US 12,269,980 B2
Silicon etching solution and method for producing silicon device using the etching solution
Yoshiki Seike, Yamaguchi (JP); Seiji Tono, Yamaguchi (JP); Kenji Kobayashi, Kyoto (JP); and Sei Negoro, Kyoto (JP)
Assigned to Tokuyama Corporation, Yamaguchi (JP); and SCREEN Holdings Co., Ltd., Kyoto (JP)
Filed by Tokuyama Corporation, Yamaguchi (JP); and SCREEN Holdings Co., Ltd., Kyoto (JP)
Filed on Aug. 23, 2022, as Appl. No. 17/821,490.
Application 17/821,490 is a continuation of application No. 16/781,013, filed on Feb. 4, 2020, granted, now 11,466,206.
Claims priority of application No. 2019-019215 (JP), filed on Feb. 5, 2019; and application No. 2019-221269 (JP), filed on Dec. 6, 2019.
Prior Publication US 2022/0403242 A1, Dec. 22, 2022
Int. Cl. C09K 13/00 (2006.01); H01L 21/306 (2006.01); H01L 21/3213 (2006.01)
CPC C09K 13/00 (2013.01) [H01L 21/30604 (2013.01); H01L 21/32134 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A silicon etching solution that is a mixed solution consisting essentially of a quaternary alkylammonium hydroxide and water, and 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 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 3 to 10 mass %, and a concentration of the compound represented by formula (1) is 3 to 20 mass %.