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Determination of the Width of the GaN/AlxGa1-xN Heterointerface Using EELS

Published online by Cambridge University Press:  02 July 2020

K.A. Mkhoyan ,
E.S. Alldredge ,
J. Silcox  and
N.W. Ashcroft
K.A. Mkhoyan
Affiliation:
School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853
E.S. Alldredge
Affiliation:
Physics Department, Cornell University, Ithaca, NY, 14853
J. Silcox
Affiliation:
School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853
N.W. Ashcroft
Affiliation:
Physics Department, Cornell University, Ithaca, NY, 14853
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Abstract

It is known that wurtzite III-V nitrides are highly polarized in the c-direction, which is usually the growth direction. This polarization (spontaneous and piezoelectric) in GaN/AlxGa1-xN heterostructure field effect transistors (HFET) results in high carrier concentrations at the interfaces, in addition to the large conduction band offset. This high-density 2D electron gas formed at a GaN/AlxGa1-xN heterointerface in its turn increases the mobility of the heterostructure. Therefore, questions about the measurement of the physical width of a GaN/AlxGa1-xN interface and the calculation of its effects on the physical characteristics of devices naturally arise. Since the electrical field distribution, as well as the location and density of the 2D electron gas, depends on the width of the GaN/AlxGa1-xN heterointerface, accurate determination of the width is critical.

Measurements with high spatial resolution EELS using transmission electron spectroscopy with a ∽2Å focused electron beam permits atomic-level studies of such specimens.

Type
Quantitative STEM: Imaging and EELS Analysis Honoring the Contributions of John Silcox (Organized by P. Batson, C. Chen and D. Muller)
Information
Microscopy and Microanalysis , Volume 7 , Issue S2: Proceedings: Microscopy & Microanalysis 2001, Microscopy Society of America 59th Annual Meeting, Microbeam Analysis Society 35th Annual Meeting, Long Beach, California August 5-9, 2001 , August 2001 , pp. 216 - 217
Copyright
Copyright © Microscopy Society of America 2001

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References

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