Effect of Nitrogen Doping on the Structure and Optical Properties of N-Type Hydrogenated Amorphous Silicon Thin Films

Hydrogenated amorphous silicon (a-Si:H) thin films doped with both Phosphor and Nitrogen are deposited by ratio frequency plasma enhanced chemical vapor deposition (PECVD). The effect of gas flow rate of ammonia (FrNH3) on the composition, microstructure and optical properties of the films has been investigated by X-ray photoelectron spectroscopy, Raman spectroscopy and ellipsometric spectra, respectively. The results show that with the increase of FrNH3, Si-N bonds appear while the short-range order deteriorate in the films. Besides, the optical properties of N-doped n-type a-Si:H thin films can be easily controlled in a PECVD system.