ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
One important challenge in SiC Bipolar Junction Transistor (BJT) fabrication is to formgood ohmic contacts to both n-type and p-type SiC. In this paper, we have examined contact studyin a SiC BJT process with sputter deposition of titanium tungsten contacts to both n-type and p-typeregions followed by annealing at different temperatures between 750 oC and 950 oC. The contactswere characterized using linear transmission line method (LTLM) structures. To see the formationof compound phases, X-ray Diffraction (XRD) θ-2θ scans were performed before and afterannealing. The results indicate that 5 minutes annealing at 950 oC of the n+ contact is sufficientwhereas the p+ contacts remain non-ohmic after 30 minutes annealing. The n+ emitter structurecontact resistivity after 5 min annealing with 750 oC and 950 oC was 1.08 × 10-3 5cm2 and4.08 × 10-4 5cm2, respectively. Small amorphous regions of silicon and carbon as well as titaniumtungsten carbide regions were observed by high-resolution transmission electron microscopy(HRTEM), whereas less carbide formation and no amorphous regions were found in a sample withunsuccessful formation of TiW ohmic contacts
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.887.pdf
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