CN112371591A

CN112371591A - Wafer cleaning device

Info

Publication number: CN112371591A
Application number: CN202011153388.0A
Authority: CN
Inventors: 许振杰; 王同庆
Original assignee: Beijing Haike Technology Co ltd
Current assignee: Beijing Haike Technology Co ltd
Priority date: 2020-10-26
Filing date: 2020-10-26
Publication date: 2021-02-19
Anticipated expiration: 2040-10-26
Also published as: CN112371591B

Abstract

The invention discloses a wafer cleaning device, which comprises: a housing; the supporting assembly is positioned in the shell and used for rotatably supporting the wafer to be cleaned, and the wafer is arranged in the vertical direction; cleaning brushes which are arranged in parallel at intervals and roll around the axes thereof; and the protective plate is arranged on the upper side of the cleaning brush and used for preventing fluid generated by rolling of the cleaning brush from splashing to the surface of the wafer.

Description

Wafer cleaning device

Technical Field

The invention belongs to the technical field of wafer cleaning, and particularly relates to a wafer cleaning device.

Background

Cleaning is one of the most important and frequent steps in semiconductor manufacturing processes. Generally speaking, in a wafer process, up to 20% of the steps are cleaning steps, and the purpose of cleaning is to avoid the pollution of trace ions and metal particles to the semiconductor device and ensure the performance and yield of the semiconductor device. The wafer cleaning method comprises the following steps: rolling brush cleaning, megasonic cleaning, and the like, wherein rolling brush cleaning is widely applied.

Patent CN209551448U discloses a wafer processing apparatus, wherein the post-processing unit comprises a roller brush device. As shown in fig. 1, the roller brush device includes a mounting shell, a wafer is rotatably disposed in the mounting shell, and the roller brush is disposed in the mounting shell in a rolling manner around an axis thereof and located at two sides of the wafer; the roller brush is contacted with the wafer, and pollutants on the surface of the wafer are removed in the rolling process of the roller brush.

The roller brush device described in fig. 1 has the following technical problems: when the wafer is cleaned, under the centrifugal force operation, the cleaning liquid containing pollutants is thrown to the surface of the wafer by the rolling brush, so that the cleaning effect of the wafer is influenced; in addition, clean air flowing in from the upper part of the box body is conveyed to the bottom of the box body through a gap between the rolling brush and the wafer so as to form a protective layer on the surface of the wafer; under the vortex effect, clean air can be mixed and flow to the wafer surface again from the gap between round brush and the box curb plate and the air that contains the pollutant, and then the cleaning effect of wafer is influenced to the guard action of weakening clean air to the wafer. Similar technical problems exist in patents CN111146116A, CN201946573U and CN 102214554B.

In addition, as the level of integration of semiconductor devices increases, semiconductor processing equipment, such as CMP equipment, needs to be equipped with multiple sets of wafer cleaning modules. In order to reduce the space occupied by the cleaning module, the distance between the side walls of the cleaning device housing is continuously compressed. The distance between the side walls of the box body is reduced, so that the problem of the back-splash of the cleaning brush is more and more obvious. Specifically, when the cleaning brush rolls around the axis thereof at a certain speed, the cleaning solution containing the contaminants adsorbed by the cleaning brush is splashed to the side wall of the box under the action of centrifugal force, and the cleaning solution on the side wall is splashed to the surface of the wafer, thereby affecting the cleaning effect of the wafer.

Disclosure of Invention

The present invention provides a wafer cleaning apparatus, which aims to solve one of the above technical problems to a certain extent. The wafer cleaning device includes: a housing;

the supporting assembly is positioned in the shell and used for rotatably supporting the wafer to be cleaned, and the wafer is arranged in the vertical direction;

cleaning brushes which are arranged in parallel at intervals and roll around the axes thereof;

and the protective plate is arranged on the upper side of the cleaning brush, and a gap which is not less than 5mm is formed between the inner side wall of the protective plate and the outer peripheral wall of the cleaning brush so as to prevent fluid generated by rolling of the cleaning brush from splashing to the surface of the wafer.

In a preferred embodiment, the guard plate has a bent structure, and covers the upper side and the outer side of the washing brush.

As a preferred embodiment, the guard plate includes a curved surface portion, a first flat surface portion, and a second flat surface portion, which are formed in one body; the first plane part is formed by extending upwards from the upper end of the curved surface part in an inclined mode, and the second plane part is formed by extending downwards from the lower end of the curved surface part in an inclined mode.

In a preferred embodiment, the curved surface portion is provided concentrically with the brush, and a gap is provided between an inner sidewall of the curved surface portion and a peripheral wall of the brush.

As a preferred embodiment, the first plane part forms an upper end included angle with a horizontal plane passing through the upper end of the curved surface part, and the second plane part forms a lower end included angle with a vertical plane passing through the lower end of the curved surface part; the upper end included angle and the lower end included angle are acute angles.

As a preferred embodiment, the guard plate is a flat plate structure, and covers the upper side and the outer side of the washing brush.

As a preferred embodiment, the guard plate is a rectangular plate, which is obliquely disposed on the upper side of the washing brush.

In a preferred embodiment, an obliquely arranged guard plate is positioned between the wafer to be cleaned and the inner side wall of the shell, and the vertical position of the end face of the guard plate close to the wafer is higher than that of the other end face of the guard plate.

As a preferred embodiment, the guard plate is made of a metal material, and the inner side wall of the guard plate is provided with a hydrophilic coating; the hydrophilic coating is formed by coating a nano hydrophilic coating, the particle radius of the nano hydrophilic coating is 50-100nm, and the thickness of the hydrophilic coating is 0.1-5 um.

As a preferred embodiment, the protector plate is made of a non-metallic material having hydrophilicity.

Compared with the prior art, the embodiment of the invention has the following beneficial effects: the protective plates are arranged for the cleaning brush and are arranged on the upper side and the rear side of the cleaning brush, so that fluid containing pollutants of the cleaning brush is effectively prevented from being splashed to the surface of the wafer, and the cleaning effect of the wafer is prevented from being influenced by secondary pollution; in addition, the arrangement of the protective plate is beneficial to optimizing the flow of gas in the shell, and the phenomenon that the clean air and the gas containing pollutants are mixed and attached to the surface of the wafer again to damage a gas protective layer formed on the surface of the wafer is prevented.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only and do not limit the scope of protection of the invention, wherein:

FIG. 1 is a schematic diagram of a wafer cleaning apparatus according to the prior art;

FIG. 2 is a schematic structural diagram of an embodiment of the wafer cleaning apparatus 1 according to the present invention;

fig. 3 is a longitudinal sectional view of the wafer cleaning apparatus 1 in fig. 2;

FIG. 4 is a schematic view of the construction of the shield of the present invention;

FIG. 5 is a perspective view of the shield of the present invention;

FIG. 6 is a schematic structural diagram of another embodiment of the wafer cleaning apparatus 1 according to the present invention;

fig. 7 is a longitudinal sectional view of the wafer cleaning apparatus 1 in fig. 6;

FIG. 8(a) is a measurement diagram of particles on the surface of a wafer using the wafer cleaning apparatus shown in FIG. 1;

FIG. 8(b) is a measurement diagram of particles on the surface of a wafer using the wafer cleaning apparatus shown in FIG. 2;

FIG. 9 is a simulated gas flow diagram of the interior of the housing of the wafer cleaning apparatus of FIG. 1;

FIG. 10 is a simulated gas flow inside the housing 10 of the wafer cleaning apparatus 1 shown in FIG. 2;

fig. 11 is a simulation diagram of the gas flow inside the housing 10 of the wafer cleaning apparatus 1 shown in fig. 6.

Detailed Description

The following describes the technical solutions related to the embodiments of the present invention in detail with reference to the specific embodiments and the accompanying drawings. The examples set forth herein are specific, non-limiting, embodiments of the present invention and are presented to illustrate the concepts and concepts of the present invention; the description is illustrative, exemplary, and schematic and is not to be construed as limiting the embodiments of the invention and the scope of the invention. In addition to all of the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious or will be easily conceived based on the disclosure of the claims and the specification thereof, and these technical solutions include those which employ any obvious replacement or modification of the embodiments described herein. In order to explain the technical means of the present invention, the following description will be given by way of specific examples. In the present invention, "Chemical Mechanical Polishing (CMP)" is also referred to as "Chemical Mechanical Planarization (CMP)", and wafer (wafer) is also referred to as substrate (substrate), which means equivalent to the actual effect.

Fig. 2 is a schematic structural diagram of the wafer cleaning device 1 according to the present invention, wherein the wafer cleaning device 1 includes a housing 10, a supporting assembly 40 and a cleaning brush 20, and the cleaning brush 20 and the supporting assembly 40 are disposed in the housing 10.

The housing 10 is a substantially rectangular housing structure, and an opening is provided at the top thereof. The carrier robot places the wafer W to be cleaned inside the housing 10 through the opening of the housing 10 or transfers the wafer W having been cleaned to the outside of the housing 10.

In the embodiment shown in fig. 2, a support assembly 40 is disposed inside the housing 10 for rotatably supporting a wafer W to be cleaned. The supporting assembly comprises a driving roller and a driven roller, and the driving roller and the driven roller are provided with clamping grooves arranged along the outer peripheral side of the roller body; the number of the driving rollers is two, the driving rollers and the driven rollers are symmetrically arranged on two sides of the driven roller, and the driving rollers and the driven rollers are arranged along the outer contour of the wafer W, so that the outer edge of the wafer W abuts against the bottom surface of the clamping groove; the wafer W vertically arranged rotates around the axis of the wafer under the driving of the driving roller. The specific structure of the support assembly 40 can be seen in the vertical cleaning unit for wafers disclosed in patent CN 107516644A.

The interior of the housing 10 forms a rectangular cavity structure, the distance between the vertically parallel side walls is 200mm-300mm, and the supporting assembly 40 and the cleaning brush 20 are arranged in the space formed between the adjacent side walls. For wafers with diameters of 200mm and 300mm, there is a certain difference in the size between the sidewalls of the corresponding housings of the wafer cleaning apparatus. With the increase of the integration of the equipment, the distance between the side walls of the shell is compressed even to be less than 200 mm.

In fig. 2, the washing brushes 20 are provided in the casing 10 in parallel at intervals. Specifically, the brush 20 is symmetrically disposed on both sides of the wafer W, as shown in fig. 3. The end of the washing brush 20 is provided with a driving means which drives the washing brush 20 to roll around its axis. The cleaning brush 20 may be made of a porous material, such as polyvinyl alcohol, and the cleaning brush 20 can absorb a large amount of cleaning solution for cleaning the surface of the wafer. The rolling brush 20 is brought into contact with the wafer W being rotated to remove contaminants from the surface of the wafer W.

In the IC process, some organic and inorganic substances are used between clean rooms, and a lot of pollutants are generated during the wafer processing due to the influence of personnel, environment and other factors. These contaminants generally include particles, organics, metal contaminants and/or oxides, and the like. The particle size of the contaminants varies from a few nanometers to hundreds of nanometers. The wafer cleaning function is to remove the contaminants attached to the wafer surface, so that the size and quantity of the contaminant particles on the wafer surface can be controlled within the process requirement range.

When the wafer is cleaned, the cleaning brush 20 rolls around the axis thereof, the rolling speed of the cleaning brush 20 is generally 200rpm to 600rpm, and the rotation speed of the cleaning brush 20 is related to the wafer cleaning process. The cleaning liquid containing the contaminants may be detached from the outer peripheral side of the brush 20 by the centrifugal force and splashed to the surface of the wafer W, so that the wafer is secondarily contaminated, and the cleaning effect of the wafer is affected. In addition, since the adjacent side wall of the housing 10 is too small, the cleaning brush 20 rolling at a certain speed will throw the cleaning solution containing the contaminants to the side wall of the housing 10, and the cleaning solution will be splashed back to the surface of the wafer from the side wall, so that the wafer is contaminated again.

In order to solve the above-mentioned problems, in the present invention, the corresponding guard plate 30 is provided for the cleaning brush 20 to prevent the fluid generated during the rolling cleaning of the cleaning brush 20 from directly splashing to the surface of the wafer W. Meanwhile, the shield 30 can prevent the cleaning liquid splashed to the sidewall of the housing 10 from splashing to the surface of the wafer W.

In fig. 2, the guard 30 has a bent structure and covers the upper side and the outer side of the brush 20 to prevent the cleaning solution containing contaminants adsorbed by the brush 20 from being thrown to the front surface of the wafer W. In the present invention, the upper side of the brush 20 means the side of the brush 20 close to the top of the casing 10, and the outer side of the brush 20 means the side of the brush 20 close to the inner sidewall of the casing 10.

In one embodiment of the present invention, the guard plate 30 is a bent sheet metal structure, and the length thereof matches with the length of the washing brush 20. Further, the guard plate 30 is required to cover the entire brush 20 to prevent the end portion of the brush 20 from throwing off the cleaning solution containing contaminants to affect the cleaning effect of the wafer edge area. In one aspect of the embodiment, the length of the guard plate 30 is 100% to 120% of the length of the washing brush 20. Preferably, the length of the guard 30 is 110% of the length of the washing brush 20, i.e., the guard 30 is 5mm to 10mm longer than the washing brush 20.

The specific structure of the protector plate 30 will be described below with reference to fig. 4. The protector plate 30 includes a curved surface portion 31, a first flat surface portion 32, and a second flat surface portion 33. The first flat portion 32 and the second flat portion 33 are respectively provided on both sides of the curved portion 31, and are formed integrally. Fig. 5 is a perspective view of the protector plate 30 in fig. 4.

In the embodiment shown in fig. 2 and 3, the curved surface portion 31 of the guard 30 is provided concentrically with the brush 20, and a gap is provided between the inner sidewall of the curved surface portion 31 and the outer peripheral wall of the brush 20, so that the effect of cleaning the wafer is prevented from being affected by interference between the rolling brush 20 and the inner sidewall of the guard 30. Preferably, the clearance between the inner peripheral wall of the curved surface portion 31 and the outer peripheral wall of the brush 20 is not smaller than 1/4, which is the diameter of the brush 20. In one aspect of the present embodiment, the clearance between the inner side wall of the curved surface portion 31 and the outer peripheral wall of the brush 20 is 3mm to 30 mm. Preferably, the clearance between the inner sidewall of the curved portion 31 and the outer peripheral wall of the brush 20 is 5.

The wafer cleaning device 1 of the invention can be applied to a cleaning procedure in a semiconductor manufacturing process. Among a plurality of procedures of wafer processing, some procedures have low requirements on wafer cleaning. Compared with other processes, post-CMP cleaning has a very high requirement for cleanliness. Especially, as the characteristic line width of the chip is gradually narrowed, the characteristic size is reduced to below 10nm, the line width is continuously close to the physical basic size, and the nano-scale particle pollution may have important influence on the performance and reliability of the chip. Therefore, the residual contamination on the wafer surface must be strictly controlled to effectively remove the nanometer-scale fine contamination on the wafer surface.

The wafer cleaning apparatus shown in fig. 2 and 3 is a part of a post-treatment module of a CMP equipment, the distance between adjacent side walls of the casing 10 is about 220mm, the brush 20 is provided in the longitudinal direction of the casing 10, and the horizontal distance between the outer peripheral wall and the side wall of the brush 20 is 10mm to 20 mm. When the wafer is cleaned, the brush 20 rolls at a speed of 200rpm or more, and the cleaning solution adsorbed thereon is directly thrown to the surface of the wafer W by centrifugal force, or the cleaning solution of the brush 20 is splashed down to the side wall and reflected from the side wall to the surface of the wafer W. According to the design requirement of the CMP process, the particle radius of the surface of the wafer processed by the wafer cleaning device 1 is not more than 25nm, and the back splash of the cleaning brush 20 seriously influences the cleaning effect of the wafer.

The provision of the protector plate 30 can solve the above problems to some extent. Specifically, the inner side wall of the guard plate 30 can block the cleaning liquid directly thrown to the surface of the wafer W, and meanwhile, the inner side wall of the guard plate 30 can also block the cleaning liquid directly thrown to the side wall of the housing 10, so that the cleaning liquid is prevented from being splashed from the side wall of the housing 10. Even if a part of the cleaning liquid splashes to the side wall of the housing 10, the outer wall of the shield 30 can prevent the cleaning liquid from splashing to the surface of the wafer W.

In fig. 4, the first flat part 32 is provided to extend obliquely upward from the upper end of the curved part 31 so as to cover the upper side of the washing brush 20 as much as possible. The first flat surface portion 32 forms an upper end angle α with a horizontal plane passing through the upper end of the curved surface portion 31, the upper end angle α is an acute angle, and the upper end angle α should be not more than 60 ° and not less than 2 °. The included angle α is related to the length of the first plane part 32, and the first plane part 32 needs to cover the cleaning brush 20 as much as possible and has an outer end spaced from the lateral surface of the wafer W with a safety distance therebetween to prevent the cleaned wafer from interfering with the guard plate 30 and causing wafer fragments. In some embodiments, the safety spacing between the end of the first planar portion 32 and the side of the wafer W is 3mm to 10 mm. Preferably, the angle α of the upper end of the guard plate 30 is 10 °, and the length of the first plane part 32 can be flexibly set according to the working condition.

Further, a second flat portion 33 extends obliquely downward from a lower end of the curved portion 31, as shown in fig. 4. The second flat portion 33 is provided to cover the rear side of the brush 20 as much as possible. The second flat portion 33 forms a lower end angle β with a vertical plane passing through the lower end of the curved portion 31, the lower end angle β being an acute angle. As an embodiment of the present invention, the lower end angle β should be not more than 45 ° and not less than 5 °. The lower end angle β is related to the length of the second flat part 33, the second flat part 33 needs to cover the rear side of the brush 20 as much as possible, and the outer end of the second flat part 33 is provided with a safety space from the inner sidewall of the casing 10 to prevent the shield plate 30 from interfering with the inner sidewall of the casing 10 when cleaning the wafer. Preferably, the angle β of the lower end of the guard plate 30 is 5 °.

As an embodiment of the present invention, the upper end included angle α should be not smaller than the lower end included angle β, so that the guard plate 30 covers the upper side and the rear side of the brush 20, and the cleaning solution of the brush 20 is prevented from being thrown to the surface of the wafer W by the centrifugal force. In fig. 4, a gap L is provided between the inner sidewall of the guard 30 and the outer peripheral wall of the brush 20 to prevent the guard 30 from interfering with the brush 20. Preferably, the gap L is not less than 5 mm.

Fig. 6 is a schematic view of another embodiment of the wafer cleaning apparatus 1 according to the present invention. In the present embodiment, the guard 30 is a thin rectangular plate, and is provided obliquely above the washing brush 20. Specifically, the guard plate 30 is located between the wafer W to be cleaned and the inner side wall of the housing 10, and the vertical position of the guard plate 30 near the end face of the wafer W is higher than the vertical position thereof near the inner side wall of the housing 10. That is, the shield 30 is disposed obliquely toward the wafer W to be cleaned. In some embodiments, the vertical position of the shield 30 near the end surface of the wafer W differs from the vertical position of the shield 30 near the inner sidewall of the housing 10 by 10mm to 20 mm.

In one aspect of the present embodiment, the angle between the guard 30 and the horizontal plane is 2 ° to 15 °, preferably, the angle between the guard 30 and the horizontal plane is 3 ° to 8 °, and the guard 30 can sufficiently shield the upper side and the rear side of the cleaning brush 20 to prevent the cleaning solution on the cleaning brush 20 from being thrown to the side surface of the wafer W.

Fig. 7 is a longitudinal sectional view of the wafer cleaning apparatus 1 corresponding to fig. 6, and the guard 30 is provided on the upper side of the brush 20. The length of the guard plate 30 can be flexibly determined according to the size of the inner space of the case 10. In some embodiments, the distance a between the upper end of the shield 30 and the wafer W to be cleaned is greater than 10 mm. The distance a needs to be greater than the distance c between the outer side surface of the cleaning brush 20 and the wafer W to ensure sufficient airflow to flow to the surface of the wafer W; meanwhile, the distance a is set to avoid interference between a manipulator for taking and placing the wafer and the guard plate 30, and smoothness of wafer cleaning is guaranteed. In fig. 7, the distance between the lower end of the guard plate 30 and the inner sidewall of the housing 10 is b, and the size of the distance b should be smaller than that of the distance a. In some embodiments, the distance b between the lower end of the guard plate 30 and the inner sidewall of the housing 10 is 2mm to 5 mm.

As another embodiment of the present invention, a gap is provided between the inner sidewall of the guard plate 30 and the outer peripheral wall of the washing brush 20, as shown in fig. 7, to prevent the guard plate 30 from interfering with the washing brush 20. Preferably, the gap is not less than 5 mm.

As one embodiment of the present invention, the guard plate 30 is detachably provided to the upper and outer sides of the washing brush 20 through not-shown coupling members, which can be horizontally moved in synchronization with the washing brush 20. The shield 30 is removable to periodically clean the inner sidewall of the shield 30 to prevent the cleaning solution containing contaminants from crystallizing on the inner sidewall of the shield 30 and falling onto the surface of the cleaning brush 20, thereby scratching or damaging the wafer. As another embodiment of the present invention, the guard 30 may be provided on the sidewall of the housing 10, which is not moved with the washing brush 20. When the brush 20 is in the open state, the guard 30 shown in fig. 2 and 3 is concentric with the brush 20.

As another embodiment of the present invention, the guard plate 30 may be made of a metal material, such as stainless steel, and the inner sidewall or the sidewall facing the washing brush 20 is provided with a hydrophilic coating to prevent the fluid thrown down onto the guard plate 30 from splashing and affecting the cleaning effect of the wafer. Because the guard plate 30 is provided with a hydrophilic coating, the fluid thrown onto the guard plate 30 can slide down to the bottom of the inner cavity of the housing 10 along the side wall of the guard plate 30. The copper ions and the magnesium ions cause ion contamination. Therefore, the shield 30 cannot select a metal containing copper and magnesium to ensure the cleaning effect of the wafer.

In one aspect of this embodiment, the hydrophilic coating is formed by coating a nano hydrophilic coating having a particle radius of 50nm to 100nm, and the nano hydrophilic coating is uniformly coated on the sidewall of the sheathing 30. The uniformity of the wall thickness of the hydrophilic coating is controlled within 0.05 um. The thickness of the hydrophilic coating of the guard plate 30 is 0.1um to 5 um. Preferably, the thickness of the hydrophilic coating of the sheathing 30 is 0.2 um.

As a variation of the above embodiment, the protector plate 30 may also be made of a non-metallic material having hydrophilicity. For example, the shield 30 may be made of a material selected from the group consisting of polytetrafluoroethylene, fluorinated ethylene propylene copolymer, nylon, and combinations thereof. Preferably, the guard plate 30 is made of polytetrafluoroethylene, and the thickness of the guard plate 30 is 2mm to 5mm, so that the size of the guard plate 30 needs to be controlled as much as possible on the premise that the guard plate 30 has certain strength, and the occupation of the guard plate 30 on the internal space of the housing 10 is reduced. As an embodiment of the present invention, the guard plate 30 may also be made of a non-metallic material, and the inner and outer sidewalls of the guard plate 30 are frosted so that the fluid dripping onto the guard plate 30 will not splash or splash as little as possible.

The wafer cleaning device can be applied to cleaning modules of a chemical mechanical polishing system, a plurality of wafer cleaning devices can be arranged in parallel, and a carrying manipulator puts wafers into the wafer cleaning device through an upper opening of a shell 10 and cleans the surfaces of the wafers. In the present invention, the cleaning brush 20 is rolled to remove the contaminants on the surface of the wafer, and it can be understood that the cleaning module may be configured with other types of wafer cleaning devices according to different cleaning grades of the wafer.

FIG. 8(a) is a view showing the measurement of particles on the surface of a wafer cleaned by the wafer cleaning apparatus shown in FIG. 1, and the wafer cleaning apparatus has a problem that the cleaning solution is splashed since the guard plate 30 is not provided. After the wafer is cleaned, the number of particles on the surface of the wafer is slightly larger. In contrast, in fig. 2, the guard plate 30 is disposed on the upper side of the brush 20, and the guard plate 30 prevents the cleaning liquid containing the contaminants of the brush 20 from directly being thrown to the surface of the wafer, and prevents the cleaning liquid on the side wall of the housing 10 from splashing back to the surface of the wafer, so that the number of particles on the surface of the wafer after the wafer is cleaned is significantly reduced, as shown in fig. 8 (b).

In the wafer cleaning apparatus of the present invention, the guard plate 30 is further provided to optimize and adjust the airflow inside the housing 10. Next, the change and action of the gas flow inside the housing 10 before and after the guard 30 is mounted will be briefly described with reference to the fluid simulation diagrams shown in fig. 9, 10, and 11.

Fig. 9 is a simulation diagram of a gas flow direction inside a housing of the wafer cleaning apparatus of fig. 1. When the wafer is cleaned, clean air flows from the opening at the top of the housing 10, and the clean air is distributed along the side surface of the wafer and forms an airflow protection layer. Since the upper portion of the washing brush 20 is not provided with a shield, most of the cleaning air flows to the bottom of the housing 10 from the gap between the washing brush 20 and the sidewall of the housing 10. Since the bottom of the casing 10 is provided with an air outlet, a large amount of pollutants are collected at the bottom of the casing. In fig. 9, the clean air moves down the side walls of the housing 10 and along the bottom of the housing 10 to the inside of the housing, where it mixes with contaminants in the bottom of the housing and spirals in a generally counterclockwise direction. The clean air containing contaminants may contact the bottom of the wafer side, thereby affecting the protective effect of the airflow protection layer. In addition, a large swirling air flow is formed at the step of the lower portion of the cleaning brush 20 on the right side of the housing 10, and the swirling air flow also affects the air flow protection layer on the outer side of the wafer.

Fig. 10 is a simulation diagram of the gas flow direction inside the housing 10 of the wafer cleaning apparatus 1 in fig. 2. In this embodiment, a bent guard 30 is provided on the upper side of the brush 20. When the wafer is cleaned, clean air flows in from the opening at the top of the housing 10, and the clean air is blocked by the shield 30 to flow downward from the gap between the brush 20 and the wafer, or the clean air flows to the lower portion of the housing 10 through the gap between the shield 30 and the brush 20. In fig. 10, the cleaning air of the lower portion of the brush 20 on the left side of the housing 10 moves toward the side surface of the wafer and moves to the outside of the housing 10, that is, the lower portion of the brush 20 forms a substantially clockwise spiral air flow. Since the clean air moves from the side of the wafer to the side of the housing, contaminants collected at the bottom of the housing are not transferred to the surface of the wafer. In addition, the lower portion of the brush 20 on the right side of the casing 10 forms two small swirling flows having a small volume, and hardly affects the air flow protection layer on the outer side of the wafer. In conclusion, the gas flow inside the housing 10 is optimized by the arrangement of the guard plate 30, and a complete airflow protection layer is formed outside the wafer, so that the number and the size of the pollutant particles on the surface of the wafer can be controlled, and the cleaning effect of the wafer is improved.

Fig. 11 is a simulation diagram of the gas flow direction inside the casing 10 of the wafer cleaning apparatus 1 in fig. 6. In the present embodiment, the guard plate 30 is a thin-walled rectangular plate structure, and the technical effect of fig. 11 is similar to that shown in fig. 9. The cleaning air of the lower portion of the brush 20 at the left side of the housing 10 moves toward the side of the wafer, and the lower portion of the brush 20 forms a substantially clockwise spiral air flow. The lower portion of the cleaning brush 20 on the right side of the housing 10 forms a small swirling air flow having a small volume, which hardly affects the air flow protection layer on the outer side of the wafer.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the above embodiments, the description of the embodiments is focused on, and these embodiments can be arbitrarily combined, and a new embodiment formed by combining them is also within the scope of the present application. For parts of one or some embodiments that are not described or specified in detail, reference may be made to the description of other embodiments.

The above embodiments and implementation manners are only used for illustrating the technical solutions of the present invention, and are not limited or restricted thereto; although the present invention has been described with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be replaced with similar or equivalent ones; such modifications and substitutions should not be considered as included within the scope of the present invention, unless they depart from the spirit or essential characteristics or points of the present invention. In other words, while embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wafer cleaning apparatus, comprising:

a housing;

2. The wafer cleaning apparatus according to claim 1, wherein the guard plate has an angled structure covering the upper side and the outer side of the cleaning brush.

3. The wafer cleaning apparatus of claim 1, wherein the shield comprises a curved portion, a first flat portion and a second flat portion, which are integrally formed; the first plane part is formed by extending upwards from the upper end of the curved surface part in an inclined mode, and the second plane part is formed by extending downwards from the lower end of the curved surface part in an inclined mode.

4. The wafer cleaning apparatus according to claim 3, wherein the curved surface portion is provided concentrically with the cleaning brush, and a gap is provided between an inner sidewall of the curved surface portion and an outer peripheral wall of the cleaning brush.

5. The wafer cleaning apparatus according to claim 3, wherein the first plane portion forms an upper end angle with a horizontal plane passing through an upper end of the curved portion, and the second plane portion forms a lower end angle with a vertical plane passing through a lower end of the curved portion; the upper end included angle and the lower end included angle are acute angles.

6. The wafer cleaning apparatus according to claim 1, wherein the guard plate has a flat plate structure, and covers the upper side and the outer side of the cleaning brush.

7. The wafer cleaning apparatus according to claim 6, wherein the guard plate is a rectangular plate which is obliquely disposed on the upper side of the cleaning brush.

8. The wafer cleaning apparatus according to claim 7, wherein an obliquely arranged guard plate is located between the wafer to be cleaned and the inner side wall of the housing, and the vertical position of the guard plate near one end face of the wafer is higher than that of the other end face thereof.

9. The wafer cleaning apparatus as claimed in claim 1, wherein the guard plate is made of a metal material, and an inner sidewall thereof is provided with a hydrophilic coating; the hydrophilic coating is formed by coating a nano hydrophilic coating, the particle radius of the nano hydrophilic coating is 50-100nm, and the thickness of the hydrophilic coating is 0.1-5 um.

10. The wafer cleaning apparatus as claimed in claim 1, wherein the shield is made of a non-metallic material having a hydrophilic property.