Structural Properties of (GaAs)1-x(Si₂)x Layers on GaAs(100) Substrates Grown by Migration-Enhanced Epitaxy

Epitaxial (GaAs) 1- x (Si 2 ) x alloy layers (0< x <0.25) were grown on GaAs (100) substrates using Migration-Enhanced Epitaxy. Structural and compositional analysis of the as-grown (GaAs) 1- x (Si 2 ) x layers indicated single-crystal zincblende structure with no evidence of phase separation throughout the entire compositional range. The lattice constant a 0 of the alloys was found to decrease linearly with increasing Si content from 0.56543 nm at x =0 to 0.5601 nm at x =0.25. Double crystal X-ray rocking curve measurements and cross-sectional transmission electron microscopy studies made on a 10 period (GaAs) 0.80 (Si 2 ) 0.20 /GaAs strained-layer superlattice indicated sharp and abrupt interfaces of high crystalline quality.