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:
Apr. 07, 2015
Filed:
Sep. 27, 2011
Itzhak Edrei, Haifa, IL;
Yakov Roizin, Afula, IL;
Itzhak Edrei, Haifa, IL;
Yakov Roizin, Afula, IL;
Tower Semiconductor Ltd., Migdal Haemek, IL;
Abstract
Flash-to-ROM conversion is performed by converting single transistor flash memory cells to single transistor ROM cells. An S-Flash memory cell is converted to a programmed ROM cell by introducing a threshold voltage implant into the channel region of the S-Flash memory cell. Alternately, an S-Flash memory cell is converted to a programmed ROM cell by introducing a threshold voltage implant into a substrate region in alignment with an edge of the gate electrode of the S-Flash memory cell. The width of the mask through which this threshold voltage implant is performed can be varied, such that the threshold voltage implant region can have different dopant concentrations, thereby allowing multiple bits to be represented by the programmed ROM cell. In another embodiment, a Y-flash memory cell is converted to a programmed ROM cell by adjusting the length of a floating gate extension region of the Y-Flash memory cell.