AlGaN films grown on trenched sapphire substrates using a low‐temperature GaNP buffer layer by MOCVD

Abstract

A technique has been developed to grow low‐dislocation‐density AlGaN films in this paper. The AlGaN film is laterally overgrown on a trenched sapphire substrate with a low‐temperature (LT) GaNP buffer layer by metalorganic chemical vapour deposition (MOCVD). The optical charactertics and microstructure of the AlGaN films have been invesigated by means of cathodoluminescence (CL), high‐resolution X‐ray diffraction (HRXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. It is shown that the dislocation densities in the Al0.07Ga0.93N film are reduced to 8.7 x 108 cm–2 (by CL) and 2.7 x 109 cm–2 (by TEM) in the whole trenched sapphire, and 4.0 x 108 cm–2 (by CL) and 1.3 x 109 cm–2 (by TEM) in the trenched area. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Al0.17Ga0.83N film with middle temperature-intermediate layer grown on trenched sapphire substrate by MOCVD

“…We have reported the modified growth method for the reduction of dislocation densities in AlGaN films grown on trenched (0 0 0 1) sapphire substrates using LT-GaNP buffer layer technique by metalorganic chemical vapor deposition (MOCVD) [7,8]. In this paper, the further reduction in the dislocation region resulted in Al 0.17-Ga 0.83 N epitaxial layer by using middle temperature (MT) intermediate layer technique.…”

Al0.17Ga0.83N Film Using Middle-Temperature Intermediate Layer Grown on (0001) Sapphire Substrate by Metal-Organic Chemical Vapor Deposition

“…We have reported the modified growth method for the reduction of dislocation densities in AlGaN films grown on trenched (0001) sapphire substrates using a LT-GaNP buffer layer technique by metal-organic chemical vapor deposition (MOCVD). 7,8) In this study, we achieved further reduction in the dislocation region in the Al 0:17 Ga 0:83 N epitaxial layer by the middle-temperature (MT) intermediate layer technique.…”