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:
Nov. 16, 2004
Filed:
May. 01, 2002
Naoki Tsuji, Hyogo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
In a non-volatile semiconductor memory device, three-layered structure of the first, second and third floating gate electrodes is implemented, and stepped portions are provided on the first interlayer insulating film surrounding the first floating gate electrode. The position of the bottom surface of the second floating gate electrode can be disposed higher than that of the upper surface of the first floating gate electrode. Consequently, compared with overlapping area of the floating gate electrode with a control gate electrode in a conventional non-volatile semiconductor device, it can be increased by the length of stepped portions on the first interlayer insulating film. Film thickness as floating gate electrode will not be as thick as conventional structures. Overlapping area of the floating gate electrode with the control gate electrode can be sufficiently secured without a portion with the maximum film thickness of floating gate electrode being larger.