Quantitative Evaluation of Gettering Efficiencies Below 1 × 1012 Atoms ∕ cm3 in p-Type Silicon Using a #2#1 Tracer

Abstract

Gettering efficiencies of copper, whose bulk concentrations are lower than in p-type silicon, have been evaluated quantitatively and the results are reported. Bulk copper introduced by intentional spiking and subsequent heat-treatment was shown to be gettered by bulk microdefects (BMDs), which had been introduced by heat-treatment prior to intentional contamination using a isotope tracer as a probe. For evaluation of gettering efficiencies, we found the trace analysis of the isotope to be critical and, thus, developed a procedure for trace analysis of bulk copper in the silicon bulk by modifying the published analytical technique, which allowed gettering efficiencies to be quantitatively evaluated for copper levels of below . We also describe a few other parameters important to the evaluation of gettering efficiencies, including out-diffusion of copper through the silicon matrix, formation of BMDs, and low-temperature out-diffusion.