Hynix Semiconductor Inc.

Keum Hwan Noh

Min Kyu Lee

Seok Jin Joo

Hyung Seok Kim

Ju In Kim

Kyung Pil Hwang

Sook Kyung Kim

Nam Kyeong Kim

Ju Yeab Lee

A method of erasing and programming a flash memory device including multi-level cells (MLCs). MLCs of a word line are selected and some of the MLCs are pre-programmed based on whether their individual threshold voltages are included in a first voltage range. The selected MLCs are pre-programmed with a pre-program (first) voltage; and the remaining MLCs are prohibited from pre-programming; then the remaining MLCs connected to the selected word line are programmed by applying a program (second) voltage that gradually rises from the pre-program voltage at a ratio of a step voltage n for the selected line.

Program method of flash memory device

Erase and program methods of a flash memory device including MLCs for increasing the program speed. In the erase method, MLCs are pre-programmed so that a voltage range in which threshold voltages of MLCs are distributed can be reduced. Therefore, a fail occurrence ratio can be reduced when erasing MLCs, the threshold voltage distribution of MLCs can be improved and an overall program time can be shortened in a subsequent program operation.

Erase method of flash memory device

Provided is a method of reading a flash memory device for depressing read disturb. According to the method, a first voltage is applied to a gate of the drain select transistor to turn on the drain select transistor, and a read voltage is applied to a gate of a selected transistor among the plurality of memory cells. Then, a pass voltage is applied to gates of unselected transistors among the plurality of memory cells. Furthermore, when the pass voltage is applied, a first pass voltage is applied and then a second pass voltage is applied after an elapse of a predetermined time following the applying of the first pass voltage. The second pass voltage has a level different from that of the first pass voltage.

Method of reading flash memory device for depressing read disturb

Erase and program methods of a flash memory device including MLCs for increasing the program speed are described. In the erase method, MLCs are pre-programmed so that a voltage range in which threshold voltages of MLCs are distributed can be reduced. Therefore, a fail occurrence ratio can be reduced when erasing MLCs, the threshold voltage distribution of MLCs can be improved and an overall program time can be shortened in a subsequent program operation.

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Seoul, South Korea

Keum Hwan Noh