Patent ID: 7795156

Claim:
A producing method of a stress-resilient semiconductor device comprising a step of forming a tunnel insulating film of a flash device, comprising: a first nitridation step of forming a first silicon oxynitride film by nitriding a silicon oxide film formed on a semiconductor silicon base by one of plasma nitridation and thermal nitridation, the plasma nitridation carrying out nitridation process by using a gas activated by plasma discharging a first gas including a first compound which has at least a nitrogen atom in a chemical formula thereof, and the thermal nitridation carrying out nitridation process using heat by using a second gas including a second compound which has at least a nitrogen atom in a chemical formula thereof, and a second nitridation step of forming a second silicon oxynitride film by nitriding the first silicon oxynitride film by the other of the plasma nitridation and the thermal nitridation, wherein additional nitrogen is supplied to create a tunnel insulating oxide film with additional nitrogen atoms near the interface with the semiconductor base to help suppress leakage of the tunnel insulating oxide film.