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:
Dec. 24, 1996
Filed:
Mar. 15, 1994
Giovanni Campardo, Bergamo, IT;
Giuseppe Crisenza, Trezzo Sull'Adda, IT;
Marco Dallabora, Melegnano, IT;
SGS-Thomson Microelectronics S.r.l., Agrate Brianza, IT;
Abstract
To reduce read and write errors caused by depleted memory array cells being turned on even when not selected, the nonselected memory cells are so biased as to present a floating terminal and a terminal at a positive voltage with respect to the substrate region. The threshold voltage of nonselected cells (i.e., the minimum voltage between the gate and source terminals for the cell to be turned on) increases due to a 'body effect', whereby the threshold voltage depends on the voltage drop between the source terminal and the substrate. The source line of a selected cell is biased to a positive value greater than that of the bit line of the selected cell. Methods for reading, writing and erasing cells using certain voltage levels are disclosed.