Epitaxial growth of 4H-SiC{0001} and reduction of deep levels

Hornoepitaxial growth of 4H-SiC{0001} by hot-wall chemical vapor deposition (CVD) and characterization of deep levels in both n- and p-type epilayers have been investigated. On 4 degrees off-axis 4H-SiC(0001), formation of macrosteps can be reduced by decreasing the C/Si ratio during CVD, though the growth condition leads to the increase in nitrogen incorporation. The 4H-SiC(000 (1) over bar) face is promising, owing to its very smooth surface morphology even on 4 degrees off-axis substrates and to its superior quality of the oxide/SiC interface. Deep level transient spectroscopy measurements in the wide temperature range from 100 K to 820 K on both n- and p-type 4H-SiC epilayers have revealed almost all the deep levels located in the whole energy range of the bandgap. Thermal annealing at 1350-1700 degrees C of epilayers has resulted in reduction of deep level concentrations by one order of magnitude. (c) 2006 Elsevier Ltd. All rights reserved.