Abstract
The annealing temperature dependence of rectifying contact characteristics on epilayers of n-GaN using a ZrB 2 /Ti/Au metallization scheme deposited by sputtering are reported. A maximum barrier height of 0.57 eV was achieved on samples annealed at 200 °C, with the reverse breakdown voltage of the diodes also a maximum after this anneal. The barrier height was essentially independent of annealing temperature up to 700 °C even though Auger electron spectroscopy depth profiling showed the onset of inter-contact metallurgical reactions at 500 °C. The Ti began to outdiffuse to the surface at temperatures of 350 °C, while the ZrB 2 /GaN interface showed no evidence of reaction even at 800 °C. The reverse current magnitude of diodes fabricated using the ZrB 2 contacts was larger than predicted by thermionic emission alone.
| Original language | English |
|---|---|
| Pages (from-to) | 2315-2319 |
| Number of pages | 5 |
| Journal | Applied Surface Science |
| Volume | 253 |
| Issue number | 4 |
| DOIs | |
| State | Published - Dec 15 2006 |
| Externally published | Yes |
Funding
The work at UF is partially supported by AFOSR grant under grant number F49620-03-1-0370, by the Army Research Office under grant no. DAAD19-01-1-0603, NSF (CTS-0301178, monitored by Dr. M. Burka and Dr. D. Senich) and the National Science Foundation (DMR 0400416, Dr. L. Hess).
Keywords
- Contacts
- GaN
- Schottky