Influence of Crystal Defects on the Generation Lifetime of Minority Carriers in Silicon

Abstract

Measurements of generation- lifetime inhomogeneities were performed on wafers containing crystal defects. The lateral resolution was 250 μm, so that the influence of single defects could be seen. The authors show that both dislocations and oxidation-induced stacking faults may severely reduce lifetime in a very small region. Moreover, examples are presented where lifetime was improved in the vicinity of the defects because of some sort of gettering action. Finally, it is shown that lifetime inhomogeneities can be avoided by performing a preoxidational back-side gettering (POGO) procedure.