Micro-Raman study of InGaP composition grown on V-grooved substrates

The influence of organometalic vapour phase epitaxy (OMVPE) growth parameters on composition of non-planar InxGa1−xP along the V-groove sidewalls is carried out by micro-Raman spectroscopy. The increased incorporation of Ga atoms at the (1 1 1) sidewalls is observed compared with the (1 0 0) patterned surface facets. Contrary to the homogeneous (1 1 1) Ga-enriched InGaP layers reported for the U-grooved overgrown structures (with the (1 0 0) bottom facets) the (1 1 1) facets exhibit parts with the different InxGa1−xP composition. An uncommon feature is the width of Ga-rich bottom area (3 μm). The obtained results indicate a possibility to suppress Ga-accumulation and to improve lattice matching of overgrown structures by a proper optimisation of growth parameters. Thus, the growth of sufficiently lattice matched GaAs/InGaP structures along a whole sidewall of the V-groove could be possible.