Patent ID: 7903466
Filing Date: 2011-03-08
Classification: G11C

Abstract:
1. A program verify method of a memory device, the method comprising: performing programming on a selected memory cell of the memory device; applying a power supply voltage to a ground line commonly connected to cell strings to which the memory cells are connected for precharging a selected bit line based on a program state of the selected memory cell of the cell strings upon program verification; applying a first voltage to a selected word line of a plurality of word lines connected to intersect the cell strings of the memory cells and applying a pass voltage to unselected word lines, precharging each of bit lines by supplying the power supply voltage to the ground line commonly connected to the cell strings; sequentially applying a bit line select signal to a gate of a transistor connected between the bit line and a page buffer according to a preset voltage level, and confirming a verify signal of the page buffer, which is output according to each voltage level; and determining whether the memory cells have been programmed according to a voltage level of the bit line select signal on which the verify signal is output based on the confirmation result.