Effect of substrate temperature on Si compensation in δ-doped InSb and AlxIn1−xSb grown by molecular beam epitaxy

Dopant compensation was studied for Si δ-doped InSb samples grown on GaAs (001) substrates. Hall-effect measurements indicate a sharp decline in electron density with increased substrate temperature when doping and cap-layer growth occur on the pseudo-(1×3) surface reconstruction, while little temperature dependence is observed for doping and growth on the c(4×4) surface reconstruction. Hall-effect measurements on samples grown with the substrate temperature differing between the dopant and cap layers rule out simple diffusion and desorption of Si atoms, and, along with secondary-ion mass spectrometry measurements, suggest that the temperature dependence of the carrier density results from compensation occurring primarily during growth of the cap layer. Similar behavior was observed in AlxIn1−xSb samples δ-doped with Si.