Novel network control in hydrogenated amorphous silicon by molecular beam deposition method

Abstract

A molecular beam deposition (MBD) method has been developed in order to study hydrogenated amorphous silicon (a-Si:H) which has a different structure from a-Si:H fabricated by conventional methods such as plasma-enhanced chemical vapor deposition (PECVD). The dependence of film properties on hydrogen ambient pressure and the electric-field bias was investigated. We found that the MBD a-Si:H has a different Si–H 2 bond structure from that of the PECVD a-Si:H and we observed that the film structure and the film properties were considerably modified by electric bias application to a substrate holder and a grid-electrode. The defect density increment of MBD a-Si:H by light exposure was noticeably small compared to that of PECVD a-Si:H. Here we discuss the structure and metastability of MBD a-Si:H in comparison with PECVD a-Si:H.