (231) arranged in an arc shape to limit the middle part of the bottom end of the wafer. A fixing 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 fixing plate (232). A knob spring (234) is arranged inside the movable plate (233). 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 an inorganic coating on a semiconductor substrate based on a polishing mechanism according to claim 2, wherein: Limiting grooves (226) for limiting the limiting member (26) are symmetrically opened on the side of the partition plate (22). A side groove (223) is opened on the side of the limiting groove (226). A stabilizing member (25) is arranged on the inner wall of the side groove (223).

4. A method for cleaning an inorganic coating on a semiconductor substrate based on a polishing mechanism according to claim 3, characterized in that: The stabilizing member (25) includes a resisting plate (253) with an arc-shaped outer surface. A limiting block (251) is fixedly connected to the side of the resisting plate (253) close to the partition plate (22). A leaf spring (252) is sleeved outside the limiting block (251). The leaf spring (252) is embedded in the inner wall of a sliding groove (24) opened on the side of the cleaning rack (2).

5. A method for cleaning an inorganic coating on a semiconductor substrate based on a polishing mechanism according to claim 3, characterized in that: The limiting member (26) includes a first fixing ring (261) slidably connected to the inner wall of the limiting groove (226) and a second fixing ring (264) fixedly connected to the inner wall of the limiting groove (226). One side of the first fixing ring (261) close to the second fixing ring (264) is connected to the second fixing ring (264) through a cross link (268) rotatably connected thereto. A telescopic spring (267) is elastically connected to the middle of the cross link (268). A first sealing ring (262) is fixedly connected to the side of the first fixing ring (261) away from the second fixing ring (264). A clamping groove (263) is opened at the other end of the first sealing ring (262). A cross link (268) is fixedly connected to the side of the first fixing ring (261). A second sealing ring (265) is fixedly connected to the side of the second fixing ring (264) away from the first fixing ring (261). A clamping block (266) which is staggeredly engaged with the clamping groove (263) is opened on the side of the second sealing ring (265).

6. A method for cleaning an inorganic coating on a semiconductor substrate based on a polishing mechanism according to claim 5, characterized in that: In the initial state, the telescopic spring (267) remains contracted, and the transverse dimension of the cross link (268) is the smallest. At this time, the sides of the first sealing ring (262) and the second sealing ring (265) are in contact, and the clamping groove (263) and the clamping block (266) are not engaged.

7. A method for cleaning an inorganic coating of a semiconductor substrate based on a polishing mechanism according to claim 4, characterized in that: 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 outside of the positioning shaft (41). A positioning plate (43) is slidably connected to the outside of the elliptical ring (42). There are two positioning plates (43) symmetrically arranged with the center of the elliptical ring (42) as the center. A runner for slidably connecting with the side of the elliptical ring (42) is provided on the side of the positioning plate (43). A push plate (431) that fits against the side of the abutting plate (253) is provided on the side of one of the positioning plates (43). A connecting plate (432) is fixedly connected to the bottom end of the other positioning plate (43). The other end of the connecting plate (432) is fixedly connected to a sliding plate (6). The part of the positioning plate (43) close to the elliptical ring (42) penetrates through a positioning bracket (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 bracket (44). The positioning plate (43) is slidably connected to a channel (11) provided on the inner wall of the cleaning tank (1).

8. A method for cleaning an inorganic coating on a semiconductor substrate based on a polishing mechanism according to claim 7, characterized in that: One side of the push plate (431) close to the abutting plate (253) is provided with an inclined surface that gradually increases from small to large, and the smallest dimension of the push plate (431) does not fit against the abutting plate (253); A top block (61) is fixedly connected to the top end of the sliding plate (6). The upper surface of the top block (61) is provided as an arc, and the middle part of the upper surface of the top block (61) fits against the bottom end of the fixing plate (232).

Images