1. Department of Physics, Key Laboratory for Irradiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064, China 2. Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China 3. International Center for Material Physics, Chinese Academy of Sciences, Shenyang 110015, China
Abstract：Bromine doped hydrogenated amorphous carbon (a-C∶Br∶H) thin films were deposited on silicon wafers by rf.-plasma enhanced chemical vapor deposition (RF-PECVD) with a frequency of 13.56 MHz at room temperature using pure bromoethane as a precursor of carbon source mixed with hydrogen (H2) as a carrier gas. The structures of the films prepared by partial pressure of mixed gas (C2H5Br/H2) were studied by Raman spectroscopy. The results indicate that the intensity of the Raman D peak is stronger, the Raman G peak positions shift up a little, and the value of ID/IG increases from 1.18 to 1.36, if the gas pressure of mixed C2H5Br/H2 is reduced gradually from 20 to 5 Pa. Meanwhile, the growth of thin film turns gradually into low energy mode promoting the transform of sp2-C from chains to rings.
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