TY - JOUR
T1 - Extraction of large valence-band energy offsets and comparison to theoretical values for strained-Si/strained-Ge type-II heterostructures on relaxed SiGe substrates
AU - Teherani, James T.
AU - Chern, Winston
AU - Antoniadis, Dimitri A.
AU - Hoyt, Judy L.
AU - Ruiz, Liliana
AU - Poweleit, Christian D.
AU - Menendez, Jose
PY - 2012/5/9
Y1 - 2012/5/9
N2 - 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 1-xGe x on unstrained-Si heterostructures.
AB - 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 1-xGe x on unstrained-Si heterostructures.
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U2 - 10.1103/PhysRevB.85.205308
DO - 10.1103/PhysRevB.85.205308
M3 - Article
AN - SCOPUS:84861551925
SN - 1098-0121
VL - 85
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 20
M1 - 205308
ER -