INVESTIGATION OF MESFET STRUCTURES BASED ON POLYCRYSTALLINE DIAMOND FILMS GROWN BY MODIFIED HF CVD TECHNIQUE

We have investigated the in∞uence of process conditions on growth of diamond thin fllm on silicon substrates for electronic applications. The developed double-bias HF CVD system allows an igniting of plasma at DC and AC voltages. Low voltage nucleation process results in improved nucleation in the early stage of diamond growth. Furthermore, next post-processing of such fllms by microwave CVD plasma is used to build conductive layer. The problem associated with the doping has been overcome by using of p-type surface conductive layer, naturally built on and in hydrogen terminated diamond surfaces. The in∞uence of surface morphology on I-V characteristics of realized metal-semiconductor fleld efiect transistors (MESFET) is discussed. K e y w o r d s: diamond, hot-fllament CVD, nucleation, MESFET