Abstract
This research attempted to use metals with lower work functions, such as Ti, Al, to form ohmic contacts to n-GaN. Then we used metals with higher work functions, such as Ni, Pd, Pt, and Au to form ohmic contacts to p-GaN. The work functions of these metals indeed influence the performance of ohmic contacts, indicating that the Fermi level of GaN is unpinned. The specific contact resistance measured and calculated by TCL model, was 2.35×10-3 Ωcm2 for as-deposited Ti/Al on GaN. After RTA processes at different temperatures in the range of 400 to approximately 900 °C, the minimum ρc of 7.4×10-5 Ωcm2 can be obtained for RTA temperature of 600 °C. The oxidized Ni/Au contact exhibited the lowest contact resistance of 1.02×10-2 Ωcm2, among Ni/Au, Pd/Au, Pt/Au contact schemes on p-GaN. It was also observed that the I-V curves of the triple-layer contact, Pt/Ni/Au, was near-linear while the others were rectifying even after annealing.
| Original language | English |
|---|---|
| Pages (from-to) | 224-233 |
| Number of pages | 10 |
| Journal | Proceedings of SPIE - The International Society for Optical Engineering |
| Volume | 3938 |
| Publication status | Published - 2000 Jan 1 |
| Event | Light-Emitting Diodes: Research, Manufacturing, and Applications IV - San Jose, CA, USA Duration: 2000 Jan 26 → 2000 Jan 27 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering
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Ohmic contacts to GaN with rapid thermal annealing. / Chi, L. W.; Lam, K. T.; Kao, Y. K.; Juang, F. S.; Tsai, Y. S.; Su, Y. K.; Chang, S. J.; Chen, C. C.; Sheu, J. K.
In: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 3938, 01.01.2000, p. 224-233.Research output: Contribution to journal › Conference article
TY - JOUR
T1 - Ohmic contacts to GaN with rapid thermal annealing
AU - Chi, L. W.
AU - Lam, K. T.
AU - Kao, Y. K.
AU - Juang, F. S.
AU - Tsai, Y. S.
AU - Su, Y. K.
AU - Chang, S. J.
AU - Chen, C. C.
AU - Sheu, J. K.
PY - 2000/1/1
Y1 - 2000/1/1
N2 - This research attempted to use metals with lower work functions, such as Ti, Al, to form ohmic contacts to n-GaN. Then we used metals with higher work functions, such as Ni, Pd, Pt, and Au to form ohmic contacts to p-GaN. The work functions of these metals indeed influence the performance of ohmic contacts, indicating that the Fermi level of GaN is unpinned. The specific contact resistance measured and calculated by TCL model, was 2.35×10-3 Ωcm2 for as-deposited Ti/Al on GaN. After RTA processes at different temperatures in the range of 400 to approximately 900 °C, the minimum ρc of 7.4×10-5 Ωcm2 can be obtained for RTA temperature of 600 °C. The oxidized Ni/Au contact exhibited the lowest contact resistance of 1.02×10-2 Ωcm2, among Ni/Au, Pd/Au, Pt/Au contact schemes on p-GaN. It was also observed that the I-V curves of the triple-layer contact, Pt/Ni/Au, was near-linear while the others were rectifying even after annealing.
AB - This research attempted to use metals with lower work functions, such as Ti, Al, to form ohmic contacts to n-GaN. Then we used metals with higher work functions, such as Ni, Pd, Pt, and Au to form ohmic contacts to p-GaN. The work functions of these metals indeed influence the performance of ohmic contacts, indicating that the Fermi level of GaN is unpinned. The specific contact resistance measured and calculated by TCL model, was 2.35×10-3 Ωcm2 for as-deposited Ti/Al on GaN. After RTA processes at different temperatures in the range of 400 to approximately 900 °C, the minimum ρc of 7.4×10-5 Ωcm2 can be obtained for RTA temperature of 600 °C. The oxidized Ni/Au contact exhibited the lowest contact resistance of 1.02×10-2 Ωcm2, among Ni/Au, Pd/Au, Pt/Au contact schemes on p-GaN. It was also observed that the I-V curves of the triple-layer contact, Pt/Ni/Au, was near-linear while the others were rectifying even after annealing.
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M3 - Conference article
AN - SCOPUS:0033738918
VL - 3938
SP - 224
EP - 233
JO - Proceedings of SPIE - The International Society for Optical Engineering
JF - Proceedings of SPIE - The International Society for Optical Engineering
SN - 0277-786X
ER -