超薄膜多中心生长过程的计算机模拟

利用计算机模拟了不同的允许扩散步数下超薄膜的多中心分形生长和团状生长现象，研究了成核及长大的动力学过程．分形生长时分形维数随团簇大小的增大而增加．分形生长和团状生长时成核率随扩散步数的增大而减小，随时间的增大而急速下降．团簇长大过程可用团簇大小S和生长时间t-t₀的幂函数(t-t₀)^κ描述．由于团簇间的分流作用，生长指数κ比经典理论值1略小，并且存在着非线性现象，即长得较大的团簇的生长指数Κ也较大.关键词：

SIMULATION ON MULTIPLE CLUSTER GROWTH IN ULTRA-THIN FILMS

The multiple cluster growth with fractal or compact morphology in ultra-thin films has been simulated with various permitted diffustion steps. It is shown that the fractal dimension increases with increasing cluster size in the fractal growth. The nucleation rate decreases with increasing diffusion steps and drops rapidly with increasing deposition time. The cluster size S can be described by a power law as S-(t-t₀)^κ, where (t-t₀) is the growth time. The growth index κ is slightly smaller than 1 given by the classical nucleation and growth theory, due to the branching effect between clusters. A nonlinear phenomenon (i.e., the larger the cluster size, the larger the growth index κ) has been obtained.