MEMORY DEVICE AND OPERATING METHOD THEREOF

The invention provides a memory device and an operating method thereof. The operation method of the memory device comprises the following steps: during programming operation, programming a plurality of threshold voltages of a plurality of switches on a plurality of string selection lines and a plurality of ground selection lines to have a first reference threshold voltage; and programming a plurality of threshold voltages of a plurality of redundant memory cells on a plurality of redundant word lines to gradually increase along a first direction from the string select lines to the plurality of word lines or a second direction from the string select lines to the plurality of word lines, and the threshold voltages of the redundant memory cells being higher than the first reference threshold voltage. And the second direction is from the grounding selection lines to the word lines. 本发明提供存储器装置与其操作方法。该存储器装置的操作方法包括：于编程操作时，编程多条串选择线与多条接地选择线上的多个开关的多个阈值电压以具有一第一参考阈值电压；以及编程多条冗余字线上的多个冗余存储器单元的多个阈值电压以沿着一第一方向或一第二方向为逐渐增加且这些冗余存