Polishing agent, polishing method, and liquid additive for polishing

Patent metadata

Field	Value
Publication number	US-10570314-B2
Application number	US-201715700480-A
Country	US
Kind code	B2
Filing date	Sep 11, 2017
Priority date	Sep 13, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

The present invention relates to a polishing agent including: metal oxide particles; an organic acid having a monodentate ligand; a nonionic polymer; and water, in which the polishing agent has a pH of from 3.0 to 7.0, and the nonionic polymer includes at least one selected from the group consisting of polyglycerin, polyoxyethylene polyglyceryl ether and polyoxypropylene polyglyceryl ether.

First claim

What is claimed is:

1. A polishing agent comprising:
cerium oxide particles;
an organic acid;
a nonionic polymer; and
water;
wherein:
the polishing agent optionally comprises an inorganic acid or a salt of the inorganic acid, and when the polishing agent comprises the inorganic acid or a salt of the inorganic acid, the inorganic acid is at least one selected from the group consisting of: nitric acid, sulfuric acid, and hydrochloric acid;
the polishing agent has a pH of from 3.0 to 7.0;
the organic acid consists of:
at least one selected from the group consisting of 2-hydroxyisobutyric acid, 2,2-bis(hydroxymethyl)propionic acid, and 2,2-bis(hydroxymethyl)butyric acid;
optionally, a monocarboxylic acid having a heterocycle;
optionally, a monocarboxylic acid having an amino group;
optionally, a monocarboxylic acid having 4 or more carbon atoms and having a hydroxyl group other than 2-hydroxyisobutyric acid, 2,2-bis(hydroxymethyl)propionic acid, or 2,2-bis(hydroxymethyl)butyric acid; and
optionally, a monocarboxylic acid having an amino group; and
the nonionic polymer comprises at least one selected from the group consisting of polyglycerin, polyoxyethylene polyglyceryl ether, and polyoxypropylene polyglyceryl ether.

2. The polishing agent according to claim 1 , wherein the monocarboxylic acid is contained in an amount of from 0.003 to 1.0 mass % based on a total mass of the polishing agent.

3. The polishing agent according to claim 1 , wherein the nonionic polymer is contained in an amount of from 0.0002 to 2.0 mass % based on a total mass of the polishing agent.

4. The polishing agent according to claim 1 , wherein the cerium oxide particles have an average secondary particle size of from 10 nm to 500 nm.

5. The polishing agent according to claim 1 , wherein the cerium oxide particles are contained in an amount of from 0.01 to 10.0 mass % based on a total mass of the polishing agent.

6. A polishing method comprising bringing a polishing pad into contact with a surface to be polished while supplying a polishing agent to perform polishing by relative movement therebetween,
wherein the surface to be polished including a surface comprising silicon oxide of a semiconductor substrate is polished using the polishing agent according to claim 1 as the polishing agent.

7. The polishing agent according to claim 1 , wherein the organic acid comprises the monocarboxylic acid having a heterocycle, and the heterocycle comprises nitrogen.

8. The polishing agent according to claim 1 , wherein the organic acid comprises the monocarboxylic acid having a heterocycle, and the heterocycle comprises a heteroatom other than nitrogen.

9. The polishing agent according to claim 1 , wherein the organic acid comprises the monocarboxylic acid having a heterocycle, and the monocarboxylic acid having a heterocycle is tetrahydrofuran-2-carboxylic acid.

10. The polishing agent according to claim 1 , wherein the organic acid comprises the monocarboxylic acid having 4 to 10 carbon atoms and having a hydroxyl group other than 2 -hydroxyisobutyric acid, 2,2-bis(hydroxymethyl)propionic acid, or 2,2-bis(hydroxymethyl)butyric acid.

11. The polishing agent according to claim 1 , wherein the nonionic polymer comprises at least one selected from the group consisting of polyglycerin and polyoxyethylene polyglyceryl ether.

12. The polishing agent according to claim 1 , wherein the nonionic polymer has a weight average molecular weight of 300 to 10,000.

13. The polishing agent according to claim 1 , wherein the nonionic polymer has a weight average molecular weight of 300 to 1,000.

14. A shallow trench isolation process, comprising applying the polishing agent of claim 1 to a surface comprising silicon oxide during chemical mechanical polishing.

15. The polishing agent according to claim 1 , wherein the organic acid comprises the monocarboxylic acid having an amino group, and the monocarboxylic acid having an amino group is N-acetylglycine.

Assignees

• Agc Inc

Inventors

• Kobayashi Genki

Classifications

• H10P95/062

  involving a dielectric removal step · CPC title

• H10P52/403

  of conductive or resistive materials · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• C08K5/09

  Carboxylic acids; Metal salts thereof; Anhydrides thereof · CPC title

• C09G1/16

  on natural or synthetic resins · CPC title