Polishing slurry for silicon, method of polishing polysilicon and method of manufacturing a thin film transistor substrate

Patent metadata

Field	Value
Publication number	US-2017145259-A1
Application number	US-201615355917-A
Country	US
Kind code	A1
Filing date	Nov 18, 2016
Priority date	Nov 20, 2015
Publication date	May 25, 2017
Grant date	—

Abstract

A polishing slurry for silicon, a method of polishing polysilicon, and a method of manufacturing a thin film transistor substrate, the slurry including a polishing particle; a dispersing agent including an anionic polymer, a hydroxyl acid, or an amino acid; a stabilizing agent including an organic acid, the organic acid including a carboxyl group; a hydrophilic agent including a hydrophilic group and a hydrophobic group, and water, wherein the polishing particle is included in the polishing slurry in an amount of about 0.1% by weight to about 10% by weight, based on a total weight of the slurry, a weight ratio of the polishing particle and the dispersing agent is about 1:0.01 to about 1:0.2, a weight ratio of the polishing particle and the stabilizing agent is about 1:0.001 to about 1:0.1, and a weight ratio of the polishing particle and the hydrophilic agent is about 1:0.01 to about 1:3.

First claim

What is claimed is:

1 . A polishing slurry for silicon, the polishing slurry comprising:
a polishing particle; a dispersing agent including at least one selected from the group consisting of an anionic polymer, a hydroxyl acid, and an amino acid; a stabilizing agent including an organic acid, the organic acid including a carboxyl group; a hydrophilic agent including a hydrophilic group and a hydrophobic group, and water, wherein:
the polishing particle is included in the polishing slurry in an amount of about 0.1% by weight to about 10% by weight, based on a total weight of the polishing slurry,
a weight ratio of the polishing particle and the dispersing agent is about 1:0.01 to about 1:0.2,
a weight ratio of the polishing particle and the stabilizing agent is about 1:0.001 to about 1:0.1, and
a weight ratio of the polishing particle and the hydrophilic agent is about 1:0.01 to about 1:3.

2 . The polishing slurry for silicon as claimed in claim 1 , wherein the polishing particle includes at least one selected from the group consisting of silica, alumina, ceria, zirconia, and titania.

3 . The polishing slurry for silicon as claimed in claim 1 , wherein an average particle size of the polishing particle is about 6 nm to about 350 nm.

4 . The polishing slurry for silicon as claimed in claim 1 , wherein the anionic polymer includes at least one selected from the group consisting of polysulfonic acid, polyacrylic acid, polymethacrylic acid, a copolymer thereof, and a salt thereof.

5 . The polishing slurry for silicon as claimed in claim 1 , wherein:
the hydrophilic agent includes an anionic hydrophilic agent or a non-ionic hydrophilic agent, the anionic hydrophilic agent includes at least one selected from the group consisting of a stearate, a sulfonate, a sulfate, and a phosphate, and the non-ionic hydrophilic agent includes at least one selected from the group consisting of polyethylene glycol, hydroxylethyl cellulose, polyvinylpyrrolidone, polyethylene amine, and a salt thereof.

6 . The polishing slurry for silicon as claimed in claim 1 , wherein:
the hydrophilic agent includes at least one selected from the group consisting of an alkylbenzene sulfonate, an alkylsulfate, and an alkylether sulfate, and a weight ratio of the polishing particle and the hydrophilic agent is about 1:0.01 to about 1:1.

7 . The polishing slurry for silicon as claimed in claim 1 , wherein the stabilizing agent includes at least one selected from the group consisting of formic acid, acetic acid, butyric acid, oxalic acid, lactic acid, and citric acid.

8 . The polishing slurry for silicon as claimed in claim 1 , wherein a pH of the polishing slurry is about 9 to about 11.

9 . A method of polishing polysilicon, the method comprising:
forming an amorphous silicon film; irradiating a laser to the amorphous silicon film to form a polysilicon film; and polishing the polysilicon film with a polishing slurry, wherein the polishing slurry includes:
a polishing particle,
a dispersing agent including at least one selected from the group consisting of an anionic polymer, a hydroxyl acid, and an amino acid,
a stabilizing agent including an organic acid, the organic acid including a carboxyl group,
a hydrophilic agent including a hydrophilic group and a hydrophobic group, and
water,
wherein:
the polishing particle is included in the polishing slurry in an amount of about 0.1% by weight to about 10% by weight, based on a total weight of the polishing slurry,
a weight ratio of the polishing particle and the dispersing agent is about 1:0.01 to about 1:0.2,
a weight ratio of the polishing particle and the stabilizing agent is about 1:0.001 to about 1:0.1, and
a weight ratio of the polishing particle and the hydrophilic agent is about 1:0.01 to about 1:3.

10 . The method as claimed in claim 9 , wherein a grain size of the polysilicon film is about 300 nm to about 320 nm.

11 . The method as claimed in claim 9 , further comprising polishing the polysilicon film with deionized water after polishing the polysilicon film with the polishing slurry.

12 . The method as claimed in claim 9 , further comprising polishing the polysilicon film with a same material as the hydrophilic agent of the polishing slurry after polishing the polysilicon film with the polishing slurry.

13 . The method as claimed in claim 9 , wherein:
the anionic polymer includes at least one selected from the group consisting of polysulfonic acid, polyacrylic acid, polymethacrylic acid, a copolymer thereof, and a salt thereof, the hydrophilic agent includes at least one selected from the group consisting of an alkylbenzene sulfonate, an alkylsulfate, and an alkylether sulfate, and the stabilizing agent includes at least one selected from the group consisting of formic acid, acetic acid, butyric acid, oxalic acid, lactic acid, and citric acid.

14 . A method of manufacturing a thin film transistor substrate, the method comprising:
forming an amorphous silicon film on a base substrate; irradiating a laser to the amorphous silicon film to form a polysilicon film; polishing the polysilicon film with a polishing slurry, the polishing slurry including:
a polishing particle,
a dispersing agent including at least one selected from the group consisting of an anionic polymer, a hydroxyl acid, and an amino acid,
a stabilizing agent including an organic acid, the organic acid including a carboxyl group,
a hydrophilic agent including a hydrophilic group and a hydrophobic group, and
water,
wherein the polishing particle is included in the polishing slurry in an amount of about 0.1% by weight to about 10% by weight, based on a total weight of the polishing slurry, a weight ratio of the polishing particle and the dispersing agent is about 1:0.01 to about 1:0.2, a weight ratio of the polishing particle and the stabilizing agent is about 1:0.001 to about 1:0.1, and a weight ratio of the polishing particle and the hydrophilic agent is about 1:0.01 to about 1:3;
patterning the polysilicon film to form a polysilicon pattern; forming a first insulation layer that covers the polysilicon pattern; forming a gate metal layer on the first insulation layer; patterning the gate metal layer to form a gate electrode; and implanting an ion into a portion of the polysilicon pattern to form an active pattern including a source region, a channel region and a drain region.

15 . The method as claimed in claim 14 , wherein a thickness of the polysilicon film after polished is about 30 nm to about 50 nm.

16 . The method as claimed in claim 14 , wherein a root-mean-square roughness of the polysilicon film after polishing is less than about 1 nm.

17 . The method as claimed in claim 14 , wherein a grain size of the polysilicon film is about 300 nm to about 320 nm.

18 . The method as claimed in claim 14 , wherein a thickness of the first insulation layer is about 30 nm to about 80 nm.

19 . The method as claimed in claim 14 , further comprising polishing the polysilicon film with deionized water after polishing the polysilicon film with the polishing slurry.

20 . The method as claimed in claim 14 , further comprising polishing the polysilicon film with a same material as the hydrophilic agent of the polishing slurry after polishing the polysilicon film with the polishing slurry.

21 . The method as claimed in claim 14 , wherein:
the anionic polymer includes at least one selected from the group consisting of polysu

Assignees

• Samsung Display Co Ltd
• Ubmaterials Lnc

Inventors

• Choo Byoung-Kwon
• Park Jin-Hyung
• NA Jeong-Kyun
• Bae Joon-Hwa
• Cheong Byoung-Ho
• Cho Joo-Woan
• Hwang In-Sun

Classifications

• 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

• C09K3/1409

  Abrasive particles per se (preparation of diamond C01B32/25) · CPC title

• H01L21/02675

  Electricity · mapped topic

• H01L29/78675

  Electricity · mapped topic