【摘要】 采用反应射频磁控溅射方法,在Si(100)基片上制备了具有高c轴择优取向的ZnO薄膜.利用原子力显微镜、透射电子显微镜、X射线衍射分析、拉曼光谱等表征技术,研究了沉积温度对ZnO薄膜的表面形貌、晶粒尺度、应力状态等结晶性能的影响;通过沉积温度对透射光谱和光致荧光光谱的影响,探讨了ZnO薄膜的结晶特性与光学性能之间的关系.研究结果显示,在室温至500℃的范围内,ZnO薄膜的晶粒尺寸随沉积温度的增加而增加,在沉积温度为500℃时达到最大;当沉积温度为750℃时,ZnO薄膜的晶粒尺度有所减小;在室温至750℃的范围内,薄膜中ZnO晶粒与Si基体之间均存在着相对固定的外延关系;在沉积温度低于500℃时,制备的ZnO薄膜处于压应变状态,而750℃时沉积的薄膜表现为张应变状态.沉积温度的不同导致ZnO薄膜的折射率、消光系数、光学禁带宽度以及光致荧光特性的变化,沉积温度对紫外光致荧光特性起着决定性的作用.此外,探讨了影响薄膜近紫外光致荧光发射的可能因素.更多还原

【Abstract】 Using reactive radio-frequency magnetron sputtering, ZnO films with strong c-axis orientation have been deposited on Si (100) substrates at temperatures ranging from room temperature (RT) to 750℃. We have studied the influence of growth temperature on the structural characteristics of the as-deposited films in morphology, grain size, microstructure, and residual stress by using atomic force microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. With the measurement of the transmission spectra and photoluminescence (PL) properties, the relationship between the crystallinity and optical properties of ZnO films have been discussed. It is found that the grain size increases with temperature up to 500℃, and then decreases at 750℃. ZnO grains have an epitaxial relationship with Si (100) substrate for the films deposited at the temperatures ranging from RT to 750℃. The films deposited below 500℃ are in the states of compressive strain while the film deposited at 750℃ is in tensile. The difference in growth temperature results in the variation of refractive index, extinction coefficient, optical energy gap, and PL properties of the films. It is concluded that growth temperature dominates the PL behavior of ZnO films. We also discuss the physical mechanism affecting the PL behavior.更多还原