Performances of a-Si:H films using hot wire assisted microwave ECR CVD technique

Abstract

We report on the growth and properties of a-Si:H films using a combination of the hot wire and microwave ECR CVD growth techniques. The films were prepared using W filaments. Films were grown at powers from 175 to 500 W, and the corresponding optical and electronic properties of the films were measured. The temperature of the substrate was varied between ∼200 and 230 °C. It was discovered in the current research that the hot wire could significantly increase the growth rate, about 30 Å/s. The H bonding and electronic properties were found to be dependent critically upon the growth rate and the substrate temperature. In such a system, the hot wire plays an important role in perfecting the microstructure as well as improving the stability and the optoelectronic properties of a-Si:H films. The experimental results indicate that the decrease in hydrogen content in the microstructure of a-Si:H films was the primary reason for the improvement of the stability and the optoelectronic properties of a-Si:H films.