Method for forming flash memory of ETOX-cell programmed by band-to-band tunneling induced substrate hot electron and read by gate induced drain leakage current

Abstract

A method of forming an ETOX-cell in a semiconductor substrate is disclosed. The method begins with forming a p-well in the substrate. Then, a drain region and a source region is formed in the p-well. The drain region is of a first dopant type and the source region is of a second dopant type (i.e. same as the dopant type of the p-well). A floating-gate and tunnel oxide stack is formed above the p-well, the floating gate formed between the drain region and the source region and only after the drain region and the source region have been formed. The floating gate is doped with the same dopant type as the p-well. Finally, a control gate is formed above the floating-gate, the floating-gate and the control gate separated by a dielectric layer. The new ETOX cells can be organized into a NOR array, but with no need of source line connections. Each cell is programmed by band-to-band induced substrate hot-electron (BBISHE) at the source, and read by GIDL at the drain side.

Dependencies are inferred from the claim text.