Brushes with non-uniform nodule density

Abstract

A brush for cleaning a surface is disclosed. The brush includes a central core and cleaning members surrounding the central core. The cleaning members have modules on them, whereby a nodule density on the cleaning members varies. Thus, a first nodule density in a first region of the cleaning members is different from a second nodule density in a second region of the cleaning members.

Description

Technical Field

[0001] [Cross - Reference to Related Applications / Claims of Priority] This patent application claims the benefit of, and priority to, U.S. Provisional Patent Application No. 62 / 898,534, filed on September 10, 2019, and U.S. Patent Application No. 16 / 996,224, filed on August 18, 2020, both entitled "Apparatus for a Brush With Non - constant Nodule Density". The entire contents of these applications are hereby incorporated by reference into this specification.

[0002] The present disclosure relates to a brush for cleaning a surface, and more particularly, to a brush having a non - constant nodule density.

Background Art

[0003] In the semiconductor manufacturing industry and other industries, brushes are used to remove contaminants from surfaces, such as from the surface of a semiconductor wafer. Conventional brushes have nodules that are used to clean the surface. Here, the brush has a constant nodule density.

[0004] The limitations and disadvantages of conventional approaches to brush adjustment and use will become apparent to those skilled in the art by comparing such approaches with some aspects of the present methods and systems described in the remainder of the present disclosure with reference to the drawings.

Summary of the Invention

[0005] Methods and apparatuses related to a brush having a non - constant nodule density are provided, substantially as shown by and described in connection with at least one of the figures, and more fully set forth in the claims.

[0006] These and / or other aspects will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings and will be more readily understood.

Brief Description of the Drawings

[0007]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7A

Figure 7B

Figure 8

Modes for Carrying Out the Invention

[0008] The drawings are not necessarily to scale. Where appropriate, like or identical reference numerals are used to refer to like or identical components.

[0009] A variety of applications and processes can benefit from physically cleaning a target surface. For example, in semiconductor manufacturing, a semiconductor wafer can be cleaned to remove potentially damaging contaminants during one or more stages of assembling an electronic circuit on the wafer. The cleaning process can involve, for example, a module on a cleaning surface of a brush contacting a surface to be cleaned, where the surface to be cleaned can be, for example, the surface of a semiconductor wafer.

[0010] It should be understood that various aspects of the present disclosure can be used for various applications, but the present disclosure describes, by way of example, cleaning the surface of a semiconductor wafer.

[0011] During the manufacturing process for a semiconductor wafer, many contaminants can be found on the surface of the semiconductor wafer, for example, in the form of organic particles and / or inorganic particles. These contaminants typically result in device failures and poor wafer yields. Further, with each new semiconductor technology node, the critical size of defects in the semiconductor wafer and the acceptable number of defects on the semiconductor wafer are reduced.

[0012] The semiconductor industry may use post-chemical mechanical planarization (pCMP) cleaning in the manufacture of semiconductor devices, where, to remove contaminants from the surface of a semiconductor wafer, a brush, such as a polyvinyl acetate (PVAc) brush, may be used in combination with a cleaning agent and / or chemicals specific to the application.

[0013] Figures 1A and 1B show two different views of an exemplary brush for cleaning a surface such as the surface of a semiconductor wafer. In FIG. 1A, a brush 100 is shown that includes a central core 110 (which may sometimes be referred to as a "mandrel") and a cleaning member 120. The cleaning member 120 can be, for example, PVAc and has nodules 122. As can be seen, the region near the longitudinal center A of the brush 100 has fewer nodules per unit area than the regions near the longitudinal ends B and C of the brush 100. That is, the nodule density is lower near the longitudinal center A of the brush 100 than near the longitudinal ends B and C of the brush. FIG. 1B shows the same brush as shown in FIG. 1A, except that the brush 100 in FIG. 1B is rotated 90 degrees about the longitudinal axis with respect to FIG. 1A.

[0014] Although not shown, one or more conduits can be provided, for example, within the central core 110 to deliver a fluid used for cleaning, such as deionized water or various chemicals. The fluid is delivered to the cleaning member 120 through an opening in the central core 110, and the fluid can contact the surface of the object to be cleaned. For example, the surface to be cleaned can be the surface of a semiconductor wafer 180.

[0015] As shown in FIGS. 1A and 1B, the nodules can form a spiral (volute) pattern. This pattern can allow contaminants, free particles, cleaning fluid, etc. to flow to one or both of the ends B and C of the brush 100. In addition, the low nodule density at the center of the brush 100 allows, for example, less contact with the central portion of the semiconductor wafer 180. This will be further explained with respect to FIG. 8.

[0016] The nodules 122 can be formed as part of the cleaning member 120 or attached to the cleaning member 120. For example, the cleaning member 120 can be formed together with the nodules 122 via a mold. The nodules 122 can be formed separately and attached to the cleaning member 120 using, for example, an adhesive.

[0017] The cross-section of the brush 100 without the nozzle module 122 can be substantially circular. The cleaning member 120 can be attached to the central core 110, for example, by friction fitting or by using one or more adhesives. Additionally, as can be seen, the spiral pattern of the nozzle module 122 moves the cleaning fluid, contaminants, etc. towards the longitudinal ends B and / or C so that the fluid, contaminants, etc. do not recontaminate, for example, the semiconductor wafer 180 during cleaning or the brush 100 used to clean the semiconductor wafer 180. The cleaning process will be described in more detail with respect to FIG. 8.

[0018] FIGS. 2A and 2B show a brush 200 similar to the brush 100. The brush 200 includes a central core 210 and a cleaning member 220 having nozzle modules 222 and 224. It can be noted that some of the nozzle modules 222 near the longitudinal center A are elongated while the nozzle modules 224 are round. However, it will be understood that the nozzle modules 222 and 224 still form a spiral pattern. Thus, in various examples of the present disclosure, different shaped nozzle modules that are conductive with respect to the pattern on the brush can be had. For example, the nozzle shape may be round, rectangular, diamond-shaped, trapezoidal, triangular, etc. Not all of the nozzle modules in the area of the brush need to be of the same shape.

[0019] As can be seen in FIGS. 2A and 2B, the area D-E around the longitudinal center A can have elongated nozzle modules 222 and the area outside the area D-E can have round nozzle modules 224. In other examples of the present disclosure, shapes other than those shown in the present disclosure may be used and different areas may have nozzle modules of different shapes.

[0020] Although it will be understood that the nozzle module 222 is physically larger than the nozzle module 224, the nozzle may be described as larger, for example, when the surface area that touches the semiconductor 180 for cleaning is larger than another surface area.

[0021] Figures 3A and 3B show a brush 300 similar to the brush 100. The brush 300 includes a central core 310 and a cleaning member 320 having nodules 322. The nodules 322 are in a lattice pattern where the nodule density varies across the brush 300. Thus, in various examples of the present disclosure, it is possible to have nodules of different shapes that are conductive with respect to the pattern on the brush. Additionally, not all nodules in a region of the brush need to be of the same shape.

[0022] Figure 4 shows a brush 400 similar to the brush 100. The brush 400 includes a central core 410 and a cleaning member 420 having nodules 422. The nodules 422 can be formed such that the pattern on the left side of the longitudinal center A is substantially symmetric with the pattern on the right side of the longitudinal center A.

[0023] Figure 5 shows a brush 500 similar to the brush 100. The brush 500 includes a central core 510 and a cleaning member 520 having elongated nodules 522. The elongated nodules 522 are in a spiral pattern where the nodule density varies across the brush 500. In the exemplary brush 500 shown in Figure 5, nodules 522 are present on the left side of the brush 500, but on the right side of the brush 500, there are substantially no nodules except near the longitudinal center A and near the end C. The nodules 522 in this example are shown only near the longitudinal center A and near the end C on the right side of the brush 500, but in various examples of the present disclosure, there may be nodules in various regions on the right side of the brush 500. In various examples of the present disclosure, the brush 500 may have nodules 522 of different shapes. That is, the nodules 522 in a region of the brush 500 may be of different shapes.

[0024] FIG. 6 shows a brush 600 similar to the brush 100. The brush 600 includes a central core 610 and a cleaning member 620 having elongated nodules 622. As can be seen, the left side of the brush 100 can be substantially symmetric with the right side of the brush 600. The elongated nodules 622 on both sides of the brush 600 are in a spiral pattern where the nodule density varies. The nodules 622 of the brush 600 are shown as being elongated, but in various examples of the present disclosure, nodules having shapes different from those described above may be included. That is, the nodules 622 in the region of the brush 600 may have different shapes.

[0025] Accordingly, exemplary brushes can use nodules having a shape similar to, for example, nodules 122 / 224 / 322. Here, the nodules 122 / 224 / 322 are arranged in a pattern similar to FIG. 6. However, since the sizes of the nodules 122 / 224 / 322 can be different from the sizes of the nodules 622, the distance between two individual nodules 122 / 224 / 322 can be different from the distance between two individual nodules 622. Accordingly, it will be understood that different shaped nodules can be used for a given nodule pattern, but the distance (arrangement) between the nodules can be made according to the type of nodules used.

[0026] FIGS. 7A and 7B show a brush 700 that does not have a uniform diameter along the longitudinal axis X. As can be seen, the diameter increases from left to right along the X axis. In FIG. 7A, the diameter of the central core 710 increases, while the thickness of the cleaning member 720 is substantially constant. In FIG. 7B, the diameter of the central core 760 is constant, while the thickness of the cleaning member 770 increases from left to right along the longitudinal axis X. The cleaning members 720, 770 can have at least the nodules as shown in FIGS. 1 to 6.

[0027] While specific examples have been shown, in other examples, different shapes may be had where the diameter varies non-linearly along the longitudinal axis X. For example, the diameter of the brush 700 / 750, the central core 710 / 760, and / or the cleaning member 720 / 770 may be slightly smaller in the central region near the longitudinal center A than near the longitudinal ends Y, Z. In another example, the diameter may be slightly larger in the central region near the longitudinal center A than near the longitudinal ends Y, Z.

[0028] In yet other examples, the central core 710 of FIG. 7A can be had with the cleaning member 770 of FIG. 7B. In some cases, the brush formed in this way may have a substantially constant outer diameter. Also, depending on the alignment state of the central core and the cleaning member, and the level of variation in the diameter change of the central core and / or the cleaning member, the brush may exhibit different inclinations from left to right.

[0029] Also, it can be noted from the module density and / or pattern in the exemplary FIGS. 1A - 4 and 6 that the module density is shown to be substantially symmetric around the longitudinal center A. However, it should be noted that it is not necessary to limit the various examples of the present disclosure in such a way. That is, as shown in FIG. 5, the module density does not have to be substantially symmetric around the longitudinal center A.

[0030] FIG. 8 shows a graph 812 of the contact of the brush 810 having a non-uniform (biased) node layout of the brush 100 of FIGS. 1A, 1B with a test surface, as compared to a graph 802 of the contact of a conventional brush 800 with the test surface. The graph 802 shows a darker region near the center of the test surface than in the direction away from the center of the test surface, which indicates that the contact is more in the central region than in the outer regions. On the other hand, the graph 812 provides a more uniform contact amount for all regions of the test surface.

[0031] When the cleaning process is being performed, the brushes 800, 810 may be rotated about their longitudinal axes in the direction R1. For example, a test surface similar to the semiconductor wafer 180 may be rotated in the exemplary direction R2 shown. By the various modules of the brush (e.g., the module 122 of the brush 100) contacting the test surface (semiconductor wafer 180), the cleaning of the test surface may be carried out. And, in addition to the contaminants and released particles from the brush 810, deionized water (DIW) and the cleaning fluid move along the direction D1 by the pattern of the module 122.

[0032] Therefore, it is implied that different cleaning levels result from different contact amounts. Further, it can be shown that if there is further contact at the center, some damage may occur to the central region due to this further contact. That is, if the outer region has sufficient contact for acceptable cleaning, the central region may be damaged due to over-cleaning. Alternatively, if the central region has sufficient contact for acceptable cleaning, the outer region may not be cleaned acceptably.

[0033] On the other hand, looking at the graph 812, it will be understood that most of the central region has substantially the same contact amount as the outer region. Therefore, the entire semiconductor wafer 180 can be cleaned more evenly, and thus the damaged area of the semiconductor wafer 180 can be reduced.

[0034] In addition to reducing contact in the central region of the surface being cleaned by a non-uniform nodule density as shown in FIGS. 1A-6, this non-uniform nodule density can also assist in reducing the amount of deionized water (DIW) near the center of the surface being cleaned. When the amount of DIW is reduced with respect to the cleaning fluid, better cleaning of the semiconductor wafer can be assisted while reducing the risk of wafer damage. Thus, in various examples of the present disclosure, a biased (reduced) nodule layout can be had, and this nodule layout can be in any form, for example, a spiral pattern, a grid pattern, or any other conductive pattern such as one that moves fluid and / or particles to at least one edge Y or Z of the brush during operation, etc. The biased region can have a contact area with nodules that is, for example, 10% to 90% less than that of the non-biased region of the brush. Further, the central region around the longitudinal center A can have any width within 10% to 90% of the longitudinal length of the brush. Further, the biased nodule region can form a continuous or discontinuous spiral pattern of any length along the brush. Here, the spiral pattern can have any width and pitch, and the width / pitch can vary in different parts of the spiral pattern.

[0035] Accordingly, it will be understood that the present disclosure provides a brush for cleaning a surface, the brush comprising a central core and a cleaning member surrounding the central core. The central core has nodules, where the first nodule density in the first region of the cleaning member is different from the second nodule density in the second region of the cleaning member. For example, in the first region as compared to the second region, there may be fewer nodules per unit area, or less contact area per unit area with the nodules.

[0036] The nodule density can be, for example, smaller at the longitudinal center of the brush than at the longitudinal ends of the brush. In some examples of the present disclosure, the nodules can form a substantially helical pattern on the cleaning member. In other examples of the present disclosure, the nodules can form a substantially grid-like pattern on the cleaning member. In various examples of the present disclosure, the nodule pattern can be substantially symmetric around the longitudinal center of the brush.

[0037] In some examples of the present disclosure, the nodules may be formed as part of the cleaning member. As an example, for instance, a mold can be used to form the cleaning member together with the nodules. In some examples of the present disclosure, after the nodules are formed separately, they may be attached to the cleaning member, for example, by an adhesive. Alternatively, the nodules may be attached to a sleeve that is placed over the cleaning member.

[0038] In examples of the present disclosure, there may be one or more nodules having a different shape from another set of nodules. For example, the first nodule may be cylindrical, while the second nodule may be elongated. Thus, the nodules can be of any of various shapes.

[0039] Also, the brush can be shaped such that one end of the brush has a different diameter from the other end of the brush, or such that two different cross-sections of the brush can have different diameters. The cross-section of the brush can be generally circular when not considering the nodules.

[0040] In examples of the present disclosure, the cleaning member may frictionally fit over the central core, or the cleaning member may be coupled to the central core by an adhesive.

[0041] At least some of the nodules can be arranged in a pattern that moves the cleaning fluid towards the longitudinal ends of the brush, and the cleaning fluid is provided to at least one or both of the brush and the surface, for example, during a cleaning process of the surface of a semiconductor wafer.

[0042] In addition, the present disclosure also provides a brush for cleaning a surface. It will be understood that the brush includes a central core and a cleaning member surrounding the central core. The cleaning member has nodules. The first nodules in the first region of the brush have a first shape, and the second nodules in the second region of the brush have a second shape. One or both of the first region and the second region can have the first nodules having the first shape and the second nodules having the second shape. The first region can be, for example, closer to the longitudinal center of the brush than the second region. In some examples of the present disclosure, the first shape can have a larger surface area, more specifically, a larger surface area in contact with the object to be cleaned, than the second shape. The first nodules and / or the second nodules can be arranged in a pattern that moves the cleaning fluid toward the longitudinal ends of the brush, and the cleaning fluid is provided to one or both of the brush and the surface, at least during the surface cleaning process.

[0043] As used herein, "and / or" means any one or more of the items in the list connected by "and / or". As an example, "x and / or y" means any element of the three-element set {(x), (y), (x, y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y and / or z" means "one or more of x, y, z". As used herein, the term "exemplary" serves as a non-limiting example, case or illustration. As used herein, the term "for example" begins a list of one or more non-limiting examples, cases or illustrations.

[0044] Although the method and / or system have been described with reference to certain aspects of the present disclosure, those skilled in the art will understand that various changes can be made and equivalents can be substituted without departing from the scope of the method and / or system. Additionally, many modifications can be made to adapt the teachings of the present disclosure to specific situations or materials without departing from the scope of the present disclosure. Accordingly, the method and / or system are not limited to the specific examples disclosed. Instead, the method and / or system include all embodiments that fall within the scope of the appended claims, literally or under the doctrine of equivalents. Some aspects of the present invention are described below. [Aspect 1] A brush for cleaning a surface, comprising a central core, and a cleaning member provided around the central core, the cleaning member comprising nodules, wherein a first nodule density in a first region of the cleaning member is different from a second nodule density in a second region of the cleaning member. [Aspect 2] The brush according to Aspect 1, wherein the nodule density is lower at the longitudinal center of the brush than at the longitudinal ends of the brush. [Aspect 3] The brush according to Aspect 1, wherein the nodules form a substantially helical pattern on the cleaning member. [Aspect 4] The brush according to Aspect 1, wherein the nodules form a substantially grid-like pattern on the cleaning member. [Aspect 5] The brush according to Aspect 1, wherein the nodule density is substantially symmetric around the longitudinal center of the brush. [Aspect 6] The brush according to Aspect 1, wherein the nodule pattern is substantially symmetric around the longitudinal center of the brush. [Aspect 7] The brush according to Aspect 1, wherein the nodules are formed as part of the cleaning member. [Aspect 8] The brush according to Aspect 1, wherein the nodules are attached to the cleaning member by an adhesive. [Aspect 9] The brush according to Aspect 1, wherein at least one nodule has a different shape from another nodule among the nodules. [Aspect 10] The brush according to Aspect 1, wherein the brush has elongated nodules near the longitudinal center of the brush. [Aspect 11] The brush according to Aspect 1, wherein a diameter of a first cross-section of the brush is larger than a diameter of a second cross-section of the brush. [Aspect 12] The brush according to Aspect 1, wherein the cross-section of the brush is substantially circular. [Aspect 13] The brush according to Aspect 1, wherein the cleaning member is frictionally fitted over the central core. [Aspect 14] The brush according to Aspect 1, wherein the cleaning member is coupled to the central core by an adhesive. [Aspect 15] The brush according to Aspect 1, wherein at least some of the nodules are arranged in a pattern that moves a cleaning fluid towards the longitudinal ends of the brush, the cleaning fluid being provided to at least one of the brush and the surface during at least the cleaning process of the surface. [Aspect 16] A brush for cleaning a surface, comprising a central core, It includes a nozzle module and a cleaning member provided around the central core. A brush in which the first nozzle module in the first region of the brush has a first shape and the second nozzle module in the second region of the brush has a second shape. [Aspect 17] The brush according to Aspect 16, wherein one or both of the first region and the second region have a first nozzle module having the first shape and a second nozzle module having the second shape. [Aspect 18] The brush according to Aspect 16, wherein the first region is closer to the longitudinal center of the brush than the second region. [Aspect 19] The brush according to Aspect 16, wherein the first shape is larger than the second shape. [Aspect 20] The brush according to Aspect 16, wherein at least one of the first nozzle module and the second nozzle module is arranged in a pattern that moves the cleaning fluid toward the longitudinal end of the brush, and the cleaning fluid is provided to one or both of the brush and the surface at least during the cleaning process of the surface.

Explanation of Symbols

[0045] 100 Brush 110 Central Core 120 Cleaning Member 122 Module 180 Semiconductor Wafer 200 Brush 210 Central Core 220 Cleaning Member 222 Module 224 Module 300 Brush 310 Central Core 320 Cleaning Member 322 Module 400 Brush 410 Central Core 420 Cleaning Member 422 Module 500 Brush 510 Central Core 520 Cleaning member 522 Module 600 Brush 610 Central core 620 Cleaning member 622 Module 700 Brush 710 Central core 720 Cleaning member 760 Central core 770 Cleaning member 800 Brush 802 Graph 810 Brush 812 Graph

Claims

1. 1. A brush for cleaning a surface, comprising: A central core; a cleaning member provided around the central core, the cleaning member including a nodule; First nodules in a first region of a longitudinal center of the brush have a first shape and second nodules in a second region of the brush have a second shape; In the first region, the nodules form a helical pattern on the cleaning member.

2. 2. The brush of claim 1, wherein one or both of the first region and the second region have first nodules having the first shape and second nodules having the second shape.

3. 2. The brush of claim 1, wherein the first region is closer to a longitudinal center of the brush than the second region.

4. 2. The brush of claim 1 wherein said first shape is larger than said second shape.

5. 2. The brush of claim 1, wherein at least one of the first nodules and the second nodules are arranged in a pattern that moves cleaning fluid toward a longitudinal end of the brush, and the cleaning fluid is provided to one or both of the brush and the surface during at least a cleaning process of the surface.

6. 1. A brush for cleaning a surface, comprising: A central core; a cleaning member provided around the central core, the cleaning member including a nodule; First nodules in a first region of a longitudinal center of the brush have a first shape and second nodules in a second region of the brush have a second shape; In the first region, the nodules form a spiral pattern on the cleaning member; A brush wherein in said second region said nodules form a non-helical pattern.

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