Abstract :
We present a study of the growth evolution of AlGaAs/GaAs heterostructures during organo-metallic chemical vapor deposition on triangular-pyramidal recess patterns etched on GaAs 111B✓ substrates. Top view secondary electron and atomic force microscopy (AFM) as well as cross sectional AFM have been used to obtain detailed information about the self-limited growth in these structures. In particular, the observation of the sharpening of initially flat bottom pyramids during AlGaAs growth enabled us to identify the different facets which, at later growth stages, define the corners of the pyramid structures and reach self-limited constant widths in the 10 nm range. During subsequent GaAs growth, these corners give rise to the formation of quantum wires and dots in these structures.
