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:
Aug. 28, 2001
Filed:
Apr. 21, 1997
Satoru Sugiyama, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An interlayer insulator film in a semiconductor device comprises a BPSG film formed to cover a circuit pattern formed on a semiconductor substrate, and a ladder structure SOG film having a ladder structure in a molecular structure, to cover the BPSG film. The ladder structure SOG /film is etched back by a dry etching to partially expose the BPSG film, /and an exposed portion of the BPSG film is selectively etched by a wet /etching of a buffered HF using the remaining SOG film as a mask, since a /selective etching ratio by the buffered HF between the ladder structure /SOG film and the BPSG film is large. Thus, a planarized interlayer /insulator film formed of the remaining BPSG film and the remaining /ladder structure SOG film is obtained.