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

Abstract

X-ray topography measurements on a 100 mm diameter GaN boule grown by the Near Equilibrium AmmonoThermal (NEAT) method revealed an improvement in dislocation density from >1 x 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.

Study on Raman scattering spectroscopy of Mn-doped GaN grown by the ammonothermal method

“…As a liquid-phase growth method for GaN crystals, the ammonothermal method not only achieves the growth of seed crystals with different planes but also has advantages such as low dislocation density and easy large-scale production. 11 The ammonothermal method is similar to the hydrothermal method, in which GaN is grown in a closed high-pressure reactor filled with NH 3 . It mainly utilizes the different solubility of GaN at different temperatures.…”

Evolution of V-pits in the ammonothermal growth of GaN on HVPE-GaN seeds

“…Recently, the phenomenon that the pit-type defects in the HVPE seed closed during ammonothermal growth was involved. 15 The growth and evolution of V-pits in the ammonothermal method have not been clarified yet. The ammonothermal growth of GaN is also considered an appropriate method to grow large area, bulk GaN at temperatures of 400–750 °C and a pressure of up to 0.4 GPa.…”

“…At present, 4 inch size c -plane GaN and 2 inch size m -plane were grown by a basic ammonothermal or an acidic ammonothermal method. 15,21,22…”

“…At present, 4 inch size c-plane GaN and 2 inch size m-plane were grown by a basic ammonothermal or an acidic ammonothermal method. 15,21,22 In this paper, we utilized an ammonothermal method to grow pit-free GaN on an HVPE seed with defects and investigated the evolution process of pit-type defects. We designed an experiment in which the GaN seeds have V-halo or V-pit defects (as shown in Fig.…”