N+p Junction Leakage Current in p/p+ Epitaxial Wafers

Abstract

The reverse-bias leakage current of silicon pn junctions formed in the p/p+ epitaxial structure have been investigated for the case in which a high density of oxygen precipitates exist in the p+ substrates. It is confirmed experimentally that the p/p+ structure has an advantage of the decrease of diffusion current even in the case of high oxygen precipitates in the p+ substrate. By calculating the minority carrier profile near the depletion region, the differences in diffusion current are well explained by the difference in the gradient of minority carrier profile at the edge of depletion region.