沉积温度和速率对电子束沉积ZnSe薄膜应力特性的影响

Influences of deposition temperature and rate on mechanical stress of electron beam deposited ZnSe thin films

在不同沉积温度和速率下,采用电子束蒸发法制备ZnSe薄膜样品,利用ZYGO GPI型干涉仪测试样品的应力行为,并采用X射线衍射(XRD)技术测试样品的晶向特征.实验结果表明,在不同条件下制备的ZnSe薄膜均呈现压应力,应力随着沉积温度升高而增大,在200℃应力达到最大值,之后应力随沉积温度升高呈下降趋势.XRD结果表明,沉积速率直接影响ZnSe薄膜的晶向结构,进而改变ZnSe薄膜内应力;当沉积速率为1.5 nm/s时,薄膜应力最小.

The stress and microstructure characteristics of zinc selenide （ZnSe） single layer deposited by electron beam evaporation at various substrate temperatures and deposition rates were investigated. The ZYGO GPI interferometer and X-ray diffractometer were employed to measure the stress and orientation features of the samples, respectively. The experimental results demonstrate that the ZnSe thin films prepared under different conditions present compressive stress. The mechanical stress is maximum at substrate temperature of 200 ℃, then the stress decreases as the temperature increases above 200 ℃. The X-ray spectroscopy reveals that the evolution of stress with deposition rate attributes to the changes of microstructure. The lowest stress was obtained at the deposition rate of 1.5 nm/s.