The invention relates to a nonvolatile semiconductor memory device including a semiconductor layer which has a source region, a drain region, and a channel forming region which is provided between the source region and the drain region; and a first insulating layer, a first gate electrode, a second insulating...http://www.google.com/patents/US20080230825?utm_source=gb-gplus-sharePatent US20080230825 - NONVOLATILE SEMICONDUCTOR MEMORY DEVICE
