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. 28, 1996
Filed:
Dec. 22, 1994
Kazuyoshi Ueno, Tokyo, JP;
Tetsuya Homma, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The semiconductor device has a multilayer structure wherein a substantially pure silicon dioxide film containing substantially no fluorine atom and a silicon dioxide film containing fluorine atoms are sequentially laminated on a substrate. Etching rate of a silicon dioxide film depends on a fluorine concentration in the film, so that a suitable etch selectivity of the silicon dioxide film containing fluorine atoms from the substantially pure silicon dioxide film can be obtained to form an oxide trench used for a trench interconnection and a via-hole used for a via-plug. The oxide film containing fluorine atoms has as good a quality as the silicon dioxide film not containing impurities has, thereby obtaining a superior characteristic of the semiconductor device. Addition of fluorine atoms reduces a specific permittivity to thereby obtain a higher speed.