By Topic

Electrical properties and microstructure of ternary Ge/Ti/Al ohmic contacts to p-type 4H–SiC

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Tsukimoto, S. ; Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan ; Sakai, T. ; Murakami, M.

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.1797546 

The high-power SiC devices require ohmic contact materials, which are prepared by annealing at temperatures lower than 800 °C. Recently, we demonstrated in our previous paper [J. Appl. Phys. 95, 2187 (2004)] that an addition of a small amount of Ge to the conventional binary Ti/Al contacts reduced the ohmic contact formation temperature by about 500 °C, and this ternary contacts yielded a specific contact resistance of approximately 1×10-4 Ω cm2 after annealing at a temperature as low as 600 °C. In this paper, the electrical properties and the microstructures of the Ge/Ti/Al contacts (where a slash “/” indicates the deposition sequence) were investigated by current-voltage measurements and transmission electron microscopy observations, respectively, in order to understand the ohmic contact formation mechanism. Ti3SiC2 compound layers (which were previously observed at the metal/SiC interface in the Ti/Al ohmic contacts after annealing at temperatures higher than 1000 °C) were observed to grow epitaxially on the SiC surface after annealing at temperatures as low as 600 °C. The Ti3SiC2 layers were believed to act as a p-type intermediate semiconductor layer, which played a key role to reduce the Schottky barrier height at the contacting metal/SiC interface. Further reduction of the conta- ct resistances of the Ge/Ti/Al contacts would be achieved by increasing the coverage of the Ti3SiC2 layers on the SiC surface.

Published in:

Journal of Applied Physics  (Volume:96 ,  Issue: 9 )