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:
Dec. 03, 2002
Filed:
Mar. 11, 1999
Hiromi Makimoto, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
There is described a method for manufacturing a semiconductor device, in which an isolation oxide film having a superior dimensional accuracy and an isolation oxide film of a high withstanding voltage are manufactured in simple processes. A semiconductor device including a plurality of isolation oxide films of different thickness is manufactured. A nitride film and a resist film are grown on a silicon substrate, and openings are formed in the resist film. Openings are formed in the nitride film while the resist film is used as a mask. Isolation oxide films are formed below the openings through thermal oxidation. An opening diameter of the large opening formed in the nitride film is set to a value of more than 0.6 &mgr;m, whereas an opening diameter of the smaller opening is set a predetermined value of less than 0.6 &mgr;m. More specifically, the removal value of the smaller opening is set to a value required for imparting a desired thickness to the isolation oxide film