MULTI-STATE NON-VOLATILE SEMICONDUCTOR MEMORY DEVICE WHICH CAN MAINTAIN CONSTANT MARGIN BETWEEN THRESHOLD VOLTAGE DISTRIBUTIONS

摘要

PURPOSE: A multi-state non-volatile semiconductor memory device is provided which can maintain a constant margin between threshold voltage distributions after program, and move a threshold voltage of a memory cell sequentially to a threshold voltage corresponding to each program data as programming the memory cell up to required threshold voltage. CONSTITUTION: The multi-state non-volatile semiconductor memory device includes: a bit line; a plurality of word lines arranged vertically to the bit line; a plurality of memory cells arranged in cross regions of the bit line and the word lines respectively; a storage circuit(MN1-MN7) having at least two latches(LT1,LT2) being connected to a corresponding input/output line respectively and latching data; and a program data judgement circuit setting the bit line with one of program voltage or program prohibit voltage during a program operation according to the logic states of data latched in the latches. The program data judgement circuit sets the bit line with the program voltage when at least one of the logic states of data latched in each latch indicates the program of the selected memory cell, and sets the bit line with the program prohibit voltage when the logic states of data latched in each latch indicate a program prohibition of the selected memory cell.