EFFECT OF MICROWAVE-POWER AND REACTIVE GAS RATIO ON THE PROPERTIES OF SILICON-NITRIDE THIN-FILMS DEPOSITED BY ECR PECVD

Silicon nitride films were deposited at room temperature on a single crystal silicon substrate by ECR PECVD (electron cyclotron resonance plasma enhanced chemical vapor deposition). Effects of the microwave power and the reactive gas ratio (SiH4/N2) on the film properties, such as, refractive index and breakdown field were investigated. It turned out that the microwave power was closely related to the change in refractive index of the silicon nitride films, while breakdown field did not change much from 6 MV/cm. It was also found that the deposition rate, refractive index, and breakdown field were changed in a certain way with respect to the change in SiH4/N2 ratio, which could be explained in terms of the activated chemical species concentrations in the plasma during deposition.