Muonium defect levels in Czochralski-grown silicon-germanium alloys

Abstract

We report Muonium (Mu) donor and acceptor levels in Czochralski-grown Silicon Germanium alloys (Cz-Si(1-x)Ge(x)). Measurement of these defect energies provides an analogous examination of Hydrogen defects that are otherwise inaccessible. Temperature-dependent Muonium fractions in several alloy samples (x = 0.20, 0.45, 0.77, 0.81, 0.84, 0.90, 0.91, 0.94, 0.98) show charge-state transitions assigned to Mu donor and acceptor ionizations. Our results indicate a deep Mu donor level across the alloy system. The Mu acceptor level is deep in pure Si and valence-band resonant in pure Ge; we specifically examine the compositional dependence of the Mu(T)(0) acceptor ionization energy in Ge-rich alloys, where this level crosses into the valence band.