Growth of GaN layers on nitrided GaAs/Si and GaAs/SIMOX composite substrates by OMVPE

摘要

We have investigated the conversion of thin MBE-grown GaAs layers deposited on (111) Si and SIMOX substrates into GaN by conventional and high resolution transmission electron microscopy. Results show that the converted area is highly faulted, and many voids are observed close to the GaN/Si interface. In the GaN layer grown at 750 deg C, the zinc-blende phase is dominant, and the wurtzitic GaN is observed when the growth temperature is raised to 900 deg C. The major defects in the wurtzitic phase are dislocations, stacking faults and inversion domains.