On the effect of the substrate pretreatment parameters on the composition and structure of plasma deposited SiO2 thin films

Abstract

The role of the substrate pretreatment using wet and dry cleaning procedures, on SiO2 thin film adhesion, integrity and composition was investigated. The SiO2 depositions were performed in a 27.12 MHz RF plasma reactor and an interelectrode space of 20 mm. The depositions were carried out on different substrates (magnesium, aluminum and c-Si) and at the low temperature of 100 °C. From the wet cleaning methods the use of 5 % HF aqueous solution was found to significantly improve the SiO2 thin film adhesion in all substrates. Even better results were achieved with the application of H2 plasma pretreatment, indicating that the etching during the plasma pretreatment results to better conditions for the film growth and the surface step coverage, especially on non-uniform and rough substrates.