Yangtze Memory Technologies Co., Ltd.

Zilong Chen

Xiang Fu

Ke Jiang

Huamin Cao

Bin Xiang

A method for conducting a read-verification operation on a target memory cell in a three-dimensional (3D) memory device includes removing fast charges of the target memory cell at a read-prepare step and measuring a threshold voltage of the target memory cell at a sensing step. Removing the fast charges of the target memory cell includes applying a prepare voltage (V) on an unselected top select gate (Unsel_TSG) of an unselected memory string, applying a first off voltage (V) on a selected word line (Sel_WL) associated with the target memory cell, and applying a pass voltage (V) on an unselected word line (Unsel_WL).

Method for reading three-dimensional flash memory

A semiconductor memory device includes a memory cell array and peripheral circuitry. The memory cell array includes a block of memory cells The peripheral circuitry can perform first program-verify loops in response to a first write operation to a first word line in a word line group to program memory cells associated with the first word line to multiple states. The word line group includes one or more word lines. Then, the peripheral circuitry determines verification start loops of the multiple states based on sensing results in the first program-verify loops, and performs second program-verify loops with the determined verification start loops of the multiple states in response to a second write operation to a second word line in the word line group.

Growing community of inventors

Hubei, China

Zilong Chen