Arsenic induced mass transport of GaAs on V-groove GaAs substrate

Abstract

We investigate the effect of As 4 over pressure annealing on clean grating profiles aligned along the [0 1 1] and [0 1 1] directions in a molecular beam epitaxy system (MBE). The grating cleaning is performed using hydrogen radicals or thermal desorption in ultra high vacuum. Subsequent annealing with As 4 causes grating deformations with a stronger effect for grating profiles aligned along the [0 1 1] direction. This deformation is enhanced after hydrogen radical cleaning and an almost complete planarization is observed for this case. The planarization conditions are determined and we demonstrate that mass transport driven by the arsenic is the principal mechanism for the [0 1 1] grating planarization. To our knowledge this is the first report on the deformation of V-groove gratings on GaAs substrate induced by mass transport.