Abstract
We demonstrate the use of germanium passivation in conjunction with a ZnO interlayer in a metal-interlayer-semiconductor structure in a source/drain (S/D) contact. The Fermi-level pinning problem resulting in the large contact resistances in S/D contacts is effectively alleviated by inserting a thin Ge passivation layer and a ZnO interlayer, passivating the GaAs surface and reducing the metal-induced gap states on the GaAs surface, respectively. The specific contact resistivity for the Ti/ZnO/Ge/n-GaAs (~2 × 1018 cm-3) structure exhibits a ~1660× reduction compared with that of a Ti/n-GaAs structure. These results suggest that the proposed structure shows promise as a nonalloyed ohmic contact in high-electron-mobility transistors.
Original language | English |
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Article number | 7151781 |
Pages (from-to) | 884-886 |
Number of pages | 3 |
Journal | IEEE Electron Device Letters |
Volume | 36 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2015 Sep 1 |
Keywords
- Fermi level unpinning
- Specific contact resistivity
- gallium arsenide
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering