S-EVC Method for Sorting Wafers with Defects that Extend to Bar Shaped SSFs

In the previous report [1], we proposed S-EVC (Selective Expansion-Visualization-Contraction) method (Fig. 1) that effectively screens for malignant BPDs (basal plane dislocations) in drift and buffer layers, which expand to SSFs (Shockley-type stacking faults), leading forward voltage degradation. The intentionally utilizes REDG (recombination enhanced dislocation glide) mechanism by UV (ultraviolet) irradiation wafer sorting replace so-called burn-in (accelerated current stress) process, is time-consuming during mass production. report, triangular were examined verify effectiveness of method, but they only occupy a much smaller area active region on chip than bar shaped SSFs. this study, improve be more practical, focused serious have non-negligible impact electrical characteristics. are mostly expanded from TED (threading edge dislocation)-converted BPD at or below substrate epitaxial layer interface. PL (photoluminescence) observation 710 nm LPF (long-pass filter), TED-converted complete extended bottom observed as same dark spot, it was confirmed both can distinguished presence absence their SSF expansion irradiation. addition, order confirm validity even virgin epi wafer, performed aluminum doped PN structured similar observed. Meanwhile, correlation between degradation quantified using PiN diodes comparing glide velocity 30°Si (g) core partials stress with stress.