On expanding recombining plasma for fast deposition of a-Si:H thin films

摘要

A high-density expanding recombining plasma is investigated for deposition of a-Si:H thin films. The deposition method allows high growth rates and it relies on separation of plasma production in a high-pressure thermal arc, and transport of fragments of injected SiH4monomer to the substrate. Some characteristics of the plasma are discussed together with an explanation of the dominant chemical kinetics, which proceed mainly through heavy-particle interactions. The deposition results indeed show very high growth rates from 2-30 nm s-1on areas of 30 cm2. The properties of the layers are characterized by measuring their refractive index (in the range 3.1-3.8) and bandgap 1.2-1.5 eV). Analysis of the oxygen content in the deposited films shows oxidation of the samples in air, which is probably associated with the microstructure of the layers.