Magnetron Sputter Epitaxy of GaN
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Electronic-grade GaN (0001) epilayers have been grown directly on Al2O3 (0001) substrates by reactive DC-magnetron sputter epitaxy (MSE) from a liquid Ga sputtering target in an Ar/N2 atmosphere. The as-grown GaN epitaxial film exhibit low threading dislocation density on the order of ≤ 1010 cm-2 obtained by transmission electron microscopy and modified Williamson-Hall plot. X-ray rocking curve shows narrow fullwidth at half maximum (FWHM) of 1054 arcsec of the 0002 reflection. A sharp 4 K photoluminescence peak at 3.474 eV with a FWHM of 6.3 meV is attributed to intrinsic GaN band edge emission. The high structural and optical qualities indicate that MSEgrown GaN epilayers can be used for fabricating high-performance devices without the need of any buffer layer. GaN (0001) thin films were grown on Al2O3 substrates by reactive high power impulse magnetron sputtering of liquid Ga targets in a mixed N2/Ar discharge. A combination of x-ray diffraction, electron microscopy, atomic force microscopy, μ-Raman microscopy, photoluminescence, time of flight elastic recoil detection, and cathodoluminescence showed the formation of both relaxed and strained domains in the same films. . While the strained domains form due to ion bombardment during growth. The relaxed domains exhibit superior structural and optical properties comparative to the strained domains, including room temperature luminescence.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press , 2011. , 35 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1470
IdentifiersURN: urn:nbn:se:liu:diva-65729ISBN: 978-91-7393-226-4Archive number: LIU-TEK-LIC-2011:9OAI: oai:DiVA.org:liu-65729DiVA: diva2:398540
2011-03-03, Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Darakchieva, Vanya, Docent
Birch, Jens, ProfessorHultman, Lars, Professor
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