Experimental evidence for complementary spatial sensitivities of capacitance and charge deep-level transient spectroscopies

Complementary capacitance and charge deep-level transient spectroscopy (DLT S) spectra of Cr-implanted 4H-SiC(n) Schottky diodes were measured to verif y the predicted spatial sensitivities of the two methods. The magnitude of the peak of the dominant 0.73 eV Cr-related defect level was taken as a mea sure of the spatial sensitivity, while analysing the capacitance and charge DLTS signals in terms of the internal and external released charges, respe ctively. The amounts of the respective internal and external charges were f ound to be equal at the crossover point x(c) between the dominant emitting level and the bulk Fermi level, the crossover being positioned by the appli ed quiescent bias at a depth where x(c)/w approximate to 0.5, w standing fo r the width of the depletion region. This is exactly the value forecast by state-of-the-art theory. Finally: the only significant difference between t he trap density profiles N-T(x), as reconstructed from the two complementar y DLTS techniques, was found close to the maximum accessible depth x.