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:
Jul. 05, 1994
Filed:
Feb. 19, 1993
Kenichi Oyama, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The invention provides a method of erasure for a non-volatile semiconductor memory device having a floating gate. For a first time interval, a voltage having one polarity is applied to a control gate of said memory device under a bias application between source and drain regions so as to accomplish an erasure by a tunneling of electrons from said floating gate through a tunneling oxide film. For a second time interval after said first time interval, a voltage having an opposite polarity to said one polarity is applied to said control gate of said memory device without bias application between said source and drain regions so as to accomplish a convergence of a threshold voltage into a voltage level by a tunneling of electrons from a channel region of said memory device to said floating gate through said tunneling oxide film.