Yangtze Memory Technologies Co., Ltd.

Kaijin Huang

Gang Liu

Jin Lyu

A memory device, a system, and a method for operating the memory device are provided. The memory device includes a first memory string and a peripheral circuit. The first memory string includes a first drain, a first drain select gate (DSG) transistor, a first drain dummy transistor between the first drain and the first DSG transistor, and a plurality of first memory cells. A first drain dummy line is coupled to the first drain dummy transistor, and a first DSG line is coupled to the first DSG transistor. The peripheral circuit is configured to, in a program operation, apply a first DSG voltage to the first DSG line and apply a first drain dummy line voltage to the first drain dummy line to turn on the first drain dummy transistor. The first drain dummy line voltage is greater than the first DSG voltage.

Memory device and program operation thereof

The present disclosure provides a method of erase and erase verification for a memory device. The method includes applying a first erase voltage to erase memory cells of the memory device. The first erase voltage is incrementally increased by a first erase step voltage until the memory cells pass an initial erase verification. The method also includes determining whether the memory cells pass or fail sub-erase verifications by applying sub-erase verification voltages. The method further includes applying a second erase voltage to erase the memory cells after the sub-erase verifications. The second erase voltage is increased from the first erase voltage by a second erase step voltage, which is smaller than the first erase step voltage and is determined according to whether the memory cells pass or fail the sub-erase verifications.

Erasing and erasing verification for three-dimensional NAND memory

In a method for erasing a memory device including memory cells, a first erase operation is performed on a selected memory cell of the memory cells based on a first erase voltage. A first verifying operation is performed on the selected memory cell based on a first erase verify voltage. A second verifying operation is subsequently performed on the selected memory cell based on a second verify voltage after the selected memory cell passes the first verifying operation. Further, a second erase operation is performed on the selected memory cell based on a second erase voltage after the selected memory cell fails the second verifying operation.

Architecture and method for NAND memory operation

In certain aspects, a memory device includes a first memory string including a first drain, a first drain select gate (DSG) transistor, first memory cells, and a first drain dummy transistor between the first drain and the first DSG transistor. The memory device also includes a first bit line coupled to the first drain, a first drain dummy line coupled to the first drain dummy transistor, a first DSG line coupled to the first DSG transistor, word lines respectively coupled to the first memory cells, and a peripheral circuit configured to perform a program operation on a target memory cell of the first memory cells coupled to a selected word line of the word lines. To perform the program operation, the peripheral circuit includes a bit line driver coupled to the first bit line and configured to apply a first bit line voltage to select the first bit line, and a word line driver coupled to the first drain dummy line and the first DSG line and configured to apply a DSG voltage to the first DSG line to turn on the first DSG transistor, and apply a drain dummy line voltage to the first drain dummy line to turn on the first drain dummy transistor. The drain dummy line voltage is greater than the DSG voltage.

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Wuhan, China

Kaijin Huang