US20160074995A1

US20160074995A1 - Chemical mechanical polishing conditioner with brushes

Info

Publication number: US20160074995A1
Application number: US14/834,030
Authority: US
Inventors: Jui-Lin Chou; Chia-Chun Wang; Chia-Feng CHIU; Wen-Jen Liao
Original assignee: Kinik Co
Current assignee: Kinik Co
Priority date: 2014-09-11
Filing date: 2015-08-24
Publication date: 2016-03-17
Also published as: TW201609318A; TWI542444B

Abstract

Provided is a CMP conditioner with brushes comprising: a substrate comprising a surface, multiple concave parts formed in the surface; multiple abrasive assemblies, each abrasive assembly comprising a metal bar and an abrasive particle, the metal bar comprising a connecting end and a dressing end, the abrasive particle mounted in the dressing end of the metal bar and protruding a tip, wherein vertical distances between the tips and a level of the surface are equal; and multiple brushes mounted in the surface, wherein ends of the brushes are higher than the tips, vertical distances between the ends of the brushes and a level of the tips ranging from 0.1 mm to 1 mm. The present invention, with precise control of the vertical distance between the tips and the level of the surface, and of the vertical distance between the ends of the brushes and a level of the tips improves the cleaning ability of the CMP conditioner with brushes for the scraps in holes of the surface of a pad and avoid problems, e.g., scraps in some holes cannot be effectively removed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority under 35 U.S.C. 119 from Taiwan Patent Application No. 103131280 filed on Sep. 11, 2014, which is hereby specifically incorporated herein by this referenced thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner, especially to a chemical mechanical polishing conditioner with brushes.
2. Description of the Prior Art(s)
Chemical mechanical polishing (CMP) is a planarization technique used in various processes. Because CMP is suitable for large scale planarization, CMP is widely applied to planarization of silicon surface or copper surface after stacking of integrated circuits. An equipment of CMP usually comprises a pad and a CMP conditioner. During a CMP process, a slurry is supplied on the pad, and then a surface of an article is pressed on the pad to polish the surface of the article; scraps produced during the polishing process accumulate and stagnate in holes of the pad, forming a hardened layer. The hardened layer decreases the polishing efficiency of the pad and shortens the lifetime of the pad. Therefore, CMP conditioner is used during the CMP process to dress the surface of the pad, so as to prolong the life time of the pad. However, a conventional CMP conditioner used to dress the surface of the pad is only capable of breaking the hardened layer and cannot remove the scraps from the holes of the pad; therefore, the effect for prolonging the life time of the pad is limited.
In view of abovementioned problem, with reference to FIG. 11 and FIG. 12, a CMP conditioner is provided and comprises a carrier 70, multiple abrasive particles 80, and multiple cleaning parts 90. The carrier 70 has multiple abrasive areas 71 and multiple brushing areas 72; the abrasive areas 71 and the brushing areas 72 are located alternatively in an annular arrangement. The abrasive particles 80 are distributed and fixed on the abrasive areas 71. The cleaning parts 90 are fixed on the brushing areas 72. Each of the cleaning parts 90 comprises multiple brushes 91 fixed on the brushing areas 72. The CMP conditioner uses the brushes 91 to sweep off the slurry containing scraps and remove the scraps in the holes; thereby recovering the abrasive efficiency of the pad and prolong the life time of the pad.
However, with reference to FIG. 12, the abrasive particles 80 of the CMP conditioner with brushes are spread on the carrier 70, heights of ends 81 of the abrasive particles 80 are non-uniform and cannot form a unified standard; hence, ends 911 of some brushes 90 are relatively higher than the ends 81 of the abrasive particles 80 and ends 911 of the other brushes 90 are relatively lower than the ends 81 of the abrasive particles 80. When the ends 911 of the other brushes 90 are relatively lower than the ends 81 of the abrasive particles 80, the brushes 91 cannot remove the scraps in the holes effectively. When the ends 911 of some brushes 90 are relatively higher than the ends 81 of the abrasive particles 80, the dressing efficiency of the abrasive particles 80 for the surface of the pad is decreased. The non-uniform heights between the ends 911 of the brushes 91 and the ends 81 of the abrasive particles 80 cause the failures to completely remove the scraps in the holes of the pad or provide non-uniform abrasive efficiencies at different regions; therefore, the CMP conditioner in the prior art still needs to be improved.

SUMMARY OF THE INVENTION

In view of abovementioned problems of the CMP conditioner in Prior Art, the present invention is to solve the problems such as the non-uniform heights between ends of brushes and ends of the abrasive particles, incomplete removal of the scraps in holes of the pad, and non-uniform abrasive efficiencies of the abrasive particles.
The present invention provides a CMP conditioner with brushes comprising:
a substrate comprising a surface and multiple concave parts, the concave parts formed in the surface;
multiple abrasive assemblies mounted in the surface, each of the abrasive assemblies comprising:

- a metal bar, the metal bar comprising a connecting end and a dressing end, the connecting ends each respectively mounted in the concave parts; and
- an abrasive particle comprising a tip, the abrasive particles mounted in the dressing ends of the metal bars, and the tips protruding from the dressing ends, vertical distances between the tips of the abrasive particles and a level of the surface being equal to form a level of the tips; and

multiple brushes mounted in the surface, ends of the brushes being farther from the surface than the tips of the abrasive particle, vertical distances between the ends of the brushes and the level of the tips of the abrasive particles ranging from 0.1 mm to 1 mm.
The CMP conditioner with brushes in the present invention, with precise control of the vertical distance between the tips of the abrasive particles and the level of the surface, and of the vertical distance between the ends of the brushes and the level of the tips of the abrasive particles, improves the cleaning ability of the CMP conditioner with brushes for the scraps in holes of surface of a pad. Besides, problems, e.g., scraps in holes of some areas of the pad cannot be effectively removed or the abrasive efficiencies of the abrasive particles are non-uniform, are avoided.
Preferably, the CMP conditioner with brushes further comprises a second substrate, the second substrate is mounted in the surface; the brushes are mounted in the second substrate. The second substrate is made of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, or polylactic acid.
Alternatively, the substrate comprises multiple drilled holes formed in the surface; the brushes are each respectively mounted in the drilled holes.
Preferably, the brushes comprise multiple soft brushes and multiple hard brushes, the soft brushes and the hard brushes are arranged alternatively. More preferably, the soft brushes are made of polypropylene or nylon; the hard brushes are made of polypropylene or nylon.
Preferably, the substrate is circular and the surface is defined into an outer area and a centre area, the outer area encompasses the centre area; the concave parts are formed in the outer area of the surface; the brushes are mounted in the centre area of the surface.
More preferably, the outer area is defined into an abrasive area and a cleaning area, the abrasive area and the cleaning area are arranged alternatively; the brushes are mounted in the centre area of the surface and the cleaning area of the outer area of the surface.
Alternatively, the substrate is circular and the surface is defined into an outer area and a centre area, the outer area encompasses the centre area, and the outer area is defined into an abrasive area and a cleaning area, the abrasive area and the cleaning area are arranged alternatively; the concave parts are formed in the abrasive area of the outer area of the surface; the brushes are mounted in the cleaning area of the outer area of the surface.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top schematic view of a CMP conditioner with brushes in accordance with Embodiment 1 of the present invention;

FIG. 2 is a cross-sectional schematic view of the CMP conditioner in accordance with Embodiment 1 of the present invention;

FIG. 3 is a schematic view of the preparation of the CMP conditioner with brushes in accordance with Embodiment 1 of the present invention;

FIG. 4 is a cross-sectional schematic view of a CMP conditioner in accordance with Embodiment 2 of the present invention;

FIG. 5 is a top schematic view of a CMP conditioner with brushes in accordance with Embodiment 3 of the present invention;

FIG. 6 is a top schematic view of a CMP conditioner with brushes in accordance with Embodiment 4 of the present invention;

FIG. 7 is a cross-sectional schematic view of a CMP conditioner with brushes in accordance with Comparative Embodiment of the present invention;

FIG. 8 is a scanning electron microscope image of a pad dressed by the CMP conditioner with brushes in accordance with Embodiment 1 of the present invention;

FIG. 9 is a scanning electron microscope image of a pad dressed by the CMP conditioner with brushes in accordance with Comparative Embodiment of the present invention;

FIG. 10 is a scanning electron microscope image of a pad dressed by a CMP conditioner in the Prior Art;

FIG. 11 is a top schematic view of the CMP conditioner in the Prior Art;

FIG. 12 is a cross-sectional schematic view of the CMP conditioner in the Prior Art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment 1

With reference to FIG. 1 and FIG. 2, the CMP conditioner with brushes of the instant embodiment comprises a substrate 10, multiple abrasive assemblies 20, and multiple brushes 30.
The substrate 10 is circular and comprises a surface 11, multiple concave parts 12, and multiple drilled holes 13. The surface 11 is defined into an outer area 111 and a centre area 112. The outer area 111 and the centre area 112 are concentric; the outer area 111 encompasses the centre area 112; in other words, the outer area 111 is in the outer circle and the centre area 112 is in the inner circle. The concave parts 12 are formed in the outer area 111 of the surface 11 and the drilled holes 13 are formed in the centre area 112 of the surface 11.
Each of the abrasive assemblies 20 comprises a metal bar 21 and an abrasive particle 22. Two ends of the metal bar 21 are a connecting end 211 and a dressing end 212. The connecting ends 211 are each respectively mounted in the concave parts 12. The abrasive particle 22 comprises a tip 221, the abrasive particles 22 are mounted in the dressing ends 212 of the metal bars 21, and the tips 221 are protruded from the dressing ends 212. Vertical distances d1 between each tip 221 of the abrasive particles 20 and a level of the outer area 111 are equal.
The brushes 30 comprise multiple soft brushes 31 and multiple hard brushes 32. The soft brushes 31 are made of polypropylene and are each respectively mounted in the drilled holes 13. Diameters of the soft brushes 31 range from 0.15 mm to 0.25 mm (diameters of the soft brushes 31 can be modified based on the length of the soft brushes 31, said diameters of the soft brushes 31 are provided just for example). The hard brushes 32 are made of polypropylene and are each respectively mounted in the drilled holes 13. Diameters of the hard brushes 32 range from 0.4 mm to 0.6 mm (diameters of the hard brushes 32 can be modified based on the length of the hard brushes 32, said diameters of the hard brushes 32 are provided just for example). When the soft brushes 31 and the hard brushes 32 are made of same material, the diameters of the hard brushes 32 are larger than the diameters of the soft brushes 31. The soft brushes 31 and the hard brushes 32 are arranged alternatively. Ends 311 of the soft brushes 31 are farther from the surface 11 than the tips 221 of the abrasive particles 22. Vertical distances d2 between the ends 311 of the soft brushes 31 and a level of the tips 221 of the abrasive particles 22 are 0.1 mm. Ends 321 of the hard brushes 32 are farther from the surface 11 than the tips 221 of the abrasive particles 22. Vertical distances d3 between the ends 321 of the hard brushes 32 and the level of the tips 221 of the abrasive particles 22 are 0.1 mm.
The preparation of the abrasive assemblies 20 in this embodiment was as follows. A bottom mold was prepared and a silicone mat was placed on a surface of the bottom mold. The substrate 10 was placed on the silicone mat and the silicone mat formed cushions within the concave parts 12 of the substrate 10. An adhering glue was injected into the concave parts 12 and the connecting ends 211 of the metal bars 21 of the abrasive assemblies 20 were mounted in the concave parts 12. A gasket for adjusting tip heights of the abrasive particles 22 of the abrasive assemblies 20 were placed on the tips 221 of the abrasive particles 22 and a top mold was placed on a side, opposite the abrasive assemblies 20, of the gasket. A fixed pressure was applied to the top mold and the bottom mold to make the vertical distances between the tips 221 of the abrasive particles 20 and a level of the surface 11 of the substrate 10 equal. The adhering glue was heated to be cured. The top mold, the bottom mold, the gasket, and the silicone mat were removed, and then the concave parts 12 of the substrate 10 were filled with the adhering glue to finish the preparation of the abrasive assemblies 20. Said preparation of the abrasive assemblies 20 was just a preferable embodiment of the present invention and did not constrain the present invention in any form.
With reference to FIG. 3, the CMP conditioner with brushes in this embodiment was accompanied with a precision jig 60 to make the vertical distance between the ends 311 of the soft brushes 31 and the level of the tips 221 of the abrasive particles 22 and the vertical distance between the ends 321 of the hard brushes 32 and the level of the tips 221 of the abrasive particles 22 0.1 mm.
The precision jig 60 comprises two surfaces, an abrasive surface 61 and a brush surface 62. The abrasive surface 61 was against the abrasive particles 22. The brush surface 62 was against the ends 311 of the soft brushes 31 and the ends 321 of the hard brushes 32. The abrasive surface 61 is relatively higher than the brush surface 62 by a stage difference d4 of 0.1 mm. During the preparation of the CMP conditioner with brushes, the surface 11 of the substrate 10 was faced down to make the ends 311 of the soft brushes 31 and the ends 321 of the hard brushes 32 against the brush surface 62 and ensure the vertical distances between the ends 311 of the soft brushes 31 and the level of the tips 221 of the abrasive particles 22 and the vertical distances between the ends 321 of the hard brushes 32 and the level of the tips 221 of the abrasive particles 22 0.1 mm.

Embodiment 2

With reference to FIG. 4, the CMP conditioner with brushes in this embodiment is similar to the CMP conditioner with brushes in Embodiment 1, the difference between these two CMP conditioners with brushes are as follows. No drilled holes are formed in the substrate 10A of Embodiment 2. The CMP conditioner with brushes of the instant Embodiment further comprises a second substrate 40A. The second substrate 40A is made of polypropylene. The second substrate 40A is mounted in the centre area 112A. The soft brushes 31A are mounted in the second substrate 40A. The soft brushes 31A are made of nylon. The vertical distances between the ends 311A of the soft brushes 31A and the level of the tips 221A of the abrasive particles 22A are 0.5 mm. The hard brushes 32A are mounted in the second substrate 40A. The hard brushes 32A are made of nylon. The vertical distances between the ends 321A of the hard brushes 32A and the level of the tips 221A of the abrasive particles 22A are 0.5 mm. The soft brushes 31A and the hard brushes 32A are mounted in the second substrate 40A, and then the second substrate 40A is mounted in the substrate 10A. The combined structure increases convenience when preparing the CMP conditioner with brushes.

Embodiment 3

With reference to FIG. 5, the CMP conditioner with brushes in this embodiment is similar to the CMP conditioner with brushes in Embodiment 1, the difference between these two CMP conditioners with brushes are as follows. The outer area 111B is defined into an abrasive area 1111B and a cleaning area 1112B and the abrasive area 1111B and the cleaning area 1112B are arranged alternatively. The concave parts 12B are formed in the abrasive area 1111B of the outer area 111B of the surface. The drilled holes 13B are formed in the centre area 112B of the surface and the cleaning area 1112B of the outer area 111B of the surface. The vertical distances between the ends of the soft brushes and the level of the tips of the abrasive particles are 1 mm. The vertical distances between the ends of the hard brushes and the level of the tips of the abrasive particles are 1 mm. The cleaning ability and dressing ability of the CMP conditioner with brushes is modified by adjusting a ratio between the soft brushes, the hard brushes, and the abrasive particles to make the CMP conditioner with brushes to be applied in various processes.

Embodiment 4

With reference to FIG. 6, the CMP conditioner with brushes in this embodiment was similar to the CMP conditioner with brushes in Embodiment 3, the difference between these two CMP conditioners with brushes are as follows. The drilled holes 13C are formed in the cleaning area 1112C of the outer area 111C of the surface. The cleaning ability and dressing ability of the CMP conditioner with brushes is modified by adjusting a ratio between the soft brushes, the hard brushes, and the abrasive particles to make the CMP conditioner with brushes to be applied in various processes.

Comparative Embodiment

With reference to FIG. 7, the CMP conditioner with brushes in this comparative embodiment is similar to the CMP conditioner with brushes in Embodiment 1, the difference between these two CMP conditioners with brushes are as follows. The ends 311D of the soft brushes 31D are relatively nearer the surface 11D compared to the tips 221D of the abrasive particles 22D. The vertical distances d5 between the ends 311D of the soft brushes 31D and the level of the tips 221D of the abrasive particles 22D are 0.1 mm. The ends 321D of the hard brushes 32D are relatively nearer the surface 11D compared to the tips 221D of the abrasive particles 22D. The vertical distances d6 between the ends 321D of the hard brushes 32D and the level of the tips 221D of the abrasive particles 22D are 0.1 mm.

Experimental Embodiment

The CMP conditioner with brushes in Embodiment 1 and Comparative Embodiment and the CMP conditioner in the Prior Art were respectively dressed pads, and then holes of the pads were examined by scanning electron microscope to observe whether the scraps were removed or not. The results respectively were shown in FIG. 8 (Embodiment 1), FIG. 9 (Comparative Embodiment), and FIG. 10 (Prior Art).
Comparing FIG. 8 (Embodiment 1) and FIG. 9 (Comparative Embodiment), when the ends of the soft brushes or the ends of the hard brushes comparing to the centre area were lower than the tips of the abrasive particles, the cleaning ability for the scraps within the holes of the pad of the CMP conditioner with brushes was ineffective.
Comparing FIG. 8 (Embodiment 1) and FIG. 10 (Prior Art), the CMP conditioner with brushes in Embodiment 1, with the precise control of the vertical distance between the tips of the abrasive particles and the level of the outer area, of the vertical distance between the ends of the soft brushes and the level of the tips of the abrasive particles, and of the vertical distance between the ends of the hard brushes and the level of the tips of the abrasive particles, a more effective cleaning ability than the CMP conditioner in the Prior Art is provided. Furthermore, problems, e.g., scraps in holes of some areas of a pad could not be effectively removed or the abrasive efficiencies of the abrasive particles were non-uniform were avoided.
With precise control of the vertical distance between the tips of the abrasive particles and the level of the outer area, of the vertical distance between the ends of the soft brushes and the level of the tips of the abrasive particles, and of the vertical distance between the ends of the hard brushes and the level of the tips of the abrasive particles, the CMP conditioner with brushes in the present invention improves the cleaning ability for the scraps in holes of surface of a pad, and thus avoids the ineffective removal of the scraps in holes of some areas of a pad or non-uniform abrasive efficiencies of the abrasive particles. Furthermore, the CMP conditioner with brushes in the present invention can be applied to pads with different conditions by varying the arrangement of the brushes and the abrasive assemblies.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

What is claimed is:

1. A chemical mechanical polishing conditioner with brushes comprising:

a substrate comprising a surface and multiple concave parts, the concave parts formed in the surface;

multiple abrasive assemblies mounted in the surface, each of the abrasive assemblies comprising:

a metal bar, the metal bar comprising a connecting end and a dressing end opposite the connecting end, wherein the connecting ends are each respectively mounted in the concave parts; and

an abrasive particle comprising a tip, the abrasive particles mounted in the dressing ends of the metal bars, and the tips protruding from the dressing ends, wherein vertical distances between the tips of the abrasive particles and a level of the surface are equal to form a level of the tips; and

multiple brushes mounted in the surface, ends of the brushes being farther from the surface than the tips of the abrasive particle, vertical distances between the ends of the brushes and the level of the tips of the abrasive particles ranging from 0.1 mm to 1 mm.

2. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the brushes comprise multiple soft brushes and multiple hard brushes, and the soft brushes and the hard brushes are arranged alternatively.

3. The chemical mechanical polishing conditioner with brushes as claimed in claim 2, wherein the soft brushes are made of polypropylene or nylon, and the hard brushes are made of polypropylene or nylon.

4. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the substrate comprises multiple drilled holes formed in the surface; the brushes are each respectively mounted in the drilled holes.

5. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the chemical mechanical polishing conditioner with brushes comprises a second substrate, the second substrate is mounted in the surface; the brushes are mounted in the second substrate.

6. The chemical mechanical polishing conditioner with brushes as claimed in claim 5, wherein the second substrate is made of polypropylene.

7. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the substrate is circular and the surface is defined into an outer area and a centre area, the outer area encompasses the centre area; the concave parts are formed in the outer area of the surface; the brushes are mounted in the centre area of the surface.

8. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the substrate is circular and the surface is defined into an outer area and a centre area, the outer area encompasses the centre area, and the outer area is defined into an abrasive area and a cleaning area, the abrasive area and the cleaning area are arranged alternatively; the concave parts are formed in the abrasive area of the outer area of the surface; the brushes are mounted in the centre area of the surface and the cleaning area of the outer area of the surface.

9. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the substrate is circular and the surface is defined into an outer area and a centre area, the outer area encompasses the centre area, and the outer area is defined into an abrasive area and a cleaning area, the abrasive area and the cleaning area are arranged alternatively; the concave parts are formed in the abrasive area of the outer area of the surface; the brushes are mounted in the cleaning area of the outer area of the surface.

10. The chemical mechanical polishing conditioner with brushes as claimed in claim 1, wherein the vertical distances between the ends of the brushes and the level of the tips of the abrasive particles are equal.