Patent ID: 8318614

Claim:
A method for forming a silicon nitride film of [SiN x /Si(100)] on a substrate by plasma CVD, said method comprising: setting a substrate in a processing chamber; supplying a source gas containing a nitrogen-containing compound and a silicon-containing compound into the processing chamber, while introducing microwaves into the processing chamber by using a plane antenna having a plurality of holes, to form a plasma; and depositing the silicon nitride film on the substrate while controlling the plasma so that electron occupation defects (traps) will be present in an energy region corresponding to the Si band gap in the film in a trap density controlled at a predetermined value, the traps making photoelectron yield from the silicon nitride film significantly higher as compared to a hydrogen-terminated silicon surface in a lower energy region than an upper end (Ev) of the Si valence band, wherein the processing temperature upon the deposition of the silicon nitride film by plasma CVD is in the range of 300° C. to 600° C., and the trap density of the silicon nitride film is made to be distributed in the range of 1×10 17 to 5×10 17 cm −3 eV −1 in the thickness direction of the film.