Au-free ohmic Ti/Al/TiN contacts to UID n-GaN fabricated by sputter deposition
| Autor: | Barbara Abendroth, David Rafaja, Valentin Garbe, Alexander Schmid, Juliane Weise, Dirk C. Meyer, Mykhaylo Motylenko, Wolfram Münchgesang |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Diffusion barrier Annealing (metallurgy) Metallurgy Analytical chemistry Intermetallic General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Sputter deposition 021001 nanoscience & nanotechnology 01 natural sciences X-ray photoelectron spectroscopy chemistry Transmission electron microscopy 0103 physical sciences 0210 nano-technology Tin Ohmic contact |
| Zdroj: | Journal of Applied Physics. 121:065703 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4975485 |
| Popis: | The fabrication and characterization of an Au-free Ti/Al/TiN (20/100/100 nm) contact stack to unintentionally doped n-GaN with TiN serving as the diffusion barrier is presented. Sputter deposition and lift-off in combination with post deposition annealing at 850 °C are used for contact formation. After annealing, contact shows ohmic behavior to n-GaN and a specific contact resistivity of 1.60 × 10−3 Ω cm2. To understand the contact formation on the microscopic scale, the contact was characterized by current–voltage measurements, linear transmission line method, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results show the formation of Ti-N bonds at the GaN/Ti interface in the as-deposited stack. Annealing leads to diffusion of Ti, Al, Ga, and N, and the remaining metallic Ti is fully consumed by the formation of the intermetallic tetragonal Al3Ti phase. Native oxide from the GaN surface is trapped during annealing and accumulated in the Al interlayer. The ... |
| Databáze: | OpenAIRE |
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