Silicon wafer alkali polishing additive and method for cleaning silicon wafer by using same

Abstract

The invention relates to a silicon wafer alkali polishing additive which comprises the following components in percentage by mass: 2%-4% of sodium persulfate, 2%-3% of sulfamic acid, 1%-2% of chitosan, 1%-2% of PEG-400, 0.1%-0.5% of sodium citrate, 0.1%-1% of salicylic acid and 0.05%-0.1% of polyvinylpyrrolidone, and the invention also relates to a method for cleaning a silicon wafer by using the alkali polishing additive. The method sequentially comprises the following steps: S1, uniformly mixing all the components according to the weight percentage, and standing for 10 minutes to obtain the alkali polishing additive; and S2, the alkali polishing additive is added into the cleaning device to clean the silicon wafer, by means of the method, EL black spots on the silicon wafer can be completely eliminated, meanwhile, the use amount of cleaning water after alkali polishing is reduced, tower footing fusion is achieved, and the effects of improving the easy-to-clean performance and smoothness, reducing consumption and conducting small-weight polishing are achieved.

Description

Technical Field

[0001] The present invention relates to the photovoltaic field, and more specifically to an alkali polishing additive for silicon wafers and a method for cleaning silicon wafers using the alkali polishing additive. Background Art

[0002] At present, the polishing of silicon wafers mainly includes two methods: acid polishing and alkaline polishing. Acid polishing has high cost and great environmental pressure, while alkaline polishing can effectively solve the cost and environmental problems of acid polishing, but alkaline polishing also has the problem of poor polishing effect. Therefore, alkaline polishing additives are usually required in the alkaline polishing process. The alkaline polishing additives on the market have technical problems such as poor stability, poor flatness, and low reflectivity. At the same time, when the alkaline polishing additives are used to polish the silicon wafer, the impurities on the surface of the silicon wafer cannot be cleaned in time, resulting in poor polishing effect.

[0003] The Chinese patent with publication number CN113290005B discloses an alkali polishing and cleaning device with a circulation filtering function and a method of using the same. By tilting the box body, the liquid in the box body can be concentrated to flow to the storage box, and filtering and recycling are completed; a reciprocating drive mechanism is used to control the back and forth movement of the silicon wafer between the alkali polishing and cleaning stations, so that the silicon wafer can be cleaned each time after the alkali polishing is completed, avoiding the accumulation of impurities on the surface of the silicon wafer affecting the alkali polishing effect. Although the cleaning device can clean the silicon wafer each time after the alkali polishing is completed, it can only process one silicon wafer at a time, resulting in low cleaning efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide an alkali polishing additive for silicon wafers in view of the shortcomings of the prior art. The additive is sodium persulfate, aminosulfonic acid, chitosan, PEG-400, sodium citrate, salicylic acid, and polyvinyl pyrrolidone. The method can completely eliminate the EL black spots on the silicon wafer, and at the same time reduce the amount of cleaning water after alkali polishing, so that the tower base is fused, thereby achieving the effects of improving the ease of cleaning, flatness, reducing consumption, and reducing weight of polishing.

[0005] The purpose of the present invention is to address the deficiencies of the prior art and to provide a method for cleaning silicon wafers using an alkali polishing additive. The alkali polishing additive is placed in an alkali polishing containing chamber, and cleaning hydrogen peroxide is placed in the cleaning containing chamber. After the silicon wafer is clamped by a clamping assembly, a lifting rod drives the silicon wafer to rotate and lift at the same time, so that the silicon wafer passes through the alkali polishing containing chamber and the cleaning containing chamber in turn, and the surface of the silicon wafer is cleaned by a brush, and the cleaning hydrogen peroxide is used to clean impurities on the surface of the silicon wafer through a water spray pipe.

[0006] The technical solutions of the present invention are as follows:

[0007] A silicon wafer alkali polishing additive comprises the following components calculated by mass percentage: 2%-4% sodium persulfate, 2%-3% aminosulfonic acid, 1%-2% chitosan, 1%-2% PEG-400, 0.1%-0.5% sodium citrate, 0.1%-1% salicylic acid, and 0.05%-0.1% polyvinyl pyrrolidone.

[0008] A method for cleaning a silicon wafer using an alkali polishing additive comprises the following steps in sequence:

[0009] S1. Mix the components uniformly according to weight percentage, and let stand for 10 minutes to obtain an alkali polishing additive;

[0010] S2. Adding alkaline polishing additives into the cleaning device to clean the silicon wafer.

[0011] As a preferred embodiment, in S2, the cleaning device includes a cleaning cylinder, a partition is provided in the middle of the cleaning cylinder for dividing the inner cavity of the cleaning cylinder into an alkali polishing containing chamber and a cleaning containing chamber, a rotating shaft is rotatably provided above the partition, a lifting assembly is provided on the rotating shaft, the lifting assembly includes a plurality of lifting rods, each of the lifting rods is provided with a clamping assembly, a cleaning assembly is provided above the alkali polishing containing chamber, a water spraying assembly is provided above the cleaning containing chamber, the clamping assembly is used to clamp the silicon wafer, the lifting assembly is used to drive the silicon wafer to rotate and lift the rotating shaft and circulate through the alkali polishing containing chamber and the cleaning containing chamber in sequence, the cleaning assembly is used to clean impurities on the surface of the silicon wafer, and the water spraying assembly is used to spray water on the surface of the silicon wafer.

[0012] As a preference, the lifting assembly also includes a plurality of slide grooves opened on the rotating shaft, a cross bearing frame fixedly arranged on the lifting rod, a guide rod fixedly arranged on the lifting rod, and a guide groove opened on the inner wall of the cleaning cylinder, wherein the guide groove is composed of an ascending section, a retaining section and a descending section, and the bottom of the guide rod is set to be spherical and cooperates with the guide groove.

[0013] Preferably, the clamping assembly includes a through slot opened on a cross-bearing frame, a screw rod rotatably arranged in the through slot, a clamping block slidably arranged on the screw rod, a bolt fixedly arranged on one side of the screw rod, and a first bevel tooth fixedly arranged on the screw rod, a plurality of the first bevel teeth are meshed with each other, and the threads on adjacent screw rods are opposite.

[0014] Preferably, the cleaning assembly includes a brush rotatably arranged on a cleaning cylinder, a second bevel tooth fixedly arranged on the brush, a gear rotatably arranged on the cleaning cylinder, a third bevel tooth fixedly arranged on the gear, and a gear ring fixedly arranged on a lifting rod, wherein the second bevel tooth is meshed with the third bevel tooth, and the gear ring is meshed with the gear.

[0015] Preferably, the water spray assembly includes a plurality of water spray pipes fixedly arranged on the cleaning cylinder, a water suction pipe fixedly arranged between the water spray pipe and the cleaning accommodating chamber, and a water suction pump fixedly arranged on the water suction pipe.

[0016] As a preference, the distances between the plurality of water spray pipes and the bottom of the cleaning cylinder gradually increase.

[0017] As a preference, a filter screen is provided in the cleaning cylinder.

[0018] As a preference, a rubber pad is provided on the clamping block.

[0019] The beneficial effects of the present invention are

[0020] 1. The present invention adopts sodium persulfate, aminosulfonic acid, chitosan, PEG-400, sodium citrate, salicylic acid and polyvinyl pyrrolidone. The method can completely eliminate the EL black spots on the silicon wafer, reduce the amount of washing water after alkali polishing, and fuse the tower base, so as to achieve the effect of improving the ease of cleaning, flatness, reducing consumption and light weight polishing.

[0021] 2. The present invention is provided with a cleaning device, which clamps the silicon wafer through the clamping assembly and then the lifting rod drives the silicon wafer to rotate and lift at the same time, so that the silicon wafer circulates through the alkali polishing accommodating chamber and the cleaning accommodating chamber in sequence for cleaning, and cleans the surface of the silicon wafer with a brush, and uses a water spray pipe to clean impurities on the surface of the silicon wafer with cleaning hydrogen peroxide, thereby improving the alkali polishing effect and efficiency of the silicon wafer.

[0022] In summary, the present invention has the advantages of good cleaning effect and high cleaning efficiency, and is suitable for the photovoltaic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of the structure of the cleaning device;

[0025] Figure 2 is a schematic diagram of the structure of the lifting assembly;

[0026] Figure 3 is a schematic diagram of the structure of the cleaning component;

[0027] Figure 4 is a schematic diagram of the structure of the clamping assembly;

[0028] Figure 5 It is a schematic diagram of the structure of the water spray assembly;

[0029] Figure 6 is a structural schematic diagram of the guide groove;

[0030] Figure 7 It is a schematic diagram of the structure of the alkali polishing accommodation chamber and the cleaning accommodation chamber;

[0031] Figure 8 It is a schematic diagram of the state when the lifting rod drives the silicon wafer to descend and enter the alkali polishing accommodation chamber;

[0032] Fig. 9 This is a schematic diagram of the state when the lifting rod drives the silicon wafer to rise and drives the brush to rotate;

[0033] Fig.10 This is a schematic diagram of the state when the lifting rod drives the silicon wafer to rise and pass through the water spray pipe;

[0034] Figure numerals: 1 cleaning device, 2 silicon wafer, 3 cleaning cylinder, 4 alkali polishing accommodating chamber, 5 cleaning accommodating chamber, 6 partition, 7 rotating shaft, 8 lifting assembly, 81 lifting rod, 82 slide groove, 83 cross bearing frame, 84 guide rod, 85 guide groove, 86 ascending section, 87 holding section, 88 descending section, 9 clamping assembly, 91 through groove, 92 screw rod, 93 clamping block, 94 bolt, 95 first bevel gear, 10 cleaning assembly, 101 brush, 102 second bevel gear, 103 gear, 104 third bevel gear, 105 gear ring, 11 water spray assembly, 111 water spray pipe, 112 water suction pipe, 113 water suction pump, 12 filter screen. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings.

[0036] Embodiment 1

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0038] A silicon wafer alkali polishing additive comprises the following components calculated by mass percentage: 2%-4% sodium persulfate, 2%-3% aminosulfonic acid, 1%-2% chitosan, 1%-2% PEG-400, 0.1%-0.5% sodium citrate, 0.1%-1% salicylic acid, and 0.05%-0.1% polyvinyl pyrrolidone.

[0039] Embodiment 2

[0040] A method for cleaning a silicon wafer using an alkali polishing additive comprises the following steps in sequence:

[0041] S1. Mix the components uniformly according to weight percentage, and let stand for 10 minutes to obtain an alkali polishing additive;

[0042] S2, adding an alkali polishing additive into the cleaning device 1 to clean the silicon wafer 2.

[0043] It is worth mentioning that Figures 1 to 10 As shown, in S2, the cleaning device 1 includes a cleaning cylinder 3, a partition 6 is provided in the middle of the cleaning cylinder 3 for dividing the inner cavity of the cleaning cylinder 3 into an alkali polishing accommodating chamber 4 and a cleaning accommodating chamber 5, a rotating shaft 7 is rotatably provided above the partition 6, a lifting assembly 8 is provided on the rotating shaft 7, the lifting assembly 8 includes a plurality of lifting rods 81, and a clamping assembly 9 is provided on the lifting rods 81, a cleaning assembly 10 is provided above the alkali polishing accommodating chamber 4, and a water spraying assembly 11 is provided above the cleaning accommodating chamber 5, the clamping assembly 9 is used to clamp the silicon wafer 2, the lifting assembly 8 is used for the rotating shaft 7 to drive the silicon wafer 2 to rotate and lift in sequence through the alkali polishing accommodating chamber 4 and the cleaning accommodating chamber 5, the cleaning assembly 10 is used to clean impurities on the surface of the silicon wafer 2, and the water spraying assembly 11 is used to spray water on the surface of the silicon wafer 2, wherein the alkali polishing additive is placed in the alkali polishing accommodating chamber 4, and the cleaning hydrogen peroxide is placed in the cleaning accommodating chamber 5, and a driving device is connected to the rotating shaft 7 to drive the rotating shaft 7 to rotate.

[0044] In addition, if Figures 2 to 10 As shown, the lifting assembly 8 also includes a plurality of slide grooves 82 provided on the rotating shaft 7, a cross bearing frame 83 fixedly arranged on the lifting rod 81, a guide rod 84 fixedly arranged on the lifting rod 81, and a guide groove 85 provided on the inner wall of the cleaning cylinder 3. The guide groove 85 is composed of an ascending section 86, a retaining section 87 and a descending section 88. The bottom of the guide rod 84 is set to be spherical and cooperates with the guide groove 85. When in use, the rotating shaft 7 can drive the lifting rod 81 to rotate when it rotates. Under the action of the guide groove 85, the guide rod 84 drives the lifting rod 81 to rise and fall during the rotation process, driving the silicon wafer 2 to pass through the alkali polishing chamber 4 and the cleaning chamber 5 in turn, so as to realize the polishing of the silicon wafer 2, so that the silicon wafer 7 moves back and forth between the alkali polishing chamber 4 and the cleaning chamber 5, thereby improving the polishing effect. In addition, a plurality of lifting rods 81 rotate at the same time, so that each lifting rod 81 can drive a single silicon wafer 2 to circulate through the alkali polishing chamber 4 and the cleaning chamber 5 in turn, thereby improving the efficiency of the alkali polishing of the silicon wafer 2.

[0045] It should be further explained that if Figures 4 to 8As shown, the clamping assembly 9 includes a through slot 91 opened on the cross bearing frame 83, a screw rod 92 rotatably set in the through slot 91, a clamping block 93 slidably set on the screw rod 92, a bolt 94 fixedly set on one side of the screw rod 92, and a first bevel tooth 95 fixedly set on the screw rod 92. Several first bevel teeth 95 are meshed with each other, and the threads on adjacent screw rods 92 are opposite. When in use, before polishing the silicon wafer 2, by rotating the bolt 94, the bolt 94 drives the side screw rod 92 and the first bevel tooth 95 on the side to rotate, thereby driving other meshed first bevel teeth 95 to rotate. The structure with opposite threads of adjacent screw rods 92 can achieve that the four clamping blocks 93 can slide relative to or toward each other at the same time, and can be adjusted according to silicon wafers 2 of different sizes, thereby achieving a high adaptability effect.

[0046] It should be emphasized that if Figure 8 and Fig.10 As shown, the cleaning assembly 10 includes a brush 101 rotatably arranged on the cleaning cylinder 3, a second bevel gear 102 fixedly arranged on the brush 101, a gear 103 rotatably arranged on the cleaning cylinder 3, a third bevel gear 104 fixedly arranged on the gear 103, and a ring gear 105 fixedly arranged on the lifting rod 81. The second bevel gear 102 is meshed with the third bevel gear 104, and the ring gear 105 is meshed with the gear 103. When in use, when the lifting rod 81 enters the descending section 88 at the alkali polishing accommodation chamber 4, it can drive the silicon wafer 2 to descend into the alkali polishing accommodation chamber 4, so that the silicon wafer is fully in contact with the alkali polishing additive, and then the lifting rod 81 enters the ascending section 86 to move the silicon wafer 2 out of the alkali polishing accommodation chamber The lifting rod 81 enters the holding section 87, and the gear ring 105 and the gear 103 are in the same plane. When the guide rod 84 slides in the holding section 87, the gear ring 105 drives the gear 103, the third bevel gear 104, the second bevel gear 102 and the brush 101 to rotate, so that the brush 101 cleans the impurities on the surface of the silicon wafer 2. When the lifting rod 81 slides to the end of the holding section 87, the brush 101 completes the cleaning of the silicon wafer 2, the gear ring 105 is separated from the gear 103, and the lifting rod 81 enters the descending section 88 at the cleaning accommodating chamber 5, so that the silicon wafer 2 enters the cleaning hydrogen peroxide for cleaning, realizing the integration of alkali polishing and cleaning of the silicon wafer 2, and enhancing the alkali polishing effect of the silicon wafer 2.

[0047] It is worth mentioning that Figures 8 to 10As shown, the water spray assembly 11 includes a plurality of water spray pipes 111 fixedly arranged on the cleaning cylinder 3, a water pump 112 fixedly arranged between the water spray pipe 111 and the cleaning chamber 5, and a water pump 113 fixedly arranged on the water pump 112. When in use, the lifting rod 81 drives the silicon wafer 2 into the cleaning hydrogen peroxide for cleaning, and then enters the ascending section 86. In the process of removing the silicon wafer 2 from the cleaning chamber 4, the water spray pipe 111 appropriately pressurizes the surface of the silicon wafer 2 without damaging the silicon wafer 2, further cleans the impurities on the surface of the silicon wafer 2, and then re-enters the descending section 88 at the alkali polishing chamber 5, re-enters the alkali polishing additive, and achieves the effect of cyclic cleaning. By spraying the silicon wafer 2 in the ascending section 86, the impurities on the surface of the silicon wafer 2 are cleaned in the form of a hedge, and at the same time, the sprayed liquid still flows into the cleaning chamber 5 to prevent the cleaning hydrogen peroxide from flowing into the alkali polishing additive.

[0048] Further, such as Figures 8 to 10 As shown, the distance between several water spray pipes 111 and the bottom of the cleaning cylinder 3 gradually increases. When the lifting rod 81 drives the silicon wafer 2 to rotate and rise, the gradually increasing arrangement of the water spray pipes 111 can prevent the water spray pipes 111 from interfering with the rising of the silicon wafer 2 while improving the cleaning of the surface of the silicon wafer 2 by the water spray pipes 111.

[0049] In addition, if Figure 6 As shown, a filter screen 12 is provided in the cleaning cylinder 3, and impurities in the alkali polishing additive and the cleaning hydrogen peroxide are filtered through the filter screen 12, so that the alkali polishing additive and the cleaning hydrogen peroxide can be reused.

[0050] like Figure 4 As shown, a rubber pad is provided on the clamping block 93 to prevent the clamping block 93 from wearing the silicon wafer 2 .

[0051] Working process

[0052] By rotating the bolt 94, the bolt 94 drives the side screw rod 92 and the first bevel gear 95 on the side to rotate, thereby driving the other meshing first bevel gears 95 to rotate, so that the four clamping blocks 93 can slide relative to or toward each other at the same time, and can be adjusted according to the silicon wafers 2 of different sizes. After the clamping is completed, the rotation of the rotating shaft 7 can drive the lifting rod 81 to rotate, and the guide rod 84 drives the lifting rod 81 to rise and fall during the rotation process under the action of the guide groove 85. When the lifting rod 81 enters the descending section 88 at the alkali polishing accommodating chamber 4, it can drive the silicon wafer 2 to descend into the alkali polishing accommodating chamber 4, so that the silicon wafer is fully in contact with the alkali polishing additive. Then the lifting rod 81 enters the ascending section 86 to move the silicon wafer 2 out of the alkali polishing accommodating chamber 4. Then the lifting rod 81 enters the holding section 87 while the gear ring 105 and the gear 103 are in the same plane. When 84 slides in the holding section 87, the ring gear 105 drives the gear 103, the third bevel gear 104, the second bevel gear 102 and the brush 101 to rotate, so that the brush 101 cleans the impurities on the surface of the silicon wafer 2. When the lifting rod 81 slides to the end of the holding section 87, the brush 101 completes the cleaning of the silicon wafer 2, the ring gear 105 disengages from the gear 103, and the lifting rod 81 enters the descending section 88 at the cleaning accommodating chamber 5, so that the silicon wafer 2 enters the cleaning hydrogen peroxide for cleaning, and then enters the ascending section 86. In the process of moving the silicon wafer 2 out of the cleaning accommodating chamber 4, the water spray pipe 111 appropriately pressurizes the surface of the silicon wafer 2 without damaging the silicon wafer 2, further cleaning the impurities on the surface of the silicon wafer 2, and then re-enters the descending section 88 at the alkali polishing accommodating chamber 5, and re-enters the alkali polishing additive to achieve a cyclic cleaning effect.

[0053] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "front and back", "left and right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the invention.

[0054] Of course, in the present technical solution, those skilled in the art should understand that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0055] The above description in conjunction with the accompanying drawings is only a preferred embodiment of the present invention, but the present invention is not limited to the above embodiment. It should be pointed out that for those skilled in the art, various modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the scope of protection of the present invention and will not affect the effect and practicality of the implementation of the present invention.

Claims

1. A silicon wafer alkali polishing additive, characterized in that: The invention comprises the following components calculated by mass percentage: 2%-4% sodium persulfate, 2%-3% aminosulfonic acid, 1%-2% chitosan, 1%-2% PEG-400, 0.1%-0.5% sodium citrate, 0.1%-1% salicylic acid, and 0.05%-0.1% polyvinyl pyrrolidone.

2. A method for cleaning silicon wafers using an alkali polishing additive according to claim 1, characterized in that: The following steps are included in sequence: S1. Mix the components uniformly according to weight percentage, and let stand for 10 minutes to obtain an alkali polishing additive; S2. Adding an alkali polishing additive into the cleaning device (1) to clean the silicon wafer (2).

3. A method for cleaning silicon wafers using the alkaline polishing additive according to claim 1-2, characterized in that: In S2, the cleaning device (1) comprises a cleaning cylinder (3), a partition (6) is provided in the middle of the cleaning cylinder (3) for dividing the inner cavity of the cleaning cylinder (3) into an alkali-polishing containing cavity (4) and a cleaning containing cavity (5), a rotating shaft (7) is rotatably provided above the partition (6), a lifting assembly (8) is provided on the rotating shaft (7), the lifting assembly (8) comprises a plurality of lifting rods (81), each of the lifting rods (81) is provided with a clamping assembly (9), and the alkali-polishing containing cavity (4) is provided with a clamping assembly (9). A cleaning assembly (10) is provided on the side, a water spray assembly (11) is provided above the cleaning accommodating chamber (5), the clamping assembly (9) is used to clamp the silicon wafer (2), the lifting assembly (8) is used to drive the silicon wafer (2) to rotate and lift the silicon wafer (2) in a rotating shaft (7) to circulate through the alkali polishing accommodating chamber (4) and the cleaning accommodating chamber (5) in sequence, the cleaning assembly (10) is used to clean impurities on the surface of the silicon wafer (2), and the water spray assembly (11) is used to spray water on the surface of the silicon wafer (2).

4. The method for cleaning silicon wafers with an alkali polishing additive according to claim 3, characterized in that: The lifting assembly (8) further comprises a plurality of slide grooves (82) provided on the rotating shaft (7), a cross bearing frame (83) fixedly provided on the lifting rod (81), a guide rod (84) fixedly provided on the lifting rod (81), and a guide groove (85) provided on the inner wall of the cleaning cylinder (3); the guide groove (85) comprises an ascending section (86), a retaining section (87) and a descending section (88); the bottom of the guide rod (84) is spherical and matches the guide groove (85).

5. The method for cleaning silicon wafers with an alkali polishing additive according to claim 4, characterized in that: The clamping assembly (9) comprises a through slot (91) provided on a cross bearing frame (83), a screw rod (92) rotatably arranged in the through slot (91), a clamping block (93) slidably arranged on the screw rod (92), a bolt (94) fixedly arranged on one side of the screw rod (92), and a first bevel tooth (95) fixedly arranged on the screw rod (92), wherein a plurality of the first bevel teeth (95) are meshed with each other, and the threads on adjacent screw rods (92) are opposite.

6. The method for cleaning silicon wafers with an alkali polishing additive according to claim 3, characterized in that: The cleaning assembly (10) comprises a brush (101) rotatably mounted on a cleaning cylinder (3), a second bevel gear (102) fixedly mounted on the brush (101), a gear (103) rotatably mounted on the cleaning cylinder (3), a third bevel gear (104) fixedly mounted on the gear (103), and a gear ring (105) fixedly mounted on a lifting rod (81); the second bevel gear (102) meshes with the third bevel gear (104), and the gear ring (105) meshes with the gear (103).

7. The method for cleaning silicon wafers with an alkali polishing additive according to claim 3, characterized in that: The water spray assembly (11) comprises a plurality of water spray pipes (111) fixedly arranged on the cleaning cylinder (3), a water suction pipe (112) fixedly arranged between the water spray pipes (111) and the cleaning accommodating chamber (5), and a water suction pump (113) fixedly arranged on the water suction pipe (112).

8. The method for cleaning silicon wafers with an alkali polishing additive according to claim 7, characterized in that: The distances between the plurality of water spray pipes (111) and the bottom of the cleaning cylinder (3) gradually increase.

9. The method for cleaning silicon wafers with an alkali polishing additive according to claim 3, characterized in that: A filter screen (12) is arranged inside the cleaning cylinder (3).

10. The method for cleaning silicon wafers with an alkali polishing additive according to claim 5, characterized in that: The clamping block (93) is provided with a rubber pad.

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