Recombination activity of light-activated copper defects in p-type silicon studied by injection- and temperature-dependent lifetime spectroscopy

Research output: Scientific - peer-reviewArticle

Details

Original languageEnglish
Article number125703
Number of pages8
JournalJournal of Applied Physics
Volume120
Issue number12
StatePublished - 26 Sep 2016
MoE publication typeA1 Journal article-refereed

Researchers

Research units

  • Karlstad Universitet

Abstract

The presence of copper contamination is known to cause strong light-induced degradation (Cu-LID) in silicon. In this paper, we parametrize the recombination activity of light-activated copper defects in terms of Shockley—Read—Hall recombination statistics through injection- and temperature dependent lifetime spectroscopy (TDLS) performed on deliberately contaminated float zone silicon wafers. We obtain an accurate fit of the experimental data via two non-interacting energy levels, i.e., a deep recombination center featuring an energy level at Ec−Et=0.48−0.62 eVEc−Et=0.48−0.62 eV with a moderate donor-like capture asymmetry (k=1.7−2.6) k=1.7−2.6)  and an additional shallow energy state located at Ec−Et=0.1−0.2 eVEc−Et=0.1−0.2 eV, which mostly affects the carrier lifetime only at high-injection conditions. Besides confirming these defect parameters, TDLS measurements also indicate a power-law temperature dependence of the capture cross sections associated with the deep energy state. Eventually, we compare these results with the available literature data, and we find that the formation of copper precipitates is the probable root cause behind Cu-LID.

ID: 8671188