SELF-LIMITING GROWTH OF QUANTUM-DOT HETEROSTRUCTURES ON NONPLANAR (111)B SUBSTRATES

We study the evolution of AlGaAs/GaAs growth during organometallic che mical vapor deposition on pyramidal recess patterns etched into GaAs{1 11}B substrates. Cross-sectional atomic force microscopy clearly demon strates the self-organized growth behavior in the inverted pyramid str uctures. During AlGaAs deposition, the side corners and the tip of the pyramid sharpen up to a self-limited radius of curvature of less than 10 nm. In addition. vertical Ga-rich AlGaAs quantum wells are formed at these corners. Subsequent GaAs growth results in the formation of G aAs quantum wires along the corners of the pyramid. These wires meet a t the tip of the pyramid, forming a quantum dot structure at this poin t. (C) 1997 American Institute of Physics.