NONLINEAR-OPTICAL MAPPING OF 3C-INCLUSIONS IN 6H-SIC-EPILAYERS

Optical second-harmonic generation (SHG) is shown to be a powerful tec hnique for identifying different polytypes of SiC-films deposited on 6 H-SiC substrates. The rotational anisotropy of the SHG radiation refle cted from homo-epitaxially grown 6H-SiC epilayers provides a clear fin gerprint of microcrystalline inclusions of 3C-SiC. The large dynamic r ange of the SHG response of more than one order of magnitude between d ifferent SiC polytypes allows a fast nondestructive mapping of SiC waf er surfaces with a lateral resolution in the mu m-regime. (C) 1997 Els evier Science S.A.