Nonvolatile semiconductor memory device

A nonvolatile semiconductor memory device comprising:

• a plurality of memory cells capable of electrically writing, erasing, and reading information,
• each of the memory cells including:
• a semiconductor substrate having a main surface;
• source/drain diffusion layers which are separately formed on the main surface of the semiconductor substrate;
• a first insulating film formed on a channel provided between the source/drain diffusion layers;
• an electric charge accumulation layer formed on the first insulating film, the electric charge accumulation layer being made of nitride or oxynitride containing at least one selected from Si, Ge, Ga, and Al, and containing n-type dopant impurity;
• a second insulating film formed on the electric charge accumulation layer;
• and
• a control gate electrode formed on the second insulating film.

A nonvolatile semiconductor memory device comprising:

• a plurality of memory cells capable of electrically writing, erasing, and reading information,
• each of the memory cells, including:
• a semiconductor substrate having a main surface;
• source/drain diffusion layers which are separately formed on the main surface of the semiconductor substrate;
• a first insulating film formed on a channel provided between the source/drain diffusion layers;
• an electric charge accumulation layer formed on the first insulating film, the electric charge accumulation layer being made of nitride or oxynitride containing at least one selected from Si, Ge, Ga, and Al, and including fine particles or nanocrystals containing n-type dopant impurity therein;
• a second insulating film formed on the electric charge accumulation layer;
• and
• a control gate electrode formed on the second insulating film.

A nonvolatile semiconductor memory device comprising:

• a plurality of memory cells capable of electrically writing, erasing, and reading information,
• each of the memory cells including:
• a semiconductor substrate having a main surface;
• source/drain diffusion layers which are separately formed on the main surface of the semiconductor substrate;
• a first insulating film formed on a channel provided between the source/drain diffusion layers;
• an electric charge accumulation layer formed on the first insulating film, the electric charge accumulation layer being made of nitride or oxynitride containing at least one selected from Si, Ge, Ga, and Al;
• an electron-supplying layer formed on the electric charge accumulation layer, the electron-supplying layer being made of metal material;
• a second insulating film formed on the electron-supplying layer;
• and
• a control gate electrode formed on the second insulating film.