METHOD FOR ERASING A NONVOLATILE MEMORY DEVICE

A method for erasing a nonvolatile memory device is provided to improve the threshold voltage distribution of the memory cell by securing the threshold voltage shift margin due to the interference and disturbance between cells. A program operation to the multi-level cell(or single-level cells) is performed(S301). An erase operation to the preprogrammed multi-level cells is performed(S302). The post program operation to the erased multi-level cells is performed(S303). The verification to the multi-level cells programmed post is performed(S304). If the verification is not passed, feed-back is performed repeatedly through post program operation until the verification is passed.