Extraction of large valence-band energy offsets and comparison to theoretical values for strained-Si/strained-Ge type-II heterostructures on relaxed SiGe substrates
Name
Teherani-2012-Extraction of large valence-band energy.pdf
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Author(s)
Teherani, James T.
Chern, Winston
Antoniadis, Dimitri A.
Hoyt, Judy L.
Ruiz, Liliana
Poweleit, Christian D.
Menendez, Jose
Date Issued
May 2012
Journal
Physical Review B
Publisher
American Physical Society
Citation
Teherani, James et al. “Extraction of Large Valence-band Energy Offsets and Comparison to Theoretical Values for strained-Si/strained-Ge type-II Heterostructures on Relaxed SiGe Substrates.” Physical Review B 85.20 (2012). ©2012 American Physical Society
Version
Final published version
Abstract
Metal-oxide-semiconductor capacitors were fabricated on type-II staggered gap strained-Si/strained-Ge heterostructures epitaxially grown on relaxed SiGe substrates of various Ge fractions. Quasistatic quantum-mechanical capacitance-voltage (CV) simulations were fit to experimental CV measurements to extract the band alignment of the strained layers. The valence-band offset of the strained-Si/strained-Ge heterostructure was found to be 770, 760, and 670 meV for 35, 42, and 52% Ge in the relaxed SiGe substrate, respectively. These values are approximately 100 meV larger than the usually recommended band offsets for modeling Si/Ge structures. It is shown that the larger valence-band offsets found here are consistent with an 800-meV average valence-band offset between Si and Ge, which also explains the type-II band alignment observed in strained-Si[subscript 1−x]Ge[subscript x] on unstrained-Si heterostructures.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
http://dx.doi.org/10.1103/PhysRevB.85.205308
