Authors: F A Mohammad Y Cao L M Porter
Publish Date: 2007/02/16
Volume: 36, Issue: 4, Pages: 312-317
Abstract
Ohmic contacts to ntype 4H and 6HSiC without postdeposition annealing were achieved using an interlayer of epitaxial InN beneath a layer of Ti The InN films were grown by reactive dc magnetron sputtering at 450°C whereas the Ti films were deposited by electronbeam evaporation at room temperature The InN films were characterized by xray diffraction XRD secondary electron microscopy SEM crosssectional transmission electron microscopy TEM and Halleffect measurements Both XRD and TEM observations revealed that the Ti and InN films have epitaxial relationships with the 6HSiC substrate as follows 0001 11bar 20 Ti∥0001 11bar 20 InN∥0001 11bar 20 6HSiC The Ti/InN/SiC contacts displayed ohmic behavior whereas Ti/SiC contacts without an InN interlayer were nonohmic These results suggest that InN reduces the Schottky barrier height at the SiC surface via a small conductionband offset and support previous reports of an electron accumulation layer at the surface of InNThe authors gratefully acknowledge the research support from the National Science Foundation Grant Nos ECS9875186 and DMR0354939 The films in this study were grown using equipment funded by the National Science Foundation Grant No DMR9802917 Valuable discussions with Dr Kumar Das Tuskegee University are also greatly appreciated
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