Structural study of AlGaAs/InGaAs superlattices grown by MBE on (III)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 degrees 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 degrees C, as a smooth surface and the lowest defect (dislocations, planar defects and stacking faults tetrahedra) density is obtained at this temperature. (C) 1997 Elsevier Science S.A.