Characteristics of Hydrogenated Amorphous Silicon Films Prepared by Electron Cyclotron Resonance Microwave Plasma Chemical Vapor Deposition Method and Their Application to Photodiodes

Abstract

The electron cyclotron resonance microwave plasma chemical vapor deposition (ECRPCVD) method has been applied to prepare a-Si:H films. A high deposition rate of 136 nm/min was achieved. Even without substrate heating and with the high deposition rate, a-Si:H films prepared by ECRPCVD have sufficient characteristics, as follows: the dark conductivity is 3-4×10-10S/cm, ηµτ is 4.2×10-5cm2/V and the optical band-gap is 1.81 eV. Furthermore, the electric characteristics are somewhat improved with substrate heating. Hydrogenated amorphous silicon films prepared by ECRPCVD without substrate heating and with a high deposition rate of 136 nm/min have been applied to ITO/a-Si:H/Cr Schottky-barrier photodiodes. These photodiodes have sufficient characteristics to be applied to image sensors for a facsimile reader and other systems.