Plasma and annealing treatments to form height-barrier Ni-based Schottky contact to n-GaN

Tae Ju Lee, Hyeong Seop Im, Tae Yeon Seong

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We investigated the combined effects of plasma and annealing treatments on the electrical and interfacial reactions of Ni/Au Schottky contacts on n-GaN for high-efficiency electronic and optoelectronic devices. Thermionic emission (TE)-based ideal current-voltage model showed that the Schottky barrier heights (SBHs) ranged from 0.68 to 0.92 eV and the ideality factors were in the range of 1.16-2.15. On the other hand, inhomogeneity model and capacitance-voltage characteristics gave similar SBHs in the range of 1.11-1.45 eV. X-ray photoemission spectroscopy (XPS) results displayed that annealing caused the Ga 2p core level to shift toward lower energies by 0.17-0.18 eV, while plasma treatment induced the Ga 2p core level to shift toward higher energies by 0.12 eV. The XPS Ni 2p core level results exhibited that annealing samples at 600°C gave rise to the formation of NiO and Ni2O3 in addition to Ni3Ga4 and Ni3Ga interfacial phases, which were confirmed by X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) results. Based on the XPS, XRD, and STEM results, the annealing and plasma-treatment-induced increase in the SBHs is described and discussed.

Original languageEnglish
Pages (from-to)Q194-Q199
JournalECS Journal of Solid State Science and Technology
Issue number10
Publication statusPublished - 2019 Jan 1


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

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