电子助进化学气相沉积金刚石中衬底温度对发射光谱的影响

采用蒙特卡罗方法，对以CH4/H2为源料气体的电子助进化学气相沉积(EACVD)金刚石中的氢原子(H_α,H_β和H_γ)、碳原子C(2p3s→2p2: λ=165.7 nm)以及CH(A2Δ→X2Π: λ=420～440 nm)的发射过程进行了模拟，研究了衬底温度对各发射谱线以及金刚石膜合成的影响。结果得知，各谱线强度随衬底温度的变化幅度很小，且在衬底表面附近的谱线强度随衬底温度的变化幅度相对于远离衬底的反应区域较大，这表明衬底温度的变化基本上不改变远离衬底的反应区域中反应基团成分，而只对衬底表面附近的反应过程有影响。由此得知，衬底温度对薄膜质量的决定性主要是由于衬底温度改变了衬底表面化学反应动力学过程和表面附近的反应基团的缘故，而不是衬底温度对反应空间中气相成分的影响。

Effect of Substrate Temperature on Optical Emission Spectra in Electron-Assisted Chemical Vapor Deposition of Diamond

The optical emission spectra of atomic hydrogen (H_α,H_β and H_γ),atomic carbon C(2p3s→2p2: λ=165.7 nm) and radical CH(A2Δ→X2Π: λ=420-440 nm) in the gas phase process of the diamond film growth with electron-assisted chemical vapor deposition (EACVD) from a gas mixture of CH4 and H2 were studied by using Monte-Carlo simulation. The effects of substrate temperature on the optical emission spectral and diamond synthesis were investigated. The results showed that the range of variation of intensities of optical emission spectra near the substrate with the substrate temperature is wider than that far from the substrate,suggesting that the substrate temperature just affects the gas phase reaction process near the substrate,and the strong dependence of the quality of diamond film on the substrate temperature is due to the change in phase process near the substrate brought by the substrate temperature.