衬底温度对ZnO薄膜氧缺陷的影响

采用射频磁控溅射在石英玻璃和单晶硅Si(100)衬底上制备了ZnO薄膜，研究了衬底温度对ZnO薄膜中氧缺陷的影响。实验发现，ZnO薄膜c轴取向性随温度的升高而增强；当衬底温度达到550。C时，XRD谱上仅出现一个强的(002)衍射峰和一个弱的(004)衍射峰，显示ZnO具有优异c轴取向性。同时，随着温度的升高，ZnO薄膜的紫外透射截止边带向高波长方向漂移，其电导率也随衬底温度的升高逐渐增大，表明薄膜中的氧缺陷逐渐增多。这种氧缺陷是由于ZnO的氧平衡分压高于Zn所致，可通过提高溅射气体中氧含量来改善。

Influence of Substrate Temperature on Oxygen Defects of ZnO Thin Films

Zinc oxide thin films have been deposited by RF magnetron sputtering on crystal Si(100) and fused silica substrates. In this paper, the influence of substrate temperature on the oxygen defects of ZnO thin films has been investigated. It was demonstrated by XRD that c-axis orientation of the filmsbecame better with increasing substrate temperature; and at the substrate temperature of 550oC, only strong XRD peak of ZnO (002) plane appeared accompanied with a weak (004) peak, which indicated that ZnO thin film was completely c-axis oriented. Besides,with the increase of substrate temperature, the UV absorption edge of the films shifted toward large wavelength, and the conductivity of the films increased. It is attributed to the oxygen defects of the films increased as the temperature elevated due to the higher vapor pressure of oxygen than that of zinc in ZnO. It is approved by the experiment that the oxygen defects in ZnO thin films can be improved by increasing oxygen ratio during sputtering.