Structural properties of low temperature plasma enhanced chemical vapor deposited silicon oxide films using disilane and nitrous oxide

Abstract

The structural properties of low temperature plasma enhanced chemical vapor deposited SiO2 films using Si2H6 and N 2O have been studied. It is observed that the degree of compaction of as-deposited SiO2 films, upon subsequent annealing, increases up to 4%. The shift of Si-O-Si stretching peak wave number of the as-deposited SiO 2 films (Δω=−20 cm−1) compared to the undensified SiO 2 films is attributed to 9.4% increase in the film density, resulting in smaller Si-O-Si bridging bond angle of 138°. It is also believed that the high temperature annealing results in the reduction of hydroxyl containing species in the film and in turn drives the dielectric constant towards that of thermal SiO2 films.