Gallium kinetics on m-plane GaN

• Published in: Applied physics letters Vol. 111; no. 2
• Main Authors: Lim, C. B., Ajay, A., Monroy, E.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 10-07-2017
• Subjects: Applied physics; Condensed Matter; Engineering Sciences; Gallium nitrides; Materials Science; Micro and nanotechnologies; Microelectronics; Molecular beam epitaxy; Morphology; Optics; Photonic; Physics; Quantum Physics; Substrates
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4993570

In this paper, we study the adsorption/desorption kinetics of gallium on (1-100)
m-GaN during molecular-beam epitaxy on bulk substrates. We demonstrate
the stabilization of a laterally contracted biatomic layer of Ga containing up to ≈2.5
times the (0001) surface atom density, on top of the GaN(1-100) surface. By assessing the
surface morphology of m-GaN layers grown under different Ga/N flux
ratios, we show that the presence of the Ga bilayer allows the growth of atomically smooth
m-GaN without accumulation of Ga droplets and in conditions (substrate
temperature and Ga/N ratio) that are compatible with the growth of
c-GaN.