Patent ID: 7183166

Claim:
A method for forming an ONO structure, comprising: providing an oxide-nitride film on a surface of a substrate, the oxide-nitride film including a first oxide layer over the substrate and a silicon nitride layer over the first oxide layer; patterning the oxide-nitride film to define bottom oxide and silicon nitride portions of an ONO stack on the substrate, the bottom oxide and silicon nitride portions having exposed sidewalls and the silicon nitride portion having an exposed surface; and performing a ISSG operation by heating the substrate to a temperature in a range about 700° C. to about 1300° C. and exposing the exposed sidewalls and the exposed surface to a gas mixture comprising O 2 and H 2 in a proportion in a range about 0.1% to about 40% (H 2 /H 2 +O 2 ) at a pressure in a range about 1 torr to about 20 torr for a time in a range about 1 to 1000 seconds, whereby components of the gas mixture react to produce a radical oxidizing agent near the heated substrate, to form an oxide layer on the exposed surface and sidewalls of the patterned silicon nitride portion and on the sidewalls of the patterned bottom oxide portion.