STUDY OF GROWTH-RATE AND COMPOSITION VARIATIONS IN METALORGANIC VAPOR-PHASE SELECTIVE-AREA EPITAXY AT ATMOSPHERIC-PRESSURE AND APPLICATION TO THE GROWTH OF STRAINED-LAYER DBR LASERS

In selective area epitaxy (SAE), a lateral variation of thickness acco mpanied by a variation of composition occurs because of the presence o f dielectric masks on the substrate surface. To take advantage of thes e behaviours for monolithic integration of electronic devices, a good control of growth rate and composition is necessary. For this aim, dif ferent bulk materials InP, InGaAs and InGaAsP have been systematically investigated as a function of the geometry of dielectric masks specia lly designed for this work. All growths were performed by metalorganic vapour phase epitaxy (MOVPE) at atmospheric pressure. An estimation o f growth rate enhancement and composition variation between the open r egions in dielectric masks and the unmasked region has been establishe d, allowing the choice of specific mask geometry for each application. Following this study, a strained multiple quantum well (MQW) structur e for a distributed Bragg reflector (DBR) laser has been selectively g rown. The standard buried ridge structure (BRS) processed presents goo d characteristics (8 mA threshold current) and we obtained a 7 nm tuni ng range with a ridge structure, which constitutes the best value repo rted with SAE.