微波ECR-CVD法制备a-C:F:H膜的红外吸收及其光学带隙  

IR Absorbance and Optical Band Gap of C:F:H Films Deposited with Microwave ECR-CVD Method

作　　者：甘肇强[1] 陆新华[2] 

机构地区：[1]苏州大学物理系,江苏苏州215006 [2]苏州大学化学系,江苏苏州215006

出　　处：《材料科学与工程》2002年第2期163-165,176,共4页Materials Science and Engineering

基　　金：江苏省自然科学基金资助项目(0 0KJB430 0 0 1 )

摘　　要：改变CHF3 CH4 流量比R =[CHF3] ([CHF3]+[CH4 ]) ,采用微波电子回旋共振等离子体化学气相沉积 (MWECR CVD)方法沉积a C :F :H薄膜。a C :F :H薄膜的结构和光学带隙使用傅立叶变换红外光谱和紫外 可见光谱来表征。红外结果表明 ,在低流量比R(R <6 4 % )下 ,薄膜的红外特征结构主要以 CF(10 6 0cm- 1 ) , CF2(112 0cm- 1 )以及 CHx(2 80 0～ 30 0 0cm- 1 )的伸缩振动为主 ;在高流量比R(R >6 4 % )下 ,薄膜表现为类聚四氟乙烯(PTFE)的结构特征 ,典型的红外特征峰是位于 12 2 0cm- 1 处的 -CF2 反对称伸缩振动。薄膜的光学带隙Eg 随流量比R的变化表现为先降后升。进一步研究表明 ,薄膜中的H和F浓度调制着薄膜的CC共轭双键结构 ,使光学带隙Eg 从 2 37到 3a\|C:F:H films are prepared by microwave ECR plasma enhanced chemical vapor deposition method with the variable CHF\-3/CH\-4 gas flow ratios.The structure of the a\|C:F:H film and its optical band gap E\-g are characterized by using fourier transform infrared spectroscopy and ultraviolet\|visible spectroscopy.The results from the FTIR for these films have shown that structural properties of the films with lower flow ratios(R<64%) are composed of \|CF,\|CF\-2 and \|CH\-x stretching modes at 1060cm -1 ,1120cm -1 and 2800\|3000cm -1 ,respectively.At higher flow ratios(R>64%),The film presents a structure of PTFE\|like, where the dominant structural monomer is \|CF\-2 with its typical infrared peak located at 1220cm -1 .The change of the optical band gap of the films with flow ratios R shows a decrease first and then a increase.Further investigation shows that conjugated C=C structures are tuned by H and F concentrations in the film which lead to the change of band gap E\-g between 2\^37eV and 3\^3eV.

关 键 词：微波ECR-CVD法 光学带隙 a-C:F:H薄膜 傅立叶变换红外光谱 紫外可见光谱 类金刚石碳膜 

分 类 号：O484[理学—固体物理]