High temperature characterization of MBE grown DyP/GaAs and DyAs/GaAs

Characterization of MBE grown DyP/GaAs and DyAs/GaAs is reported. DC characterization, including I-V and C-V measurements, was performed at different temperatures from 25 to 200°C. High frequency characterization of DyP/GaAs Schottky diodes was also performed by measuring the scattering parameters (S parameters) as a function of frequency. A cut-off frequency of close to 2.5 THz was determined from the equivalent circuit parameters for the Schottky diodes having an area of 10 μm². DyP is lattice matched to GaAs, with a room temperature mismatch of less than 0.01% and is stable in air with no sign of oxidation, even after months of ambient exposure. High quality DyP and DyAs epilayers were consistently obtained for growth temperatures ranging from 500 to 600°C with growth rates between 0.5 and 0.7 μm/hr. DyP epilayers are n-type with electron concentrations of 3×10²⁰ to 4×10²⁰ cm^-3 room temperature mobilities of 250 to 300 cm2/V·s, and a barrier height of 0.81 eV to GaAs. DyAs epilayers are also n-type with carrier concentrations of 1×10²¹ to 2×10²¹ cm ^-3, and mobilities between 25 and 40 cm²/V·s