硫系玻璃基底PECVD法沉积光学薄膜工艺研究

摘要

针对硫系玻璃(IRG204)的低软化点特点,为研究等离子体辅助化学气相沉积法(PECVD)在硫系玻璃基底低温沉积薄膜的可行性以及工艺条件,通过氩离子轰击工艺确定基底可承受的离子辅助轰击强度和时间,并在此基础上,以100℃的温度分别制备了SiNx,SiOxNv和SiOxFv薄膜.采用椭偏仪检测薄膜的折射率和厚度,傅里叶红外光谱仪检测薄膜的红外透过率,按GJB 2485-95标准对膜层进行耐摩擦测试.结果表明:氩离子清洗工艺中,射频功率为300W,Ar气流量为50 sccm,压强为30 Pa及轰击时间在30 min以内,对基底材料无损伤.轰击时间为5 min时,镀制的SiNx,SiOxNv和SiOxFy薄膜折射率分别为1.74,1.54和1.39,略低于常规工艺,消光系数小于10-5,与常规工艺无明显差异;镀制的薄膜满足膜层牢固度测试.利用该方法在硫系玻璃上沉积光学薄膜可行,并通过红外光谱分析确定,该方法制备的薄膜材料适用于近红外和中红外波段.%The feasibility and technological conditions of low temperature deposition of chalcogenide glass (IRG204) by PECVD method were studied according to the characteristics of low softening point of IRG204.The material properties of IRG204 were characterized by argon ion bombardment,and the appropriate ion assisted bombardment strength and time were obtained.On this basis,the SiNx,SiOxNy and SiOxFy film were prepared on the chalcogenide glass substrate at 100 ℃,and the refractive index and thickness of thin films were measured by ellipsometry,the infrared transmittance of the films was detected by fourier transform infrared spectroscopy (FTIR).Finally,the film was tested by GJB 2485-95 standard.The results show:While the RF power is 300 W,Ar gas flow rate is 50 sccm,pressure is 30 Pa and bombardment time is less than 30 min,there is no damage to the substrate material.The refractive index of deposition of SiNx,SiOxNy and SiOxFy thin film was 1.74,1.54 and 1.39 respectively when the bombardment time is 5 min.The refractive index is slightly lower than that of the conventional process,and the extinction coefficient is less than 10-5.The prepared films meet the friction test.Therefore,it is feasible to use this method to deposit optical thin films on chalcogenide glass.The infrared spectrum analysis results show the thin films prepared by this method are applied to the near infrared and mid infrared bands.