Capacitance–voltage measurements on plasma enhanced chemical vapor deposited silicon nitride films

Abstract

Silicon nitride films of varying composition have been deposited with nitrogen dilution onto p-type silicon substrates at 250 °C by plasma enhanced chemical vapor deposition technique. Careful and detailed capacitance–voltage (C–V) measurements have been undertaken in the metal-insulator-semiconductor configuration. Silicon-rich films are found to exhibit large symmetric hysteresis loops in the C–V curve while the nitrogen-rich films display much smaller asymmetric hysteresis loops. Furthermore, the minimum interface state density is observed to decrease with the increase in nitrogen to silicon ratio. In this study we have observed that the concentration of both electron as well as hole traps are much lower for the nitrogen-rich films.