Cleaning brush assembly and wafer cleaning device

Abstract

The present invention discloses a cleaning brush assembly and a wafer cleaning device. The cleaning brush assembly comprises a cleaning brush and a liquid inlet mechanism connected to one end of the cleaning brush, the liquid inlet mechanism comprises a liquid inlet end cover, a follower shaft and a bearing assembly; the liquid inlet end cover has a liquid inlet end, one side of the liquid inlet end cover is provided with a protruding thin shaft and an annular side wall surrounding the thin shaft, an annular groove is formed between the thin shaft and the annular side wall, the thin shaft is hollow and connected to the liquid inlet end through a first passage inside the liquid inlet end cover; one end of the follower shaft is sleeved on the outer peripheral side of the thin shaft and extends into the annular groove so that the thin shaft is inserted into the central through hole of the follower shaft, the other end of the follower shaft extends into the cleaning brush, the central through hole runs through the follower shaft to connect the first passage with the cleaning brush so as to introduce liquid into the cleaning brush; the bearing assembly is sleeved on the outer peripheral side of the follower shaft.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor wafer processing, and in particular to a cleaning brush assembly and a wafer cleaning device. Background Art

[0002] In the semiconductor field, the cleanliness of the wafer surface is one of the important factors affecting the reliability of semiconductor devices. In the wafer manufacturing process, such as deposition, plasma etching, photolithography, electroplating, etc., it is possible to introduce contamination and / or particles on the wafer surface, resulting in a decrease in the cleanliness of the wafer surface and a low yield of manufactured semiconductor devices. Chemical Mechanical Planarization (CMP) is a global flattening ultra-precision surface processing process. Due to the large amount of chemical reagents and abrasives used in chemical mechanical polishing, a large amount of abrasive particles and grinding by-products and other contaminants will remain on the wafer surface after polishing is completed. These contaminants will have an adverse effect on subsequent processes.

[0003] In order to achieve the goal of no contaminants on the wafer surface, it is necessary to remove the contaminants on the wafer surface to prevent the contaminants from remaining on the wafer surface before the process. Therefore, during the wafer manufacturing process, multiple surface cleanings are required to remove contaminants such as metal ions, atoms, organic matter and particles attached to the wafer surface.

[0004] There are several wafer cleaning methods, such as roller brush cleaning and megasonic cleaning, among which roller brush cleaning is more widely used. Patent CN102768974B discloses a wafer cleaning device. The wafer cleaning device includes: a frame; a wafer cleaning device, which is arranged on the frame; a wafer scrubbing device, which is arranged on the frame and located on the downstream side of the wafer cleaning device; a wafer drying device, which is arranged on the frame and located on the downstream side of the wafer scrubbing device; and a manipulator, which is movably arranged on the frame for vertically clamping and transporting wafers.

[0005] However, the existing roller brush structure is unreasonable and there is a problem of pollutant leakage, which will cause secondary pollution to the wafer and affect the cleaning effect. Summary of the invention

[0006] The embodiments of the present invention provide a cleaning brush assembly and a wafer cleaning device, aiming to solve at least one of the technical problems existing in the prior art.

[0007] A first aspect of an embodiment of the present invention provides a cleaning brush assembly, comprising a cleaning brush and a liquid inlet mechanism connected to one end of the cleaning brush, wherein the liquid inlet mechanism comprises a liquid inlet end cover, a follower shaft and a bearing assembly;

[0008] The liquid inlet end cover has a liquid inlet end, and one side of the liquid inlet end cover is provided with a protruding thin shaft and an annular side wall surrounding the thin shaft, an annular groove is formed between the thin shaft and the annular side wall, the thin shaft is hollow and connected with the liquid inlet end through a first passage inside the liquid inlet end cover; one end of the follower shaft is sleeved on the outer peripheral side of the thin shaft and extends into the annular groove so that the thin shaft is inserted into the central through hole of the follower shaft, and the other end of the follower shaft extends into the cleaning brush, and the central through hole passes through the follower shaft to connect the first channel with the cleaning brush so as to introduce liquid into the cleaning brush; the bearing assembly is sleeved on the outer peripheral side of the follower shaft.

[0009] In one embodiment, there is a narrow gap between the inner wall of the follower shaft and the thin shaft, and the width of the gap is 0.1-1 mm.

[0010] In one embodiment, a discharge port is further provided at the bottom of the liquid inlet end cover, and the discharge port is connected to the annular groove through a second passage inside the liquid inlet end cover to discharge the liquid entering the annular groove.

[0011] In one embodiment, the liquid inlet mechanism further includes a sleeve, and the sleeve is sleeved on the annular side wall and the outer peripheral side of the bearing assembly.

[0012] In one embodiment, the sleeve is provided with a ventilated air-sealing passage, and the air-sealing passage is connected to the bearing assembly.

[0013] In one embodiment, the liquid inlet mechanism further includes a front end cover, and the front end cover is sleeved on the outer peripheral side of the follower shaft.

[0014] In one embodiment, a sealing ring is installed at the end of the inner wall of the follower shaft for sealing between the follower shaft and the thin shaft.

[0015] In one embodiment, the sealing ring is fixed by a gland.

[0016] In one embodiment, the bearing assembly includes two bearings placed side by side and a spacer sleeve located between the two bearings.

[0017] A second aspect of an embodiment of the present invention provides a wafer cleaning device, comprising:

[0018] A wafer rotating assembly, used for supporting the wafer and driving the wafer to rotate;

[0019] The cleaning brush assembly as described above is arranged on both sides of the wafer and rolls around its own axis to brush the surface of the wafer;

[0020] The cleaning brush driving mechanism is used to support the cleaning brush and drive the cleaning brush to move and rotate.

[0021] The beneficial effects of the embodiments of the present invention include: the thin shaft of the liquid inlet end cover is extended into the follower shaft, and the liquid is introduced into the follower shaft through the thin shaft, which can prevent the liquid from leaking outward and achieve the purpose of liquid blocking. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, but these drawings are only schematic and do not limit the scope of protection of the present invention, wherein:

[0023] Figure 1 A schematic structural diagram of a wafer cleaning device provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of a cleaning brush assembly provided in one embodiment of the present invention;

[0025] Figure 3 A schematic diagram of the structure of a liquid inlet mechanism provided by an embodiment of the present invention;

[0026] Figure 4 and Figure 5 A cross-sectional view of a liquid inlet mechanism provided in one embodiment of the present invention;

[0027] Figure 6 and Figure 7 A cross-sectional view of a liquid inlet mechanism provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, which include technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein. It should be understood that, unless otherwise specified, for ease of understanding, the following description of the specific embodiments of the present invention is based on the description of the relevant equipment, devices, components, etc. in the original static natural state without external control signals and driving forces.

[0029] In addition, it should be noted that the terms used in this application to indicate orientation, such as front, back, up, down, left, right, top, bottom, front, back, horizontal, vertical, etc., are merely for convenience of description to help understand relative positions or directions, and are not intended to limit the orientation of any device or structure.

[0030] In order to illustrate the technical solution of the present invention, the following description will be given with reference to the accompanying drawings and in combination with embodiments.

[0031] In this application, chemical mechanical polishing is also referred to as chemical mechanical planarization, and a wafer is also referred to as a chip, a silicon wafer, a base wafer or a substrate, which have the same meaning and practical function.

[0032] Figure 1 It is a structural schematic diagram of a wafer cleaning device 1 provided in one embodiment of the present invention. The wafer cleaning device 1 comprises a housing 10 , a wafer rotating assembly 20 , a cleaning brush assembly 40 , and a cleaning brush driving mechanism 30 .

[0033] like Figure 1 As shown, in one embodiment of the present invention, the wafer rotation assembly 20 is disposed on the upper portion of the base, and the wafer to be cleaned is supported by the wafer rotation assembly 20 and rotated around the axis of the wafer.

[0034] Among them, the wafer rotation assembly 20 includes a fixed seat, a pair of active rollers and a driven roller, and the active rollers and the driven rollers are equipped with a slot for supporting the wafer, and the slot is arranged around the outer peripheral side of the rollers. The active roller and the driven roller are arranged on the fixed seat and the slot is located in the same plane. The driven roller is arranged in the middle of the fixed seat, and the active roller is symmetrically arranged on both sides of the driven roller. A pair of active rollers and driven rollers are arranged along the outer edge contour of the wafer, and the wafer placed on the wafer rotation assembly 20 is limited by the slot, and the outer edge of the wafer is arranged tangent to the bottom surface of the slot. The active roller is equipped with a drive motor, and the drive motor drives the active roller to rotate. The friction between the outer edge of the wafer and the roller drives the wafer to rotate around its axis.

[0035] In one embodiment, a rotation speed sensor for detecting the rotation speed of the wafer is disposed on the driven roller, and the rotation speed sensor can be implemented by a Hall sensor or a photoelectric switch sensor.

[0036] like Figure 1 As shown, in one embodiment of the present invention, the cleaning brush assembly 40 includes a cleaning brush 41 and a liquid inlet mechanism 42. The cleaning brush 41 is a cylindrical structure, which is made of a material with good water absorption, such as polyvinyl alcohol (PVA). The two cleaning brushes 41 are respectively a first cleaning brush and a second cleaning brush, which are respectively arranged on both sides of the wafer to be cleaned, and can roll around their own axes to contact the surface of the wafer to be cleaned for brushing. The cleaning brush 41 becomes soft after being filled with liquid, and can be used to brush the wafer, so the cleaning brush 41 needs to be kept filled with liquid at all times during the cleaning process.

[0037] The cleaning brushes 41 located on both sides of the wafer can move horizontally to move away from or close to the wafer. When the cleaning brush 41 is away from the wafer, a certain gap is reserved between the cleaning brush 41 and the wafer, and the wafer handling robot can clamp the wafer to take away the cleaned wafer or put down the uncleaned wafer; when the cleaning brush 41 moves close to the wafer, the cleaning brush 41 abuts against the wafer and cleans the surface of the wafer in a contact manner.

[0038] like Figure 1 As shown, in one embodiment of the present invention, the cleaning brush driving mechanism 30 is used to drive two cleaning brushes 41 to move toward each other and clamp the wafer at a certain angle for rolling brushing. The cleaning brush driving mechanism 30 includes a cleaning brush supporting assembly and a cleaning brush moving assembly.

[0039] The cleaning brush support assembly is used to support two cleaning brushes 41 located on both sides of the wafer to be cleaned.

[0040] The cleaning brush moving assembly is connected to the cleaning brush supporting assembly to drive the cleaning brush supporting assembly and the cleaning brush 41 thereon to move as a whole. The cleaning brush moving assembly includes a guide rail, a lead screw and a driving member. The guide rail and the lead screw are respectively connected to the cleaning brush supporting assembly so that the cleaning brush supporting assembly moves along the guide rail under the drive of the lead screw. The driving member is arranged at the end of the lead screw. The driving member drives the lead screw to move, thereby driving the cleaning brush supporting assembly and the cleaning brush 41 to move as a whole, so that both ends of the cleaning brush 41 contact or move away from the wafer at the same time. Furthermore, lead screws are respectively arranged at both ends of the cleaning brush 41, so that the moving distances of the two ends of the cleaning brush 41 can be adjusted respectively.

[0041] Combine the following Figure 1 Briefly describe the wafer cleaning operation method.

[0042] First, the robot places the wafer to be cleaned on the wafer rotating assembly 20. At this time, a certain distance is reserved between the cleaning brush 41 and the side of the wafer to provide working space for the robot. Under the action of friction, the wafer rotating assembly 20 drives the wafer to rotate around its axis.

[0043] Next, a fluid spraying device (not shown) sprays a cleaning liquid, such as an acidic or alkaline cleaning liquid, toward the rotating wafer;

[0044] Next, the cleaning brush 41 rolls around its axis and moves toward the position of the wafer, so that the cleaning brush 41 contacts the surface of the wafer; the cleaning brush 41 rolls and scrubs the surface of the wafer to remove pollutants on the surface of the wafer, thereby scrubbing the surface of the wafer;

[0045] After the wafer is scrubbed, the cleaning brush 41 moves toward the outside of the wafer, and the cleaning brush 30 is separated from the surface of the wafer;

[0046] Next, the fluid injection device (not shown) continues to spray the cleaning liquid toward the rotating wafer. After a period of time, the robot transfers the cleaned wafer to the next process.

[0047] Figure 2 A cleaning brush assembly 40 provided in an embodiment of the present invention is shown, which includes a cleaning brush 41 and a liquid inlet mechanism 42 connected to one end of the cleaning brush 41 .

[0048] like Figure 2 As shown, in one embodiment, one end of the cleaning brush 41 is connected to the liquid inlet mechanism 42, and the other end of the cleaning brush 41 is connected to the cleaning brush driving mechanism 30. The cleaning brush 41 can be made of a porous material, such as polyvinyl alcohol, and the cleaning brush 41 can absorb a large amount of cleaning liquid used to scrub the surface of the wafer. The cleaning liquid is continuously provided to the cleaning brush 41 through the liquid inlet mechanism 42, so that the cleaning brush 41 is kept wet. Among them, the cleaning liquid can be an acidic or alkaline solution, or it can be deionized water.

[0049] like Figures 3 to 7 As shown, the liquid inlet mechanism 42 includes a liquid inlet end cover 50 , a follower shaft 60 and a bearing assembly 70 .

[0050] like Figures 4 to 7 As shown, in one embodiment, the liquid inlet end cover 50 has a liquid inlet end 51, and one side of the liquid inlet end cover 50 is provided with a protruding thin shaft 52 and an annular side wall 53 surrounding the thin shaft 52, and an annular groove 54 is formed between the thin shaft 52 and the annular side wall 53, and the thin shaft 52 is hollow and connected to the liquid inlet end 51 through a first passage 55 inside the liquid inlet end cover 50.

[0051] The liquid inlet end 51 is disposed on the top of the liquid inlet end cover 50, and the liquid inlet end 51 is connected to the factory liquid supply pipe to supply liquid to the first passage 55 inside the liquid inlet end cover 50. The thin shaft 52 has a through hollow structure to achieve liquid circulation.

[0052] In one embodiment, a discharge port 56 is further provided at the bottom of the liquid inlet end cover 50 for discharging liquid and gas. The discharge port 56 is connected to the annular groove 54 through a second passage 57 inside the liquid inlet end cover 50 to discharge the liquid entering the annular groove 54. In the process of continuously delivering the cleaning liquid to the cleaning brush 41, the liquid seeping from the gaps can be collected in the annular groove 54 and discharged through the discharge port 56 without entering the box body 10.

[0053] like Figures 4 to 7 As shown, in one embodiment, one end of the follower shaft 60 is sleeved on the outer peripheral side of the thin shaft 52 and extends into the annular groove 54, so that the thin shaft 52 is inserted into the central through hole 61 of the follower shaft 60, and the other end of the follower shaft 60 extends into the cleaning brush 41. The central through hole 61 penetrates the follower shaft 60 to connect the first channel with the cleaning brush 41, thereby introducing liquid into the cleaning brush 41.

[0054] In this embodiment, the liquid flows through the path of: entering from the liquid inlet end 51, entering the follower shaft 60 through the first passage 55 of the liquid inlet end cover 50 and the hollow structure of the thin shaft 52, and then flowing into the cleaning brush 41 through the central through hole 61 of the follower shaft 60, thereby infiltrating the cleaning brush 41.

[0055] In one embodiment, the thin shaft 52 of the liquid inlet end cover 50 extends into the central through hole 61 of the follower shaft 60, and there is a narrow gap between the inner wall of the follower shaft 60 and the thin shaft 52, and the width of the gap is 0.1-1mm. Further, the width of the gap is preferably 0.1-0.5mm, and further preferably 0.2mm.

[0056] In one embodiment, the central through hole 61 of the follower shaft 60 is a stepped hole, and the diameter of the portion of the central through hole 61 where the thin shaft 52 is inserted is larger than the other portion located downstream of the fluid path.

[0057] In the embodiment of the present invention, the purpose of liquid blocking is achieved by utilizing the matching gap between the follower shaft 60 and the thin shaft 52 of the liquid inlet end cover 50, which can prevent contamination and ensure a stable flow of cleaning liquid supply. Because the gap is small, the amount of liquid seeping out of it is very small, and it has no effect on the liquid flow into the cleaning brush 41. Even if there is seeping liquid, it can flow away through the discharge port 56.

[0058] like Figures 4 to 7 As shown, in one embodiment, a bearing assembly 70 is also installed on the follower shaft 60. The bearing assembly 70 is sleeved on the outer peripheral side of the follower shaft 60 and is adjacent to the annular side wall 53, so as to realize the rotation of the follower shaft 60. The bearing assembly 70 is installed in the sleeve 90.

[0059] Specifically, the bearing assembly 70 includes two bearings 71 placed side by side and a spacer sleeve 72 located between the two bearings 71 .

[0060] like Figures 4 to 7 As shown, in one embodiment, the liquid inlet mechanism 42 further includes a front end cover 80 , which is sleeved on the outer peripheral side of the follower shaft 60 and is close to the sleeve 90 .

[0061] There is a gap between the follower shaft 60 and the front end cover 80 , and the width of the gap is 0.1-1 mm, preferably 0.25 mm.

[0062] like Figures 4 to 7 As shown, in one embodiment, the liquid inlet mechanism 42 further includes a sleeve 90 , which is sleeved on the annular side wall 53 and the outer circumferential side of the bearing assembly 70 .

[0063] One end of the sleeve 90 is sealed with a liquid inlet end cover 50 , and the other end is fixed with a front end cover 80 .

[0064] like Figures 4 to 7 As shown, in one embodiment, the sleeve 90 is provided with a ventilated air sealing channel 91 , one end of the air sealing channel 91 is connected to an air inlet 92 provided on the sleeve 90 , and the other end of the air sealing channel 91 is connected to the bearing assembly 70 .

[0065] The air-sealing channel 91 can achieve air sealing in the gap between the bearing assembly 70, the follower shaft 60 and the thin shaft 52, thereby preventing the cleaning liquid from entering the housing 10 through the gap between the bearing assembly 70, the follower shaft 60 and the front cover 80. The air-sealing channel 91 can also prevent the water vapor in the housing 10 from entering the liquid inlet mechanism 42 through the gap between the follower shaft 60 and the front cover 80, thereby avoiding the bearing wear caused thereby and improving the service life.

[0066] It is understandable that if an air seal is not provided, the bearing 71 will wear during operation, and part of the generated debris will directly enter the housing 10 through the cleaning liquid, sputtering onto the wafer surface and causing contamination; the other part will reach the roller brush through the central through hole 61 of the follower shaft 60, thereby contaminating the roller brush and reducing the cleaning effect.

[0067] Therefore, an air sealing channel 91 is provided on the wall of the sleeve 90 to prevent the liquid inside the housing 10 from entering the liquid inlet assembly, and also to prevent the wear debris of the bearing 71 from entering the housing 10 .

[0068] like Figure 6 and Figure 7 As shown, in another embodiment, the inner wall of the follower shaft 60 is provided with a sealing ring 62 at the end thereof for sealing between the follower shaft 60 and the thin shaft 52. The sealing ring 62 is fixed by a gland 63 and then integrally installed in the sleeve 90. The sealing ring 62 may be a Gly ring.

[0069] The present invention changes the liquid inlet method of the liquid inlet mechanism 42 of the cleaning brush. The cleaning liquid in the liquid inlet end cover 50 can directly reach the cleaning brush 41 through the follower shaft 60, thereby avoiding the flow loss of the cleaning liquid. At the same time, because the cleaning liquid does not pass through the bearing assembly 70, the wear debris of the bearing 71 will not pollute the cleaning liquid, thereby improving the cleaning effect.

[0070] The drawings of this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0072] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A cleaning brush assembly, characterized in that: It includes a cleaning brush and a liquid inlet mechanism connected to one end of the cleaning brush, wherein the liquid inlet mechanism includes a liquid inlet end cover, a follower shaft and a bearing assembly; The liquid inlet end cover has a liquid inlet end, and one side of the liquid inlet end cover is provided with a protruding thin shaft and an annular side wall surrounding the thin shaft, an annular groove is formed between the thin shaft and the annular side wall, the thin shaft is hollow and communicates with the liquid inlet end through a first passage inside the liquid inlet end cover; one end of the follower shaft is sleeved on the outer peripheral side of the thin shaft and extends into the annular groove so that the thin shaft is inserted into the central through hole of the follower shaft, and the other end of the follower shaft extends into the cleaning brush, and the central through hole penetrates the follower shaft to connect the first passage with the cleaning brush so as to introduce liquid into the cleaning brush; the bearing assembly is sleeved on the outer peripheral side of the follower shaft; The bottom of the liquid inlet end cover is also provided with a discharge port, and the discharge port is communicated with the annular groove through a second passage inside the liquid inlet end cover to discharge the liquid entering the annular groove.

2. The cleaning brush assembly according to claim 1, characterized in that: There is a narrow gap between the inner wall of the follower shaft and the thin shaft, and the width of the gap is 0.1-1 mm.

3. The cleaning brush assembly according to claim 1, characterized in that: The liquid inlet mechanism further comprises a sleeve, and the sleeve is sleeved on the annular side wall and the outer peripheral side of the bearing assembly.

4. The cleaning brush assembly according to claim 3, characterized in that: The sleeve is provided with a ventilated air sealing channel, and the air sealing channel is connected to the bearing assembly.

5. The cleaning brush assembly according to claim 1, characterized in that: The liquid inlet mechanism also includes a front end cover, which is sleeved on the outer peripheral side of the follower shaft.

6. The cleaning brush assembly according to claim 1, characterized in that: The inner wall of the follower shaft is provided with a sealing ring at the end thereof, which is used for sealing between the follower shaft and the thin shaft.

7. The cleaning brush assembly according to claim 6, characterized in that The sealing ring is fixed by a gland.

8. The cleaning brush assembly according to any one of claims 1 to 7, characterized in that: The bearing assembly includes two bearings placed side by side and a spacer sleeve located between the two bearings.

9. A wafer cleaning device, characterized in that: include: A wafer rotating assembly, used for supporting the wafer and driving the wafer to rotate; The cleaning brush assembly according to any one of claims 1 to 8, which is arranged on both sides of the wafer and rolls around its own axis to brush the surface of the wafer; The cleaning brush driving mechanism is used to support the cleaning brush and drive the cleaning brush to move and rotate.

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