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.

Date of Patent:
Sep. 29, 2020

Filed:

Jul. 31, 2019
Applicant:

Sandisk Technologies Llc, Addison, TX (US);

Inventors:

Hong-Yan Chen, San Jose, CA (US);

Wei Zhao, Fremont, CA (US);

Assignee:

SanDisk Technologies LLC, Addison, TX (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C 11/22 (2006.01); G11C 11/406 (2006.01);
U.S. Cl.
CPC ...
G11C 11/2297 (2013.01); G11C 11/2255 (2013.01); G11C 11/2257 (2013.01); G11C 11/2273 (2013.01); G11C 11/40626 (2013.01);
Abstract

Techniques are described for maintaining a pre-charge voltage in a NAND string in a program operation. After a pre-charge voltage is applied to the channel of a NAND string, the word line voltages are controlled to avoid a large channel gradient which generates electron-hole pairs, where the electrons can pull down the channel boosting level on the drain side of the selected word line. In one approach, the word line voltages of a group of one or more source side word lines adjacent to the selected word line are increased directly from the level used during pre-charge to a pass voltage. The word line voltages of other source side word lines, and of drain side word lines, can be decreased and then increased to the pass voltage to provide a large voltage swing which couples up the channel.


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