热退火对ZnO薄膜表面形貌与椭偏特性的影响  

Thermal Annealing Effect on Characteristics of Surface Morphology and Ellipsometric of Zinc Oxide Film

作　　者：刘磁辉[1] 林碧霞[1] 王晓平[1] 朱俊杰[1] 钟声[1] 傅竹西[1] 

机构地区：[1]中国科学技术大学物理系,安徽合肥230026

出　　处：《发光学报》2004年第2期151-155,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金重大研究计划重点课题(90201038)

摘　　要：利用原子力显微镜(AFM)和椭偏仪对溅射制备的硅基ZnO薄膜的热退火表面形貌与椭偏特性进行了研究。结果发现:未退火或低温退火(≤850℃)薄膜的形貌呈现较弱的各向异性,晶粒尺寸大小较为均匀,尺寸约为50 nm。当经高温退火后,ZnO薄膜的晶粒尺寸明显增大,同时伴随晶粒尺寸分布非均匀化,较大的尺寸可达400 nm,而较小的尺寸仅为50 nm。此外,椭偏测量表明:椭偏参数在不同的退火温区的变化呈现明显差别;当退火温度高于850℃时,薄膜的结构有明显的变化。Zinc oxide, as one of novel photoelectric materials, has been drawn much attention recently due to its many advantages. For example, its large band gap of 3.37 eV and high excitonic binding energy of 60 meV make ZnO a good candidate for developing short wavelength optoelectronic devices. Furthermore, the p-doping ZnO can be produced and the p-n structure of ZnO can be formed on the silicon substrate, their characteristics make ZnO to be compatible with Si-based integrated circuits. Hence, ZnO film has wider application in optical and electronic industries. ZnO films can be easily prepared by several techniques such as reactive sputtering, chemical vapor deposition, and molecular beam epitaxy. The film prepared by sputtering has good adhesive to the substrate and its composition can be easily controlled in the deposition process. However, as compared to the films prepared by other methods, the stress of sputtering film is more obvious, the grain size is smaller and the defect density of grain interface is rather larger accordingly. Such disadvantages of sputtering film may degrade its physical properties, such as the intensity of photoluminescence, quantum efficiency of emission and respondence of current-voltage (I-V) behavior. Many studies have demonstrated that the thermal annealing process is a conventional way to improve the quality of sputtering film. For example, after annealing ZnO film in high temperature, it was found from the deep level tran- sient spectroscopy (DLTS) and I-V measurements that some deep energy levels, which might depress the intensity of luminescence of the film, could be removed from the film and the electrical properties of the film were also optimized. As to further understand the thermal annealing effect on the properties of ZnO film, in this paper we utilize atomic force microscopy (AFM) and ellipsometry to study the ann

关 键 词：氧化锌薄膜材料 热退火 原子力显微镜 椭偏测量 半导体材料 椭偏参数 薄膜结构 

分 类 号：O472.1[理学—半导体物理]