Formation of Ti/Al ohmic contacts on Si-doped GaN epilayers by low temperature annealing
- 24 May 2000
- journal article
- Published by IOP Publishing in Semiconductor Science and Technology
- Vol. 15 (6) , 585-588
- https://doi.org/10.1088/0268-1242/15/6/317
Abstract
Ohmic contacts have been fabricated on Si-doped GaN using Ti/Al by low temperature annealing at 500 °C. A contact resistivity of 8.6×10-6 ohm cm2 was obtained for n-GaN samples doped to 3.67×1018 cm-3. Secondary ion mass spectrometry (SIMS) analysis showed that Al diffused through the Ti layer after annealing. Furthermore, energy dispersive x-ray spectroscopy (EDS) analysis showed that reaction products of Al, Ti, Ga and N were present at the interface. Hence, a complex ternary or quaternary nitride as a possible low barrier height material to n-GaN may have resulted in good ohmic contact. Photoluminescence (PL) showed that there was no degradation in the epilayer quality of the film after annealing at 500 °C for 25 minutes.Keywords
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