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:
Apr. 02, 1996
Filed:
Dec. 23, 1993
Toshiro Nakanishi, Kawasaki, JP;
Yasuhisa Sato, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method of forming a non-volatile semiconductor memory device includes the steps of forming a generally periodical undulation on a surface of a silicon substrate with a pitch of 1-20 nm, by cleaning the surface of the substrate by a cleaning solution to form a native silicon oxide film that covers the surface of the silicon substrate with a thickness that changes generally periodically, followed by a selective etching process applied to the native silicon oxide film thus formed to expose the surface of the silicon substrate, and forming a tunneling oxide film on the undulated surface of the substrate by applying a thermal oxidation such that the tunneling oxide film has a thickness that changes generally periodically with a pitch of 1-20 nm.