Effects of oxygen-related defects on the leakage current of silicon p/n junctions

Abstract

The reverse-bias leakage characteristics of silicon pn junctions have been investigated with particular attention to the effects of various types of oxygen-related defects, such as oxygen precipitates, oxidation induced stacking fault, and grown-in defects. The effects of oxygen-related defects on the leakage current of pn junctions in intrinsic gettering wafers and precipitation annealed wafers have been investigated quantitatively, and the field oxidation temperature used to form pn junctions has been found to be an important factor in determining the pn junction leakage current because oxygen-related defects are formed during low temperature field oxidation. It has also been found that grown-in oxidation induced stacking faults degrade the leakage characteristics. Grown-in defects that are well known to degrade the oxide breakdown characteristics were found to have some effects on the increase of the leakage current. In addition, it is recognized that the leakage current of pn junctions formed in wafers that have a relatively high concentration of interstitial oxygen has a transient component, caused by oxygen-related hole traps, which might also be the origin of the 1/f noise observed in pn junctions.