Structural study of AlGaAs/InGaAs superlattices grown by MBE on (111)B GaAs substrates

AlGaAs/InGaAs strained layers superlattices (SLS) have been grown by molecular beam epitaxy on (111)B and (100) GaAs substrates at different temperatures (520, 540 and 560 °C). The heterostructures are studied by transmission electron microscopy, scanning electron microscopy and low-temperature photoluminescence. The controversy concerning the growth temperature for In-based/Al-based III-V alloys on (111)B GaAs is discussed. In this context, the (111)B and their corresponding (100) structures are compared. The best growth temperature is 560 °C, as a smooth surface and the lowest defect (dislocations, planar defects and stacking faults tetrahedra) density is obtained at this temperature.