| 摘要 |
PURPOSE:To improve the characteristics of a MISFET, a nonvolatile memory unit, etc., by obtaining a high dielectric constant insulating film of good boundary surface characteristics by reacting directly the plasma of mitrogen, ammonia, etc., and a silicon wafer at low temperatures and using the insulating film as a gate insulating film. CONSTITUTION:In a reaction tube 1 surrounded by a microwave resonator 3 and a subheater 2, a sample supporting base 4 on which a silicon wafer 5 is mounted is arranged and the tube 1 is evacuated sufficiently by a sorption pump 6 via a needle valve 7. Next, monitoring with a vacuum gauge 9, a needle valve 7' is opened adjusting N2 flow and the pressure in the tube and N2 gas is fed from a bomb 8 to the tube 1. Then the gas is heated by the heater 2 and plasma is excited by the resonator 3, N2 plasma and silicon are made to react directly and an Si3N4 film is formed on the wafer 5. By so doing, an insulating film of good barrier characteristics against impurity diffusion can be obtained, which is suitable for MISFET's, etc. |
