METHOD FOR PRODUCING III NITRIDE BASED COMPOUND SEMICONDUCTOR SUBSTRATE AND SEMICONDUCTOR ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a III nitride based compound semiconductor substrate in which through dislocation is suppressed. SOLUTION: A GaN layer 31 is etched into insular spots, stripes or lattice and provided with a level difference and the bottom part is formed to become the recess of an original substrate 1. Using the upper surface and the side face at the upper stage of level difference as nuclei, GaN 32 is grown epitaxially in the lateral direction and the upper part of the lower stage of level difference (recess of the original substrate 1) is filled before GaN 32 is also grown epitaxially above. Upper part of the part where GaN 32 is grown epitaxially in the lateral direction may be a region where propagation of through dislocation in the GaN layer 31 is suppressed. The remaining GaN layer 31 is removed by etching along with the upper layer GaN 32 and when GaN 33 is grown epitaxially using the upper surface and the side face at the upper stage of the remaining GaN layer 32 as nuclei, a GaN substrate 30 in which through dislocation is suppressed significantly can be obtained. The GaN substrate 30 can be separated easily when the contact area (GaN layer 31) with the original substrate 1 is decreased.