AlGaInAs selective area growth by LP-MOVPE: experimental characterisation and predictive modelling

Abstract

Thickness and composition profiles of AlGaInAs-based layers grown by low-pressure metal organic vapour phase epitaxy in the regime of selective area growth (SAG) have been modelled and measured experimentally. Experimental thickness profiles of InP, GaAs and GaAlAs bulk layers grown in the SAG regime have been precisely fitted with a three-dimensional vapour phase-diffusion model, and the characteristic diffusion length coefficient (D/k) for In, Ga and Al extracted. The D/k diffusion parameter for aluminium has been calculated and found intermediate between the indium and gallium ones. The diffusion model predict both thickness and compositional variations of AlGaInAs layers selectively grown for different mask patterns. The excellent agreement obtained between calculated and measured profiles makes this modelling tool essential for engineering of future SAG integrated optical devices.