Silicon Thin Film with Columnar Structure Formed by RF Diode Sputtering

Abstract

The morphology of amorphous silicon (a-Si) thin films prepared by rf diode sputtering was examined. The self-bias potential drops sharply with deceasing argon gas pressure below 30 mTorr and strongly influences the morphology of the sputtered a-Si films. In particular, a film deposited at a pressure of 20 mTorr has a very highly oriented columnar structure and each column has a dome-shaped top. The experimental results show that the self-bias potential is an important determinant of sputtered a-Si film microstructure.