Bit line control decoder circuit, virtual ground type nonvolatile semiconductor storage device provided with the decoder circuit, and data read method of virtual ground type nonvolatile semiconductor storage device

Abstract

There is provided a virtual ground type nonvolatile semiconductor storage device capable of effectively suppressing a leak current to the adjacent cell and thereby achieving high-speed read. During read operation, a ground potential GND is applied to a bit line SBL connected to the source region of one memory cell transistor MC subjected to read. Moreover, a read drain bias potential Vread is applied to a bit line SBL connected to the drain region of the memory cell transistor MC . A bit line SBL connected to the drain region of a first adjacent memory cell transistor MC is put into a floating state. A potential Vdb equal to the read drain bias potential Vread is applied to a bit line SBL connected to the drain region of a second adjacent memory cell transistor MC