DIFFERENCE IN-DIFFUSION LENGTH OF GA ATOMS UNDER AS-2 AND AS-4 FLUX IN MOLECULAR-BEAM EPITAXY

The surface diffusion length of Ga adatoms under As-2 or As-4 flux has been measured using V-grooved GaAs (001) substrates in molecular beam epitaxy: The diffusion length on the (001) surface toward the [110] d irection, of Ga adatoms under As-2 flux is about half of that under As -4 flux. A smaller number of Ga atoms under As-2 flux migrate to the ( 001) ridge surface from the sidewall surface than those under As-4 flu x. Furthermore, the Al0.6Ga0.4As layer on the V-grooved GaAs substrate grown under As-2 Bur preserve the V-shape, whereas the V-shape cannot be preserved during the growth under As-4 flux. The GaAs quantum wire structures which have Al0.6Ga0.4As barrier layeres are fabricated und er As-2 flux.