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. 02, 2004
Filed:
Dec. 31, 2002
Jun Ohtani, Hyogo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
In a non-volatile semiconductor memory device, three word line voltage circuits generating different voltages are provided. A voltage selecting circuit pre-selecting one voltage from the three different voltages is provided. In an ONO film in which lower silicon oxide film is formed thinner than upper silicon oxide film, word line voltage generating circuit is pre-selected, and in a write operation a voltage of 7V lower than the normal voltage of 9V is applied. In ONO film in which upper silicon oxide film is formed thinner than lower silicon oxide film, word line voltage generating circuit is pre-selected, and in a write operation a voltage of 11V higher than the normal voltage of 9V is applied. Thus, the non-volatile semiconductor memory device capable of retaining charges as information stably is attained.