Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-05-12T08:18:22.894Z Has data issue: false hasContentIssue false
  • English
  • Français

Ti/AlNi/W Ohmic Contacts to P-Type SiC

Published online by Cambridge University Press:  01 February 2011

Bang-Hung Tsao ,
Jacob Lawson  and
James Scofield
Bang-Hung Tsao
Affiliation:
bang.tsao@wpafb.af.mil, University of Dayton Research Institute, Metals and Ceramics, 300 College Park, Dayton, OH, 45469-0179, United States, 9372556549, 9372553211
Jacob Lawson
Affiliation:
jacob.lawson@wpafb.af.mil, University of Dayton Research Institute, Metals and Ceramics, 300 College Park, Dayton, OH, 45469-0179, United States
James Scofield
Affiliation:
james.scofield@wpafb.af.mil, AFRL/PRPE, WPAFB, OH, 45433, United States
Get access

Abstract

Improved AlNi-based ohmic contacts to p-type 4H-SiC have been achieved using low energy ion (Al+) implantation, the addition of a thin Ti layer, and a novel two-step implant activation anneal process. Resistivities sometimes as low as 5×10−5 Ω-cm2 were reached by doping the surface region of lightly p-doped 4H-SiC epilayers via low energy Al+ implantation. Acceptor activation was achieved by annealing the samples with a 1400+1700°C two-step sequence in an Ar atmosphere, which also yielded improved surface morphology when implanted samples were capped with photo resist during the anneals. In this study, Ti/AlNi/W contacts on implanted layers were compared to Ti/AlNi/Au contacts. Even though the resistivities are higher than those of the Ti/AlNi/W system, the reduced anneal temperature, 650°C for Ti/AlNi/Au compared to 950°C for Ti/AlNi/W implies that Ti/AlNi/Au is a promising stacking configuration. Furthermore, the effects of a longer 30 minute anneal time at 600 − 700°C, in atmospheric pressure Ar ambients was observed. Namely, the 2 minute annealing cycle used for the Ti/AlNi/W study resulted in higher anneal temperatures before ohmic characteristics were seen. This same anneal time was not sufficient for the Ti/AlNi/Au samples, whereas increasing the cycle time to 30 minutes resulted in ohmic behavior at a much lower temperature. Increasing the anneal time however, had little or no impact on reducing the required anneal temperature of the Ti/AlNi/W.

Keywords

deviceselectrical propertiespackaging
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 911: Symposium B – Silicon Carbide 2006 – Materials, Processing and Devices , 2006 , 0911-B11-03
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Davis, R.F. et al.: Materials Science and Engineering, Vol. B1, (1988), p77.Google Scholar
[2] Liu, S., Tsao, Bang-Hung, and Scofield, J: 6th Int'l High Temp. Elect. Conf., CD-ROM, (2002).Google Scholar
[3] Crofton, J., Beyer, L., Williams, J., Luckowski, E., and DeLucca, J.: Solid State Electronics, Vol. 41, No 11, (1997), 1725.Google Scholar
[4] Mahoney, S.E., Hull, B.A., Lin, J.Y., and Crofton, J.: Solid State Electronics, Vol. 46 (2002), p689.Google Scholar
[5] Tsao, Bang-Hung, Lawson, Jacob and Scofield, J: ICSCRM 2005, CD-ROM.Google Scholar
[6] Tsao, Bang-Hung, Lawson, Jacob and Scofield, J: 3rd International Energy Conversion Engineering Conference 2005, CD-ROMGoogle Scholar