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

Silicon nitride films of varying composition have been deposited with nitro gen dilution onto p-type silicon substrates at 250 degrees C by plasma enha nced chemical vapor deposition technique. Careful and detailed capacitance- voltage (C-V) measurements have been undertaken in the metal-insulator-semi conductor configuration. Silicon-rich films are found to exhibit large symm etric hysteresis loops in the C-V curve while the nitrogen-rich films displ ay much smaller asymmetric hysteresis loops. Furthermore, the minimum inter face state density is observed to decrease with the increase in nitrogen to silicon ratio. In this study we have observed that the concentration of bo th electron as well as hole traps are much lower for the nitrogen-rich film s. (C) 2000 American Institute of Physics. [S0021-8979(00)05007-6].