Current-voltage and capacitance-voltage behavior of high-resistivity (AlxGa1−x)yIn1−yP on GaAs

Unintentionally doped layers of (AlxGa1−x)y In1−y P with energy gaps of approximately 2.0 eV were grown lattice matched to GaAs by organometallic vapor phase epitaxy. These layers were high resistivity. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were made on Cr/Au (AlxGa1−x)y In1−y P-GaAs metal-insulator-semiconductor capacitors. These measurements gave a ln I variation with V1/2 as observed for insulators such as Si3N4 on Si. This conduction behavior is characteristic of the Frenkel–Poole effect which is the electric field enhanced thermal excitation of trapped electrons into the conduction band. The C-V measurements were similar to the small hysteresis behavior of high-resistivity oxygen-doped AlxGa1−xAs on GaAs.