DEPOSITION OF SILICON-NITRIDE BY LOW-PRESSURE ELECTRON-CYCLOTRON-RESONANCE PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION IN N-2 AR/SIH4/

Plasma deposition of silicon nitride on silicon substrates in a microw ave electron cyclotron resonance N-2/Ar/SiH4 discharge was studied as a function of gas pressure (1-5 mTorr), gas composition, and discharge power (250-1000 W). The dependencies of deposition parameters on disc harge characteristics obtained at 1 mTorr appear to be essentially dif ferent from those at higher pressures. Optical emission spectroscopy w as used for plasma characterization. A high degree of ionization and d issociation of gas molecules was observed under present plasma conditi ons. It is shown that the contribution of ionized species to film depo sition is comparable with that of neutral ones under high power and lo w pressure conditions. The best quality of films was obtained at a mod erate rather than the highest available dissociation degree of silane. (C) 1997 American Vacuum Society.