ZnS衬底上二维亚波长结构抗反射表面的制备及性能研究

Fabrication and Characterization of 2-Dimensional Sub-Wavelength Antireflective Surface on ZnS Substrate

采用接触式紫外光刻和反应离子刻蚀工艺在ZnS衬底上制备二维亚波长结构抗反射表面。在优化的光刻工艺下,以CH4、H2及Ar的混合气体为刻蚀剂,研究了刻蚀工艺对刻蚀速率和刻蚀形貌的影响。结果表明,刻蚀速率随着射频功率的增大线性增大,随着工作压强的增加先增大后减小,随着CH4含量的增大先增大后降低。功率过大会导致刻蚀产物发生二次沉积,CH4流量过高会导致聚合物的生成加剧,这些都会影响刻蚀形貌。最后在优化的刻蚀工艺下制备出了8～12μm波段具有较好的宽波段增透效果的二维亚波长结构。

The 2-dimensional sub-wavelength antireflective structures（AR-SWS） were fabricated on ZnS substrate by contact ultraviolet lithography,and reactive ion etching.The surface microstructures were characterized with scanning electron microscopy and atomic force microscopy.The impacts of the conditions of lithography and etching on morphologies of the surface were studied.The results show that the etching conditions strongly affect the surface patterns.For example,the etching rate increases with an increase of RF power;the rate varies in an increase-then-decrease mode,as the pressure and the CH4 flow rate increase.However,high RF power results in re-deposition of the etched matters;and large CH4 flow rate promotes the polymer layer growth.The 2-dimensional sub-wavelength AR-SWS,in a bandwidth of 8 μm to 12 μm,were successfully fabricated under the optimized lithography and etching conditions.