High-resolution elemental profiles of the silicon dioxide/4H-silicon carbide interface

High-resolution elemental profiles were obtained from SiO2(N)/4H-SiC structures by spatially resolved electron energy-loss spectroscopy (EELS) performed in the scanning transmission electron microscopy mode. The results show that following annealing in NO, N was exclusively incorporated within similar to 1 nm of the SiO2(N) /4H-SiC interface. Mean interfacial nitrogen areal densities measured by EELS were similar to(1.0 +/- 0.2) x 10(15) cm(-2) in carbon-face samples and (0.35 +/- 0.13) x 10(15) cm(-2) in Si-face samples; these results are consistent with nuclear reaction analysis measurements. Some of the interface regions in the C-face samples also showed excess carbon that was not removed by the NO annealing process, in contrast with previous results on Si-face samples. (c) 2005 American Institute of Physics.