STM AND RHEED STUDY OF INAS GAAS QUANTUM DOTS OBTAINED BY SUBMONOLAYER EPITAXIAL TECHNIQUES/

Formation of uniform arrays of InAs quantum dots on GaAs(100) singular and vicinal (3 degrees towards [011] direction) surfaces crucially de pends on the deposition mode chosen. For dots formed with continuous A s flux impinging on the surface and simultaneous submonolayer In depos ition cycles, intentional substrate misorientation significantly decre ases the density of dots and stimulates their ordering along the [001] direction. On the contrary, growth using alternate In and As depositi on cycles results in a reduced density of dots for singular surfaces a nd in strongly increased dot concentration for vicinal ones. Ordering of dots in chains along [001] and [010] directions is observed for the alternative deposition on singular substrates.