Method for reducing defects in epitaxially grown on the group III-nitride materials

Abstract

The present invention discloses a method to grow group III-nitride materials on a non-native substrate with much reduced threading dislocation (TD) density and smooth surface by using MBE. The first layer is to suppress the formation of screw TD while the second layer is to bend the propagation of edge TD. After that, the migration enhanced epitaxy (MEE) approach is used to smoothen the second layer surface before a main layer of group III-nitride is growth to the thickness required for different applications. All of these steps are performed in the MBE reactor by carefully control over the arrival rate and sequence of group III atoms and nitrogen radicals onto the sample substrate. By using reflective high energy electron diffraction (RHEED), the change of each layer's surface morphology can be monitored during the growth to achieve the high quality group III-nitride materials.