Structural and electrical characterization of epitaxial DyP/GaAs and DyAs/GaAs grown by MBE

Details of the structural and electrical properties of epitaxial DyP/GaAs and DyAs/GaAs are reported. Both DyP and DyAs have been grown by solid source MBE with growth temperatures ranging from 500 to 600/spl deg/C and growth rates between 0.5 and 0.7 /spl mu/m/hr. DyP epilayers are n-type with measured electron concentrations on the order of 3 to 4/spl times/10/sup 20/ cm/sup -3/, room temperature mobilities of 250 to 300 cm/sup 2//Vs, and a barrier height of about 0.81 eV to GaAs at room temperature. DyAs epilayers are also n-type with concentrations of 1 to 2/spl times/10/sup 21/ cm/sup -3/, and mobilities between 25 and 40 cm/sup 2//Vs. DyP is stable in air with no signs of oxidation even after months of exposure.