Defects in GaN Films Grown on Si(111) Substrates by Metal-Organic Chemical Vapor Deposition

We report the transmission-electron microscopy study of the defects in wurtzitic GaN films grown on Si(111) substrates with AlN buffer layers by the metal-organic chemical vapor deposition method. The In_0.1Ga_0.9N/GaN multiple quantum well (MQW) reduced the dislocation density by obstructing the mixed and screw dislocations passing through the MQW. No evident reduction of the edge dislocations density by the MQW was observed. It was found that dislocations with screw component can be located at the boundaries of sub-grains slightly in-plane misoriented.