TY - JOUR
T1 - Characterization of high quality InN grown on production-style plasma assisted molecular beam epitaxy system
AU - Gherasoiu, I.
AU - O'Steen, M.
AU - Bird, T.
AU - Gotthold, D.
AU - Chandolu, A.
AU - Song, D. Y.
AU - Xu, S. X.
AU - Holtz, M.
AU - Nikishin, S. A.
AU - Schaff, W. J.
N1 - Funding Information:
Work at Texas Tech University was supported by the National Science Foundation (ECS-0609416) and the J. F. Maddox Foundation.
PY - 2008
Y1 - 2008
N2 - In this work, the authors report step-flow growth mode of InN on [0001] oriented GaN templates, using a production-style molecular beam epitaxy system, Veeco GEN200, equipped with a plasma source. Using adaptive growth conditions, they have obtained a surface morphology that exhibits the step-flow features. The root mean squared roughness over an area of 5×5 μ m2 is 1.4 nm with monolayer height terrace steps (0.281 nm), based on atomic force microscopy. It has been found that the presence of In droplets leads to defective surface morphology. From x-ray diffraction, they estimate edge and screw dislocation densities. The former is dominant over the latter. Micro-Raman spectra reveal narrow E22 phonon lines consistent with excellent crystalline quality of the epitaxial layers. The Hall mobility of 1 μm thick InN layers, grown in step-flow mode, is slightly higher than 1400 cm2 V s, while for other growth conditions yielding a smooth surface with no well-defined steps, mobility as high as 1904 cm2 V s at room temperature has been measured. The samples exhibit high intensity photoluminescence (PL) with a corresponding band edge that shifts with free carrier concentration. For the lowest carrier concentration of 5.6× 1017 cm-3, they observe PL emission at ∼0.64 eV.
AB - In this work, the authors report step-flow growth mode of InN on [0001] oriented GaN templates, using a production-style molecular beam epitaxy system, Veeco GEN200, equipped with a plasma source. Using adaptive growth conditions, they have obtained a surface morphology that exhibits the step-flow features. The root mean squared roughness over an area of 5×5 μ m2 is 1.4 nm with monolayer height terrace steps (0.281 nm), based on atomic force microscopy. It has been found that the presence of In droplets leads to defective surface morphology. From x-ray diffraction, they estimate edge and screw dislocation densities. The former is dominant over the latter. Micro-Raman spectra reveal narrow E22 phonon lines consistent with excellent crystalline quality of the epitaxial layers. The Hall mobility of 1 μm thick InN layers, grown in step-flow mode, is slightly higher than 1400 cm2 V s, while for other growth conditions yielding a smooth surface with no well-defined steps, mobility as high as 1904 cm2 V s at room temperature has been measured. The samples exhibit high intensity photoluminescence (PL) with a corresponding band edge that shifts with free carrier concentration. For the lowest carrier concentration of 5.6× 1017 cm-3, they observe PL emission at ∼0.64 eV.
UR - http://www.scopus.com/inward/record.url?scp=42949154333&partnerID=8YFLogxK
U2 - 10.1116/1.2899412
DO - 10.1116/1.2899412
M3 - Article
AN - SCOPUS:42949154333
VL - 26
SP - 399
EP - 405
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
SN - 0734-2101
IS - 3
ER -