Growth of Cubic GaN by Metal Organic Molecular Beam Epitaxy

Abstract

Growth of GaN on sapphire (0001) substrates by metalorganic molecular beam epitaxy (MOMBE) was studied using triethyl gallium (TEGa) and rf plasma excited active nitrogen. A series of samples were grown under various TEGa flow rates while growth temperature (800°C) and nitrogen supply were fixed. With increasing TEGa flow rate, the dominant polytype of grown layer changed from hexagonal GaN (h-GaN) to cubic GaN (c-GaN). From the dependence of growth rate on TEGa flow rates, it was revealed that a Ga-stabilized growth condition results in the growth of c-GaN. This preferential growth mode was applied to the growth of c-GaN on cubic 3C-SiC (001) substrates.