Details
| Original language | English |
|---|---|
| Article number | S04 |
| Pages (from-to) | S13-S20 |
| Journal | Semiconductor Science and Technology |
| Volume | 22 |
| Issue number | 1 |
| Publication status | Published - 28 Nov 2006 |
Abstract
The complex dielectric functions ε(ω) from 0.74 to 6.6 eV of pseudomorphically strained Si1-yCy (0 < y < 0.014) alloys grown on Si (0 0 1) were determined using spectroscopic ellipsometry. Interference effects due to surface overlayers and multiple reflections at the substrate/epilayer interface were subtracted. We also report the critical-point parameters (amplitude, energy, broadening, phase angle and dimension) of the E′0, E1, E2 and E′1 interband transitions. While the E1 energy gap increases linearly with increasing C content, in good agreement with a continuum elasticity model (taking into account the effects of biaxial stress and alloying with C based on a linear interpolation of the Si and diamond E1 energies), the E′0 gap stays approximately constant and the E2 gap shows a significant decrease. The amplitudes of all critical points decrease by about 50% and the broadenings increase by about 50-80% when adding 1.4% C. The phase angles remain approximately the same as in Si, except for E′1. The changes in the critical-point parameters can be understood due to the lattice relaxation (four Si nearest neighbours move towards C) and the strong alloy scattering, with obvious implications for ultrafast or high-field electronic transport in such alloys. Since the Si 1-yCy alloys are under a tensile biaxial stress, the measured ordinary dielectric function is also affected by piezo-optical effects, which were calculated using literature data for bulk Si.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Electrical and Electronic Engineering
- Materials Science(all)
- Materials Chemistry
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In: Semiconductor Science and Technology, Vol. 22, No. 1, S04, 28.11.2006, p. S13-S20.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Dielectric functions, elasto-optical effects, and critical-point parameters of biaxially stressed Si1-yCy alloys on Si (0 0 1)
AU - Zollner, Stefan
AU - Liu, J. P.
AU - Zaumseil, P.
AU - Osten, H. J.
AU - Demkov, A. A.
PY - 2006/11/28
Y1 - 2006/11/28
N2 - The complex dielectric functions ε(ω) from 0.74 to 6.6 eV of pseudomorphically strained Si1-yCy (0 < y < 0.014) alloys grown on Si (0 0 1) were determined using spectroscopic ellipsometry. Interference effects due to surface overlayers and multiple reflections at the substrate/epilayer interface were subtracted. We also report the critical-point parameters (amplitude, energy, broadening, phase angle and dimension) of the E′0, E1, E2 and E′1 interband transitions. While the E1 energy gap increases linearly with increasing C content, in good agreement with a continuum elasticity model (taking into account the effects of biaxial stress and alloying with C based on a linear interpolation of the Si and diamond E1 energies), the E′0 gap stays approximately constant and the E2 gap shows a significant decrease. The amplitudes of all critical points decrease by about 50% and the broadenings increase by about 50-80% when adding 1.4% C. The phase angles remain approximately the same as in Si, except for E′1. The changes in the critical-point parameters can be understood due to the lattice relaxation (four Si nearest neighbours move towards C) and the strong alloy scattering, with obvious implications for ultrafast or high-field electronic transport in such alloys. Since the Si 1-yCy alloys are under a tensile biaxial stress, the measured ordinary dielectric function is also affected by piezo-optical effects, which were calculated using literature data for bulk Si.
AB - The complex dielectric functions ε(ω) from 0.74 to 6.6 eV of pseudomorphically strained Si1-yCy (0 < y < 0.014) alloys grown on Si (0 0 1) were determined using spectroscopic ellipsometry. Interference effects due to surface overlayers and multiple reflections at the substrate/epilayer interface were subtracted. We also report the critical-point parameters (amplitude, energy, broadening, phase angle and dimension) of the E′0, E1, E2 and E′1 interband transitions. While the E1 energy gap increases linearly with increasing C content, in good agreement with a continuum elasticity model (taking into account the effects of biaxial stress and alloying with C based on a linear interpolation of the Si and diamond E1 energies), the E′0 gap stays approximately constant and the E2 gap shows a significant decrease. The amplitudes of all critical points decrease by about 50% and the broadenings increase by about 50-80% when adding 1.4% C. The phase angles remain approximately the same as in Si, except for E′1. The changes in the critical-point parameters can be understood due to the lattice relaxation (four Si nearest neighbours move towards C) and the strong alloy scattering, with obvious implications for ultrafast or high-field electronic transport in such alloys. Since the Si 1-yCy alloys are under a tensile biaxial stress, the measured ordinary dielectric function is also affected by piezo-optical effects, which were calculated using literature data for bulk Si.
UR - http://www.scopus.com/inward/record.url?scp=34247270178&partnerID=8YFLogxK
U2 - 10.1088/0268-1242/22/1/S04
DO - 10.1088/0268-1242/22/1/S04
M3 - Article
AN - SCOPUS:34247270178
VL - 22
SP - S13-S20
JO - Semiconductor Science and Technology
JF - Semiconductor Science and Technology
SN - 0268-1242
IS - 1
M1 - S04
ER -