Optical absorption in alloys of Si, Ge, C, and Sn

Orner, B. A.; Hits, D.; Kolodzey, J.; Guarin, F.; Powell, Adrian R.; Iyer, S. Venkatakrishna

doi:10.1063/1.362489

Cited by 10 publications

(3 citation statements)

References 20 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental data of Ref. [2] has the same trend as ours (i.e., increasing band gap) with results of 1.099 eV and 1.119 eV for Si 0:92 Ge 0:08 and Si 0:91 Ge 0:08 C 0:01 , respectively. But, other experimental data show an opposite trend (i.e., decreasing band gaps) [7][8]; in comparing with experimental results care is needed as the sample preparation procedures can influence the material properties.…”

supporting

confidence: 68%

“…Incoporation of a low carbon concentration into substitutional sites of SiGe might be able to relieve the inherent strain of the SiGe layers grown on a Si substrate [1][2][3][4][5] while changing the band gap energy. This prospect would allow for tuning the lattice constant and band gap independently by adjusting the composition ratios and offers an additional degree of freedom for band gap engineering, which is not attainable by standard Si technology or SiGe heteroepitaxy [6].…”

mentioning

confidence: 99%

“…Limited experimental data is available with large intervals between the sampling points preventing the extraction of reliable information for low carbon concentrations [1]. Futhermore, some experimental reports suggest a decrease in the energy band gap if the C content is increased [7][8], but others suggest an increase in the energy band gaps [2][3][4]. Different theoretical methods [1,[9][10][11] or specimen preparation techniques [12] can lead to significantly different results.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Composition dependent energy band gaps for the ternary alloy Si_1−x−yGe_xC_y

Shim

Bae

Lim

et al. 2003

Physica Status Solidi (b)

View full text Add to dashboard Cite

The universal tight binding method based on sp 3 s * basis functions is used to calculate the electronic structure of the ternary alloy Si 1ÀxÀy Ge x C y . The dependences of the fundamental band gaps ðEðGÞ, EðDÞ, EðLÞ, and EðXÞÞ are obtained and investigated for small concentrations of carbon (0 y 0.05). It is found that the presence of carbon in the alloy Si 1ÀxÀy Ge x C y results in a very significant change (i.e., reduction) of the alloy bond length with a small change of the energy band gaps. The energy band gap increases upon adding carbon to the strained alloy. However, the energy band gap decreases upon adding carbon while keeping the alloy lattice matched to the substrate Si. The calculated band gaps are in good agreement with the limited available experimental data and ab initio results.The crystalline silicon-germanium-carbon (c-Si 1ÀxÀy Ge x C y ) alloys are promising semiconductor candidates for heterojunction devices. Incoporation of a low carbon concentration into substitutional sites of SiGe might be able to relieve the inherent strain of the SiGe layers grown on a Si substrate [1][2][3][4][5] while changing the band gap energy. This prospect would allow for tuning the lattice constant and band gap independently by adjusting the composition ratios and offers an additional degree of freedom for band gap engineering, which is not attainable by standard Si technology or SiGe heteroepitaxy [6]. However there are limitations on achieving complete substitution due to the low solubility of C in Si and the tendency of carbon to form silicon carbide, or C-C bonds [5].The energy band gaps and the lattice constants of the alloy are important parameters for device design. However, very little theoretical or experimental work on the alloy Si 1ÀxÀy Ge x C y has been reported. Limited experimental data is available with large intervals between the sampling points preventing the extraction of reliable information for low carbon concentrations [1]. Futhermore, some experimental reports suggest a decrease in the energy band gap if the C content is increased [7][8], but others suggest an increase in the energy band gaps [2][3][4]. Different theoretical methods [1,[9][10][11] or specimen preparation techniques [12] can lead to significantly different results. With this situation as background, the present work aims to provide reliable band gap calculations. The full electronic band structure of the alloy Si 1ÀxÀy Ge x C y is determined within the UTB method [13] based on sp 3 s* basis functions including the first nearest neighbor interactions, in which the excited s-like state s * is

show abstract

supporting

confidence: 68%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Composition dependent energy band gaps for the ternary alloy Si_1−x−yGe_xC_y

Shim

Bae

Lim

et al. 2003

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

Infrared Characterization of Device‐Quality Silicon

Medernach¹

2001

Handbook of Vibrational Spectroscopy

View full text Add to dashboard Cite

Vibrational spectroscopy is the major optical characterization technique for semiconductor device‐quality silicon and its associated compounds. The vibrational bands in silicon result from phonon absorption and impurities such as oxygen (O 2 ), nitrogen (N 2 ) and carbon (C). Information relating to the thickness dependence of the phonon bands and the baseline distortions created by free carriers, roughness, and multiple reflections is provided. A discussion of various new and old techniques used to determine the interstitial O 2 , substitutional C and SiO x precipitates is presented. Further discussion includes the methods to determine the thickness of epitaxial silicon and SiGe composite layers, and the more recent developments including numerical simulations and concentration profiles of epitaxial layers. A brief review is given for the measurement techniques and calibrations of oxide, doped oxide and nonoxide layer thickness that is crucial to semiconductor device fabrication. The application of photoluminescence (PL) and Raman methods are also briefly discussed.

show abstract