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:
Mar. 18, 1997
Filed:
Jul. 18, 1995
Kazuo Itabashi, Kawasaki, JP;
Fujitsu Limited, , JP;
Abstract
The method for fabricating a semiconductor device comprising the steps of: forming a first oxide film 12 on a surface of a semiconductor substrate 10 and forming a first nitride film 14 on a surface of the first oxide film 12, the first nitride film 14 having a predetermined pattern; isotropically etching the first oxide film 12, with the first nitride film 14 as a mask, to partially expose the surface of the semiconductor substrate 10 and form a hollow 16 just under an end portion of the first nitride film 14; forming a second oxide film 18, thinner than the first oxide film 12, at least on the surface of the semiconductor substrate 10 exposed at the outside of the first nitride film 14 and on a inner surface of the hollow 16; depositing a second silicon nitride film 20 on at least the second oxide film 18, the second silicon nitride film 20 being more liable to oxidation than the first silicon nitride film 14; and oxidizing a region where the first silicon nitride film 14 is absent, with the first silicon nitride film 14 as a mask, to form a device isolation film 24. The second silicon nitride film 20 is formed of a silicon nitride film which is more liable to oxidation, so that when the device isolation film 24 is formed by oxidizing away the second silicon nitride film 20, thickness disuniformity can be decreased.