Abstract
The annealing temperature (25-700°C) dependence of Schottky contact characteristics on n-GaN using a TiB 2/Ti/Au metallization scheme deposited by sputtering is reported. The Schottky barrier height increased from 0.65 to 0.68 eV as the anneal temperature was varied from 25°C to 350°C and decreased to 0.55 eV after annealing at 700°C. The barrier height showed no measurable dependence on measurement temperature up to 150°C. The elemental profile obtained from samples annealed at 350°C showed limited Ti diffusion from the elemental Ti layer into the gold layer. Annealing at 700°C produced significant out-diffusion of this layer, while the TiB 2 layer retained its stability. These contacts show promise for applications requiring good thermal stability, such as power amplifiers, but much more work is needed to establish their long-term reliability. In addition, TiB 2 has a strong propensity for oxidation, and it is imperative that overlayers such as Au be deposited in the same deposition chamber.
| Original language | English |
|---|---|
| Pages (from-to) | 658-662 |
| Number of pages | 5 |
| Journal | Journal of Electronic Materials |
| Volume | 35 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2006 |
| Externally published | Yes |
Funding
The work at UF is partially supported by the AFOSR (F49620-03-1-0370), the Army Research Office (DAAD19-01-1-0603), and the NSF (CTS-0301178, monitored by Dr. M. Burka and Dr. D. Senich, and DMR 0400416, Dr. L. Hess).
| Funders | Funder number |
|---|---|
| National Science Foundation | CTS-0301178, DMR 0400416 |
| Air Force Office of Scientific Research | F49620-03-1-0370 |
| Army Research Office | DAAD19-01-1-0603 |
| University of Florida |
Keywords
- GaN
- Schottky barrier height
- Thermal stability