Heteroepitaxial selective growth of InxGa1−xAs on SiO2-patterned GaAs(001) by molecular beam epitaxy

Selective growth of InxGa1−xAs on a SiO2-mask patterned GaAs(001) substrate by molecular beam epitaxy (MBE) is reported. A simple model for selective growth is derived from the general rate equation of thin film growth. Based on this model, heteroepitaxial selective growth of InxGa1−xAs with x up to 0.07 is demonstrated at 595°C, which is within the range of typical MBE growth temperatures for GaAs but is above the desorption temperature of In atoms from a GaAs surface. An incorporation rate of In atoms of about 0.22% for a Ga flux of 2.0×1013atoms∕cm2s was measured at this temperature. The concentration of In atoms effectively incorporated into the InxGa1−xAs layer is linearly proportional to the supplied In flux in the range 0.7–9.2×1014atoms∕cm2s. The extremely low, but finite, In incorporation is utilized for the growth of 5nm thick InxGa1−xAs∕GaAs quantum wells and ∼300nm thick InxGa1−xAs layers. Together with selective growth, the surface morphology and optical properties of high-temperature grown InxGa1−xAs are characterized.