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:
May. 12, 1992
Filed:
Feb. 20, 1991
Nobuatsu Watanabe, Nagaokakyo-shi, Kyoto, JP;
Yong-Bo Chong, Kyoto, JP;
Toshio Tatsuno, Osaka, JP;
Tomoyoshi Okada, Osaka, JP;
Akira Izumi, Kyoto, JP;
Keiji Toei, Kyoto, JP;
Abstract
In oxide film removing equipment for removing a SiO.sub.2 film on a semiconductor substrate by using hydrogen fluoride, a liquid mixture of hydrogen fluoride and methyl alcohol is prepared in a chemical factory beforehand. The liquid mixture of hydrogen fluoride and methyl alcohol is heated to generate azeotropic vapor at a semiconductor works and the vapor is used to remove the SiO.sub.2 film on the substrate. The liquid mixture of hydrogen fluoride and methyl alcohol previously prepared in the chemical factory increases safety during an operation at the semiconductor works.