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:
Jan. 13, 2015
Filed:
Apr. 18, 2013
Applicant:
Sandisk Technologies Inc., Plano, TX (US);
Inventors:
Assignee:
SanDisk Technologies, Inc., Plano, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 21/28 (2006.01); H01L 27/115 (2006.01); H01L 29/788 (2006.01); H01L 29/66 (2006.01);
U.S. Cl.
CPC ...
H01L 29/788 (2013.01); H01L 29/66825 (2013.01); H01L 27/11524 (2013.01); H01L 27/11541 (2013.01);
Abstract
A NAND flash memory chip is formed by depositing two N-type polysilicon layers. The upper N-type polysilicon layer is then replaced with P-type polysilicon and barrier layer in the array area only, while maintaining the upper N-type polysilicon layer in the periphery. In this way, floating gates are substantially P-type while gates of peripheral transistors are N-type.