Transmission electron microscopic study of GaAs/Ge heterostructures grown by low-pressure metal organic vapor phase epitaxy

GaAs/Ge heterostructures were grown under different growth conditions by lo w-pressure metal organic vapor phase epitaxy (LP-MOVPE) and investigated by transmission electron microscopy (TEM). Abrupt heterointerface and antipha se domain (APD)-free single domain GaAs epilayers on Ge substrates were ach ieved under specific growth conditions. The lattice indexing of high-resolu tion transmission electron microscopy (HRTEM) exhibited excellent lattice l ine matching between the GaAs epilayer and the Ge substrate. These results led us to conclude that the optimal growth parameters for achieving high-qu ality GaAs/Ge heterostructure are As/Ga ratio of similar to 88:1, growth ra te of similar to 3 mu m/h, and growth temperature of 675 degrees C, (C) 200 0 Elsevier Science Ltd. All rights reserved.