US 11,056,172 B1
Flash memory and operation method thereof for controlling raising speed of the read pass voltage
Che-Ping Chen, Taipei (TW); Ya-Jui Lee, Taichung (TW); Shin-Jang Shen, HsinChu County (TW); and Yih-Shan Yang, Hsinchu (TW)
Assigned to MACRONIX INTERNATIONAL CO., LTD., Hsinchu (TW)
Filed by MACRONIX International Co., Ltd., Hsinchu (TW)
Filed on Apr. 28, 2020, as Appl. No. 16/860,349.
Int. Cl. G11C 7/22 (2006.01); G11C 11/4076 (2006.01); G11C 11/4074 (2006.01); G11C 11/4099 (2006.01); G11C 11/4094 (2006.01); G11C 11/408 (2006.01); G11C 16/04 (2006.01); G11C 16/32 (2006.01); G11C 16/34 (2006.01); G11C 16/26 (2006.01); G11C 16/06 (2006.01)
CPC G11C 11/4076 (2013.01) [G11C 7/22 (2013.01); G11C 11/4074 (2013.01); G11C 11/4085 (2013.01); G11C 11/4094 (2013.01); G11C 11/4099 (2013.01); G11C 16/0483 (2013.01); G11C 16/06 (2013.01); G11C 16/26 (2013.01); G11C 16/32 (2013.01); G11C 16/3418 (2013.01); G11C 16/3427 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A flash memory, comprising:
a plurality of memory cell strings, where each of the memory cell strings comprises a plurality of memory cells; and
a pass voltage generator coupled to the memory cell strings, configured to provide a pass voltage to a plurality of word lines of a plurality of unselected memory cells of a selected memory string,
wherein during a reading operation, the pass voltage generator raises the pass voltage from a first voltage at a first time point, and raises the pass voltage to a second voltage at a second time point,
wherein the second voltage is lower than a target voltage times a preset ratio, the first time point is earlier than a start time point of a bit line voltage received by the selected memory cell, and the second time point occurs at the start time point of the bit line voltage,
wherein the pass voltage generator raises the pass voltage to the target voltage in a sensing time interval after the second time point and wherein the preset ratio is 90%.