| 摘要 |
PURPOSE:To decrease a capturing level in a nitride film and to solve a problem that an erasing time is much longer than a writing time, by mixing a minute amount of oxygen in the nitride film of an MNOS type non-voltatile memory, and converting SiNx in the nitride film into oxynitride SiNxOy. CONSTITUTION:Thermal oxidation of a P-type Si substrate 1 is performed, and a very thin oxide film of SiO2 2 with a thickness of 15-50Angstrom is formed. A nitride film of SiNx 10 is formed by a CVD method by using SiH4 and N2 (or NH3) thereon to a thickness of 100-500Angstrom . Now, oxygen ions are implanted 4 in the nitride film SiNx, and oxynitride SiNxOy 3 is obtained. Then, a capturing level having a deep energy level, which is present at the interface between the oxide film SiO2 and the nitride film SiN2, is made to disappear by the oxygen ion, and a nitride film having high resistivity is obtained. Therefore discharge is hard to occur to the side of a gate electrode through the nitride film SiNx when memories are held. Thus the memory holding characteristic of the MNOS type non-volatile memory is improved. |
