Details
| Original language | English |
|---|---|
| Pages (from-to) | 3016-3020 |
| Number of pages | 5 |
| Journal | Journal of applied physics |
| Volume | 79 |
| Issue number | 6 |
| Publication status | Published - 15 Mar 1996 |
| Externally published | Yes |
Abstract
We investigate the influence of carbon on the optical transitions of Si1-yCy and Si1-x-yGex:Cy layers grown pseudomorphically on a Si(001) substrate also including full strain compensation. The layers were investigated by spectroscopic ellipsometry and electroreflectance spectroscopy for carbon fractions y≤1.2 at. % and germanium fractions up to x=16 at. %. The spectra were analyzed by measuring and fitting electroreflectance spectra at 80 K and ellipsometry data at room temperature, resulting for both techniques in a weak and nearly linear dependence on the carbon fraction at all transitions. The results of both techniques are compared and discussed. The strong line broadening for increasing carbon fractions can be caused by a high scattering efficiency of the carbon. Our results indicate that the interpretation of optical spectra of carbon-containing alloys cannot be performed straightforwardly by simple interpolating between the appropriate band structures of silicon, germanium, and carbon. An analysis based on strain-induced contributions only also does not describe the experimental results correctly. For a complete description of the observed energy shifts detailed band structure calculations and further experimental data are necessary.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- General Physics and Astronomy
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In: Journal of applied physics, Vol. 79, No. 6, 15.03.1996, p. 3016-3020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Critical points of Si1-yCy and Si1-x-yGexCy layers strained pseudomorphically on Si(001)
AU - Kissinger, W.
AU - Osten, H. J.
AU - Weidner, M.
AU - Eichler, M.
PY - 1996/3/15
Y1 - 1996/3/15
N2 - We investigate the influence of carbon on the optical transitions of Si1-yCy and Si1-x-yGex:Cy layers grown pseudomorphically on a Si(001) substrate also including full strain compensation. The layers were investigated by spectroscopic ellipsometry and electroreflectance spectroscopy for carbon fractions y≤1.2 at. % and germanium fractions up to x=16 at. %. The spectra were analyzed by measuring and fitting electroreflectance spectra at 80 K and ellipsometry data at room temperature, resulting for both techniques in a weak and nearly linear dependence on the carbon fraction at all transitions. The results of both techniques are compared and discussed. The strong line broadening for increasing carbon fractions can be caused by a high scattering efficiency of the carbon. Our results indicate that the interpretation of optical spectra of carbon-containing alloys cannot be performed straightforwardly by simple interpolating between the appropriate band structures of silicon, germanium, and carbon. An analysis based on strain-induced contributions only also does not describe the experimental results correctly. For a complete description of the observed energy shifts detailed band structure calculations and further experimental data are necessary.
AB - We investigate the influence of carbon on the optical transitions of Si1-yCy and Si1-x-yGex:Cy layers grown pseudomorphically on a Si(001) substrate also including full strain compensation. The layers were investigated by spectroscopic ellipsometry and electroreflectance spectroscopy for carbon fractions y≤1.2 at. % and germanium fractions up to x=16 at. %. The spectra were analyzed by measuring and fitting electroreflectance spectra at 80 K and ellipsometry data at room temperature, resulting for both techniques in a weak and nearly linear dependence on the carbon fraction at all transitions. The results of both techniques are compared and discussed. The strong line broadening for increasing carbon fractions can be caused by a high scattering efficiency of the carbon. Our results indicate that the interpretation of optical spectra of carbon-containing alloys cannot be performed straightforwardly by simple interpolating between the appropriate band structures of silicon, germanium, and carbon. An analysis based on strain-induced contributions only also does not describe the experimental results correctly. For a complete description of the observed energy shifts detailed band structure calculations and further experimental data are necessary.
UR - http://www.scopus.com/inward/record.url?scp=0030108860&partnerID=8YFLogxK
U2 - 10.1063/1.362705
DO - 10.1063/1.362705
M3 - Article
AN - SCOPUS:0030108860
VL - 79
SP - 3016
EP - 3020
JO - Journal of applied physics
JF - Journal of applied physics
SN - 0021-8979
IS - 6
ER -