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
Citations
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Journal ArticleDOI
Growth, Electrical Characterization, and Electroluminescence of GaN/SiC Heterojunction Diodes and Bipolar Transistors Fabricated on SiC Off-Axis Substrates
TL;DR: In this article, the authors investigated the impact of base doping concentration and SiC polytype (4H and 6H) on the characteristics of GaN/SiC heterojunction diodes.
Journal ArticleDOI
Statistical investigation of dislocation induced leakage current paths in AlGaN/GaN HEMT structures on Si and the impact of growth conditions
TL;DR: In this paper , the role of impurity segregation at dislocation cores due to growth-dependent locally characteristic strain fields as for example induced by specific dislocation reactions at the AlGaN/GaN interface is discussed as the origin.
Journal ArticleDOI
The effect of growth temperature on structural quality of GaN/AlN quantum wells by metal-organic chemical vapour deposition
Z F Ma,Zhao Donglan,Y T Wang,Dongwei Jiang,S. M. Zhang,Junbo Zhu,Z. S. Liu,B J Sun,Hui Yang,J.W. Liang +9 more
TL;DR: In this paper, the effect of the growth temperature on the surface and interface quality for the GaN/AlN multiquantum well (MQW) layer grown by metal-organic vapour chemical deposition is investigated.
Dissertation
Near junction thermal management of GaN HEMTs via wafer bonding
TL;DR: Palacios et al. as discussed by the authors proposed and examined wafer-bonded GaN-on-SiC HEMTs as a thermally efficient alternative to growth structures, and compared the thermal properties of this novel structure to the state-of-the-art.
Journal ArticleDOI
Deep-Level Defects Induced Degradation of Negative Differential Resistance in GaN-Based Resonant Tunneling Diodes
TL;DR: In this article , the authors proposed that deep-level defects in epitaxial materials can significantly affect the negative differential resistance (NDR) of GaN-based RTDs, and they confirmed the existence of 0.21 and 0.54 eV deep level defects at the active region tunneling interface.
References
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Journal ArticleDOI
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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.