Investigation of silicon-germanium films deposited by plasma-enhanced chemical vapor deposition using laser assistance

To avoid the undesirable thermal treatment in high temperature, we proposed a new technique to deposit Si-Ge films on Si substrate in room temperature and without thermal post-annealing process. Since CO₂ laser can be used as an energy source to induce gas-phase pyrolysis of SiH₄ in a reactor, we used CO₂ laser to assist the deposition of Si-Ge films on Si substrate in a conventional plasma-enhanced chemical deposition system (PECVD). An external CO₂ laser beam with a wavelength of 10.6 μm was guided into the chamber of the conventional PECVD system. To deposit Si-Ge films on Si substrate without heating, argon-diluted SiH₄ (4%) and GeH₄ were used as reactant gas sources. In this study, the surface morphology of a-SiGe:H thin films grown with various laser power densities was examined using atomic force microscopy (AFM). The bonding configuration was analyzed by Raman spectroscopy and Fourier transmission infrared (FTIR) spectroscopy. copyright The Electrochemical Society.