Differences in the electrical properties of the interfaces of PECVD silicon nitride with amorphous and crystalline silicon

Abstract An original method is described for the determination of the flatband voltage in metal-insulator-a-Si:H devices based on capacitance-frequency measurements at variable temperature done in the accumulation regime. The comparison with results obtained on c-Si devices shows for the first time that the density of positive fixed charge in PECVD silicon nitride increases when going from amorphous to crystalline and from n to p-type substrate. A model of tunneling of holes from the plasma-irradiated substrate to Si-Si or Si dangling bonds in silicon nitride is proposed to explain our results and others from the literature.