使用倾角电子束蒸发技术制备了TiO2雕塑薄膜, 通过对雕塑薄膜在不同退火温度和退火时间下进行热处理, 发现热处理工艺可以优化薄膜的双折射特性和相位延迟性能。实验结果表明, TiO2雕塑薄膜的最佳退火条件为500 ℃下处理4 h, 其双折射值达0.115左右, 远高于未处理时的最大双折射值(0.06)。椭偏仪测试结果表明, 最优条件下热处理后的薄膜, 在550 nm处相位延迟量达90°, 可以作为该波长处的λ/4波片使用。因此, 热退火是改善雕塑薄膜双折射性能的一种简单实用的方法。

TiO2 sculptured thin films are prepared by oblique angle electron beam deposition. After heat treatment at different annealing temperature and time, the properties of birefringence and phase retardance are optimized. The results illustrate that the optimum annealing condition is for 4 h at 500 ℃ and the maximum birefringence is up to 0.115, which is far higher than the as-deposited films. According to the measurement of ellipsmetry, the phase retardance is about 90°at 550 nm, which means that it is suitable as a wave plate. Therefore, thermal annealing is a useful and feasible method to improve birefringence of sculptured thin films.