Growth of carbon-doped <i>p</i>-type In<i>x</i>Ga1−<i>x</i>As (0&amp;lt;<i>x</i>≤0.53) by metalorganic chemical vapor deposition

Abstract

Carbon doping of InxGa1−xAs grown on GaAs and InP substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) using CCl4 has been investigated for In mole fractions as high as x=0.53. P-type conduction was obtained over the entire composition range studied, with hole concentrations above 1×1020 cm−3 for x&amp;lt;0.12, and as high as 1×1019 cm−3 for In0.53Ga0.47As lattice-matched to InP. These high carbon concentrations were achieved by employing very low V/III ratios and low growth temperatures. The alloy composition was found to be dependent on several growth parameters, including CCl4 partial pressure, V/III ratio, and growth temperature. This may be due to surface reactions (etching) involving chlorine-containing compounds during growth. Samples grown at low temperature (∼500 °C) and lattice matched to InP exhibited an increase in hole concentration upon post-growth annealing.