Evaluation of growth mode and optimization of growth parameters for GaAs epitaxy in V-shaped trenches on Si

Abstract

We report the selective area growth of GaAs in V-shaped trenches on Si (001) substrates via metal-organic chemical vapor deposition (MOCVD). High quality GaAs thin films were achieved using a two-step growth process and the aspect ratio trapping method. The evolution of GaAs growth in V-shaped trenches was investigated at all its stages, nucleation layer growth, crystallization, and top layer growth, with the help of in situ normal incidence reflectance measurements. A schematic growth mode was proposed and verified by scanning electron microscope (SEM). We also investigated the impact of nucleation layer thickness and reactor pressure on the crystal quality of GaAs selectively grown on Si through high resolution X-ray diffraction (HRXRD) measurements.