From periodic monomolecular step array to macrosteps in pure and Si-doped MBE-grown GaAs on vicinal (001) surfaces
Laboratoire de Microstructures et de Microélectronique
(L2M), CNRS, B.P. 107, 92225 Bagneux Cedex, France
Accepted: 15 May 1997
Steps and terraces on GaAs (001) vicinal surfaces misoriented towards (111) or are studied after MBE growth for a large range of misorientation angle ( to ) using ex situ contact mode AFM. The terrace width distribution and correlation length are well explained by thermodynamical equilibrium of interacting steps. The step-step interaction is much larger than in elemental materials and is dominated by dipole rather than elastic interaction. Step bunching is never observed on clean surfaces for any misorientation. However, for Si-doped layers, the surface disorder increases and formation of macrosteps occurs at very high doping.
PACS: 81.15.Np – Solid phase epitaxy; growth from solid phases / 68.35.Bs – Surface structure and topography / 61.16.Ch – Scanning probe microscopy: scanning tunneling, atomic force, scanning optical, magnetic force, etc
© EDP Sciences, 1997