Nonvolatile semiconductor memory device and programming method thereof

摘要

A nonvolatile semiconductor memory device of the present invention has a well voltage detecting circuit. The well voltage detecting circuit detects whether a pocket p-type well voltage is equal to or is lower than a detection voltage (e.g., 0.1V) and outputs a detection signal at a high or low level. When the pocket p-type well voltage is identical to or lower than the detection voltage, a word line select signal generating circuit generates row select signals of respective rows in response to the detection signal. With this device, in case a well voltage of the pocket p-type well is increased due to applying a voltage into an unselected bit line, program and pass voltages are supplied to word lines at a point of time when the increased well voltage becomes lower than the detection voltage of the well voltage detecting circuit.