Non-volatile semiconductor memory device utilizing an oxidation suppressing substance to prevent the formation of bird's breaks

A method of manufacturing a non-volatile semiconductor memory device, said method comprising the steps of:

• forming a gate insulation film on a semiconductor substrate;
• forming a first conductive layer over the gate insulation film;
• introducing a first oxidization suppressing substance to an upper surface of the first conductive layer;
• forming an interpoly insulation film on the upper surface of the polysilicon layer;
• and
• forming a second conductive layer over an upper surface of the interpoly insulation film,
• wherein nitrogen ions are implanted in the step of introducing a first oxidization suppressing substance.

A method of manufacturing a non-volatile semiconductor memory device, said method comprising the steps of:

• forming a gate insulation film on a semiconductor substrate;
• forming a first conductive layer over the gate insulation film;
• forming an interpoly insulation film on the first conductive layer;
• introducing an oxidization suppressing substance to an upper surface of the interpoly insulation film;
• and
• forming a second conductive layer over the upper surface of the interpoly insulation film,
• wherein nitrogen ions are implanted in the step of introducing an oxidization suppressing substance.

A non-volatile semiconductor memory device comprising:

• a semiconductor substrate having a first conductivity type;
• diffusion regions having a second conductivity type opposite to the first conductivity type, the diffusion regions being formed in a surface of the semiconductor substrate at predetermined locations;
• a gate insulation film formed on the semiconductor substrate;
• a first conductive layer formed over the gate insulation film, the first conductive layer having an upper surface containing a first oxidization suppressing substance;
• an interpoly insulation film formed on the upper surface of the first conductive layer, the interpoly insulation film having an upper surface containing a second oxidization suppressing substance;
• and
• a second conductive layer over the upper surface of the interpoly insulation film.

A method of manufacturing a non-volatile semiconductor memory device, said method comprising the steps of:

• forming a gate insulation film on a semiconductor substrate;
• forming a first conductive layer over the gate insulation film;
• introducing a first oxidization suppressing substrate to an upper surface of the first conductive layer;
• forming an interpoly insulation film on the upper surface of the first conductive layer;
• introducing a second oxidization suppressing substance to an upper surface of the interpoly insulation film;
• and
• forming a second conductive layer over the upper surface of the interpoly insulation film.