金属氧化物薄膜在中波红外光谱区内光学常数色散特性

Dispersive Properties of Optical Constants of Some Metallic Oxide Thin Films in the Mid-Infrared Regions

基于金属氧化物薄膜材料在中波红外波段应用的需求,研究了含水状态的TiO2、HfO2、Ta2O5和Y2O34种金属氧化物薄膜在中波红外波段内（2.5～5μm）光学常数的色散特性。利用电子束蒸发沉积技术,在超光滑的硅表面制备了4种氧化物薄膜,基于洛仑兹振子介电常数色散模型,通过透射率光谱反演计算了4种氧化物薄膜的光学常数。研究结果表明：4种氧化物均有少量的水分子、羟基,水含量从少到多的薄膜依次为TiO2、HfO2、Ta2O5和Y2O3,在远离水吸收的位置,消光系数从小到大的薄膜分别为TiO2、HfO2、Ta2O5和Y2O3;在电子束蒸发沉积工艺条件下,为了降低水的影响,TiO2和HfO2是中红外波段较为理想的金属氧化物薄膜材料。

Based on the application demands of metallic oxide thin films in the mid-infrared, the optical constants dispersion characteristics of four kinds of metallic oxide films of TiO2, HfO2, Ta2O5 and Y2O3 in the mid-infrared （2.5～5μm） region in moisture state are studied, the four kinds of metallic oxide films are prepared on the super polishing silicon substrates using electron beam evaporation deposition technology, and based on the Lorentz oscillator dielectric constant dispersion model, the optical constants of the four kinds of oxide thin films are calculated using the transmittance spectra inversion method. The results show that all the four kinds of oxide films have a small amount of water molecules and hydroxyl. In increasing order of water content of these films are TiO2, HfO2, Ta2O5 and Y2O3, and far away from the location of the water absorption, in increasing order of extinction coefficient of these films areTiO2, HfO2, Ta205 and Y2 03. In order to reduce the effects of water absorption, Ti02 and Hf02 are the comparative ideal metallic oxide materials in the mid-infrared region under the condition of the electron beam evaporation deposition process.