Patent ID: 7092291

Claim:
A charge injection method of a nonvolatile semiconductor memory device, for changing a data storage status by injecting charges to a charge storage layer of a memory transistor comprising a body region of a first conductive type formed in a semiconductor substrate or formed as a semiconductor layer supported by a base body, a source region and a drain region made by a second conductive type semiconductor regions formed to be distant from each other in the body region, a stacked insulation film formed on the body region and including a charge storage layer, and a gate electrode formed on the stacked insulation film for controlling electric fields of the charge storage layer and the body region, comprising, when injecting the charges to the charge storage layer, the steps of: applying different voltages to the source region and the drain region; applying a voltage between the different voltages respectively applied to the source region and the drain region to the body region for turning on a diode formed by the source region of a second conductive type and the body region of a first conductive type; and applying a voltage having a polarity in accordance with charges to be injected to the gate electrode.