US 12,230,344 B2
Word line layer dependent stress and screen voltage
Yidan Liu, Shanghai (CN); Chao Xu, Shanghai (CN); and Liang Li, Shanghai (CN)
Assigned to Sandisk Technologies, Inc., Milpitas, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jul. 21, 2023, as Appl. No. 18/356,801.
Claims priority of provisional application 63/424,652, filed on Nov. 11, 2022.
Prior Publication US 2024/0161849 A1, May 16, 2024
Int. Cl. G11C 29/00 (2006.01); G11C 29/12 (2006.01)
CPC G11C 29/12005 (2013.01) [G11C 2029/1202 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a three-dimensional memory structure comprising layers of data word lines and NAND strings of non-volatile memory cells that extend through the layers of the data word lines, wherein each data word line is connected to a group of the non-volatile memory cells on different NAND strings; and
one or more control circuits in communication with the three-dimensional memory structure, wherein the one or more control circuits are configured to:
concurrently apply a set of test voltages to a corresponding set of the data word lines in the three-dimensional memory structure, wherein the test voltage applied to a particular data word line has a magnitude that depends on which layer the particular data word line resides; and
test the three-dimensional memory structure in response to the set of test voltages concurrently applied to the corresponding set of the data word lines.