UV scanning photoluminescence spectroscopy applied to silicon carbide characterisation

An UV scanning photoluminescence (SPL) equipment has been developed in order to study both structural defects at a microscopic scale and the homogeneity of physical properties at the wafer scale in silicon carbide. In one hand, the optical signature of micropipes, screw dislocation and triangular defects are presented. In most of the cases the SPL signal decrease for micropipes because of the defect geometry. In the case of dislocation, a signal exhaust in the neighbourhood of the defect is observed and attributed to the gettering effect of non radiative traps at the immediate vicinity of the defect. For triangular defects, we tentatively ascribe the PL spectra observed to Shockley stacking faults. In the other hand, a method to obtain the minority carrier lifetime mapping from the integrated PL signal is described. The mapping of this parameter is of prime interest both for the material quality control and for bipolar deviceʹs development.