MBE growth of tilted superlattices: advances and novel structures

The vicinal surface ordering required for the TSL deposition has been studied as a function of temperature and composition for Ga_xAl_1-xAs, GaSb and AlSb surfaces. The interface sharpness observed during the Al-Ga co-deposition and self-organization on a vicinal surface has been modeled using a stochastic kinetics method. The modeling reproduces well the observations. To avoid critical effects of the tilt parameter variations, a novel structure, the serpentine superlattice, has been proposed. This structure has a "build in" two-dimensional confinement and yields uniform luminescence properties over large wafer areas. Finally, the TSL concept has been demonstrated for a novel system, the GaSb-AlSb system.