离子束辅助沉积Al_2O_3薄膜的微观状态及其物理特性研究

Microstructures and Physical Properties of Al_2O_3 FilmsSynthesized by lon Beam Assisted Deposition

本文利用透射电子显微镜、原子力显微镜、X光电子能谱等微观分析手段 ,系统研究了氧离子束辅助离子束沉积方法制备的Al2 O3 薄膜的化学成分、微观结构、表面形貌及其随退火温度的变化 ,并对Al2 O3 薄膜折射率、显微硬度和膜基结合强度等物理特性及其随沉积温度的变化进行了详细研究。研究发现 :用离子束辅助沉积制备的薄膜基本满足Al2 O3 的标准成分配比 ;在沉积温度低于 5 0 0℃制备的Al2 O3 薄膜以非晶Al2 O3 相a Al2 O3 为主 ;Al2 O3 薄膜的表面粗糙度、折射率、显微硬度随沉积温度的增加而增加 ;当沉积温度高于 2 0 0℃时 ,薄膜与基体间的膜基结合强度将随沉积温度的增加而下降。分析表明 :薄膜表面形貌与晶体内部的结构相变有关 ,薄膜的退火相变途径为a Al2 O380 0℃ γ Al2 O310 0 0℃ γ Al2 O3 +α Al2 O312 0 0℃ α Al2 O3 。

Al 2O 3 films have been synthesized by ion beam assisted deposition(IBAD).Electron microscopy,atomic force microscopy,and X ray diffraction analysis have been applied to characterize the microstructures,morphologies,and compositions of the films and their annealing behaviors.We have found that the films synthesized by IBAD are stoichiometrical Al 2O 3 films.When the substrate temperatures are lower than 500 ℃,the films are dominated by amorphous phase a Al 2O 3 and the surface roughness,refraction index,and micro hardness increase with the increase of substrate temperature.The adhesion property of the film to substrate,however,will go bad when the substrte temperature is higher than 200 ℃.The change of film morphology is related with the microstructures of the films during annealing.The process of phase transition of film is a Al 2O 3800 ℃γ Al 2O 31000 ℃γ Al 2O 3+ α Al 2O 31200 ℃ α Al 2O 3.