Nonvolatile semiconductor memory device having a gate stack and method of manufacturing the same

Abstract

A nonvolatile semiconductor memory device includes a semiconductor substrate having a source region and a drain region, and a gate stack formed on the semiconductor substrate between and in contact with the source and drain regions. The gate stack includes, in sequential order from the substrate: a tunneling film; a first trapping material film doped with a first predetermined impurity, the first trapping material film having a higher dielectric constant than the nitride film (SiN); a first insulating film having a higher dielectric constant than a nitride film; and a gate electrode. Such a nonvolatile semiconductor memory device can effectively control the trap density according to the doping concentration, thereby increasing the write/erase speed of data at a low operating voltage.