Dislocation reduction with quantum dots in GaN grown on sapphire substrates by molecular beam epitaxy

David Smith, Daming Huang, Michael A. Reshchikov, Feng Yun, T. King, Hadis Morkoç, Cole W. Litton

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We have investigated a novel approach for improving GaN crystal quality by utilizing a stack of quantum dots (QDs) in GaN grown on sapphire substrates by molecular beam epitaxy. The GaN films were grown on GaN/AlN buffer layers containing multiple QDs and characterized using x-ray diffraction, photoluminescence, atomic force microscopy, and transmission electron microscopy. The density of the dislocations in the films was determined by defect delineation wet chemical etching and atomic force microscopy. It was found that the insertion of a set of multiple GaN QD layers in the buffer layer effectively reduced the density of the dislocations in the epitaxial layers. As compared to a density of ∼10 10 cm -2 in typical GaN films grown on AlN buffer layers, a density of ∼3×10 7 cm -2 was demonstrated in GaN films grown with the QD layers. Transmission electron microscopy observations confirmed termination of threading dislocations by the QD layers.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsR.B. Wehrspohn, R Marz, S Noda, C Soukoulis
Pages33-38
Number of pages6
Volume722
StatePublished - 2002
EventMaterials and Devices for Optoelectronics and Microphotonics - San Francisco, CA, United States
Duration: Apr 1 2002Apr 5 2002

Other

OtherMaterials and Devices for Optoelectronics and Microphotonics
CountryUnited States
CitySan Francisco, CA
Period4/1/024/5/02

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Smith, D., Huang, D., Reshchikov, M. A., Yun, F., King, T., Morkoç, H., & Litton, C. W. (2002). Dislocation reduction with quantum dots in GaN grown on sapphire substrates by molecular beam epitaxy. In R. B. Wehrspohn, R. Marz, S. Noda, & C. Soukoulis (Eds.), Materials Research Society Symposium - Proceedings (Vol. 722, pp. 33-38)