Method of erasing a non-volatile memory

Abstract

A method of erasing a non-volatile memory. The non-volatile memory is positioned on a substrate of a semiconductor wafer and has a memory array region. The memory array region has memory cells, word lines and a substrate line electrically connected to the substrate of each memory cell in the memory array region. The erasing method is to control a potential difference between a word line not to be erased and the substrate to within a specific range, then supply a predetermined first potential to a word line to be erased, thereafter float the word line not to be erased, and finally supply the substrate line with a predetermined second potential. The potential difference between the first and the second potential drive the charges stored in the floating gate of the memory cell electrically connected to the word line to be erased to move into the channel through the tunneling oxide layer to complete the erasing. The charges stored in the floating gate of the memory cell electrically connected to the word line not to be erased will be affected by factors such as an initial potential supplied to the word line not to be erased, the floated word line not to be erased, a change of the substrate potential, and a voltage coupling effect between the substrate and the word line not to be erased. So, the potential difference between the word line not to be erased and the substrate can be controlled to a specific range, and the memory cell not to be erased is not affected.