衬底温度对ZnO薄膜生长过程和微结构的影响

从原子尺度上去研究薄膜生长过程中温度对薄膜取向性、缺陷结构以及薄膜完整性的影响和作用规律, 对于解释薄膜生长的物理本质、控制生长条件、提高薄膜制备的质量具有重要意义. 本文应用基于反应力场的分子动力学方法研究了ZnO薄膜(000l)表面作为衬底的薄膜沉积生长过程, 初步讨论了衬底温度(200、500和800 K)变化对沉积较薄ZnO膜质量的影响, 部分结果与实验观察相符. 结果表明, 衬底温度在500 K左右时, 沉积原子结构径向分布函数曲线特征峰尖锐、明显, 有序度较高, 注入和溅射对薄膜完整性影响较小, 沉积形成的薄膜结构稳定而又致密. 在预置衬底表面平坦的情况下薄膜呈现一种链岛状的生长模式, 每原子层均具有两种生长取向, 导致其生长前锋交汇处形成了一种新的有序缺陷.

Effect of Substrate Temperature on the Growth and Microstructure of ZnO Film

Understanding the effect of temperature on the orientation, microstructure, integrity, and growth mechanism of ZnO films on the atomic scale is needed to clarify the process of film growth, control deposition conditions, and improve film quality. Using the reaction force field method of molecular dynamics, we theoretically studied the effect of substrate temperature (200, 500, and 800 K) on the quality of ZnO films. Some of our results agree with experimental observations. We found that the radial distribution function curves of the deposited structures were sharp and highly ordered. The thin film formed at 500 K possessed the most stable and ordered structure of those investigated. The film grew with an island mechanism, and two orientations were present on every deposited atomic plane, which led to the formation of a special fault structure at interfacial regions.