INVESTIGATIONS OF SELECTIVELY GROWN GAN INGAN EPITAXIAL LAYERS/

We have studied GaN/InGaN heterostructures grown by selective area low pressure metalorganic vapor phase epitaxy (LP-MOVPE). A GaN layer alr eady grown on the c-face of sapphire has been used as substrate, partl y masked by SiO2. In a second epitaxial step a GaN/InGaN single hetero structure and GaN/InGaN/GaN double heterostructures were grown on the unmasked rectangular fields. We obtained good selectivity Fur GaN and for InGaN. A larger growth rate as compared to planar epitaxy and stro ng growth enhancement at the edges was observed. Spatially resolved me asurements of the luminescence show an increase in indium incorporatio n of about 80% at the edges. Besides the larger indium offering at the edges, this is due to an enhanced growth rate. Very smooth facets are obtained. The influence of pressure on the surface morphology and gro wth enhancement was investigated. (C) 1997 Elsevier Science S.A.