Semi-insulating InP grown by low pressure MOCVD

Fe-doped semi-insulating InP layers have been successfully grown in a vertical flow, low pressure metalorganic chemical vapor deposition (LPMOCVD) system, and used as current blocking layers in buried crescent (BC) laser structures emitting at 1.51 µm. Triethylindium ((C₂H₂)₃In), phosphine (PH₃) and iron pentacarbonyl (Fe(CO)₅) were used as the reactant gases. Process variables have been identified which produce high resistivity (10⁷ to 10₈ Ω-cm) InP having featureless surface morphology, and layer thickness and doping uniformity. There is optical and x-ray diffraction evidence for the presence of an unidentified In-Fe-P second phase associated with markedly degraded surface morphology under nonoptimized growth conditions. Early BC lasers incorporating LPMOCVD grown, Fe-doped InP blocking layers have operated CW with threshold currents as low as 12 m A and optical output > 18 mW.