A study of dislocations in InGaN/GaN multiple-quantum-well structure grown on (1120) sapphire substrate

摘要

Transmission electron microscope (TEM) and X-ray diffraction (XRD) measurements performed on an InGaN/GaN multiple-quantum-well (MQW) structure deposited on (1120) and (0001) sapphire substrates have been investigated. The grown MQW deposited on (1120) sapphire substrate are still oriented along the (0001)direction due to an Unusual growth mechanism, which is confirmed by XRD measurement. TEM measurements of the initial stage of the High-temperature GaN growth after the low-temperature buffer GaN layer on (1120) sapphire are different from the TEM results obtained for GaN on (0001) sapphire substrate, unlike the XRD patterns which were identical.