Secondary ion mass spectroscopic depth profile analysis of oxygen contamination in hydrogenated microcrystalline silicon

Oxygen contamination of samples fabricated by very high-frequency plasma-enhanced chemical vapor deposition with the variation of silane concentration and discharge power was studied by secondary ion mass spectroscopy. The results showed that oxygen content in the samples depended strongly on the silane concentration and discharge power. Microcrystalline silicon thin films with higher crystalline volume fraction has relatively higher oxygen content. Oxygen contamination of samples was also related with the background vacuum, especially for microcrystalline silicon thin films. Therefore, higher background vacuum is extremely necessary in the fabrication of high-quality microcrystalline silicon thin films.