High quality GaN crystal grown by hydride vapor-phase epitaxy on SCAATTM

Abstract

GaN crystal with 4.2 mm thickness and size lager than 2 inch without cracks and pits was realized by hydride vapor-phase epitaxy (HVPE) on an acidic ammonothermal (SCAATTM) seed. The average threading dislocation (TD) density was as small as 1.4 × 103 cm−2. Multi-photon excitation photoluminescence revealed that complete one-to-one correspondence of TD at the interface between the seed and epilayer was realized. A comparison between HVPE-GaN film grown on SCAATTM seed and that grown on a conventional self-standing HVPE-GaN seed showed the smaller TDD of SCAATTM than conventional one resulted in a smaller change of residual stress in the crystal.