# US 10,478,939 B2 · Polishing method

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- Number: US 10,478,939 B2
- Document ID: US10478939B2
- Status: Granted
- Kind: B2
- Application number: 15/760,619
- Filed: 2016-09-21
- Published: 2018-09-13
- Granted: 2019-11-19
- Earliest claimed: 2015-09-30
- Assignees: Fujimi Incorporated
- Applicants: Fujimi Incorporated
- Inventors: Yukinobu Yoshizaki; Satoru Yarita; Shogo Onishi
- Web page: https://patentgrep.com/patent/US10478939B2

## CPC

- B24B 37/044: {characterised by the composition of the lapping agent}
- B24B 37/00: Lapping machines or devices; Accessories (B24B3/00 takes precedence)
- C09G 1/02: containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)}
- C09K 3/1436: {Composite particles, e.g. coated particles}
- C09K 3/1463: {Aqueous liquid suspensions}
- H10P 52/402: {of semiconductor materials}
- H10P 52/403: {of conductive or resistive materials}
- H10P 95/062: {involving a dielectric removal step}
- B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- C09G: POLISHING COMPOSITIONS (French polish C09F11/00); SKI WAXES
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

The present invention provides a means allowing achievement of sufficient planarization of the surface of an object to be polished containing two or more types of materials. The present invention is a polishing method for polishing an object to be polished containing two or more types of materials by using a polishing composition, the polishing method including equalization of the surface zeta potential of the object to be polished.

## Claims

### Claim 1

A polishing method for polishing an object to be polished containing tungsten and at least one of silicon oxide film and silicon nitride by using a polishing composition, the polishing method comprising
equalization of the surface zeta potential of said tungsten and at least one of said silicon oxide film and said silicon nitride,
wherein the equalization is carried out by including a potential equalizing agent having an adsorbing group for adsorption onto said tungsten and at least one of said silicon oxide film and said silicon nitride and a functional group for providing zeta potential in the polishing composition,
wherein the potential equalizing agent is dicyandiamide diethylenetriamine formalin condensate.

### Claim 2 (depends on 1)

The polishing method according to claim 1, wherein the polishing composition contains abrasive grains, and a surface of the abrasive grain is coated with a silane coupling agent or an ionic dispersant and is provided with zeta potential.

### Claim 3 (depends on 2)

The polishing method according to claim 2, wherein a maximum absolute value of a difference between the surface zeta potential after equalization of the surface zeta potential of said tungsten or at least one of said silicon oxide film and said silicon nitride and the surface zeta potential of the abrasive grains is 20 mV or more and 200 mV or less.

### Claim 4 (depends on 1)

A method for planarizing an object to be polished containing tungsten and at least one of silicon oxide film and silicon nitride by polishing the object to be polished using the polishing method set forth in claim 1 using a polishing composition in which the polishing composition contains a potential equalizing agent which has an adsorbing group for adsorption onto said tungsten and at least one of said silicon oxide film and said silicon nitride and a functional group for providing zeta potential.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the object to be polished contains tungsten and silicon oxide film, and the method comprises equalization of the surface zeta potential of the tungsten and the silicon oxide film.

### Claim 6

A polishing method for polishing an object to be polished containing tungsten and at least one of silicon oxide film and silicon nitride by using a polishing composition, the polishing method comprising
equalization of the surface zeta potential of said tungsten and at least one of said silicon oxide film and said silicon nitride,
wherein the equalization is carried out by impregnating the object to be polished in a potential equalizing agent having an adsorbing group for adsorption onto said tungsten and at least one of silicon oxide film and silicon nitride and a functional group for providing zeta potential,
wherein the potential equalizing agent is dicyandiamide diethylenetriamine formalin condensate.