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:
Jul. 16, 1996
Filed:
Dec. 20, 1994
Applicant:
Inventors:
Takashi Tsuchiya, Urawa, JP;
Masami Watase, Kawasaki, JP;
Katsuya Okumura, Poughkeepsie, NY (US);
Toru Watanabe, Hopewell Junction, NY (US);
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
G03F / ;
U.S. Cl.
CPC ...
430-5 ; 430323 ; 430324 ; 216 12 ; 216 48 ; 216 47 ;
Abstract
A photoresist pattern is formed on a quartz substrate. The quartz substrate is dipped into a silicon oxide supersaturated solution of hydrofluoric acid, and a silicon oxide is precipitated out of the supersaturated solution, thereby forming an SiO.sub.2 film on that exposed surface of the quartz substrate which is not covered with the photoresist pattern. After that, the photoresist pattern is ashed by oxygen plasma, and the ashed pattern is removed. The SiO.sub.2 film remaining on the quartz substrate serves as a phase shifter.