Journal ArticleDOI
Dislocation mediated surface morphology of GaN
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TLDR
In this article, the surface morphology of GaN films grown by metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) was studied using atomic force microscopy (AFM).Abstract:
The surfaces of GaN films grown by metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) were studied using atomic force microscopy (AFM). Due to the high dislocation densities in the films (108 cm−2), the typical surface morphologies of layers grown by both techniques were dominated by three dislocation mediated surface structures—pinned steps, spiral hillocks, and surface depressions. The characteristics of these surface structures were found to depend on growth technique (MOCVD vs MBE) and the group-III to group-V ratio used in the growth of MBE GaN films. Pinned steps, created by the intersections of mixed character dislocations with the free surface, were found on all GaN films. The pinned steps were observed to be predominantly straight on the MOCVD GaN and curved into spiral hillock formations on the MBE GaN. Spiral growth hillocks form when pinned steps grow outward and around the dislocation under step-flow growth conditions. The tightness of the spiral hillocks on MBE G...read more
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Ab initio study of Ga-GaN system: Transition from adsorbed metal atoms to a metal–semiconductor junction
TL;DR: In this paper, a GaN(0001)-GaN system with various thicknesses of a metallic Ga layer was studied, and it was shown that during transition from a bare GaN-0001 surface to a m-s heterostructure, the Fermi level stays pinned at a Ga-broken bond highly dispersive surface state to Ga-Ga states at the m−s interface.
Journal ArticleDOI
Growth of 2 μm Crack-Free GaN on Si(111) Substrates by Metal Organic Chemical Vapor Deposition
TL;DR: In this paper, a 2 μm high quality crack-free GaN film was successfully grown on 2-inch Si(111) substrates by metal organic chemical vapor deposition with a high temperature AlN/graded-AlGaN multibuffer and an Al N/GaN superlattice interlayer.
Journal ArticleDOI
Kinetic roughening during gas-source molecular-beam epitaxy of gallium nitride
TL;DR: In this paper, the authors used ex situ atomic force microscopy (AFM) to investigate the evolution of GaN surface roughness as a function of growth time and found that the surface width scales as the thickness of the sample.
Journal ArticleDOI
Smooth surface morphology and low dislocation density of p-GaN using indium-assisted growth
Kexiong Zhang,Hongwei Liang,Hongwei Liang,Rensheng Shen,Shiwei Song,Dongsheng Wang,Yang Liu,Xiaochuan Xia,Dechao Yang,Yingmin Luo,Guotong Du,Guotong Du +11 more
TL;DR: The influence of flow rate ratio of indium to magnesium (In/Mg ratio) on the quality of p-GaN thin films was investigated by atomic force microscope, X-ray diffraction, Hall measurement and secondary ion mass spectroscopy as discussed by the authors.
Journal ArticleDOI
Epitaxial growth of improved GaN epilayer on sapphire substrate with platinum nanocluster
TL;DR: In this article, the epitaxial growth of a GaN epilayer on a sapphire substrate coated with platinum nanocluster (SSPN) by metalorganic chemical vapor deposition was reported.
References
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Journal ArticleDOI
The Growth of Crystals and the Equilibrium Structure of their Surfaces
TL;DR: In this paper, it was shown that the rate of growth of a surface containing dislocations is proportional to the square of the supersaturation for low values and to the first power for high values of the latter.
Book
Organometallic Vapor-Phase Epitaxy: Theory and Practice
TL;DR: The OMVPE process as mentioned in this paper is a process of physical processes occurring on the surface of the Earth, and it has been used in many applications in the computer science community, e.g. superlattice structures.
Journal ArticleDOI
Role of threading dislocation structure on the x‐ray diffraction peak widths in epitaxial GaN films
B. Heying,X. H. Wu,Stacia Keller,Youli Li,D. Kapolnek,Bernd Keller,Steven P. DenBaars,James S. Speck +7 more
TL;DR: In this article, the authors demonstrate that the anomalously low (002) x-ray rocking curve widths for epitaxial hexagonal GaN films on (001) sapphire are a result of a specific threading dislocation geometry.
Book
Physics of Semiconductors and Their Heterostructures
TL;DR: In this article, the authors present a free electron picture of Crystalline Structures and a wave diffraction from Crystals, and then show how to use it for high field transport in Semiconductors.