Carbon Structural Transitions and Ohmic Contacts on 4H-SiC
Authors: Lu, Weijie; Mitchel, William C.; Thornton, Candis A.; Landis, G.R.; Collins, W. Eugene
Source: Journal of Electronic Materials, Volume 32, Number 5, 1 May 2003 , pp. 426-431(6)
Abstract:The structural properties of sputtered carbon films on SiC are investigated using X-ray photoelectron spectroscopy (XPS) and Raman scattering. The as-deposited films are amorphous with an sp2/sp3 ratio of 1. The sp2 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 10-3-10-4 Ωcm2 on the carbon/SiC after annealing from 1050°C to 1350°C.
Document Type: Research Article
Publication date: May 1, 2003