Dependence of electrical properties on work functions of metals contacting to p-type GaN
| Autor: | Seiji Nagai, Junichi Umezaki, Masayoshi Koike, Hidenori Ishikawa, Yasuo Koide, Setsuko Kobayashi, Masanori Murakami, Shiro Yamasaki |
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| Rok vydání: | 1997 |
| Předmět: |
Materials science
Annealing (metallurgy) Schottky barrier Contact resistance Tantalum Analytical chemistry General Physics and Astronomy chemistry.chemical_element Surfaces and Interfaces General Chemistry Chemical vapor deposition Condensed Matter Physics Surfaces Coatings and Films Metal chemistry visual_art visual_art.visual_art_medium Work function Ohmic contact |
| Zdroj: | Applied Surface Science. :373-379 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/s0169-4332(97)80110-9 |
| Popis: | The effects of GaN surface treatments and work functions of the contact metals on the electrical properties at the p-GaN/metal interfaces were investigated. A contamination layer consisting of GaO x and adsorbed carbons was found on the GaN substrate grown by metalorganic chemical vapor deposition. Most of the contamination layer was removed by annealing the Ni and Ta contacts at temperatures close to 500°C, resulting in slight increase of the current injection from the contact metal to the GaN. The resistance at the p-GaN/metal interfaces decreased exponentially with increasing the metal work functions, indicating that the Schottky barrier heights were sensitive to the metal work functions. The present study concluded that the contact metal with the large work function should be chosen to obtain for the non-reacted (non-alloyed) ohmic contacts to the p-GaN. However, non-reacted ohmic contacts to the p-GaN did not provide the low contact resistance required for blue laser diodes. |
| Databáze: | OpenAIRE |
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