A nonvolatile memory device, a nonvolatile memory cell, and a plurality of transistors, and a method of adjusting a threshold value of a non-decaying memory cell (a nonvolatile memory device, a nonvolatile memory cell, and a nonvolatile memory cell, VOLATILE MEMORY CELL AND EACH OF PLURAL TRANSISTORS)

摘要

After a drain or a source is charged in a non-decaying semiconductor memory device composed of floating gate type memory cells, it is in an electrically floating state, and a signal alternately changing between a positive potential and a negative potential is applied to the control gate of the memory cell, The charge stored in the gate is reduced, whereby the sliced voltage of the memory cell is converged to a predetermined voltage. Therefore, the write / erase operation of this memory device can be reliably performed in a short time.