Detailed Study On Physical Properties Of Silicon Nitride Films Deposited By Plasma Enhanced Chemical Vapour Deposition System

Abstract

Amorphous silicon nitride films have been deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) technique using silane (SiH₄) and ammonia (NH₃) as source gases. Investigations have been made in detail to understand the influence of process parameters such as RF power, substrate temperature, gas flow ratio, working pressure etc, on the optical, electrical and surface properties in order to obtain dielectric Si₃N₄ films for semiconductor device applications. Amorphous nature of the films has been verified by Raman and AFM Analysis. Dielectric Si₃N₄ films with an average optical transmittance value of 86.5 %, electrical resistance of 2.71 GΩ and band gap of 2.72 eV have been deposited with the optimum process parameters of 250 °C, 7 W and 1:3 ratio (SiH₄:NH₃) at an average deposition rate of 63.7 nm/min.