不同CHF3/CH4流量比下沉积a-C∶F∶H薄膜键结构的红外分析

通过微波电子回旋共振等离子体化学气相沉积方法使用CH₄/CHF₃源气体制备a-C∶F∶H薄膜.红外结果表明,a-C∶F∶H薄膜随着流量比R=CHF₃]/CHF₃]+CH₄])的变化存在结构上的演变,R<64%时,薄膜主要是以类金刚石(DLC)特征的结构为主;当R>64%时,薄膜表现为一个类聚四氟乙烯(PTFE)的结构,结构单体主要为CF₂.同时这种结构上的变化影响着薄膜 关键词： a-C∶F∶H薄膜 傅里叶变换红外光谱 紫外可见光谱

INFRARED ANALYSIS OF BOND CONFIGURATION FOR THE a-C:F: H FILMS DEPOSITED AT VARIABLE CHF3/CH4 FLOW RATIOS

a-C∶F∶H films are prepared by microwave ECR plasma-enhanced chemical vapor deposition method at variable CHF₃/CH₄ gas flow raitos. The results from the Fourier transform-infra-red abserption for these films have shown that a structural evolution of the a-C∶F∶H film occurs at variable flow ratios R =CHF₃]/(CHF₃]+CH₄]). The main structure of the films is diamond-like carbon (DLC) characteristics for R less than 64%. The film presents a structure of PTFE-like as R is larger than 64%, where the dominant structural monomer is —CF₂. Meanwhile, this structural evolution has also an influence on optical gap of the films. Optical gap decreases with the increase of flow ratios in the region of DLC-like characteristics, while increasing in the PTFE-like region. The transmittance of the a-C∶F∶H film is close to 100% for R larger than 92%.