Method for fabricating group iii nitride compound semiconductors and group iii nitride compound semiconductor devices

Abstract

The present invention provides a Group III nitride compound semiconductor with suppressed generation of threading dislocations. A GaN layeris subjected to etching, so as to form an island-like structure having a shape of, for example, dot, stripe, or grid, thereby providing a trench/mesa structure, and a maskis formed at the bottom of the trench such that the upper surface of the maskis positioned below the top surface of the GaN layer. A GaN layeris lateral-epitaxially grown with the top surfaceof the mesa and sidewallsof the trench serving as nuclei, to thereby bury the trench, and then epitaxial growth is effected in the vertical direction. In the upper region of the GaN layerformed above the maskthrough lateral epitaxial growth, propagation of threading dislocations contained in the GaN layercan be prevented.