Simultaneous interfacial misfit array formation and antiphase domain suppression on miscut silicon substrate

The authors describe simultaneous interfacial misfit (IMF) array formation along with antiphase domain (APD) suppression in highly mismatched (Δa0/a0=13%) AlSb grown on a 5° miscut Si (001) substrate. Strain energy from the AlSb/Si heterojunction is accommodated by a self-assembled two-dimensional array of pure 90° dislocations confined to the interface. The 13% lattice mismatch establishes the AlSb/Si IMF period of ∼3.46 nm. This IMF spacing is well matched to the step length of the 5° miscut Si (001) substrate. Furthermore, the miscut substrate geometry suppresses APD formation due to the double step height. The resulting bulk material has both very low defect density (∼7×105/cm2) and very low APD density (∼103/cm2) confirmed by transmission electron microscope images. This material is expected to be desirable for electronic III-V devices on Si substrates.