Silicon nitride film and nonvolatile semiconductor memory device

A silicon nitride film for use as a charge storage layer of a nonvolatile semiconductor memory device, wherein the volume density of traps in the film at an energy position corresponding to the mid-gap of silicon is distributed in the range of 1×1017 to 5×1017 cm−3 eV−1 in the thickness direction of the film.

A silicon nitride film for use as a charge storage layer of a nonvolatile semiconductor memory device, wherein the film is formed by a plasma CVD method comprising:

• introducing a source gas containing a nitrogen-containing compound and a silicon-containing compound into a processing chamber of a plasma processing apparatus;
• introducing microwaves into the processing chamber by means of a plane antenna having a plurality of slots, thereby generating a plasma of the source gas;
• and depositing a silicon nitride film on a processing object in the plasma.

A nonvolatile semiconductor memory device comprising a charge storage layer of a single-layer or multi-layer structure between a semiconductor layer and a gate electrode, wherein at least one layer of the charge storage layer is comprised of a silicon nitride film, and the trap density of the film, in terms of the surface density, is in the range of 5×1010 to 1×1013 cm−2 eV−1.

A nonvolatile semiconductor memory device comprising a charge storage layer of a single-layer or multi-layer structure between a semiconductor layer and a gate electrode, wherein at least one layer of the charge storage layer is comprised of a silicon nitride film, and the trap density of the film, in terms of the volume density at an energy position corresponding to the mid-gap of silicon, is distributed in the range of 1×1017 to 5×1017 cm−3 eV−1 in the thickness direction of the film.