Radio Frequency Power Dependence of Defect Density at Hydrogenated Amorphous Silicon Interface

Abstract

ABSTRACTA hydrogenated amorphous silicon (a-Si:H) interface fabrication technology for the plasma CVD method, which can produce low interface defect density, is presented. The relation between the interface defect density and radio frequency (RF) power was investigated. As a result, the difference between the interface defect density and the bulk defect density decreased with increasing the RF power. A high RF power (25 W) a-Si:H buffer layer 5 nm thick was deposited on the interface before depositing low RF power (5 W) a-Si:H layer with a low bulk defect density. It has been found that the ideal defect density distribution, which shows the uniform distribution with the very low defect density (4.2×1014 cm) from the i/i interface to the bulk, can be accomplished by 5 nm buffer layer.