Three-dimensional memory and control method thereof

Abstract

The present invention relates to a three-dimensional memory and a control method thereof. The three-dimensional memory comprises a plurality of memory strings and a plurality of word lines, each of the memory strings comprises a plurality of memory cells arranged in series, each of the memory cells is located at a corresponding cell depth in the memory strings, and the plurality of memory cells located at the same cell depth are connected with the same word line. The method comprises the following steps: applying a first virtual programming voltage to unprogrammed memory cells, so that the plurality of unprogrammed memory cells connected to the same word line are programmed to the same programming state, and the programming state is one of a plurality of programming states corresponding to a plurality of threshold voltages. According to the invention, the influence of various interferences on a part of programming blocks including unprogrammed memory cells is reduced, the broadening of threshold voltage distribution is inhibited, a read window is enlarged, and the reliability of data in the part of programming blocks is improved.

Description

technical field [0001] The invention relates to the manufacturing field of integrated circuits, in particular to a three-dimensional memory and a control method thereof. Background technique [0002] In order to overcome the limitations of two-dimensional memory devices, memory devices with a three-dimensional (3D) structure have been developed and mass-produced in the industry, which improves integration density by three-dimensionally arranging memory cells on a substrate. 3D NAND flash memory is a three-dimensional memory device. With the development of multi-value storage technology, the number of stacked layers of three-dimensional storage devices is gradually increasing, making the data volume of a single programming block larger and larger. A programming block in which all memory cells in the programming block have been programmed is called a close block. In actual use, in a programming block, only part of the memory cells corresponding to the word lines are programm...

AI Technical Summary

Problems solved by technology

The programmed memory cells in some programming blocks are subject to various disturbances in the memory, which leads to the broadening of the distribution of the threshold voltage of the programming state, resulting in a reduction in the read window and reducing the reliability of the data.

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