Initial nanoheteroepitaxial growth of GaAs on Si(100) by OMVPE

Abstract

Initial growth studies of GaAs on an array of Si islands nanostructured on (100) oriented silicon-on-insulator substrates show that growth occurs through a mixture of selective-area and 3D growth modes. An optimum initiation growth temperature must tune the growth conditions to the geometry of the seed array so that selective-area control is maintained while defect density is minimized. The optimum temperature for a square array of Si islands, 500 nm in pitch, and 100 nm to 280 nm in diameter, is ∼600°C. This temperature yields single-crystal nucleation on each Si island while maintaining selective-area growth mode control. Transmission electron microscope (TEM) analysis of optimized and non-optimized grown GaAs/Si heterostructures show that they accommodate 0.4-0.7% strain. Further reduction in stacking-fault defects attributed to side wall growth may be possible through masking of side wall or annealing.