Stress-engineered growth of homoepitaxial GaN crystals using hydride vapor phase epitaxy. Issue 62 (17th October 2018)

• Record Type: Journal Article
• Authors: Lee, Moonsang; Park, Sungsoo
• Is Part Of: RSC advances. Volume 8:Issue 62(2018)
• Page Start: 35571
• Page End: 35574
• Publication Date: 2018-10-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra06438e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We report the growth of a 3.5 mm-thick bulk GaN layer using a stress-engineered homoepitaxy method without any external processes. Abstract : We report the growth of a 3.5 mm-thick bulk GaN layer using a stress-engineered homoepitaxy method without any external processes. We employ a gradient V/III ratio during the growth, which enables a 3.5 mm-thick bulk GaN layer with a smooth surface and high crystal quality to be obtained. For a constant V/III ratio of 10, the bulk GaN layer has a flat surface; however, microcracks emerge in the GaN layer. For a constant V/III ratio of 38, the bulk GaN layer has a rough surface, without microcracks. On the other hand, by decreasing the V/III ratio from 38 to 10, the structural properties of the GaN layers are successfully controlled. The higher V/III ratio in the initial growth stage leads to a rough surface, and reduced stress and dislocation density in the bulk GaN layers, while the lower V/III ratio in the second stage of the growth provides an opposite trend, confirmed by Raman spectroscopy and X-ray measurements. We expect that this study will offer a new opportunity to achieve the growth of high-crystallinity bulk GaN without ex situ and complicated processes.