SAW characteristics of AlN films deposited on various substrates using ECR plasma enhanced CVD and reactive RF sputtering

摘要

Highly c-axis oriented AlN films were deposited on SiO/sub 2//Si, Si/sub 3/N/sub 4//Si, Si(100) and Si(111) substrates using ECR plasma enhanced CVD (ECR PECVD) and reactive RF sputtering. The AlN films deposited by ECR PECVD had lower surface roughness and lower insertion loss than the sputter-deposited films. ECR PECVD film showed phase velocity of 3270 m/s, whereas sputter-deposited film showed phase velocity of 5100 m/s. The contents of impurities (especially oxygen) was thought to play an important role in the degree of c-axis orientation and SAW velocity.