Solid State Phenomena Vol. 376

Abstract: The reliability issue of the bipolar degradation in 4H-SiC devices has not been completely eliminated. We have been proposing a screening method for latent defects causing this reliability issue utilizing UV irradiation, which we call the E-V-C (Expansion-Visualization-Contraction) method. This method is based on the property that the REDG (recombination-enhanced dislocation glide) mechanism that causes the bipolar degradation can be reproduced by UV irradiation. However, in order to apply this method as a screening method, accurate quantification of the correlation between current density in forward bias and UV irradiance is required. In this article, we estimated the extent to which the carrier lifetime of the sample affects the quantification of the correlation and found that it had a non-negligible degree of influence on the correlation. Then, we tried to find if there is a simple method for estimating carrier lifetime that can be incorporated in the screening process, and report on our attempts in progress.