Polishing method, polishing agent and cleaning agent for polishing

Patent metadata

Field	Value
Publication number	US-2021299814-A1
Application number	US-202017010729-A
Country	US
Kind code	A1
Filing date	Sep 2, 2020
Priority date	Mar 24, 2020
Publication date	Sep 30, 2021
Grant date	—

Abstract

According to one embodiment, a polishing method includes supplying a polishing agent to be between a polishing pad and to-be-polished surface, then polishing the to-be-polished surface with the polishing agent while rotating at least one of the to-be-polished surface and the polishing pad. The polishing agent includes abrasive grains and an organic polymer. The organic polymer makes a reversible phase transition between a gel state and a sol state depending on temperature.

First claim

What is claimed is:

1 . A polishing method, comprising:
supplying a polishing agent to be between a to-be-polished surface and a polishing cloth; and polishing the to-be-polished surface with the polishing agent while rotating at least one of the to-be-polished surface and the polishing cloth, wherein the polishing agent comprises abrasive grains and an organic polymer which makes a reversible phase transition between a gel state and a sol state depending on a temperature.

2 . The polishing method according to claim 1 , wherein
the polishing of the to-be-polished surface includes a first polishing stage in which the temperature of the polishing cloth is higher than the temperature of the polishing agent at time of the supplying, and the viscosity of the organic polymer in the first polishing stage is higher than the viscosity of the organic polymer at time of the supplying.

3 . The polishing method according to claim 2 , wherein
the polishing of the to-be-polished surface further includes a second polishing stage in which the temperature of the polishing cloth is lower than that in the first polishing stage, and the viscosity of the organic polymer in the second polishing stage is lower than the viscosity of the organic polymer in the first polishing stage.

4 . The polishing method according to claim 3 , wherein a shear rate applied to the organic polymer in the second polishing stage is higher than that in the first polishing stage.

5 . The polishing method according to claim 2 , wherein
the polishing of the to-be-polished surface further includes a second polishing stage in which a shear rate applied to the organic polymer is higher than that in the first polishing stage, and the viscosity of the organic polymer in the second polishing stage is lower than the viscosity of the organic polymer in the first polishing stage.

6 . The polishing method according to claim 1 , wherein the organic polymer comprises an alkyl cellulose.

7 . The polishing method according to claim 1 , wherein the organic polymer is a thermoresponsive polymer which is in a sol state at a temperature of not higher than a lower critical solution temperature and which makes a phase transition to a gel state when heated to a temperature exceeding the lower critical solution temperature.

8 . The polishing method according to claim 7 , wherein
in the supplying of the polishing agent, the temperature of the polishing agent is not higher than the lower critical solution temperature, and the polishing of the to-be-polished surface includes a first polishing stage, in which the temperature of the polishing cloth is higher than the lower critical solution temperature, and a second polishing stage, in which the temperature of the polishing cloth is not higher than the lower critical solution temperature.

9 . The polishing method according to claim 7 , further comprising:
discharging the polishing agent from the polishing cloth, wherein in the discharging of the polishing agent, the temperature of the polishing cloth is not higher than the lower critical solution temperature.

10 . The polishing method according to claim 1 , wherein the organic polymer is a thermoresponsive polymer which is in a sol state at a temperature exceeding an upper critical solution temperature and which makes a phase transition to a gel state when cooled to a temperature of not higher than the upper critical solution temperature.

11 . The polishing method according to claim 10 , wherein
in the supplying of the polishing agent, the temperature of the polishing agent exceeds the upper critical solution temperature, and the polishing of the to-be-polished surface includes a first polishing stage, in which the temperature of the polishing cloth is not higher than the upper critical solution temperature, and a second polishing stage, in which the temperature of the polishing cloth is higher than the upper critical solution temperature.

12 . The polishing method according to claim 10 , further comprising:
discharging the polishing agent from the polishing cloth, wherein in the discharging of the polishing agent, the temperature of the polishing cloth exceeds the upper critical solution temperature.

13 . The polishing method according to claim 7 , further comprising:
cleaning the polishing cloth with a cleaning agent, wherein the cleaning of the polishing cloth includes a supplying stage of the cleaning agent in which the temperature of the cleaning agent is at a temperature at which the cleaning agent is kept in a sol state, and a cleaning stage in which the cleaning agent is at a temperature at which the cleaning agent transitions to a gel state.

14 . A polishing agent, comprising:
a solvent; abrasive grains dispersed in the solvent; and an organic polymer which makes a reversible phase transition between a gel state and a sol state depending on a temperature.

15 . The polishing agent according to claim 14 , wherein the organic polymer comprises an alkyl cellulose.

16 . The polishing agent according to claim 14 , wherein the organic polymer is in a sol state at a temperature of not higher than a lower critical solution temperature, and is in a gel state at a temperature exceeding the lower critical solution temperature.

17 . The polishing agent according to claim 14 , wherein the organic polymer is in a sol state at a temperature exceeding an upper critical solution temperature, and is in a gel state at a temperature of not higher than the upper critical solution temperature.

18 . The polishing agent according to claim 14 , wherein the solvent is water.

19 . A cleaning agent for polishing processes, the cleaning agent comprising:
a polymer comprising a first monomer having a moiety which makes a reversible phase transition between a gel state and a sol state depending on a temperature and a second monomer having a moiety which chelates a metal ion.

Assignees

• Kioxia Corp

Inventors

• Sakashita Mikiya
• Kataoka Yumiko
• Matsui Yukiteru

Classifications

• B24B37/005

  Control means for lapping machines or devices · CPC title

• B24B37/015 Primary

  Temperature control · CPC title

• C09G1/02

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

• C08L1/08

  Cellulose derivatives · CPC title

• B24B37/013

  Devices or means for detecting lapping completion · CPC title