Method for forming underlying insulation film

A method for forming an insulating film, comprising:

• plasma nitriding a surface of a substrate before formation of a HfSiO film on the substrate,
• forming a HfSiO film on the substrate,
• generating plasma based on a process gas comprising at least an oxygen atom-containing gas on the HfSiO film, and
• irradiating the surface of the HfSiO film with the plasma, to thereby form an oxide film at the interface between the HfSiO film and the substrate,
• wherein the oxide film has a thickness of 6-12 Å.

A method for forming an insulating film, comprising:

• plasma nitriding a surface of a substrate before formation of a HfSiO film,
• forming a HfSiO film on the substrate,
• generating plasma based on a process gas comprising at least an oxygen atom-containing gas on the HfSiO film,
• irradiating the surface of the HfSiO film with the plasma to thereby form an oxide film at the interface between the HfSiO film and the substrate, and
• nitriding the surface of the HfSiO film,
• wherein the oxide film has a thickness of 6-12 Å.

A method for forming an electronic device, comprising:

• forming a high-dielectric constant gate insulating film on a substrate,
• generating plasma based on a process gas comprising at least an oxygen atom-containing gas on the high-dielectric constant gate insulating film,
• irradiating a surface of the high-dielectric constant gate insulating film with the plasma, to thereby form an oxide film at the interface between the high-dielectric constant gate insulating film and the substrate,
• nitriding the surface of the high-dielectric constant gate insulating film after formation of the oxide film, and
• forming a gate electrode on the high-dielectric constant gate insulating film,
• wherein the oxide film has a thickness of 6-12 Å.