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:
Jun. 07, 2016

Filed:

Jan. 21, 2015
Applicant:

Sandisk Technologies Inc., Plano, TX (US);

Inventors:

Hong-Yan Chen, Sunnyvale, CA (US);

Yingda Dong, San Jose, CA (US);

Wei Zhao, Fremont, CA (US);

Charles Kwong, Redwood City, CA (US);

Assignee:

SanDisk Technologies Inc., Plano, TX (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C 19/08 (2006.01); G11C 16/26 (2006.01); G11C 16/04 (2006.01);
U.S. Cl.
CPC ...
G11C 16/26 (2013.01); G11C 16/0483 (2013.01);
Abstract

Read disturb is reduced in a charge-trapping memory device such as a 3D memory device by optimizing the channel boosting voltage in an unselected NAND string. A pass voltage applied to the unselected word lines can cause a large gradient in the channel which leads to electron-hole formation and a hot electron injection (HEI) type of read disturb. When the selected word line is close to the source-side of the NAND string, HEI disturb occurs on the drain-side of the selected word line. To avoid this disturb, a spike is provided in the control gate voltage of a drain-side selected gate transistor to temporarily connect the channel to the bit line, lowering the voltage of the associated channel region. A similar approach is used for a drain-side selected word line. The spike may be omitted when the selected word line is mid-range.


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