Hj. Im et al., NANOMETER-SCALE INVESTIGATION OF METAL-SIC INTERFACES USING BALLISTIC-ELECTRON-EMISSION MICROSCOPY, Journal of electronic materials, 27(4), 1998, pp. 345-352
We report ballistic-electron emission microscopy (BEEM) investigation
of Pd, Pt Schottky contacts on 6H-, 4H-SiC, and Pd/15R-SiC. Measured S
chottky barrier heights of 6H- and 4H-SiC samples appear spatially uni
form up to the fitting error due to noise (0.03-0.04 eV and 0.1-0.2 eV
for 6H- and 4H-SiC, respectively). In 4H-SiC, we observed an addition
al conduction band minimum (CBM) similar to 0.14 eV above the lowest C
BM, which provide direct experimental verification of band theoretical
calculation results. Additionally, we sometimes observed enhancement
in ballistic transmittance over regions intentionally stressed by hot
electron injection using BEEM. We also report recent results on Pd/15R
-SiC sample indicating a higher CBM similar to 0.5 eV above the lowest
CBM. In Pd/15R-SiC, interesting large variations in BEEM spectra at d
ifferent locations were observed, possibly suggesting an inhomogeneous
metal/semiconductor interface.