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:
Feb. 04, 1997
Filed:
Jun. 01, 1995
Kenji Hakozaki, Tenri, JP;
Shin-ichi Sato, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
According to the present invention, a method for producing a nonvolatile semiconductor memory device is provided. The method includes the steps of: forming stripe-shaped silicon portions including a plurality of first portions to be used as a plurality of floating gates and a plurality of second portions interposed between two adjacent portions of the plurality of first portions by patterning a silicon film; forming a conductive film so as to cover an insulating film; forming a control gate so as to cover the plurality of first portions of the stripe-shaped silicon portions by patterning the conductive film; converting the plurality of second portions of the stripe-shaped silicon portions into a silicon oxide film, and forming the plurality of floating gates from the plurality of first portions by thermally oxidizing the plurality of second portions; and implanting impurity ions through the silicon oxide film into the active region on the semiconductor substrate by using the control gate as a mask, thereby forming a source region and a drain region in the active region.