Area-Selective Epitaxial Growth of GaAs on GaAs(111)A Substrates by Migration-Enhanced Epitaxy

Abstract

We have carried out area-selective epitaxial growth of GaAs on GaAs(111)A substrates using migration-enhanced epitaxy and have investigated the pyramidal hillocks formed on the grown surface. Scanning electron microscopy and atomic force microscopy observations indicate that these hillocks can be classified into two types: hillocks with small top plateaus and those with large plateaus. Investigations on the growth condition dependence of surface morphology and plan-view transmission electron microscopy observation have revealed that both types of hillocks are caused by stacking faults. Hillock cores are found to be stacking fault tetrahedra, whose formation processes result in two types of hillocks. Additionally, we have succeeded in improving the surface flatness by increasing the surface arsenic pressure during growth.