Damage-free and hydrogen-free nitridation of silicon substrate by nitrogen radical source

New damage free nitridation process of a silicon substrate is proposed with the use of a nitrogen radical source. The process also realized the hydrogen-free film that ensured high resistance against high temperature oxidation processes. It was also found that thicker than 3 nm films could be synthesized at room temperature using atomic N radicals. The metal insulator semiconductor (MIS) diode composed of radical nitride Si3N4 shows no hysteresis in capacitance voltage characteristics even after the annealing at 950 degreesC. It was demonstrated that the application of Si3N4 films to the most advanced field effect transistors became much easier than the conventional processes with the use of radical nitridation.