阅读说明：本技术 一种硅片抛光垫清洗装置及清洗方法 (Silicon wafer polishing pad cleaning device and cleaning method ) 是由 祝斌 王彦君 裴坤羽 武卫 刘建伟 刘园 孙晨光 由佰玲 谢艳 杨春雪 刘秒 于 2019-11-19 设计创作，主要内容包括：本发明提供一种硅片抛光垫清洗装置,包括用于储存清洗液的第一水槽和第二水槽、用于清洗上抛光垫和下抛光垫的刷子以及用于控制所述刷子移动的机械臂；所述刷子上端面与所述上抛光垫接触,所述刷子下端面与所述下抛光垫接触；所述第一水槽通过第一水管与所述第二水槽连通,所述第二水槽通过所述第二水管与所述刷子连通；设置在所述刷子上下端部的喷嘴均与所述机械臂轴线成一定角度。本发明还提出一种硅片抛光垫清洗方法。本发明提出的清洗装置,可完全去除抛光垫表面附着的SiO<Sub>2</Sub>胶体颗粒、抛光药液和硅粉,自动化程度高,清洗效果好且效率高。(The invention provides a silicon wafer polishing pad cleaning device, which comprises a first water tank, a second water tank, a brush and a mechanical arm, wherein the first water tank and the second water tank are used for storing cleaning liquid; the upper end surface of the brush is contacted with the upper polishing pad, and the lower end surface of the brush is contacted with the lower polishing pad; the first water tank is communicated with the second water tank through a first water pipe, and the second water tank is communicated with the brush through a second water pipe; the nozzles arranged at the upper end and the lower end of the brush form a certain angle with the axis of the mechanical arm. The invention also provides a cleaning method of the silicon wafer polishing pad. The cleaning device provided by the invention can completely remove SiO attached to the surface of the polishing pad 2 Colloidal particles, polishing liquid medicine and silica flour, degree of automation is high, and the cleaning performance is good and efficient.)

1. The silicon wafer polishing pad cleaning device is characterized by comprising a first water tank, a second water tank, a brush and a mechanical arm, wherein the first water tank and the second water tank are used for storing cleaning liquid; the upper end surface of the brush is contacted with the upper polishing pad, and the lower end surface of the brush is contacted with the lower polishing pad; the first water tank is communicated with the second water tank through a first water pipe, and the second water tank is communicated with the brush through a second water pipe; the nozzles arranged at the upper end and the lower end of the brush form a certain angle with the axis of the mechanical arm.

2. The silicon wafer polishing pad cleaning apparatus as claimed in claim 1, wherein said angle is 60 °.

3. The silicon wafer polishing pad cleaning apparatus according to claim 1 or 2, wherein said brush central axis is perpendicular to said upper polishing pad end face and said lower polishing pad end face, respectively; and a channel with a T-shaped structure is arranged in the brush, the second water pipe penetrates through the mechanical arm and is communicated with one end of the channel, and the nozzle is communicated with the other two ends of the channel.

4. The silicon wafer polishing pad cleaning device according to claim 3, wherein the upper and lower end surfaces of the brush are provided with nozzle assemblies, and the nozzle is arranged in the middle of the nozzle assembly; the sprayer component is arranged at the central axis of the end face of the brush in a hanging mode and extends outwards along the length direction of the brush.

5. The silicon wafer polishing pad cleaning device according to claim 4, wherein the nozzle assembly further comprises a collet for clamping the nozzle and an adjusting member for adjusting the angle of the nozzle, and the nozzle, the collet and the adjusting member are arranged in sequence from inside to outside.

6. The silicon wafer polishing pad cleaning device according to claim 5, wherein brush assemblies are further disposed on the upper and lower end surfaces of the brush, the brush assemblies are disposed in the same direction as the nozzle assembly, the brush assemblies are disposed outside the nozzle assembly, and a gap is formed between the brush assemblies and the nozzle assembly.

7. The silicon wafer polishing pad cleaning apparatus as set forth in any one of claims 1 to 2 and 4 to 6, wherein a low pressure water pump is provided in the first water tank; and a high-pressure water pump is arranged in the second water tank.

8. A method for cleaning a silicon wafer polishing pad, characterized by using the cleaning apparatus according to any one of claims 1 to 7, comprising the steps of: cleaning fluid penetrates through the mechanical arm from the first water tank and the second water tank in sequence through the second water pipe to enter the brush, and then is respectively sprayed to the upper polishing surface and the lower polishing surface through the nozzle;

in the process, the upper polishing surface and the lower polishing surface synchronously rotate in opposite directions, and the mechanical arm drives the brush to horizontally move from outside to inside along the radius of the lower polishing surface;

the first water tank water pressure is less than the second water tank water pressure.

9. The method of claim 8, wherein the first water tank has a water pressure of 10-20 bar; the second water tank water pressure is 80-120 bar.

10. The method of claim 8 or 9, wherein the brush assembly and the nozzle move horizontally with respect to the lower polishing surface.

Technical Field

The invention belongs to the technical field of semiconductor silicon wafer polishing, and particularly relates to a silicon wafer polishing pad cleaning device and a cleaning method.

Background

The chemical mechanical polishing can obtain a relatively flat surface and a relatively high polishing rate, and the obtained flatness is two orders of magnitude higher than that of other methods, so that the method is an effective method for realizing global planarization. But part of the SiO in the polishing solution during the chemical mechanical polishing process₂The colloidal particles may agglomerate together to form larger particles, and such large particles may adhere to a coarser polishing pad during polishing, with polishingIncreased number of times of SiO deposition on the polishing pad₂The colloid has more and more large particles, so that the surface of the silicon wafer is scratched in the polishing process. The current chemical mechanical polishing is easy to have brush leakage phenomenon due to unreasonable structural design, and a lot of SiO₂The colloid particles are not cleaned completely, and polishing solution and silicon powder are remained on the polishing pad, so that the cleaning effect is poor, a plurality of defective products appear in subsequent polishing, and the product quality is seriously influenced.

Disclosure of Invention

The invention aims to provide a silicon wafer polishing pad cleaning device and a silicon wafer polishing pad cleaning method, solves the technical problems that brush leakage is easy to occur and the cleaning effect is poor when the existing polishing pad is cleaned, and completely removes SiO attached to the surface of the polishing pad₂Colloidal particles, polishing liquid medicine and silica flour, degree of automation is high, and the cleaning performance is good and the cleaning efficiency is high.

In order to solve the technical problems, the invention adopts the technical scheme that:

a silicon wafer polishing pad cleaning device comprises a first water tank, a second water tank, a brush and a mechanical arm, wherein the first water tank and the second water tank are used for storing cleaning liquid; the upper end surface of the brush is contacted with the upper polishing pad, and the lower end surface of the brush is contacted with the lower polishing pad; the first water tank is communicated with the second water tank through a first water pipe, and the second water tank is communicated with the brush through a second water pipe; the nozzles arranged at the upper end and the lower end of the brush form a certain angle with the axis of the mechanical arm.

Further, the angle is 60 °.

Further, the central axis of the brush is respectively perpendicular to the end face of the upper polishing pad and the end face of the lower polishing pad; and a channel with a T-shaped structure is arranged in the brush, the second water pipe penetrates through the mechanical arm and is communicated with one end of the channel, and the nozzle is communicated with the other two ends of the channel.

Further, the upper end face and the lower end face of the brush are respectively provided with a nozzle assembly, and the nozzle is arranged in the middle of the nozzle assembly; the sprayer component is arranged at the central axis of the end face of the brush in a hanging mode and extends outwards along the length direction of the brush.

Furthermore, the spray head assembly further comprises a sleeve clamp for clamping the nozzle and an adjusting piece for adjusting the angle of the nozzle, and the nozzle, the sleeve clamp and the adjusting piece are sequentially arranged from inside to outside.

Furthermore, the upper end face and the lower end face of the brush are also provided with hairbrush assemblies, the hairbrush assemblies and the spray head assemblies are arranged in the same direction, the hairbrush assemblies are arranged on the outer sides of the spray head assemblies, and gaps are reserved between the hairbrush assemblies and the spray head assemblies.

Further, a low-pressure water pump is arranged in the first water tank; and a high-pressure water pump is arranged in the second water tank.

A silicon wafer polishing pad cleaning method adopts the cleaning device, and comprises the following steps: cleaning fluid penetrates through the mechanical arm from the first water tank and the second water tank in sequence through the second water pipe to enter the brush, and then is respectively sprayed to the upper polishing surface and the lower polishing surface through the nozzle;

in the process, the upper polishing surface and the lower polishing surface synchronously rotate in opposite directions, and the mechanical arm drives the brush to horizontally move from outside to inside along the radius of the lower polishing surface;

the first water tank water pressure is less than the second water tank water pressure.

Further, the water pressure of the first water tank is 10-20 bar; the second water tank water pressure is 80-120 bar.

Further, the brush assembly and the nozzle move horizontally relative to the lower polishing surface.

The cleaning device designed by the invention has simple structure and easy control, solves the technical problem that the prior polishing pad is easy to leak during cleaning, and completely removes SiO attached to the surface of the polishing pad₂Colloidal particles, polishing liquid medicine and silica flour, degree of automation is high, and the cleaning performance is good and the cleaning efficiency is high.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for cleaning a silicon wafer polishing pad according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a movement path of a cleaning device according to an embodiment of the present invention;

FIG. 3 is a top view of a robotic arm in cooperation with a brush according to one embodiment of the present invention;

FIG. 4 is a schematic view of a brush according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view A-A of one embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a connector according to an embodiment of the present invention;

FIG. 7 is a view of the mating of the spray head assembly with the housing according to one embodiment of the invention;

FIG. 8 is a top view of an adjustment member according to an embodiment of the present invention.

In the figure:

10. a first water tank 11, a low pressure water pump 12 and a first water pipe

20. A second water tank 21, a high pressure water pump 22, and a second water pipe

30. Robot arm 31, first robot arm 32, and second robot arm

33. Adaptor 34, motor 40, brush

41. Brush 411, housing 412, connector

413. Channel 414, gasket 415, retainer ring

416. Spring thrust plate 42, brush component 421 and first brush head

422. Second brush head 423, brush holder 43, nozzle assembly

431. Nozzle 432, collet 433, regulating part

4331. Adjusting cap 4332, adjusting disc 44 and connecting assembly

441. Connecting disc 442, water inlet head 50 and upper polishing disc

51. Upper polishing pad 52, motor 60, lower polishing disk

61. Lower polishing pad 62, motor

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

FIG. 1 shows an apparatus for cleaning a polishing pad for silicon wafers, which is mainly used for cleaning SiO adhered to the surface of the polishing pad₂Colloidal particles, polishing liquid medicine and silica flour solve the technical problem that brush leakage and poor cleaning effect occur easily in the prior art. Wherein, the polishing pad comprises an upper polishing pad 51 and a lower polishing pad 61, the upper polishing pad 51 is fixedly arranged on the lower end surface of the upper polishing disc 50, and is driven by a motor 52 and controls the rotation of the upper polishing pad 51; the lower polishing pad 61 is fixedly mounted on the upper end surface of the lower polishing disk 60, the lower polishing pad 61 is driven and controlled by the motor 62 to rotate, the upper polishing pad 51 and the lower polishing pad 61 have the same size and rotate in opposite directions, in the embodiment, the upper polishing pad 51 rotates clockwise, the lower polishing pad 61 rotates counterclockwise, and the upper polishing pad 51 and the lower polishing pad 61 rotate at the same speed.

The present embodiment proposes a silicon wafer polishing pad cleaning apparatus, as shown in fig. 1-2, comprising a first tank 10 and a second tank 20 for storing a cleaning solution, a brush 40 for cleaning an upper polishing pad 51 and a lower polishing pad 61, and a robot arm 30 for controlling the movement of the brush 40. The upper end surface of the brush 40 is in contact with the upper polishing pad 51, and the lower end surface of the brush 40 is in contact with the lower polishing pad 61. The low pressure water pump 11 is provided in the first water tank 10, the high pressure water pump 21 is provided in the second water tank 20, the first water tank 10 is communicated with the second water tank 20 through the first water pipe 12, and the second water tank 20 is communicated with the brush 40 through the second water pipe 22. The cleaning liquid placed in the first water tank 10 and the second water tank 20 is pure water, and the pure water is discharged from the low-pressure water pump 11 in the first water tank 10 and enters the second water tank 20 through the first water pipe 12; the pure water is discharged from the high-pressure water pump 21 in the second water tank 20 through the second water pipe 22, passes through the robot arm 30 through the second water pipe 22, reaches the nozzles 431 provided at the upper and lower ends of the brush 40 through the passages 413 provided inside the brush 40, and is finally sprayed onto the surfaces of the upper polishing pad 51 and the lower polishing pad 61. As shown in fig. 2, the cleaned area of the lower polishing disk 61 is a ring structure, and the structure of the upper polishing disk 51 is the same and is omitted here; the mechanical arm 30 drives the brush 40 to horizontally move between the upper polishing pad 51 and the lower polishing pad 61, namely the brush 40 linearly moves from outside to inside along the radius of the lower polishing pad 61 relatively, the structural arrangement of the mechanical arm 30 can completely drive the brush 40 to clean the upper polishing pad 51 and the lower polishing pad 61, and the occurrence of interference can be avoided. Further, the nozzles 431 in the upper and lower end surfaces of the brush 40 are formed at an angle θ, preferably 60 °, to the central axis of the robot arm 30, as shown in fig. 3, and thus, it is easier to clean particles and solution on the surface of the polishing pad, and the cleaning effect is better.

In this embodiment, the low pressure water pump 11 and the high pressure water pump 21 are respectively disposed in the first water tank 10 and the second water tank 20, and the low pressure water pump 11 and the high pressure water pump 21 both use denver frequency conversion water pumps, wherein the water pressure of the first water tank 10 is 10-20bar, and the water pressure of the second water tank 20 is 80-120bar, so that a large pressure difference is formed between the first water tank 10 and the second water tank 20, and the cleaning solution is introduced into the high pressure water tank from the low pressure water tank, and after the discharged pure water cleaning solution is pumped by the high pressure water pump 21, the jet impulse force is increased, so that it is easy to increase the SiO cleaning solution on the polishing pad₂The colloid particles are washed clean, the stability of pure water cleaning pressure can be ensured, and the brush in the brush 40 is repeatedly cleaned, so that the cleaning effect of the brush 40 is better, the cleanliness of the surface of the polishing pad can be ensured, the surface quality of the subsequent polished silicon wafer is improved, and the polishing degree of the silicon wafer is ensured. Automatic control valves are arranged on the low-pressure water pump 11 and the high-pressure water pump 21, position sensors are arranged on the first water tank 10 and the second water tank 20 and used for monitoring the height of pure water cleaning liquid in each water tank, when the pure water cleaning liquid is higher than the highest water level or lower than the lowest water level, the position sensors can provide information for an external controller (omitted in the drawing), an operator is prompted to pay attention to the change of the water level in the water tanks, and the position sensors are common monitoring structures in the field and are not detailed herein.

The mechanical arm 30 comprises a first mechanical arm 31 and a second mechanical arm 32, one end of the first mechanical arm 31 is hinged to the second mechanical arm 32, the other end of the first mechanical arm 31 is connected with an adapter 33, the second mechanical arm 32 is connected with an engine 34, and the mechanical arm 30 is connected with the brush 40 through the adapter 33, wherein the first mechanical arm 31 is of a hollow cylindrical structure, a channel is arranged in the middle of the adapter 33, and the second water pipe 22 penetrates through the first mechanical arm 31 and the adapter 33 to be communicated with the channel 413 in the brush 40, so that pure water cleaning liquid can be conveyed. The brush 40 is vertically disposed between the upper polishing pad 51 and the lower polishing pad 61, and the motor 34 provides power to the second robot arm 32 to make the second robot arm 32 pull the first robot arm 31, so as to drive the brush 40 to make horizontal linear movement.

Further, as shown in fig. 4 to 5, the brush 40 includes a brush body 41, a brush assembly 42 disposed at upper and lower ends of the brush body, a nozzle assembly 43, and a connecting assembly 44 disposed at a side of the brush body 41, wherein the brush assembly 42 directly contacts the polishing pad, the nozzle assembly 43 is spaced apart from a surface of the polishing pad, the connecting assembly 44 is connected to the adaptor 33 of the robot arm 30, and the connecting assembly 44 is fixedly disposed at a height center of the housing 411. The channel 412 in the brush body 41 is of a T-shaped configuration, with one end communicating with the adaptor 33 and the other end communicating with the nozzle 431. The brush assembly 42 and the spray head assembly 43 both extend outwards along the central axis of the brush body 41 and are arranged in parallel, and the spray head assembly 43 is arranged in the brush assembly 42; both brush assembly 42 and spray head assembly 43 are disposed perpendicular to the axis of attachment assembly 44. The pure water cleaning liquid is discharged by the high pressure water pump 21 and then enters the spray head assembly 43 through the second water pipe 22 via the passage 413 for spraying and cleaning, and simultaneously the brush assembly 42 synchronously and horizontally cleans along with the nozzle 431, thereby cleaning the SiO on the polishing pad₂The colloid particles and the polishing pad automatically rotate, the rotating polishing pad can sweep away the residual silicon powder and polishing solution along with the washing of pure water, and the brush 40 is controlled by the mechanical arm 30 to horizontally move, so that the polishing pad is cleaned.

Specifically, as shown in fig. 5, the brush body 41 is a circular column-shaped structure, and includes a housing 411 and a holder 412 disposed inside the housing 411, two symmetrically disposed holders 412 are disposed in the housing 411, the structure of the holder 412 is as shown in fig. 6, one end of the holder 412 is embedded in the housing 411, a gasket 414 is further disposed between the housing 411 and the holder 412, and an outer wall of the holder 412 is fitted with an inner wall of the housing 411; the other end of the holder 412 is suspended and detachably connected to the nozzle 431 of the nozzle assembly 43, and the holder 412 and the nozzle 431 are coaxially disposed on the central axis of the housing 411.

As shown in fig. 7, the brush assembly 42 includes a brush base 423 having a cylindrical structure, one end of the brush base 423 is embedded and fixed on an end surface of the housing 411, and at least two spring thrust plates 416 are further disposed on a circumference of a position where the housing 411 is engaged with the brush base 423 to prevent the brush assembly 42 from rotating, so that the brush assembly 42 is fixedly connected to the housing 411. The other end of the brush seat 423 is provided with a first brush head 421 and a second brush head 422, as shown in fig. 3, the first brush head 421 and the second brush head 422 are uniformly arranged along the circumference of the brush seat 423 in the same direction, the first brush head 421 is arranged close to the outer wall of the brush seat 423, the second brush head 422 is arranged at the inner side of the first brush head 421, and the first brush head 421 and the second brush head 422 are arranged in a staggered manner; the diameter of the first brush head 421 is not less than the diameter of the second brush head 422, the arrangement of the structure enables the first brush head 421 and the second brush head 422 to completely cover the upper end surface of the brush seat 423, no gap is left at the position where the brush passes through, and then the brush component 42 at each end side can clean impurities and polishing liquid on the polishing pad, and the cleaning range is wide and no dead angle is left. The double-sided brush assembly 42 can ensure the cleaning effect, improve the cleaning efficiency, save the cleaning time, ensure the cleanliness of the surface of the polishing pad, lay a foundation for subsequent polishing of monocrystalline silicon wafers and reduce the production cost.

A retaining ring 415 is also provided between the connection of the brush assembly 42 and the housing 411 to protect the engagement of the brush assembly 42 with the housing 411. The brush assembly 42 is a wearing part, and the brush assembly 42 designed in this embodiment is detachably connected to the housing 411, so that the brush assembly 42 is easy to replace, the brush head can be replaced at any time, and the service life of the brush is further prolonged. In this embodiment, the brush assembly 42 is fixedly connected to the housing 411, in the actual cleaning process, the upper polishing pad 51 and the lower polishing pad 61 rotate in opposite alignment, the end faces of the upper polishing pad 51 and the lower polishing pad 61 perpendicular to the brush 40 move along the radius horizontal straight line of the polishing pads, the brush assembly 42 and the nozzle 431 are fixed relative to the upper and lower polishing pads, the brush 40 is cleaned by moving horizontally along with the mechanical arm 30, the brush assembly 42 with the structure can prevent the pure water cleaning liquid from splashing transversely, so that the pure water is completely cleaned and utilized, the utilization rate of the cleaning liquid is increased, the consumption of electric energy is also avoided, and the production cost is reduced.

As shown in fig. 7 and 8, the nozzle assembly 43 is suspended at the central axis of the two ends of the housing 411, connected to the connector 412, and extends outward along the length direction of the brush body 41, and there is a gap between the nozzle assembly 43 and the brush assembly 42. Specifically, the head assembly 43 includes a nozzle 431 for spraying water, a collet 432 for clamping the nozzle 431, and an adjusting member 433 for adjusting a spraying angle θ of the nozzle 431, and the nozzle 431, the collet 432, and the adjusting member 433 are coaxially disposed and sequentially disposed on a central axis of the housing 411 from the inside to the outside. The nozzle 431 is a flat nozzle that is commercially available, and the collet 432 is fitted to the nozzle 431 and is fixed to the end surface of the housing 411 together with the nozzle 431. The flat nozzle 431 not only increases the spraying area, but also increases the spraying wide angle, and is beneficial to the cleaning effect.

The adjusting part 433 comprises an adjusting cap 4331 and an adjusting disc 4332, as shown in fig. 8, the outer wall of the adjusting cap 4331 is of a hexagonal structure and is embedded in the adjusting disc 4332, a threaded through hole is formed in the center of the adjusting cap 4331 and is in threaded fit with the outer wall of the upper end of the shell 411 to fix the collet 432 therein, and the inner wall of the upper section of the adjusting cap 4331 is in fit with the outer wall of the collet 432; the outer wall of the adjusting disc 4332 is circular, a plurality of through holes are formed in the periphery of the adjusting disc 4332, the nozzle 431 is fixed by rotating the adjusting cap 4331 after the angle of the nozzle 431 is adjusted, and then the through holes in the position of the nozzle 431 are fixed by bolts, so that the adjusting disc 4332 and the adjusting cap 4331 are matched and screwed with each other, the nozzle 431 is completely fixed, and the spraying angle theta of the nozzle 431 is fixed. In the present embodiment, the upper and lower nozzles 431 are both at an angle of 60 ° with the central axis of the robot arm 30, and the arrangement of this angle can increase the spraying area of the nozzles 431 and ensure the impact force of the sprayed pure water. Preferably, the spraying angle of the spray head 431 can be adjusted according to actual requirements, which is conventional knowledge in the art and will not be described in detail herein.

The connecting assembly 44 comprises a connecting disc 441 and a water inlet head 442, the connecting disc 441 is of a cuboid structure, one side of the connecting disc 441 close to the shell 411 is matched with the outer wall of the shell 411, and one side of the connecting disc 441 far away from the shell 411 is of a rectangular structure; the water inlet head 442 is arranged in the connecting disc 441 and is embedded in the side wall of the shell 411, the water inlet head 442 is provided with a through hole communicated with the channel 13, and the connecting disc 441 and the water inlet head 442 are integrally fixed on the shell 411 through symmetrically arranged screws.

The working process in this embodiment: the upper polishing surface 51 and the lower polishing surface 61 synchronously and reversely rotate, the mechanical arm 30 drives the brush 40 to horizontally move from outside to inside along the radius of the lower polishing surface 61, and further drives pure water cleaning solutions sequentially from the first water tank 10 and the second water tank 20 to penetrate through the mechanical arm 30 through the second water pipe 22, and then reach nozzles 431 arranged at the upper end and the lower end of the brush 40 through a channel 413 arranged in the brush 40 to be sprayed out, and finally are respectively sprayed on the surfaces of the upper polishing pad 51 and the lower polishing pad 61; during the cleaning process, the brush assembly 42 and the nozzle 431 are fixed with respect to the upper and lower polishing pads, and the brush assembly 42 and the nozzle 431 are horizontally and linearly moved along with the robot arm 30, thereby completing the cleaning of the upper and lower polishing pads 51 and 61.

In this embodiment, the double-sided brush 40 is completely adapted to the polishing machine with the aligned polishing disk structure, and pure water cleaning liquid enters the high-pressure second water tank 20 from the low-pressure first water tank 10, so as to increase the cleaning pressure of the cleaning liquid, ensure the stability of the impact pressure and the cleaning pressure of the cleaning liquid sprayed by the brush 40, and completely clean the SiO on the polishing pad₂Colloidal particles, residual silicon powder and polishing solution. Meanwhile, the cost for replacing the brush can be further reduced by the design of high-pressure water. The robot arm 30 can stably control the brush 40 to move linearly in water along the radius of the polishing pad, so that the brush assembly 42 and the nozzle 431 are fixed relative to the upper and lower polishing pads, and the cleaning effect is ensured by performing horizontal movement on the robot arm 30. The brush assembly 42 with double-layer staggered design completely covers each cleaned position, seamless omission cleaning is guaranteed, high-pressure pure water cleaning and the brush assembly 42 are matched with each other to enable the whole cleaning effect to be better, and SiO (silicon dioxide) on the polishing pad is completely removed₂The colloid particles, the residual silicon powder and the polishing solution ensure the cleanliness of the polishing pad, improve the cleaning efficiency and reduce the costAnd the subsequent silicon wafer is prevented from being scratched, and the polishing quality of the silicon wafer is ensured.

A silicon wafer polishing pad cleaning method adopts the cleaning device, and comprises the following steps:

the pure water cleaning solution is discharged from the low pressure water pump 11 in the first water tank 10, enters the second water tank 20 through the first water pipe 12, is discharged from the high pressure water pump 21 in the second water tank 20, passes through the robot arm 30 through the second water pipe 22, enters the brush 40, is discharged from the high pressure water pump 21 in the second water tank 20, passes through the robot arm 30 through the second water pipe 22, reaches the nozzles 431 arranged at the upper and lower ends of the brush 40 through the passages 413 arranged in the brush 40, and is sprayed onto the surfaces of the upper polishing pad 51 and the lower polishing pad 61.

In the cleaning process, the water pressure of the first water tank 10 is less than that of the second water tank 20, specifically, the water pressure of the first water tank 10 is 10-20bar, the water pressure of the second water tank 20 is 80-120bar, so that a great pressure difference is formed between the first water tank 10 and the second water tank 20, the pure water cleaning liquid enters the high-pressure water tank from the low-pressure water tank, the discharged pure water cleaning liquid is pumped and discharged by the high-pressure water pump 21, the jetting impulsive force is increased, the SiO2 colloid particles on the polishing pad are easily flushed, and the stability of the pure water cleaning pressure can be ensured. And the brush in the brush 40 is repeatedly cleaned, so that the cleaning effect of the brush 40 is better, the cleanliness of the surface of the polishing pad can be further ensured, the surface quality of a subsequent polished silicon wafer is further improved, and the polishing degree of the silicon wafer is ensured. The upper polishing surface 51 and the lower polishing surface 61 rotate synchronously and reversely, the mechanical arm 30 drives the brush 40 to move horizontally along the radius of the lower polishing surface 61 from outside to inside, meanwhile, the brush assembly 42 and the nozzle 431 are fixed relative to the upper polishing pad and the lower polishing pad, and the brush assembly 42 and the nozzle 431 move horizontally and linearly along with the mechanical arm 30; when the brush 40 moves to the center of the inner side of the polishing pad, the upper polishing disk 50 and the lower polishing disk 60 are separated, and the mechanical arm 30 drives the brush 40 to retract to the initial position; then, the upper polishing disk 50 and the lower polishing disk 60 are combined, the brush assemblies 42 at the upper end and the lower end of the brush 40 are respectively contacted with the upper polishing surface 51 and the lower polishing surface 61, and the mechanical arm 30 is controlled to enable the brush 40 to continuously move from outside to inside along the radius of the lower polishing surface 61; the number of reciprocations can be adjusted according to actual requirements, thereby completing the cleaning of the upper polishing pad 51 and the lower polishing pad 61.

The cleaning device designed by the invention has simple structure and easy control, solves the technical problem that the prior polishing pad is easy to leak during cleaning, and completely removes SiO attached to the surface of the polishing pad₂Colloidal particles, polishing liquid medicine and silica flour, degree of automation is high, and the cleaning performance is good and the cleaning efficiency is high.

The embodiments of the present invention have been described in detail, and the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.