退火处理对ZnO薄膜结晶性能的影响

Influence of Postdeposition Annealing on Crystallinity of Zinc Oxide Films

研究了退火处理对 Zn O薄膜结晶性能的影响 .Zn O薄膜由直流反应磁控溅射技术制得 ,并在 O2 气氛中不同温度 (2 0 0～ 10 0 0℃ )下退火 ,利用 X射线衍射 (XRD)、原子力显微镜 (AFM)和 X射线光电子能谱 (XPS)对其结晶性能进行了研究 ,提出了一个较为完善的 Zn O薄膜退火模型 .研究表明 :热处理可使 c轴生长的薄膜取向性增强 ;随退火温度的升高 ,薄膜沿 c轴的张应力减小 ,压应力增加 ;同时晶粒度增大 ,表面粗糙度也随之增加 .在 6 4 0℃的应力松弛温度 (SRT)下 ,Zn O薄膜具有很好的 c轴取向 ,沿 c轴的应力处于松弛状态 ,晶粒度不大 ,表面粗糙度较小 ,此时 Zn O薄膜的结晶性能最优 .

The influence of postdeposition annealing on the crystallinity of ZnO films is investigated.ZnO films are prepared by DC reactive magnetron sputtering,and then annealed in oxygen ambient at different temperature (200～1000℃).The properties are examined by X-ray diffraction (XRD),atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).An annealing model for ZnO films is proposed,through which the effect of annealing treatment on the crystallinity of ZnO films is discussed in detail.The as-grown films possessed c -axis orientation,which is enhanced in the annealing process.When the annealing temperature shows up,the tensile stress along c -axis orientation decreases,while the compressive stress increases;at the same time,the grain size of the film is reduced,which results in a much rougher surface.ZnO films possessed a better crystallinity at the stress release temperature (SRT) about 640℃,such as high c -axis orientation,almost stress free and low surface roughness.