摘要
利用蒙特卡罗(Monte Carlo)方法模拟了Cu薄膜在四方基底上的三维生长过程。模型中考虑了三个主要的原子热运动过程:原子沉积、原子扩散、原子脱附,各过程发生的概率是由各运动的速率来决定的。讨论了基底温度、沉积速率及原子覆盖度对Cu薄膜的表面形貌及表面粗糙度的影响。模拟结果表明:随基底温度升高或沉积速率下降,岛的平均尺寸增大,数目减少,薄膜以层状生长方式生长;Cu薄膜表面粗糙度随温度的升高而减小,当基底温度处于某一临界温度之内时,表面粗糙度随沉积速率的变化很大,但当基底温度超过临界温度时,表面粗糙度随沉积速率的变化很小;薄膜的粗糙度与薄膜亚单层的形核密切相关。
The Cu film growth on surfaces of square-lattice substrate was modeled and simulated in 3-dimensional Monte Carlo method.The model considers three major thermodynamic processes：the deposition,diffusion and desorption of individual Cu atom,with the probabilities depending on the deposition rate,diffusion coefficient,and desorption rate,respectively.The impacts of the film growth conditions,such as the substrate temperature,deposition rate,and Cu coverage,on the microstructures of the film were calculated.The results show that the substrate temperature and deposition rate strongly affects the microstructures of the film.For instance,as the substrate temperature rises up,or the deposition rate decreases,the layer-by-layer growth mode dominates,with small islands coalescing into bigger ones,resulting in smoother surfaces.Below the critical temperature,an increase of the deposition rate roughens the surfaces;whereas above the critical temperature,the deposition rate weakly influences the surface roughness.Possible mechanisms were also tentatively discussed.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2012年第4期328-331,共4页
Chinese Journal of Vacuum Science and Technology
基金
国家重点基础研究发展计划资助项目(2005CB321704)
国家杰出青年科学基金项目(10925209)
