a-Ge/Au双层膜退火后分形区的形成

本文用透射电子显微镜观察了a-Ge/Au双层膜在不同退火温度后出现的分形区域,并计算了它们的分数维数。100℃退火时,触发分形结晶区的成核位较少,形成良好的具有无规分叉、自相似的分形区,分数维数为1.785±0.01。200℃退火时,成核位迅速增加,除了分数维数为:1.818±0.008的分形区外,还出现孤立的无枝叉结构的岛状区域。300℃退火时,只出现尺寸很不相同的两种岛状区域,对上述枝叉伏、岛状区域的出现以及a-Ge膜的晶化和Au膜缩聚之间的关系进行了讨论。 关键词：

APPEARENCE OF FRACTAL REGION IN ANNEALED a-Ge/Au BILAYER THIN FILMS

Fractal regions in a-Ge/Au bilayer thin films after annealing at different temperatures were investigated by TEM, and fractal dimensions were calculated. For 100℃ annealing, un-cleating positions are fewer, large tenuous scale-invariant regions formed with fractal dimension of 1.785±0.01, for 200℃ annealing, uncleating positions increased rapidly, besides thic- ker fractal region with fractal dimension of 1.818±0.008, many isolated island-like regions formed. After 300℃ annealing, only two kind of island-like regions formed with very different size. The relationship between crystallization of a-Ge film, condensation of Au film and mechanism of appearence of fractal region was discussed based on structural and quantitative analyses.