Intrinsic compressive stress in polycrystalline films with negligible grain boundary diffusion
Intrinsic compressive stress in polycrystalline films with negligible grain boundary diffusion
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DOI：
10.1063/1.1575916
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发表时间：
2003-06
影响因子：
3.2
通讯作者：
B. Sheldon;A. Ditkowski;R. Beresford;E. Chason;J. Rankin
中科院分区：
文献类型：
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作者：
B. Sheldon;A. Ditkowski;R. Beresford;E. Chason;J. Rankin
这里开发的模型描述了连续多晶膜（即，超过单个岛已经合并成连续膜的点）。这些应力是由于多余的吸附原子在晶界的插入。当薄膜顶部的应变能被表面吸附原子的局部过剩化学势平衡时，就会出现稳态。与这种压缩应力机制相关的应变梯度取决于该过程的动力学。在没有晶界扩散的情况下，这些应变分布由原子插入速率和生长速率的比率决定。稳态应变和应变演化动力学也取决于两个关键的长度尺度，晶粒尺寸和膜厚度。这两个长度的比率（即，如果晶粒尺寸足够小，晶粒纵横比）也可以对应变演化的热力学驱动力具有显著影响。模型...
The model developed here describes compressive stress evolution during the growth of continuous, polycrystalline films (i.e., beyond the point where individual islands have coalesced into a continuous film). These stresses are attributed to the insertion of excess adatoms at grain boundaries. Steady state occurs when the strain energy at the top of the film is balanced by the local excess chemical potential of surface adatmos. Strain gradients associated with this compressive stress mechanism depend on the kinetics of the process. In the absence of grain boundary diffusion, these strain profiles are determined by the ratio of the atom insertion and growth rates. The steady-state strain and the strain evolution kinetics also depend on the two key length scales, the grain size, and the film thickness. The ratio of these two lengths (i.e., the grain aspect ratio) can also have a significant influence on the thermodynamic driving force for strain evolution if the grain sizes are sufficiently small. The model ...