等离子体增强化学气相沉积氮化碳薄膜过程中的光学发射谱研究

利用光学发射谱技术对直流辉光放电等离子体增强的化学气相沉积氮化碳薄膜过程中的等离子体进行了原位诊断,结果表明主要的辐射有N2的第二正系跃迁、N2^ 的第一负系跃迁、CN和NH的紫外跃迁。研究了气源中氢气含量、放电电流及沉积气压的变化对N2（337.1nm),N2^ (391.4nm)和CN(388.3nm)辐射强度的影响,并在此基础上探讨了这几种跃迁的激发机制,其结果为氮化碳合成中优化沉积参数、控制实验过程提供了依据。

Spectroscopic Diagnoses of Glow Discharge Plasma for the Carbon Nitride Growth Process

Plasma diagnostics is performed during dc.glow discharge plasma-enhanced chemical vapor deposition (PECVD)on nitride thin films using optical emission spectra.Several molecular bands such as the second positive series of N 2 transitions,the first negative series of N + 2 and the CN,NH violet bands are identified.Variations of the emission intensities of N 2(337.1 nm),N + 2(391.4 nm) and CN(388.3 nm) are investigated as the function of the percentage of H 2,discharge current and deposition pressure.The related excitation mechanism of the species emission is discussed.Experimental results show that adding a small amount of H 2(about 5%) into the gas source will be beneficial to produce all the active species.Higher discharge current will result in an increase of the active species concentration while there is maximum emission intensity at medium gas pressure at about 4 kPa.The collisions between the species,including metastable nitrogen and hydrogen are related with the concentration variations of the measured species.All the results and discussion provide reference data for optimizing the deposition parameters and controlling the deposition process in the synthesis of carbon nitride thin films.