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:
May. 17, 2016
Filed:
Feb. 09, 2015
Sandisk Technologies Inc., Plano, TX (US);
Yongke Sun, Pleasanton, CA (US);
Yingda Dong, San Jose, CA (US);
SanDisk Technologies Inc., Plano, TX (US);
Abstract
An erase operation for a memory cells in a block provides a consistent and sufficient erase depth regardless of the number of programmed word lines in the block. A lower erase-verify voltage is used for a first-programmed word line of a set of word lines than for remaining word lines in the set. As a result, the resistance of a memory cell of the first-programmed word line dominates during sensing of the NAND string so that the number of erase loops can be controlled in a predictable way regardless of the number of programmed word lines. The lower erase-verify voltage can be optimized so that it does not change the number of erase loops to complete an erase operation, compared to the case where a common erase-verify voltage is used on all word lines.