大気圧プラズマCVD法によるアモルファスSiの高速成膜に関する研究 (第1報) 回転電極型大気圧プラズマCVD装置の設計・試作

A new technique for high speed a-Si deposition using the atmospheric pressure plasma with the cylindrical rotary electrode was developed. The advantages of using rotary electrode are as follows; 1) the reactant gases can be introduced efficiently into the small gap between the electrode and the substrate and 2) a large rf power can be supplied without thermal damage of the electrode. A 150 MHz VHF power supply was employed to avoid the ion bombardment of the electrode and the substrate. In the consequence of these advantages, high density radicals are produced and high quality amorphous silicon films can be deposited with high growth rate. The silicon films were fabricated in gas mixtures containing helium, hydrogen and monosilane. They were investigated by Raman spectroscopy and scanning electron microscopy (SEM). The results showed that amorphous silicon films with uniform structure were grown on the glass substrates. The maximum deposition rate was 38nm/s, which was extremely faster than those of the previous techniques. It was also found from the SEM obsevation that the thickness of the silicon films were uniform and no particles were observed inside the films.