A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process an...A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process and the silicon thin films are studied by using optical emission spectroscopy （OES） and Fourier transfer infrared （FTIR） spectroscopy, respectively. The results show that when the silane concentration changes from 10% to 1%, the peak frequency of the Si-H stretching mode shifts from 2000 cm-1 to 2100 cm-1, while the peak frequency of the Si-H wagging-rocking mode shifts from 650 cm-1 to 620 cm-1. At the same time the SiH^＊/Ha intensity ratio in the plasma decreases gradually. The evolution of the infrared spectra and the optical emission spectra demonstrates a morphological phase transition from amorphous silicon （a-Si：H） to microcrystalline silicon （μc-Si：H）. The structural evolution and the p-c-SiH formation have been analyzed based on the variation of Ha and SiH^＊ intensities in the plasma. The role of oxygen impurity during the plasma process and in the silicon films is also discussed in this study.展开更多
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA050602)the International Cooperation Project between China-Greece Government (Grant No. 2009DFA62580)the National Basic Research Program of China (Grant Nos. 2011CBA00705, 2011CBA00706, and 2011CBA00707)
文摘A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） method. The deposition process and the silicon thin films are studied by using optical emission spectroscopy （OES） and Fourier transfer infrared （FTIR） spectroscopy, respectively. The results show that when the silane concentration changes from 10% to 1%, the peak frequency of the Si-H stretching mode shifts from 2000 cm-1 to 2100 cm-1, while the peak frequency of the Si-H wagging-rocking mode shifts from 650 cm-1 to 620 cm-1. At the same time the SiH^＊/Ha intensity ratio in the plasma decreases gradually. The evolution of the infrared spectra and the optical emission spectra demonstrates a morphological phase transition from amorphous silicon （a-Si：H） to microcrystalline silicon （μc-Si：H）. The structural evolution and the p-c-SiH formation have been analyzed based on the variation of Ha and SiH^＊ intensities in the plasma. The role of oxygen impurity during the plasma process and in the silicon films is also discussed in this study.
