TEM investigation of a processed InGaN based laser grown by PAMBE on bulk GaN substrate

The structural investigation of the processed InGaN/GaN LDs and LEDs structures are performed by Transmission Electron Microscopy. A plasma assisted molecular beam epitaxy (PAMBE) process is used to fabricate laser structures on high pressure bulk GaN substrates. The indium composition inside the active multi quantum wells (MQW) region is measured by the analysis of the local lattice distortion using lattice fringes images. The characterization of different defects in the laser's structure is given in this paper. Defects, crossing the entire active region of the laser structure, have been detected. These defects can be related to the discontinuities of the Au/Ni contact. The local heating caused by the local non-uniform current density can be the origin of these defects. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)