Infoscience

Journal article

Surface morphology of GaN grown by molecular beam epitaxy

The surface morphology of GaN(0001) grown on Si(111) by molecular beam epitaxy using ammonia has been studied by near-field microscopy techniques. Two distinct morphologies are observed, depending on the growth kinetics. When using Ga-rich growth conditions, the roughness is independent of the epitaxial layer thickness, while it increases with growth time under N-rich growth conditions. Also, the morphological pattern is different for the two regimes of growth and is not related to the crystallographic subgrains delimited by edge dislocations. However, under Ga-rich growth conditions, screw-type dislocations give rise to a spiral growth mode that imposts both the morphological pattern and the surface roughness. (C) 2001 Elsevier Science B.V. All rights reserved.

Fulltext

Related material