The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 11, 2025
Filed:
Jul. 29, 2021
Tokuyama Corporation, Yamaguchi, JP;
TOKUYAMA CORPORATION, Yamaguchi, JP;
Abstract
A silicon etching liquid which is characterized by containing a quaternary ammonium hydroxide represented by formula (1), a quaternary ammonium salt represented by formula (2) and water, and which is also characterized in that the concentration of the quaternary ammonium salt represented by formula (2) is more than 1% by mass but not more than 50% by mass. (1): RRRRN·OH(In formula (1), R, R, Rand Rmay be the same groups or different groups, and each represents an optionally substituted alkyl group, aryl group or a benzyl group.) (2): RRRRN·X(In formula (2), R, R, Rand Rmay be the same groups or different groups, and each represents an optionally substituted alkyl group having from 1 to 16 carbon atoms; and X represents BF, a fluorine atom, a chlorine atom or a bromine atom.)