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

Patent metadata

Field	Value
Publication number	US-11466206-B2
Application number	US-202016781013-A
Country	US
Kind code	B2
Filing date	Feb 4, 2020
Priority date	Feb 5, 2019
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

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):R1O—(CmH2mO)n—R2  (1)wherein R1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 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.

First claim

The invention claimed is:

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 %.

Assignees

• Tokuyama Corp
• Screen Holdings Co Ltd

Inventors

• Seike Yoshiki
• Tono Seiji
• Kobayashi Kenji
• Negoro Sei

Classifications

• H10P50/667

  by liquid etching only · CPC title

• H10P50/642

  Chemical etching · CPC title

• H10P50/644

  Anisotropic liquid etching (H10P50/61 takes precedence) · CPC title

• C09K13/00 Primary

  Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40}) · CPC title

• C30B33/10

  in solutions or melts · CPC title