We demonstrate ohmic contacts to SiC using carbon films after thermal annealing. Carbon films are deposited on 4H-SiC and 6H-SiC substrates using a radio frequency sputtering method. The carbon/SiC samples convert from Schottky behavior to ohmic behavior after annealing in the temperature range from 1150 to 1350°C. Nanosize graphitic flakes are identified after annealing by Raman spectroscopy and are associated with the ohmic behavior of the contacts. The contact behavior of carbon films on 4H-SiC and 6H-SiC after annealing are compared and the polytype of the SiC has no effects on the structural evolution of the carbon films during annealing. This study reveals that the structural evolution of carbon is associated with formation of ohmic contacts on SiC and that nanosize graphitic flakes play a determinative role in the formation of ohmic contacts.
The structural properties of sputtered carbon films on SiC are investigated using X-ray photoelectron spectroscopy (XPS) and Raman scattering. The asdeposited films are amorphous with an sp 2 /sp 3 ratio of 1. The sp 2 carbon structures gradually increase with increasing temperatures and consist of amorphous aromatic-like carbon, polyene-like carbon, and nano-size graphite flakes. Schottky contacts on carbon/SiC are converted to ohmic contacts after annealing. The concentration of nano-graphitic flakes relative to the aromatic-like and polyene-like carbon increases nearly linearly with annealing temperature. Stacked graphitic structures are not observed. The specific contact resistivities are at 10 Ϫ3 -10 Ϫ4 ⍀cm 2 on the carbon/SiC after annealing from 1050°C to 1350°C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.