3-d electrically programmable and erasable single-transistor non-volatile semiconductor memory device

Abstract

A non-volatile memory device includes a source region, a drain region, and a channel region therebetween. The channel region has a length extending from the source region to the drain region and a channel width in the direction perpendicular to the channel length direction. The device includes a floating gate positioned between the source and the drain in the channel length direction. The width of the floating gate is less than the channel width. A control gate covers a top surface and a side surface of the floating gate. The control gate also overlies an entirety of the channel region. Erasure of the cell is accomplished by Fowler-Nordheim tunneling from the floating gate to the control gate. Programming is accomplished by electrons migrating through an electron concentration gradient from a channel region underneath the control gate into a channel region underneath the floating gate and then injecting into the floating gate.