Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T00:47:02.050Z Has data issue: false hasContentIssue false

Quantitative Strain and Compositional Studies of InxGa1−xAs Epilayer in a GaAs-based pHEMT Device Structure by TEM Techniques

Published online by Cambridge University Press:  23 April 2014

Duggi V. Sridhara Rao*
Affiliation:
Defence Metallurgical Research Laboratory, DRDO, Kanchanbagh, Hyderabad 500058, India
Ramachandran Sankarasubramanian
Affiliation:
Defence Metallurgical Research Laboratory, DRDO, Kanchanbagh, Hyderabad 500058, India
Kuttanellore Muraleedharan
Affiliation:
Defence Research and Development Organisation, DRDO Bhawan, Rajaji Marg, New Delhi 110011, India
Thorsten Mehrtens
Affiliation:
Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
Andreas Rosenauer
Affiliation:
Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
Dipankar Banerjee
Affiliation:
Department of Materials Engineering, Indian Institute of Science, Bengaluru 560012, India
*
*Corresponding author.[email protected]
Get access

Abstract

In GaAs-based pseudomorphic high-electron mobility transistor device structures, strain and composition of the InxGa1−xAs channel layer are very important as they influence the electronic properties of these devices. In this context, transmission electron microscopy techniques such as (002) dark-field imaging, high-resolution transmission electron microscopy (HRTEM) imaging, scanning transmission electron microscopy-high angle annular dark field (STEM-HAADF) imaging and selected area diffraction, are useful. A quantitative comparative study using these techniques is relevant for assessing the merits and limitations of the respective techniques. In this article, we have investigated strain and composition of the InxGa1−xAs layer with the mentioned techniques and compared the results. The HRTEM images were investigated with strain state analysis. The indium content in this layer was quantified by HAADF imaging and correlated with STEM simulations. The studies showed that the InxGa1−xAs channel layer was pseudomorphically grown leading to tetragonal strain along the [001] growth direction and that the average indium content (x) in the epilayer is ~0.12. We found consistency in the results obtained using various methods of analysis.

Type
Materials Applications
Copyright
© Microscopy Society of America 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, T.G., Chen, Z.G., Kulakovskii, V.D., Uddin, A. & Vallin, J.T. (1987). Variation of the critical layer thickness with In content in strained In x Ga1−x As-GaAs quantum wells grown by molecular beam epitaxy. Appl Phys Lett 51(10), 752754.Google Scholar
Beanland, R. (2005). Dark field transmission electron microscope images of III-V quantum dot structures. Ultramicroscopy 102(2), 115125.Google Scholar
Grillo, V. (2009). The effect of surface strain relaxation on HAADF imaging. Ultramicroscopy 109, 14531464.CrossRefGoogle ScholarPubMed
Grieb, T., Müller, K., Fritz, R., Schowalter, M., Neugeborhn, N., Knaub, N., Volz, K. & Rosenauer, A. (2012). Determination of the chemical composition of GaNAs using STEM-HAADF imaging and STEM strain state analysis. Ultramicroscopy 117, 1523.Google Scholar
Howes, M.J. & Morgan, D.V. (1985). Gallium Arsenide: Materials, Devices, and Circuits (Wiley Series in Solidstate Devices and Circuits). Chichester: John Wiley and Sons. ISBN-13:978-0719557293.Google Scholar
JEMS (2001). Electron Microscopy Software, Version 1.0724W2001, developed by Stadelmann, P., EPFL, Switzerland.Google Scholar
Litvinov, D., Gerthsen, D., Rosenauer, A., Schowalter, M., Passow, T., Feinaugle, P. & Hetterich, M. (2006). Transmission electron microscopy investigation of segregation and critical floating-layer content of indium for island formation in In x Ga1−x As. Phys Rev B 74, 165306.CrossRefGoogle Scholar
Marmalyuk, A.A., Akchurin, R.K.H. & Gorbylev, V.A. (1998). Evaluation of elastic constants of AlN, GaN, and InN. Inorgan Mater 34(7), 691694.Google Scholar
McCaffrey, J.P., Washewski, Z.R., Robertson, M.D. & Corbett, J.M. (1997). Measurement of indium segregation in strained In x Ga1−x As/GaAs quantum wells by transmission electron microscopy. Phil Mag A 75(3), 803821.Google Scholar
Mehrtens, T., Müller, K., Schowalter, M., Hu, D., Schaadt, D.M. & Rosenauer, A. (2013). Measurement of indium concentration profiles and segregation efficiencies from high angle annular dark-field scanning transmission electron microscopy images. Ultramicroscopy 131, 19.Google Scholar
Peng, L.M., Ren, G., Dudarev, S.L. & Whelan, M.J. (1996). Robust parameterisation of electronic and absorptive electron atomic scattering factors. Acta Cryst A 52, 257276.Google Scholar
Pennycook, S.J. & Nellist, P.D. (2011). Scanning Transmission Electron Microscopy: Imaging and Analysis. New York: Springer. ISBN-978-1-4419-7199-9.CrossRefGoogle Scholar
Rosenauer, A., Kaiser, S., Reisinger, T., Zweck, J., Gebbardt, W. & Gerthsen, D. (1996). Digital analysis of high resolution transmission electron microscopy lattice images. Optik 102(2), 6369.Google Scholar
Rosenauer, A., Schowalter, M., Glas, F. & Lamoen, D. (2005). First-principles calculations of 002 structure factors for electron scattering in strained In x Ga1−x As. Phys Rev B 72, 085326.Google Scholar
Rosenauer, A. (2003). Transmission Electron Microscopy of Semiconductor Nanostructures: Analysis of Composition and Strain State. In Springer Tracts in Modern Physics, Vol. 182, Hohler, G., Fukuyama, H., Kuhn, J., Muller, T.h., Ruckenstein, A., Steiner, F., Trumper, J. & Wolfle, P. (Eds.), pp. 5784. Berlin-Heidelberg, New York: Springer. ISBN 3-450-00414-9.Google Scholar
Rosenauer, A., Gries, K., Müller, K., Pretorius, A., Schowalter, M., Avramescu, A., Engl, K. & Lutgen, S. (2009). Measurement of specimen thickness and composition in Al x Ga1−x N/GaN using high-angle annular dark field images. Ultramicroscopy 109, 11711182.CrossRefGoogle Scholar
Sridhara Rao, D.V., Muraleedharan, K. & Humphreys, C.J. (2011). TEM specimen preparation techniques. In Microscopy: Science, Technology, Applications & Education, Vol. 2, Mendez-Vilas, A. & Diaz, J. (Eds.), pp. 12321244. Spain: Formatex. ISBN-13:978-84-614-6190-5.Google Scholar
Walther, T. (2006). A new experimental procedure to quantify annular dark field images in scanning transmission electron microscopy. J Microscopy 221, 137144.CrossRefGoogle ScholarPubMed