Li Hongfei, Guo Yuzheng, Robertson John
Engineering Dept, Cambridge University, Cambridge, CB2 1PZ, UK.
College of Engineering, Swansea University, Swansea, UK.
Sci Rep. 2017 Nov 30;7(1):16669. doi: 10.1038/s41598-017-16803-6.
Density functional supercell calculations of the Schottky barrier heights (SBH) of metal germanides and silicides on Si or Ge find that these vary with the facet, unlike those of elemental metals. In addition, silicides and germanides show a stronger dependence of their SBHs on the work function than those of elemental metals, as seen experimentally. Both effects are beyond the standard metal induced gap states model. NiSi is found to have a much lower SBH on n-Si(100) than on n-Si(111), as seen experimentally. It is shown how such results can be used to design lower SBH contacts for n-Ge, which are needed technologically. The SBHs of the better behaved Si/silicide interfaces can be used to benchmark the behavior of the less well behaved Ge-germanide interfaces for this purpose. The dependence of the SBH of epitaxial Pb-Si(111) on its reconstruction is also covered.
对硅化物和锗化物在硅或锗上的肖特基势垒高度（SBH）进行的密度泛函超胞计算发现，与元素金属不同，这些势垒高度随晶面而变化。此外，如实验所见，硅化物和锗化物的SBH对功函数的依赖性比元素金属更强。这两种效应都超出了标准的金属诱导能隙态模型。如实验所见，发现NiSi在n-Si(100)上的SBH比在n-Si(111)上低得多。展示了如何利用这些结果来设计技术上所需的用于n-Ge的更低SBH接触。性能较好的Si/硅化物界面的SBH可用于为此目的对性能较差的Ge-锗化物界面的行为进行基准测试。还涵盖了外延Pb-Si(111)的SBH对其重构的依赖性。
