Short-Length Step Morphology on 4° Off Si-Face Epitaxial Surface Grown on 4H-SiC Substrate
We developed a production technology for epitaxial growth with a smooth surface morphology for 4º off Si-face 4H-SiC epitaxial layers on 100 mm-diameter substrates. High-contrast topography images by optical surface analyzer revealed that a step bunching free surface was obtained throughout the whole area of the wafer surface. However, short-length steps still remained locally on the epitaxial surfaces. Using photoluminescence imaging, it was clarified that the short-length steps were morphological in nature and did not contain stacking faults. The short-length steps were generated by step-flow growth pinning caused by the shallow pits of threading screw dislocations revealed by molten KOH etching.
Anton J. Bauer, Peter Friedrichs, Michael Krieger, Gerhard Pensl, Roland Rupp and Thomas Seyller
K. Momose et al., "Short-Length Step Morphology on 4° Off Si-Face Epitaxial Surface Grown on 4H-SiC Substrate", Materials Science Forum, Vols. 645-648, pp. 115-118, 2010