Microcrystalline Silicon Films Deposited by Electron Cyclotron Resonance Plasma Chemical Vapor Deposition Using Helium Gas

Abstract

We have investigated the growth of microcrystalline silicon films by electron cyclotron resonance plasma chemical vapor deposition (ECR-PCVD) using He as the ECR gas at substrate temperatures in the range of 180 to 550°C with He to silane ratios (He/SiH 4 ) of 1, 4, and 9. With ratios of 4 and 9, the volume fractions of microcrystalline silicon increase with temperature and exceed 90% at 550°C. To study the role of He plasma, we prepared silicon films using a layer-by-layer technique and found that long exposure to He plasma changes the structure of amorphous silicon to microcrystalline.