Electrical Properties of Oval Defects in GaAs Grown by MBE

Abstract

Oval defect electrical properties and effects on FETs are investigated. The oval defect consists of a core and a hillock surrounding it. The core has a disturbed crystal structure, whereas the hillock has almost the same crystal quality as the normal epi-layers. Source-drain conductances decrease due to high defect resistivity. FET breakdown voltages are affected by the core location, that is, a leakage current increases due to dislocations and stacking faults which exist in the vicinity of the core-hillock boundary. These results indicate that oval defects should be eliminated in the achievement of electrical devices.