Dresser for polishing cloth and manufacturing method therefor

Details Dresser for polishing cloth and manufacturing method therefor Dresser for polishing cloth and manufacturing method therefor

2000-07-10

2001-09-25

Banks, Derris H. (Department: 3723)

Abrading

Abrading process

With tool treating or forming

C451S443000, C451S548000

Reexamination Certificate

active

06293854

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a dresser for a polishing cloth used for removing clogging or foreign material in a step of Chemical and Mechanical Polishing (hereinafter referred to as CMP) and to a manufacturing method therefor.
DESCRIPTION OF RELATED ART
In steps of manufacturing highly integrated electronic circuits such as integrated circuits, CMP processing is generally used to remove surface defects such as protrusions, crystal lattice defects, scoring, or roughness on a conductive layer, a dielectric layer or an insulation layer formed on a substrate or wafer. In CMP processing, a wafer is pressed on an abrasive cloth made of polyurethane foam or the like by a predetermined load, adhered to a disk surface plate, and the wafer is polished by rotating both the wafer and the cloth with an abrasive fluid called a chemical slurry. A preparation in which abrasive particles such as iron oxide, barium carbonate, cerium oxide, or colloidal silica are suspended in an abrasive fluid such as potassium hydroxide, dilute hydrochloric acid, aqueous hydrogen peroxide, or iron nitrate, is used as the chemical slurry, and this produces a higher polishing rate and high selectivity for each layer.
CMP is performed many times in steps for stacking various kinds of electronic circuits. When the number of CMPs is increased, particles or polishing dust burrows into minute cracks, causing clogging, and this reduces the polishing rate. Accordingly, operations called dressing, by which the surface of the polishing cloth is replaced to restore the polishing speed, are required to be executed often or regularly. For this operation, an instrument called a dresser for a CMP polishing cloth is used.
Since diamond grit is an excellent dressing material, a dresser for CMP polishing cloth employing diamond grit is discussed. For example, a method of electrodepositing the diamond grit on stainless steel by nickel plating has been proposed. Also, in Japanese Unexamined Patent Application Publication No. 10-12579, a method of brazing the diamond grit on the stainless steel by a metallic-brazing material has been proposed.
However, the nickel plating material or the metallic-brazing material is dissolved by strongly acidic chemical slurry, and the slurry is contaminated and the diamond grit is peeled, potentially causing scoring on the surface of the wafer.
Therefore, a dresser for CMP abrasive cloth in which dissolution of metal or peeling-off of diamond grit might not occur in CMP is anticipated.
SUMMARY OF THE INVENTION
The present invention was made to solve the above problem. The technical challenge thereof is to provide a dresser for CMP polishing cloth and a manufacturing method therefor in which bonding material for holding the diamond grit will not be attacked by the strongly acid chemical slurry, causing contamination of the slurry by metallic dissolution or peeling off of the diamond grit CMP processing for the highly integrated electronic component such as an integrated circuit.
It is another challenge to provide the dresser for polishing and a manufacturing method therefor which is obtained by simple means and in which the bonding material will not be dissolved by the chemical slurry.
To solve the above challenges, the first dresser for the polishing cloth according to the present invention is characterized in that the dresser face comprises a sintered product obtained by mixing a bonding member comprising a silicon and/or silicon alloy with the diamond grit, and forming and sintering the mixture, the surface of the diamond grit being provided with a carbide film generated by sintering silicon in the bonding material into the diamond, whereby the diamond grit is firmly bonded with the bonding material.
The second dresser polishing cloth according to the present invention is characterized in that the dresser face comprises a sintered product obtained by mixing the bonding member comprising a silicon and/or silicon alloy with the diamond grit coated with a carbide film of a metal in group IV, V or VI of the periodic table, and forming and sintering the mixture, the diamond grit being firmly bonded to the carbide film in the sintered product.
In the dresser for a polishing cloth, the sintered product is adhered on the surface of a pedestal, the product is finished into specified size, and the diamond grit is exposed by planarizing and dressing on the dressing surface.
On the other hand, the manufacturing method of the first dresser for an abrasive cloth according to the present invention is characterized in that a carbide film is produced on the surface of the diamond grit by sintering the diamond into the silicon in the bonding member, by mixing the bonding material comprising the silicon or the silicon alloy with the diamond grit, the mixture being formed and sintered, and in that the sintered product for dressing, in which the diamond grit is firmly bonded with the bonding material, is obtained.
Furthermore, the manufacturing method for the second dresser for abrasive cloth according to the present invention is characterized in that silicon and/or silicon alloy is mixed with diamond grit coated with carbide film of metal in group IV, V, or VI in the periodic table, and forming and sintering the mixture, thereby yielding the sintered product for dressing in which said diamond is firmly bonded with the bonding member by the carbide film.
According to the dresser for abrasive cloth and the manufacturing method therefor, in CMP processing of highly integrated electronic circuit material such as integrated circuits, the bonding material comprising silicon and/or silicon alloy has excellent acid-resistance in acidic solutions such as nitric acid. As a result, polishing fluid is not contaminated, and this simplifies the wafer cleaning step after CMP.
Furthermore, according to the present invention, the dresser for abrasive cloth and the manufacturing method in which the bonding material will not be dissolved by the chemical slurry, is obtained by simple means.


REFERENCES:
patent: 5921856 (1999-07-01), Zimmer
patent: 5989405 (1999-11-01), Murata et al.
patent: 10-012579 (1998-01-01), None

Affiliated with

Also associated with

Rating

Dresser for polishing cloth and manufacturing method therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Dresser for polishing cloth and manufacturing method therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dresser for polishing cloth and manufacturing method therefor will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2437978