Abstract
Improved performance of the ohmic contacts on n-GaN has been demonstrated with the use of MoAu as the capping layer on TiAl metallization. Contact resistance as low as 0.13 Ω-mm was achieved in these ohmic contacts when annealed at 850°C for 30 sec. We have studied the long-term thermal stability of these contacts at 500°C, 600°C, 750°C, and 850°C, respectively. The Ti/Al/Mo/Au metallization forms low contact-resistance ohmic contacts on n-GaN that are stable at 500°C and 600°C after 25 h of thermal treatment. The ohmic-contact performance degrades after 10 h of thermal treatment at 750°C, while the contacts exhibit nonlinear current-voltage (I-V) characteristics after 1 h of thermal treatment at 850°C with the formation of oxide on the surface of the contacts accompanied by surface discoloration. The intermetallic reactions taking place in the contacts during the long-term thermal treatments were studied using Auger electron spectroscopy (AES), and the surface morphology was characterized using atomic force microscopy (AFM).
Original language | English |
---|---|
Pages (from-to) | 335-340 |
Number of pages | 6 |
Journal | Journal of Electronic Materials |
Volume | 32 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2003 |
Keywords
- GaN
- Ohmic contacts
- Thermal stability
- Ti/Al/Mo/Au
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry