Growth and photoreflectance characterization of GaAs impact ionization avalanche transit time diodes

The organometallic vapor phase epitaxial growth of GaAs double-drift Read i mpact ionization avalanche transit time diodes where the p-type layers were doped with carbon is described. Ka-band oscillation testing yielded averag e performance of 3.5 W with 16% efficiency for pulse lengths > 1 mu s and 1 0.5 W with 13% efficiency for pulse lengths < 1 mu s; these RF performances are similar to conventionally grown vapor phase epitaxy IMPATTs where the p-type dopant was zinc. Photoreflectance spectra obtained from diode struct ures were found to be dominated by the electric field in the avalanche regi on and hence are sensitive to the amount of charge in the doping spikes tha t determine the electric field in that region.