Extraction of large valence-band energy offsets and comparison to theoretical values for strained-Si/strained-Ge type-II heterostructures on relaxed SiGe substrates

被引：37

作者：

Teherani, James T. ^{[1
]}

Chern, Winston ^{[1
]}

Antoniadis, Dimitri A. ^{[1
]}

Hoyt, Judy L. ^{[1
]}

Ruiz, Liliana ^{[2
]}

Poweleit, Christian D. ^{[3
]}

Menendez, Jose ^{[3
]}

机构：

[1] MIT, Cambridge, MA 02139 USA

[2] Univ Texas Brownsville, Brownsville, TX 78520 USA

[3] Arizona State Univ, Tempe, AZ 85287 USA

来源：

PHYSICAL REVIEW B | 2012年 / 85卷 / 20期

基金：

美国国家科学基金会;

关键词：

DEFORMATION POTENTIALS; QUANTUM-WELLS; MOBILITY; GAP; STRESS; HETEROJUNCTIONS; LUMINESCENCE; SPECTROSCOPY; PARAMETERS; INTERFACE;

D O I：

10.1103/PhysRevB.85.205308

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

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-Si1-xGex on unstrained-Si heterostructures.

引用

页数：10