CHEMICAL MECHANICAL POLISHING CONDITIONER AND FABRICATION METHOD THEREOF

Abstract

A chemical mechanical polishing conditioner comprises a substrate and at least one abrasive unit. The abrasive unit is provided on the substrate, and the abrasive unit comprises a supporting layer, an abrasive layer and a stress-relief layer. The supporting layer is provided with a working face far away from the substrate and a non-working face opposite to the working face. The abrasive layer is provided on the working face of the supporting layer, and the abrasive layer is a first diamond-plated film formed by chemical vapor deposition method. The first diamond-plated film is provided with a plurality of abrasive tips. The stress-relief layer is provided on the non-working face of the supporting layer, and the stress-relief layer is a second diamond-plated film formed by chemical vapor deposition method. A thermal stress-relieving effect may be exerted by the stress-relief layer, so as to reduce warpage or deformation of the supporting layer.

Description

FIELD OF THE INVENTION

The present invention is related to a chemical mechanical polishing conditioner and fabrication method thereof, particularly to a chemical mechanical polishing conditioner with excellent flatness and fabrication method thereof.

BACKGROUND OF THE INVENTION

Chemical mechanical polishing (CMP) is a flattening technology commonly used in semiconductor processing. In a common CMP processing, a polishing pad (or abrasive pad) fixed at a rotary table is used to contact with and apply a force to a silicon wafer carried on a spinning carrier. The carrier and the rotary table are rotated, while a polishing slurry is supplied to the polishing pad during polishing. In general, fragments derived by polishing and the polishing slurry are accumulated in pores of the polishing pad, such that the polishing pad is consumed and the effect of polishing on semiconductor is then reduced. Therefore, it is necessary to use a conditioner for the removal of fragments and polishing slurry remained in the polishing pad.

A conventional conditioner may be found in U.S. Pat. No. 6,872,127B2, disclosing a polishing pad conditioning disks for chemical mechanical polisher comprising, in one embodiment, a rigid and non-brittle substrate, a plurality of pyramid-shaped protrusions extending from the substrate in a matrix of rows and columns, a plurality of grooves extending between the protrusions, a seed layer provided on the plurality of protrusions, and a contact layer provided on the seed layer. The substrate may be a stainless steel substrate. The seed layer may include titanium nitride. The contact layer may be a chemical vapor deposition diamond film In addition, referring to Taiwan Patent No. 1492291, a chemical mechanical polishing conditioner and fabrication method thereof is disclosed. The chemical mechanical polishing conditioner comprises a substrate and an abrasive layer. The abrasive layer comprises a plurality of abrasive units, in which the abrasive layer includes chemical vapor deposition diamond material, while the abrasive units are provided with one or a plurality of grooves, an apex, and an inclined plane formed between each of the grooves and the apex. Moreover, each of the abrasive units is presented as a conical shape or a cylindrical shape.

In the prior art mentioned above, the diamond films are all deposited by chemical vapor deposition process at processing temperature no less than hundreds of degrees. When the temperature is reduced, warpage or deformation of the substrate may be resulted from different thermal expansion coefficients between the diamond film and the substrate, so as to affect flatness of the diamond film Thus, there is still room for improvement.

SUMMARY OF THE INVENTION

It is the main object of the present invention to solve the problem of poor flatness of a diamond film in the conventional chemical mechanical polishing conditioner having the diamond film deposited by chemical vapor deposition process.

For achieving the above object, the present invention provides a chemical mechanical polishing conditioner, comprising a substrate and at least one abrasive unit provided on the substrate. The abrasive unit comprises a supporting layer provided with a working face far away from the substrate and a non-working face opposite to the working face; an abrasive layer provided on the working face of the supporting layer, the abrasive layer being a first diamond-plated film formed by chemical vapor deposition method, the first diamond-plated film being provided with a plurality of abrasive tips; and a stress-relief layer provided on the non-working face of the supporting layer, the stress-relief layer being a second diamond-plated film formed by chemical vapor deposition method.

In one embodiment of the present invention, the substrate is provided with at least one recessed portion for accommodating the abrasive unit.

In one embodiment of the present invention, the substrate is provided with at least one through-hole for accommodating the abrasive unit.

In one embodiment of the present invention, the substrate is a plane substrate.

In one embodiment of the present invention, the substrate is selected from the group consisting of a stainless steel substrate, a die steel substrate, a metal alloy substrate, a ceramic substrate and a polymer substrate.

In one embodiment of the present invention, the material of the supporting layer is silicon or silicon carbide.

In one embodiment of the present invention, a plurality of projecting tips are formed on the working face of the supporting layer through a machining process, while the abrasive layer is allowed for cladding the working face of the supporting layer and thus provided with the abrasive tips corresponding to the projecting tips.

In one embodiment of the present invention, the first diamond-plated film is subjected to a machining process to form said abrasive tips.

In one embodiment of the present invention, the machining process is selected from the group consisting of a grinding, a laser machining, an electro-discharge machining, a dry etching and a wet etching.

In one embodiment of the present invention, a bonding layer is further provided between the substrate and the abrasive unit.

In one embodiment of the present invention, the material of the bonding layer is selected from the group consisting of a ceramic material, a brazing material, an electroplating material, a metal material and a polymer material.

In one embodiment of the present invention, the brazing material is selected from the group consisting of Fe, Co, Ni, Cr, Mn, Si and Al.

In one embodiment of the present invention, the polymer material is selected from the group consisting of epoxy resin, polyester resin, polyacrylate resin and phenolic resin.

For achieving the above object, the present invention further provides a fabrication method of chemical mechanical polishing conditioner comprising the steps as follows:

step S1: providing a supporting layer having a working face and a non-working face opposite to the working face;

step S2: providing an abrasive layer and a stress-relief layer on the working face and the non-working face of the supporting layer, respectively, to form an abrasive unit by chemical vapor deposition method, the abrasive layer and the stress-relief layer being a first diamond-plated film and a second diamond-plated film, respectively, the first diamond-plated film being provided with a plurality of abrasive tips; and

step S3: bonding the abrasive unit to a substrate.

In one embodiment of the present invention, in step S2, the abrasive layer is firstly formed on the working face of the supporting layer and the stress-relief layer is then formed on the non-working face of the supporting layer.

In one embodiment of the present invention, in step S2, the plurality of projecting tips are firstly formed on the working face of the supporting layer through a machining process, and the abrasive layer is then formed on the working face, such that the first diamond-plated film is provided with the abrasive tips corresponding to the projecting tips.

In one embodiment of the present invention, in step S2, the abrasive layer is provided on the working face of the supporting layer, and the abrasive tips are formed on the first diamond-plated film through a machining process.

In one embodiment of the present invention, the machining process is selected from the group consisting of a grinding, a laser machining, an electro-discharge machining, a dry etching and a wet etching.

In one embodiment of the present invention, the substrate is provided with at least one recessed portion for accommodating the abrasive unit.

In one embodiment of the present invention, the substrate is provided with at least one through-hole for accommodating the abrasive unit.

In one embodiment of the present invention, the substrate is a plane substrate.

In one embodiment of the present invention, the substrate is selected from the group consisting of a stainless steel substrate, a die steel substrate, a metal alloy substrate, a ceramic substrate and a polymer substrate.

In one embodiment of the present invention, the material of the supporting layer is silicon or silicon carbide.

To sum up, the effect of the present invention, in comparison with prior art, is achieved by the use of the formation of the first diamond-plated film and the second diamond-plated film as the abrasive layer and the stress-relief layer at two sides of the supporting layer, respectively. Consequently, the forces, resulting in deformation, acting on the two sides of the supporting layer are equal when temperature is decreased from a higher temperature to a lower temperature during chemical vapor deposition process, so as to reduce deformation of the supporting layer. In other words, the effect of relieving a thermal stress is exerted by the stress-relief layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is a cross-sectional diagram according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional diagram according to a second embodiment of the present invention.

FIGS. 3A to 3F are diagrams illustrating the fabrication process according to one embodiment of the present invention.

FIGS. 4A to 4C are diagrams illustrating the fabrication process according to another embodiment of the present invention.

FIGS. 5A to 5C illustrate flatness measurement of a supporting layer before a first diamond-plated film and a second diamond-plated film are formed in one embodiment of the present invention.

FIGS. 6A to 6C illustrate flatness measurement of the supporting layer after the first diamond-plated film is formed in one embodiment of the present invention.

FIGS. 7A to 7C illustrate flatness measurement of the supporting layer after the first diamond-plated film and the second diamond-plated film are formed in one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed description and technical content of the present invention will be described, in conjunction with drawings, as follows.

Referring to FIGS. 1 and 2, there are shown cross-sectional diagrams according to a first embodiment and a second embodiment, respectively, of the present invention. A chemical mechanical polishing conditioner of the present invention comprises a substrate 10 and at least one abrasive unit 20. The abrasive unit 20 is provided on the substrate 10, and the abrasive unit 20 comprises a supporting layer 21, an abrasive layer 22 and a stress-relief layer 23. The supporting layer 21 is provided with a working face 211 located at one side far away from the substrate 10 while used for bearing the abrasive layer 22, and a non-working face 212 opposite to the working face 211. The abrasive layer 22 and the stress-relief layer 23 are a first diamond-plated film and a second diamond-plated film, respectively, formed by chemical vapor deposition method. In this connection, the abrasive layer 22 is provided on the working face 211 of the supporting layer 21 and provided with a plurality of abrasive tips 221, while the stress-relief layer 23 is provided on the non-working face 212 of the supporting layer 21. In this embodiment, the chemical mechanical polishing conditioner further comprises a bonding layer 30, provided between the substrate 10 and the abrasive unit 20, for bonding the abrasive unit 20 to the substrate 10. Moreover, one abrasive unit 20 is provided in the first embodiment as illustrated in FIG. 1, while a plurality of abrasive units 20 are provided in the second embodiment as illustrated in FIG. 2.

Next, a fabrication method of chemical mechanical polishing conditioner of the present invention will be described. Referring to FIGS. 3A to 3F cooperatively, there are shown diagrams of fabrication process according to one embodiment of the present invention. Firstly, the supporting layer 21 of silicon or silicon carbide is provided, as illustrated in FIG. 3A. Subsequently, the first diamond-plated film (namely, the abrasive layer 22), composed of polycrystalline diamond material and provided with a rough top surface 22a, is deposited on the working face 211 of the supporting layer 21 by chemical vapor deposition method, as illustrated in FIG. 3B. Subsequently, planarization process is performed on the top surface 22a in mechanical or chemical polishing or abrasive manner, such that the top surface 22a is provided with a planar surface, as illustrated in FIG. 3C. Afterwards, patterning process is performed on the planarized abrasive layer 22 through a machining process, so as to form a plurality of abrasive tips 221. In this connection, each of the abrasive tips 221 may be preferably formed as a pyramid shape as illustrated in FIG. 3D, while the machining process may be grinding, laser machining, electro-discharge machining, dry etching or wet etching. Then, the second diamond-plated film (namely, the stress-relief layer 23), is deposited on the non-working face 212 of the supporting layer 21 by chemical vapor deposition method, as illustrated in FIG. 3E. Finally, the bonding layer 30 is then used for bonding the abrasive unit 20 to the substrate 10, with the bonding layer 30 being provided between the substrate 10 and the abrasive unit 20, as illustrated in FIG. 3F.

Referring to FIGS. 4A to 4C continuously, there are shown diagrams of fabrication process according to another embodiment of the present invention. In another embodiment of the present invention, as illustrated in FIG. 4A, the supporting layer 21 of silicon or silicon carbide is provided firstly, the supporting layer 21 having the working face 211 and the non-working face 212. Subsequently, a plurality of projecting tips 211a are formed on the working face 211 of the supporting layer 21 through a machining process, as illustrated in FIG. 4B. In this connection, each of the projecting tips 211a may be preferably formed as a pyramid shape, the machining process being possibly grinding, laser machining, electro-discharge machining, dry etching or wet etching. Afterwards, the first diamond-plated film (namely, the abrasive layer 22), composed of polycrystalline diamond material, is then formed on the working face 211, such that the first diamond-plated film is provided with a plurality of abrasive tips 221 corresponding to the projecting tips 211a, as illustrated in FIG. 4C. The following steps are the same as those in the previous embodiment referred to FIGS. 3E and 3F, and should not be described further.

In the fabrication processes of the above embodiments, an intermediate layer is further provided between the supporting layer 21 and the abrasive layer 22 and/or between the supporting layer 21 and the stress-relief layer 23, primarily in consideration of the difference in expansion coefficient or lattice dimension between the first and second diamond-plated films and the supporting layer 21, possibly leading to insufficient adhesive strength, and thus resulting in delamination during polishing process, of the abrasive layer 22 and/or the stress-relief layer 23. Therefore, various methods, such as physical or chemical vapor deposition, soft soldering, hard soldering and etc., may be used to form the intermediate layer on the working face 211 and/or the non-working face 212 of the supporting layer 21. Forming the first diamond-plated film firstly and then forming the second diamond-plated film is taken as an example in the above embodiments, but the present invention is not limited thereto. In other embodiments, it is also possible to form the second diamond-plated film firstly and then form the first diamond-plated film, or it is also possible to form the first diamond-plated film and the second diamond-plated film at the same time. Moreover, the abrasive tip 221 formed as a pyramid shape assuming a pointed top is taken as an example in the above embodiments, but the present invention is not limited thereto. The abrasive tip 221 may be also formed as a flat top or other shapes with polishing capability as required.

In the present invention, the substrate 10 may be selected from stainless steel substrate, die steel substrate, metal alloy substrate, ceramic substrate and polymer substrate. In addition, the substrate 10 may be provided with at least one recessed portion used for accommodating the abrasive unit 20, as illustrated in FIG. 1 or FIG. 2. Alternatively, the substrate 10 may be also provided with a through-hole for the abrasive unit 20 to be accommodated therein, or the substrate 10 may be a plane substrate. Moreover, the material of the bonding layer 30 may be ceramic material, brazing material, electroplating material, metal material or polymer material. In this connection, the brazing material may be metal or alloy including Fe, Co, Ni, Cr, Mn, Si or Al, while the polymer material may be epoxy resin, polyester resin, polyacrylate resin or phenolic resin.

For further verification of the effect of the present invention, measurement on flatness with respect to the supporting layer 21 is performed before the first diamond-plated film (the abrasive layer 22) and the second diamond-plated film (the stress-relief layer 23) are formed, after the first diamond-plated film (the abrasive layer 22) is formed, and after the first diamond-plated film (the abrasive layer 22) and the second diamond-plated film (the stress-relief layer 23) are formed. Referring to FIGS. 5A to 5C, firstly, the measuring lines L1, L2, L3, and L4 are presented horizontally, suggesting that the supporting layer 21 is provided with excellent and uniform flatness before the first diamond-plated film (the abrasive layer 22) and the second diamond-plated film (the stress-relief layer 23) are formed. Referring to FIGS. 6A to 6C continuously, the measuring lines L1, L2, L3, and L4 are presented as a topography of middle projection with recessed rim in two ends, suggesting that the supporting layer 21 is presented unevenly resulted from deformation significantly after the first diamond-plated film (the abrasive layer 22) is formed, which is just the problem in conventional art at present. Referring to FIGS. 7A to 7C further, as shown in these figures, the measuring lines L1, L2, L3, and L4 are presented horizontally, suggesting that the problem of deformation of the supporting layer 21 illustrated in FIG. 6A is eliminated, such that excellent and uniform flatness is presented on the supporting layer 21 again, after the second diamond-plated film (the stress-relief layer 23) is further formed on the non-working face 212 of the supporting layer 21. Therefore, the problem in conventional art is truly eliminated.

The effect of the present invention, in comparison with prior art, is achieved by the use of the formation of the first diamond-plated film and the second diamond-plated film as the abrasive layer and the stress-relief layer at two sides of the supporting layer, respectively. Consequently, the forces, resulting in deformation, acting on the two sides of the supporting layer are equal when temperature is decreased from a higher temperature to a lower temperature during chemical vapor deposition process, so as to reduce deformation of the supporting layer. In other words, the effect of relieving a thermal stress is exerted by the stress-relief layer.

While this invention has been detailed described in connection with what is presently considered to be preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. That is to say, various variations and modifications made in accordance with the patent claims should fall within the scope of the present invention.

Claims

1. A chemical mechanical polishing conditioner, comprising:

a substrate; and

at least one abrasive unit provided on said substrate, said abrasive unit comprising:

a supporting layer provided with a working face far away from said substrate and a non-working face opposite to said working face;

an abrasive layer provided on said working face of said supporting layer, said abrasive layer being a first diamond-plated film formed by chemical vapor deposition method, said first diamond-plated film being provided with a plurality of abrasive tips; and

a stress-relief layer provided on said non-working face of said supporting layer, said stress-relief layer being a second diamond-plated film formed by chemical vapor deposition method.

2. The chemical mechanical polishing conditioner according to claim 1, wherein said substrate is provided with at least one recessed portion for accommodating said abrasive unit

3. The chemical mechanical polishing conditioner according to claim 1, wherein said substrate is provided with at least one through-hole for accommodating said abrasive unit.

4. The chemical mechanical polishing conditioner according to claim 1, wherein said substrate is a plane substrate.

5. The chemical mechanical polishing conditioner according to claim 1, wherein said substrate is selected from the group consisting of a stainless steel substrate, a die steel substrate, a metal alloy substrate, a ceramic substrate and a polymer substrate.

6. The chemical mechanical polishing conditioner according to claim 1, wherein the material of said supporting layer is silicon or silicon carbide.

7. The chemical mechanical polishing conditioner according to claim 1, wherein a plurality of projecting tips are formed on said working face of said supporting layer through a machining process, while said abrasive layer is allowed for cladding said working face of said supporting layer and thus provided with said abrasive tips corresponding to said projecting tips.

8. The chemical mechanical polishing conditioner according to claim 1, wherein said first diamond-plated film is subjected to a machining process to form said abrasive tips.

9. The chemical mechanical polishing conditioner according to claim 8, wherein said machining process is selected from the group consisting of a grinding, a laser machining, an electro-discharge machining, a dry etching and a wet etching.

10. The chemical mechanical polishing conditioner according to claim 1, further comprising a bonding layer provided between said substrate and said abrasive unit.

11. The chemical mechanical polishing conditioner according to claim 10, wherein the material of said bonding layer is selected from the group consisting of a ceramic material, a brazing material, an electroplating material, an metal material and a polymer material.

12. The chemical mechanical polishing conditioner according to claim 11, wherein said brazing material is selected from the group consisting of Fe, Co, Ni, Cr, Mn, Si and Al.

13. The chemical mechanical polishing conditioner according to claim 11, wherein said polymer material is selected from the group consisting of epoxy resin, polyester resin, polyacrylate resin and phenolic resin.

14. A fabrication method of chemical mechanical polishing conditioner, comprising the steps of

step S1: providing a supporting layer having a working face and a non-working face opposite to said working face;

step S2: providing an abrasive layer and a stress-relief layer on said working face and said non-working face of said supporting layer, respectively, to form an abrasive unit by chemical vapor deposition method, said abrasive layer and said stress-relief layer being a first diamond-plated film and a second diamond-plated film, respectively, said first diamond-plated film being provided with a plurality of abrasive tips; and

step S3: bonding said abrasive unit to a substrate.

15. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein in step S2, said abrasive layer is firstly formed on said working face of said supporting layer, and said stress-relief layer is then formed on said non-working face of said supporting layer.

16. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein in step S2, a plurality of projecting tips are firstly formed on said working face of said supporting layer through a machining process, and said abrasive layer is then formed on said working face, such that said first diamond-plated film is provided with said abrasive tips corresponding to said projecting tips.

17. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein in step S2, said abrasive layer is provided on said working face of said supporting layer, and said abrasive tips are formed on said first diamond-plated film through a machining process.

18. The fabrication method of chemical mechanical polishing conditioner according to claim 17, wherein said machining process is selected from the group consisting of a grinding, a laser machining, an electro-discharge machining, a dry etching and a wet etching.

19. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein said substrate is provided with at least one recessed portion for accommodating said abrasive unit

20. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein said substrate is provided with at least one through-hole for accommodating said abrasive unit.

21. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein said substrate is a plane substrate.

22. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein said substrate is selected from the group consisting of a stainless steel substrate, a die steel substrate, a metal alloy substrate, a ceramic substrate and a polymer substrate.

23. The fabrication method of chemical mechanical polishing conditioner according to claim 14, wherein the material of said supporting layer is silicon or silicon carbide.