Activation characteristics and defect structure in Si-implanted GaAs-on-Si

Undoped metalorganic chemical vapor deposited GaAs layers on Si substrates were implanted with 29Si ions (5×1012 cm−2 dose at 100 keV energy) to form a shallow n-type region. The net donor activation (74%) and electron mobility (3014 cm2 V−1 s−1) after rapid thermal annealing (900 °C, 10 s) were compared to those obtained for similar implants into bulk GaAs. There was a slight improvement in the proton backscattering yield from the GaAs-Si interface region after the annealing cycle, consistent with cross-sectional transmission electron microscopy data showing an alignment of defects in annealed samples.