US 11,894,066 B2
Semiconductor memory device and method of operating the semiconductor memory device
Soo Yeol Chai, Icheon-si (KR)
Assigned to SK hynix Inc., Icheon-si (KR)
Filed by SK hynix Inc., Icheon-si (KR)
Filed on Sep. 22, 2021, as Appl. No. 17/481,927.
Claims priority of application No. 10-2021-0045947 (KR), filed on Apr. 8, 2021.
Prior Publication US 2022/0328107 A1, Oct. 13, 2022
Int. Cl. G11C 7/00 (2006.01); G11C 16/26 (2006.01); H03K 19/21 (2006.01); G11C 16/04 (2006.01)
CPC G11C 16/26 (2013.01) [G11C 16/0483 (2013.01); H03K 19/21 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method of operating a semiconductor memory device detecting a threshold voltage distribution for memory cells included in a page selected from among a plurality of memory cells, wherein each of the plurality of memory cells stores N bit of data, the method comprising:
selecting a target state, in which the threshold voltage distribution is to be detected, from among an erase state and first to (2N-1)-th program states, wherein N is a natural number;
determining a plurality of read voltages for dividing a voltage range in which a threshold voltage of the selected target state is distributed; and
performing a plurality of sensing operations using the plurality of read voltages on the selected page,
wherein masking to the target state is applied in each of the plurality of sensing operations.