摘要:
[PROBLEMS] To provide a semiconductor storage device having excellent electrical characteristics (writing/erasing characteristics) by excellent nitrogen concentration profile of a gate insulating film and to provide a method for manufacturing such device. [MEANS FOR SOLVING PROBLEMS] In a semiconductor device manufacturing method relating to a first embodiment of this invention, a method for manufacturing a semiconductor storage device which operates by transferring charges through a gate insulating film formed between a semiconductor substrate and a gate electrode includes a process of introducing oxynitriding species previously diluted by using a gas for plasma excitation into a plasma processing apparatus, generating the oxynitriding species by plasma, and forming an oxynitride film on the semiconductor substrate as the gate insulating film. The oxynitriding species contain an NO gas of 0.00001-0.01% to the total gas quantity introduced into the plasma processing apparatus.