Efficient reduction of defects in (1120) non-polar and (1122) semi-polar GaN grown on nanorod templates

Journal Article · Mon Mar 11 00:00:00 EDT 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4795619· OSTI ID:22162779

Bai, J.; Gong, Y.; Xing, K.; Yu, X.; Wang, T. ^[1]

---

1. Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

(1120) non-polar and (1122) semi-polar GaNs with a low defect density have been achieved by means of an overgrowth on nanorod templates, where a quick coalescence with a thickness even below 1 {mu}m occurs. On-axis and off-axis X-ray rocking curve measurements have shown a massive reduction in the linewidth for our overgrown GaN in comparison with standard GaN films grown on sapphire substrates. Transmission electron microscope observation demonstrates that the overgrowth on the nanorod templates takes advantage of an omni-directional growth around the sidewalls of the nanostructures. The dislocations redirect in basal planes during the overgrowth, leading to their annihilation and termination at voids formed due to a large lateral growth rate. In the non-polar GaN, the priority <0001> lateral growth from vertical sidewalls of nanorods allows basal plane stacking faults (BSFs) to be blocked in the nanorod gaps; while for semi-polar GaN, the propagation of BSFs starts to be impeded when the growth front is changed to be along inclined <0001> direction above the nanorods.

• OSTI ID: 22162779
• Journal Information: Applied Physics Letters, Vol. 102, Issue 10; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNIHILATION
CHEMICAL VAPOR DEPOSITION
COALESCENCE
CRYSTAL DEFECTS
CRYSTAL GROWTH
DENSITY
DISLOCATIONS
GALLIUM NITRIDES
NANOSTRUCTURES
REDUCTION
SAPPHIRE
SEMICONDUCTOR MATERIALS
STACKING FAULTS
SUBSTRATES
THICKNESS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
X-RAY DIFFRACTION