Electrically programmable and erasable nonvolatile semiconductor memory device and operating method therefor - Patent US5898606(A)

Filed: Apr 30, 1997

Published: Apr 27, 1999

Abstract

In erasing, electrons are simultaneously injected into floating gates from sources of a plurality of memory cells. Thus, the threshold voltages of the plurality of memory cells are increased. In programming, electrons are emitted from a floating gate of a selected memory cell to a drain. Thus, the threshold voltage of the selected memory cell is reduced.