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:
Sep. 28, 1999
Filed:
May. 06, 1998
Hitoshi Araki, Yokkaichi, JP;
Kazuo Hatakeyama, Tokyo-to, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
The non-volatile semiconductor device includes a sub control gate in addition to the conventional structure having a control gate and a floating gate. When writing or erasing is performed, by applying various to the control gate and the sub control gate, the potential of the floating gate which is capacitively connected to the control and sub control gates is determined. Accordingly, the floating gate voltage is maintained at lower control voltage compared to conventional one by selecting larger coupling ratio. The sub control gate covering a part where charge concentration apt to occur avoids charge concentration and deterioration of the tunnel oxide film.