Comparative investigation of Schottky barrier height of Ni/n-type Ge and Ni/n-type GeSn

作者:Jheng Li Sian; Li Hui; Chang Chiao; Cheng Hung Hsiang*; Li Liang Chen
来源:AIP Advances, 2017, 7(9): 095324.
DOI:10.1063/1.4997348

摘要

We report an investigation of the Schottky barrier height (SBH) of Ni/n-type Ge and Ni/n-type GeSn films that is annealed at a wide range of temperatures. Both voltage-and temperature-dependent current-voltage (I-V) measurements are performed. From the analysis of these nonlinear I-V traces, the SBH is found and the results shows that the SBH of Ni/n-type GeSn (a) is smaller than that of Ni/n-type Ge and (b) decreases with the Sn content of the surface GeSn layer associated with the thermal annealing. By modeling the composition-and strain-dependent energy bandgap (E-g), the relationship between the SBH and Eg is established and it is found that SBH/E-g similar to 0.8. These results suggest that the GeSn film could serve as an interfacial layer for the reduction of the SBH in Ge-based electronic devices that are desirable for applications.

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