Patent ID: 8637921

Claim:
A nonvolatile trapped-charge memory device, comprising: a tunneling layer on a substrate, a charge trapping layer on the tunneling layer, wherein the charge trapping layer comprises an oxygen-rich oxynitride to form a SONOS-type device, and a blocking layer on the charge trapping layer, wherein the tunneling layer thickness is no greater than 2.5 nm and further comprises: a first region comprising approximately 25% of the tunneling layer thickness proximate to the substrate having a nitrogen concentration lower than a middle region, and a second region comprising approximately 25% of the tunneling layer thickness proximate to the charge trapping layer having a nitrogen concentration higher than the middle region, wherein the middle region is located between the first region and the second region, and wherein the nitrogen concentration decreases from a first interface between the second region and the charge trapping layer to the middle region, and from the middle region to a second interface between the first region and the substrate to reduce nitrogen and hydrogen trap density at the second interface, and wherein the middle region and the second region comprising approximately 75% of the tunneling layer, the second region comprises a nitrogen concentration that is at least 1×10 21 atoms/cm 3 .