IP Library › Granted Patent US 11,466,206
Granted Patent B2
US 11,466,206 · App. 16/781,013 · Granted Oct 11, 2022

Silicon etching solution and method for producing silicon device using the etching solution

Inventors: Yoshiki Seike (Yamaguchi, JP); Seiji Tono (Yamaguchi, JP); Kenji Kobayashi (Kyoto, JP); Sei Negoro (Kyoto, JP)
Assignees: Tokuyama Corporation; SCREEN Holdings Co., Ltd.
C09K13/00H01L21/30604H01L21/32134
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Quick Facts
Patent No.
US 11,466,206
App. No.
16/781,013
Granted
Oct 11, 2022
Kind
B2
Abstract

A silicon etching solution includes a mixed solution comprising a quaternary alkylammonium hydroxide and water and further comprises a compound represented by the following formula (1): R 1 O—(C m H 2m O) n —R 2   (1) wherein R 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m is an integer of 2 to 6, and n is 1 or 2.

Claims (24)

1. A silicon etching solution that is a mixed solution consisting essentially of a quaternary alkylammonium hydroxide, water and a compound represented by the following formula (1):

R 1 O—(C m H 2m O) n —R 2   (1)

wherein R 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 2 is an alkyl group having 1 to 6 carbon atoms, m is an integer of 2 to 6, and n is 1 or 2,

wherein a concentration of the quaternary alkylammonium hydroxide is 0.05 to 10 mass %, and a concentration of the compound represented by the formula (1) is 0.1 to 3 mass %.

2. The silicon etching solution according to claim 1 , wherein the quaternary alkylammonium hydroxide is tetramethyl ammonium hydroxide.

3. The silicon etching solution according to claim 1 , wherein the compound represented by formula (1) is ethylene glycol monopropyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, or dipropylene glycol dimethyl ether.

4. An etching method, comprising:

providing the silicon etching solution according to claim 1 ; and

etching a silicon wafer, a polysilicon film or an amorphous silicon film with said silicon etching solution irrespective of a dissolved oxygen concentration in said silicon etching solution.

5. An etching method, comprising:

providing the silicon etching solution according to claim 1 ; and

etching a silicon wafer, a polysilicon film or an amorphous silicon film with said silicon etching solution to thereby lowering an etching rate ratio which is a ratio (R N /R A ) of an etching rate (R N ) in which a silicon etching solution is degassed of dissolved oxygen to an etching rate (N A ) in which a silicon etching solution is saturated with dissolved oxygen.

6. A method for producing a silicon device, comprising:

providing the silicon etching solution according to claim 1 ; and

etching a silicon wafer, a polysilicon film or an amorphous silicon film with said silicon etching solution.

7. A silicon etching solution that is a mixed solution comprising a quaternary alkylammonium hydroxide, water and a compound represented by the following formula (1):

R 1 O—(C m H 2m O) n —R 2   (1)

wherein R 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 2 is an alkyl group having 1 to 6 carbon atoms, m is an integer of 2 to 6, and n is 1 or 2,

wherein a concentration of the quaternary alkylammonium hydroxide is 0.05 to 10 mass %, and a concentration of the compound represented by the formula (1) is 0.1 to 3 mass %, and

wherein the etching solution does not contain a surfactant.

8. A silicon etching solution that is a mixed solution consisting of a quaternary alkylammonium hydroxide, water and a compound represented by the following formula (1):

R 1 O—(C m H 2m O) n —R 2   (1)

wherein R 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 2 is an alkyl group having 1 to 6 carbon atoms, m is an integer of 2 to 6, and n is 1 or 2,

wherein a concentration of the quaternary alkylammonium hydroxide is 0.05 to 10 mass %, and a concentration of the compound represented by the formula (1) is 0.1 to 3 mass %.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 4, 2020
From: SEIKE, YOSHIKI; TONO, SEIJI
To: TOKUYAMA CORPORATION; SCREEN HOLDINGS CO., LTD.
Reel/Frame 051707/0952 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 4, 2020
From: KOBAYASHI, KENJI; NEGORO, SEI
To: TOKUYAMA CORPORATION; SCREEN HOLDINGS CO., LTD.
Reel/Frame 051708/0020 →
Priority Claims (2)
JP JP2019-019215 · Feb 5, 2019 · national
JP JP2019-221269 · Dec 6, 2019 · national
Continuity (1)
Related Publication 20200248076A1 · Aug 6, 2020