Characterization of dislocations in MOCVD-grown GaN using a high temperature annealing method

Abstract

In this paper, a high temperature annealing (HTA) method is proposed to characterize dislocations in GaN prepared by metal–organic chemical vapor deposition (MOCVD) on c-plane (0001) sapphire. The templates were each annealed at different temperatures for 5 min. Molten KOH–NaOH eutectic (E) etching was also applied (at 500 °C for 30 min) to test and verify this new method. A comparison between the HTA template and the E etching template was made. The morphology and distribution of HTA pits and E etching pits were examined using scanning electron microscopy (SEM). Atomic force microscopy (AFM) was employed to study the shape of the HTA pits. Transmission electron microscopy (TEM) and cathodoluminescence (CL) investigation were used to further confirm the origin and density of the dislocations.