Assessment of dislocation reduction on 100 mm diameter bulk GaN grown by the NEAT method

Abstract

Abstract X-ray topography measurements on a 100 mm diameter GaN boule grown by the Near Equilibrium AmmonoThermal method revealed an improvement in dislocation density from >1 × 106 cm−2 to between 2 × 105 and 5 × 105 cm−2, an improvement greater than two to five times from seed to growth. This data builds on previous X-ray diffraction and defect selective etching to quantify the reduction in defect density that is closely associated with increasing growth thickness. This result indicates that there is a pathway to further dislocation reduction by increasing growth thickness for GaN crystals including those of 100 mm or larger diameter. Further reduction of the dislocation density of large-area substrates will lead to GaN power devices with reduced leakage current under reverse bias and better device performance.