Diffusion and effusion of hydrogen in microcrystalline silicon

摘要

The diffusion and effusion of hydrogen in hydrogenated microcrystalline silicon films deposited in an electron cyclotron resonance reactor were studied for various deposition temperatures T_s.For deposition temperatures below 250 deg C, hydrogen effusion is found to be dominated by desorption of hydrogen from internal surfaces folllwoed by rapid out-diffusion of H_2. Higher substrate temperatures result in an increased hydrogen stability suggesting the growth of a more compact material.For this latter type of samples,a suggesting the growth of a more compact material.For this latter type of samples,a hydrogen diffusion coefficient similar as in compact plasma-grown a-Si:H films is found despite a different predominant bonding of hydrogen according to infrared absorption.