Strain measurement in thin pseudomorphic SiGe layers of submicron wires using Raman spectroscopy

Dietrich, B.; Bugiel, E.; Frankenfeldt, H.; Harker, A. H.; Jagdhold, U.; Tillack, Bernd; Wolff, Anders

doi:10.1016/0038-1101(95)00317-7

Cited by 11 publications

(16 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12 Since the quantum wire samples do not use poly-Si, the results are independent of this uncertainty. The calculated curves also agree well with the experiments of Dietrich et al 11 for the quantum wires.…”

Section: Comparison With Experimentssupporting

confidence: 81%

“…Similar structures are also used in the lattice mismatched stripes and substrates. 11,18 In the back scattering geometry used in the experiments, only the Raman frequency 3 is observed. 5 The strain induced shift of the Raman spectrum from the point (x,z), ͑measured from unstrained Si shift at 521 cm Ϫ1 ) is denoted by ⌬ 3 p (x,z), (p indicates peak frequency of the spectrum͒.…”

Section: A Earlier Workmentioning

confidence: 99%

“…9,10 More recently stress distribution in the lattice mismatched quantum wires and in the substrate on which they are grown has been studied. 11,12 Techniques of stress calculations and measurement are the same regardless of whether the strain is caused by thermal mismatch or lattice mismatch. Raman technique has been used successfully in measuring stresses in lattice mismatched epilayers.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A method to interpret micro-Raman experiments made to measure nonuniform stresses: Application to local oxidation of silicon structures

Pinardi

Jain

Willander

et al. 1998

Journal of Applied Physics

View full text Add to dashboard Cite

A method is described to calculate the Raman spectrum from a nonuniformly strained sample taking into account the effects that arise due to finite depth of penetration and diameter of the laser beam. Both the parallel and the focused beams are considered. The case of stress in a Si substrate decaying monotonically with depth z (rapidly near the interface and slowly at larger depths) is considered in detail. The predicted Raman shifts are found to be sensitive to both the distribution of stress and to the absorption coefficient α for the laser light wavelength used. It is found that light scattered from distances much larger than 1/α still contribute significantly to the observed Raman spectrum. The observed shift in the peak of the spectrum does not correspond to the stress close to the interface. If the stress decays more rapidly than the light intensity, the Raman line that originates from the unstrained lower part of the substrate dominates. For transparent material (α=0) and unfocused beam the Raman spectrum consists of only the unstrained Si line; the contribution to Raman line from the strained interface region is completely masked. For measurements of stresses near the interface short wavelength light with an absorption depth of 5–10 nm is recommended. The calculated and observed Raman shifts in a local oxidation of silicon (a processing technique for isolation) with polysilicon buffer between the nitride stripe and the Si substrate are compared. The agreement between the calculated and the observed Raman shifts is very good. The salient points of our approach which enabled us to obtain this agreement are: We took into account the effects of laser beam width, penetration depth, and focusing; we included the stresses in the polysilicon layer and near the polysilicon/silicon interface, and we included contributions from large depths.

show abstract

Section: Comparison With Experimentssupporting

confidence: 81%

Section: A Earlier Workmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A method to interpret micro-Raman experiments made to measure nonuniform stresses: Application to local oxidation of silicon structures

Pinardi

Jain

Willander

et al. 1998

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…The application of the methods outlined in this paper to interpret Raman spectra measured by Dietrich et al 22 on quantum wire stripes of Ge 0.11 Si 0.89 (150 nm wide and epitaxially strained by growth on (001) silicon) is described in Ref. 23 and is briefly summarised here.…”

Section: Examples Of Applications Ge 011 Si 089 Strained Quantum Wiresmentioning

confidence: 99%

Spatially resolved stress analysis using Raman spectroscopy

Atkinson

Jain

1999

J. Raman Spectrosc.

View full text Add to dashboard Cite

Raman spectroscopy using a laser microprobe (also called micro-Raman) is becoming more widely used to study stress distribution in solids, particularly in micro-electronic device structures, because of its potential for high spatial resolution. Typically the diameter of the focused laser beam is 1 µm but the penetration depth can vary from tens of nanometres to several millimetres and thus samples a potentially large volume of the strained structure. Each point within this volume scatters light with a Raman wavenumber characteristic of the local stress at that point. Because the beam is usually focused, the distribution of light intensity in this volume and the interpretation of the resulting spectrum, is complicated. Recently we have developed a method to calculate theoretically the Raman spectra from such structures using stress fields calculated by Finite Element Modelling. The method is summarised here and illustrated with application to two examples; a SiGe quantum wire stripe on silicon and a nitride stripe on silicon. The errors incurred by using simpler data analysis methods are discussed and found to be significant.

show abstract

“…Raman spectroscopy has been applied previously to analyzing the strain in a variety of SiGe mesa and wire heterostructures [6][7][8] with modeling of the results based on the finite element method. [9][10][11] Comparatively little Raman work has been performed on SiGe dot heterostructures, [12][13][14] where dots with a small ͑50-60 nm͒ or large ͑300-1000 nm͒ diameter were investigated.…”

Section: Introductionmentioning

confidence: 99%

Elastic relaxation of dry-etched Si/SiGe quantum dots

et al. 1998

View full text Add to dashboard Cite

Elastic relaxation of the compressive strain due to the lattice mismatch between SiGe and Si has been studied with both x-ray diffraction and Raman scattering in small ͑30-100 nm͒ dry-etched Si/SiGe quantum dots fabricated from high-quality multilayers grown on ͑001͒-oriented Si. The Raman spectroscopic investigations showed that the dot alloy layers have relaxed by approximately 65% from their fully strained value and that a compensating tensile strain has been induced in the Si layers. The relaxation is essentially independent of the dot size and the values derived experimentally compare well with analytical and numerical model calculations. ͓S0163-1829͑98͒07731-5͔

show abstract

Strain measurement in thin pseudomorphic SiGe layers of submicron wires using Raman spectroscopy

Cited by 11 publications

References 8 publications

A method to interpret micro-Raman experiments made to measure nonuniform stresses: Application to local oxidation of silicon structures

A method to interpret micro-Raman experiments made to measure nonuniform stresses: Application to local oxidation of silicon structures

Spatially resolved stress analysis using Raman spectroscopy

Elastic relaxation of dry-etched Si/SiGe quantum dots

Contact Info

Product

Resources

About