Modular Approach for Metal–Semiconductor Heterostructures with Very Large Interface Lattice Misfit: A First-Principles Perspective

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• 作者：Weiyu Xie ; Michael Lucking ; Liang Chen ; Ishwara Bhat ; Gwo-Ching Wang ; Toh-Ming Lu ; Shengbai Zhang
• 刊名：Crystal Growth & Design
• 出版年：2016
• 出版时间：April 6, 2016
• 年：2016
• 卷：16
• 期：4
• 页码：2328-2334
• 全文大小：464K
• ISSN：1528-7505

文摘

Realizing high-quality heteroepitaxy of a wide variety of films of very large lattice misfit, f ≥ 10%, with the substrate is a great challenge, but also a potential advancement, because the films may be made threading-dislocation-free as all the dislocations will be confined at the interface. In spite of the numerous experimental findings in the literature, first-principles theory for such systems is virtually nonexistent due to their intrinsic heterogeneity; namely, away from the interface, the film is strain free, but at the interface, not only strain but also misfit dislocation develop. Here, a modular approach is proposed to study such heterogeneous films by a combined first-principles and elasticity theory method to predict, for example, their epitaxial relationship. Four representative metal–semiconductor interfaces, Al(111)/Si(111), Cu(111)/Si(111), Cu(001)/Si(001), and CaF₂(111)/Ni(001), are considered. By taking into account the chemical bonding information at the interface by first-principles theory, our results show good agreement with experiments. Moreover, by constructing the electron localization function (ELF) that utilizes the first-principles results, we are able to demonstrate the formation of interfacial covalent bonds between Si and metal atoms.