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本文利用BCF模型研究了应变对圆形岛形貌稳定性的影响.通过Gibbs-Thomson关系将应变引入该模型中,讨论了在失配应变、外场应变以及沉积流量、线张力和远场流量等因素共同作用下圆形岛的稳定性,并得到了相应的扰动增长率以及临界沉积流量.研究结果表明:较大的失配应变和远场流量都能促进岛在生长过程中失稳,而线张力可以抑制岛的失稳.随着岛的生长,岛的半径越大越趋于稳定,当岛生长到临界半径后,临界沉积流量随着失配应变的增大而增大.在外场应变存在的情况下,外场负应变对岛的生长起稳定作用并使临界沉积流量减小;相反,正应变促进岛的失稳,且使临界流量增大.这些结论对在薄膜生长过程中控制原子岛的形貌及其稳定性提供了重要的理论依据.
In this paper, the BCF model is used to study the effect of strain on the morphological stability of a circular island. Strain is introduced into the model by the Gibbs-Thomson relationship. The effects of mismatch strain, field strain, sedimentation flux, line tension and far- And the corresponding growth rate of perturbation and the critical sedimentation flow rate are obtained.The results show that both large mismatch strain and far-field flow can promote the instability of the island during growth With the growth of the island, the larger the radius of the island, the more stable the island becomes. When the island grows to the critical radius, the critical sedimentation flow increases with the increase of the mismatch strain. In the presence of external strain, the negative strain stabilizes the island growth and decreases the critical deposition flux. On the contrary, normal strain promotes the instability of the island and increases the critical flux. The morphology of the island and its stability provide an important theoretical basis.