Surface morphology evolution of m-plane (1(1)over-bar00) GaN during molecular beam epitaxy growth: Impact of Ga/N ratio, miscut direction, and growth temperature

Jiayi Shao, Birck Nanotechnology Center, Purdue University
Liang Tang, Birck Nanotechnology Center, Purdue University
Colin Edmunds, Purdue University
Geoff C. Gardner, Birck Nanotechnology Center, Purdue University
Oana Malis, Birck Nanotechnology Center, Purdue University
Michael J. Manfra, Birck Nanotechnology Center, Purdue University

Date of this Version



Copyright 2013 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 114, 023508 (2013); and may be found at The following article has been submitted to/accepted by Journal of Applied Physics. Copyright 2013 Jiayi Shao, Liang Tang, Colin Edmunds, Geoff Gardner, Oana Malis and Michael Manfra. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


We present a systematic study of morphology evolution of [1 (1) over bar 00] m-plane GaN grown by plasma-assisted molecular beam epitaxy on free-standing m-plane substrates with small miscut angles towards the -c [000 (1) over bar] and +c [0001] directions under various gallium to nitrogen (Ga/N) ratios at substrate temperatures T = 720 degrees C and T = 740 degrees C. The miscut direction, Ga/N ratio, and growth temperature are all shown to have a dramatic impact on morphology. The observed dependence on miscut direction supports the notion of strong anisotropy in the gallium adatom diffusion barrier and growth kinetics. We demonstrate that precise control of Ga/N ratio and substrate temperature yields atomically smooth morphology on substrates oriented towards _c [0001] as well as the more commonly studied -c [000 (1) over bar] miscut substrates. (C) 2013 AIP Publishing LLC.


Nanoscience and Nanotechnology