Comparison of GaAs grown on standard Si (511) and compliant SOI (511)

Gallium arsenide (GaAs) films were grown by molecular beam epitaxy (MBE) on a (511) silicon substrate and a compliant (511) silicon-on-insulator (SOI) substrate. The top silicon layer of the compliant (511) SOI was thinned to similar to 1000 Angstrom. The five inch diameter SOI wafer was created by wafer bonding. The GaAs (004) x-ray diffraction (XRD) reflection showed a 25% reduction in the full width half maximum (FWHM) for GaAs on a compliant (511) SOI as compared to GaAs on a silicon substrate. Cross section transmission electron microscopy (XTEM) clearly indicates a different dislocation structure for the two substrates. The threading dislocation density is reduced by at least an order of magnitude in the compliant (511) SOI as compared to the (511) silicon. XTEM found dislocations and damage was generated in the top silicon layer of the compliant SOI substrate after GaAs growth.