射频负偏压对沉积类金刚石薄膜结构和性能的影响

Effect of RF negative bias on structure and performance of DLC films prepared by ECR-RF-PECVD

在不同的射频负偏压作用下,利用微波电子回旋共振(ECR)等离子体源化学气相沉积技术在单晶硅表面进行制备类金刚石薄膜研究。利用傅立叶变换红外吸收光谱(FTIR)和原子力显微镜(AFM)对薄膜的结构成分和形貌进行了分析表征,同时对所制备的薄膜摩擦系数进行了测试。结果表明:所制备的薄膜具有典型的含H类金刚石结构特征,薄膜结构致密均匀、表面粗糙度小。随着负偏压的增大,红外光谱中2800cm-1～3000cm-1波段的C-H伸缩振动吸收峰的强度先升高后降低,在射频功率为50W时达到最大,所对应的薄膜摩擦系数是先降低再升高,在射频功率为50W时达到最小。

Diamond-like carbon （DLC） films were prepared on monocrystalline silicon surface by way of microwave ECR- RF-PECVD （electron cyclotron resonance-radio frequency-plasma enhanced chemical vapor deposition） under different negative biases. The film＇s chemical composition structure and morphology were characterized by Fourier transformation infrared spectroscopy （FTIR） and atomic force microscopy （AFM）, with its friction coefficient determined through testing. The results showed that the smooth and compact DLC fibns are typically hydrogenated and that with the increasing RF bias the intensity of the absorption peak due to C-H stretching vibration in the range from 2800cm^-1 to 3000cm^-1 of infrared spectra increases first then decreases and becomes maximum when the RF power is 50W. On the contrary, the friction coefficient of the film decreases first then increases and becomes minimum when the RF power is 50W.