Microstructure of Ti/Al ohmic contacts for n-AlGaN
- 2 November 1998
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 73 (18), 2582-2584
- https://doi.org/10.1063/1.122512
Abstract
Transmission electron microscopy was employed to evaluate the microstructure of Al/Ti ohmic contacts to AlGaN/GaN heterostructure field-effect transistor structures. Contact resistance was found to depend on the structure and composition of the metal and AlGaN layers, and on atomic structure of the interface. A 15–25-nm-thick interfacial layer was observed at the contact-AlGaN interface. Formation of such nitrogen-containing layers appears to be essential for ohmic behavior on n-type III-nitride materials suggesting a tunneling contact mechanism. Contact resistivity was found to increase with Al fraction in the AlGaN layer.
This publication has 12 references indexed in Scilit:
- Ultrahigh Si+ implant activation efficiency in GaN using a high-temperature rapid thermal process systemApplied Physics Letters, 1998
- Investigation of the mechanism for Ohmic contact formation in Al and Ti/Al contacts to n -type GaNApplied Physics Letters, 1997
- Microstructure of Ti/Al and Ti/Al/Ni/Au Ohmic contacts for n-GaNApplied Physics Letters, 1996
- Hall measurements and contact resistance in doped GaN/AlGaN heterostructuresApplied Physics Letters, 1996
- Very low resistance multilayer Ohmic contact to n-GaNApplied Physics Letters, 1996
- A bilayer Ti/Ag ohmic contact for highly doped n-type GaN filmsApplied Physics Letters, 1996
- Emerging gallium nitride based devicesProceedings of the IEEE, 1995
- Low resistance ohmic contacts on wide band-gap GaNApplied Physics Letters, 1994
- Electronic structures and doping of InN, N, and NPhysical Review B, 1989
- Effect of ion-beam sputter damage on Schottky barrier formation in siliconApplied Physics Letters, 1981