Depth Profiling of Carrier Lifetime in Thick 4H-SiC Epilayers Using Two-Photon Absorption
Depth profiling of the ambipolar carrier lifetime was performed in n-type, 140mm thick silicon carbide (SiC) epilayer using excitation by two-photon absorption (TPA) with a pulsed 586nm laser, and confocal measurement of time resolved photoluminescence (TRPL) decay from the excited region. A depth resolution of ≈10mm was obtained. The PL decay curves were analyzed using a recently developed formalism that takes into account the TPA excitation, carrier diffusion and surface/interface recombination. The carrier lifetime decreases near the top surface of the epitaxial layer as well as near its interface with the substrate.
Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis
N. A. Mahadik et al., "Depth Profiling of Carrier Lifetime in Thick 4H-SiC Epilayers Using Two-Photon Absorption", Materials Science Forum, Vol. 924, pp. 265-268, 2018