Deposition of Thin SiOx Films by Direct Precursor Injection in Atmospheric Pressure Microwave Torch (TIA)

Abstract

AbstractAn axial injection torch (TIA, Torche à Injection Axiale) contained in an open air deposition chamber has been exploited to deposit thin silicon oxide films. The organosilicon precursor, tetramethylsilane (TMS), was injected directly in the plasma gas. A parametric study was carried out to study the effects of microwave power, precursor quantity and torch to substrate distance on the film deposition process. Inorganic films were obtained without the addition of oxygen in the system as the oxygen got incorporated in the plasma from the open air, as shown by optical spectroscopic studies on the plasma. The deposited films were characterised using different techniques like Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), elastic recoil detection analysis (ERDA), Rutherford backscattering spectroscopy (RBS) and nuclear resonance analysis (NRA). These analyses helped understanding the factors affecting the film deposition process. Results show that at short processing time, low microwave plasma power and precursor quantity at an optimised torch to substrate distance, thin non‐porous hydrogenated silicon oxide‐like films can be deposited at low substrate temperatures of around 370 K using this technique.