Electron and hole capture kinetics at gold-hydrogen complexes in n-type silicon

The capture kinetics of both electrons and holes at gold-hydrogen-related deep levels have been studied in n-type silicon using the techniques of deep-level transient spectroscopy (DLTS) and the related technique of minority carrier transient spectroscopy (MCTS). Four deep levels are observed in the bandgap, labelled G1 to G4. G1 and G4 are electron levels, and G2 and G3 are hole levels detected by MCTS that have previously been reported for gold-hydrogen complexes in p-type silicon. The combination of DLTS and MCTS in single-measurement techniques has enabled analysis of the carrier recombination processes occurring at the various deep levels by measuring the majority and minority carrier capture cross sections of each deep level. Based on this, it is proposed that a single type of Au-H defect is responsible for three of the observed levels, G1, G2 and G4, with the defect having a single donor (G2), and both single-(G4) and double-acceptor (G1) charge states. G3 is found to be a combination of two closely spaced levels with similar hole capture cross sections but different values of electron capture cross section.