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:
Jun. 07, 1994
Filed:
Oct. 20, 1992
Tokuhiko Tamaki, Osaka, JP;
Shinichi Imai, Osaka, JP;
Tadashi Kimura, Hyogo, JP;
Yoshimasa Inamoto, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The invention provides an improved dry etching method for selectively etching a silicon nitride layer 3 formed on the surface of a SiO.sub.2 layer 2 formed on a p-type semiconductor substrate, the method comprising the steps of supplying a mixed gas of HBr and ClF.sub.3 to a reaction chamber wherein SiBr.sub.4, caused, during the dry etching, by a reaction of the silicon nitride layer 3 and the HBr contained in the mixed gas, partly deposits on an etching wall of the p-type semiconductor substrate 1 while at the same time an excess of the SiBr.sub.4 reacts, between the p-type semiconductor substrate 1 and a wall of the reaction chamber, with the ClF.sub.3 contained in the mixed gas to produce a fluoride. The fluoride thus produced can be easily discharged to the outside, since it is more volatile.