SELF-LIMITING OMCVD GROWTH OF GAAS ON V-GROOVED SUBSTRATES WITH APPLICATION TO INGAAS GAAS QUANTUM WIRES/

We demonstrate that the formation of GaAs quantum wires on self-limiti ng AlGaAs grown on V grooves occurs via a transient increase of the gr owth rates in a set of different nanofacets. Upon growth of sufficient ly thick layers on AlGaAs, the GaAs surface reaches a self-limiting pr ofile as well, through an equalization of the relative growth rates on these facets. Atomic force microscopy studies show that the step dens ity in the facets along the groove evolves with GaAs thickness in the same way as the facets extension, thus suggesting a role of the step d istribution in the establishment of the self-limiting profiles. The se lf-limiting GaAs groove profile is much broader than the AlGaAs one at corresponding growth temperatures; however, it can be sharpened down to a radius of curvature of 5 nm for T = 550 degrees C. Under these co nditions, GaAs was successfully used as a barrier material for growing vertical arrays of self-ordered InGaAs wires.