METALORGANIC CHEMICAL-VAPOR-DEPOSITION GROWTH OF GA-RICH (X-GREATER-THAN-0.5) GAXIN1-XP ON GAAS

Epitaxial layers of GaxIn1-x P (0.5 less-than-or-equal-to x less-than- or-equal-to 1.0) were grown on GaAs substrates by metalorganic chemica l vapor deposition (MOCVD), using TMI (trimethylindium), TMG (trimethy lgallium), TEG (triethylgallium), and phosphine. Despite the lattice m ismatch between the epitaxial layer and the substrate, specular surfac es were obtained at high growth temperature (770-degrees-C) and a long interval time (tau = 60 s), where tau is defined as the period betwee n column V gas switching (AsH3 --> PH3) and column III source injectio n. It is also observed that the surface morphology depends on the Ga p recursors. When TEG is used as a Ga precursor, specular surfaces are o btained for 0.77 less-than-or-equal-to x less-than-or-equal-to 1.00, w here x is the solid composition ratio of GaxIn1-xP. When TMG is used a s a Ga precursor , specular surfaces are obtained for 0.81 less-than-o r-equal-to x less-than-or-equal-to 0.95. By measuring with the X-ray d ouble-crystal method, it is observed that the rocking curve around the GaAs substrate was split into two peaks due to the GaAsP film formed during the interval time. The FWHM (full width at half maximum) of Gax In1-xP against x showed a peak of 800 arc sec at x = 0.8.