Impact of Fe and Cu Contamination on the Minority Carrier Lifetime of Silicon Substrates

Abstract

The effects of trace amounts of Fe and Cu in p‐ and n‐type silicon were investigated with microwave photoconductance decay and surface photovoltage. The wafers received controlled amounts of surface contamination of Fe and Cu that are relevant for ultralarge scale integrated technologies. The substrate doping type has a strong impact on the effect of the metallic impurities. Fe, as expected, strongly degrades the minority carrier lifetime of p‐type substrates. On the other hand, the impact of Fe on n‐type silicon is at least one order of magnitude lower than on p‐type. In contrast, Cu is highly detrimental to n‐type material, but has no significant impact on the minority carrier properties of p‐type silicon for the contamination levels studied.