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. 18, 2000
Filed:
Jul. 30, 1998
Junichi Kato, Osaka, JP;
Atsushi Hori, Osaka, JP;
Matsushita Electronics Corporation, Osaka, JP;
Abstract
A method for fabricating a nonvolatile semiconductor memory device according to the present invention includes the steps of: forming a first mask to define a channel of a memory cell in a semiconductor substrate; doping an impurity into the semiconductor substrate by using the first mask, thereby forming a first doped region in the semiconductor substrate; forming a second mask so as to overlap at least one of a first region of the semiconductor substrate where a source is to be formed and a second region of the semiconductor substrate where a drain is to be formed and at least part of the first mask; etching the semiconductor substrate by using the first and second masks, thereby forming a recessed portion in a region of the semiconductor substrate that is not covered with the first and second masks; forming a second doped region in the recessed portion of the semiconductor substrate; and removing the first and second masks, and forming a gate structure including a first insulating film, a floating gate electrode, a second insulating film and a control gate electrode at least over a side surface of the recessed portion and the channel defined by the first mask.