RAMAN-SCATTERING CHARACTERIZATION OF STRAINED GAAS INAS LAYERS GROWN BY MOVPE/

GaAs layers have been grown for different times by MOVPE on InAs (001) substrates at different growth temperatures and on InAs (111) substra te of A and B polarities. A residual tensile strain has been evidenced by Raman measurements of the LO and TO phonon red-shifts. On the (001 ) surface, the best quality of the layer is found at 550 degrees C, wh ere a quasi 2D growth is observed, whereas in the (111) case a 3D grow th of pyramidal islands is present on both surface polarities and bett er uniformity is found for the growth on the A polar surface. Copyrigh t (C) 1996 Elsevier Science Ltd