Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel: DFG Deutsche Nationallizenzen  (49)
Datenquelle
  • Artikel: DFG Deutsche Nationallizenzen  (49)
Materialart
Erscheinungszeitraum
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 1934-1937 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report on x-ray diffraction measurements of the substitutional carbon content y in pseudomorphic Si1−yCy (y〈0.02) layers grown on (100)-oriented silicon substrate. The samples were grown by molecular beam epitaxy and investigated during post growth annealing in situ by an x-ray powder diffractometer. Despite the tensile strain in the 100-nm-thick layers and the high carbon supersaturation, the samples were stable up to 800 °C. Beyond this temperature range, the substitutional carbon content decreased exponentially during isothermal annealing. This effect can be explained by the precipitation of the carbon and the nucleation and diffusion limited growth of SiC nanocrystals. Since no strain relief by the introduction of misfit dislocations was detectible, we conclude that contrary to the mechanism of strain relief in Si1−xGex, in comparably strained Si1−yCy epilayers, the main high temperature process is precipitation. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 6683-6688 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A new method for unambiguous reconstruction of crystal-lattice strains in epitaxially grown layers from high-resolution x-ray diffraction data is proposed. The technique uses x-ray diffracted intensity profiles collected for two different radiation wavelengths. We enhance the theory for the previously developed algorithm for model-independent determination of crystal-lattice strain profiles in single crystals with epitaxially grown top-surface layers. The method relies on the retrieval of the scattered x-ray wave phase from its intensity profile via a logarithmic Hilbert transform. This phase-retrieval technique is always associated with the problem of complex polynomial root finding. A practical procedure for the mapping of complex polynomial roots is proposed to distinguish true and virtual zeros. This allows the phase of the diffracted x-ray wave to be retrieved unambiguously. The method was applied to determine physical dimensions and concentration composition of a Si/Si1−xGex/Si alloy multilayer structure typical for SiGe heterobipolar transistor device. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 6711-6715 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Molecular beam epitaxial growth of Si1−yCy alloys pseudomorphically strained on the (2×1) reconstructed Si(001) has been investigated as a function of growth conditions. An important question concerns the relation between substitutional and interstitial carbon incorporation, which has a large impact on electrical and optical properties of these layers. We show that the interstitial-to-substitutional carbon ratio is strongly influenced by the growth conditions, such as growth temperature and Si growth rate. Both reduction in growth temperature and increase of the overall growth rate lead to an increase in the substitutional-to-interstitial carbon ratio. However, these changes in growth conditions can also cause some deterioration in crystal quality. The carbon incorporation behavior is well described by first order kinetics. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 2191-2196 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A method is presented to simultaneously investigate in situ the relaxation and diffusion behavior of Si1−xGex layers on silicon substrates using a conventional x-ray powder diffractometer with a high-temperature attachment. The method allows the direct determination of the time and temperature dependence of the relaxation and of the maximum Ge content. The diffusivity of Ge in silicon was studied by x-ray diffraction and secondary ion mass spectroscopy measurements. A nonlinear dependence of the effective diffusion coefficient on the Ge content was deduced by solving a diffusion equation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 65 (1989), S. 98-104 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Phosphorus was implanted at doses below amorphization threshold in virgin silicon and in silicon containing interstitial dislocation loops. The loops were formed by high-dose Si+ implantation and 900 °C, 30 min annealing. Triple-crystal x-ray diffraction and junction depth measurements combined with secondary ion mass spectrometry were used for the analysis of implant defects and the determination of P distribution, respectively. Annealings were carried out in furnace in the range between 600 and 900 °C, and by electron beam at 1000 °C for 10 s. The results obtained show that the presence of loops strongly reduces the phosphorus anomalous diffusion. This phenomenon is the consequence of the absorption by the loops of the interstitial excess coming from dissolution of the clusters produced by the P implant. The influence of the loop position with respect to the P distribution on the extent of P diffusivity is analyzed and discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 1834-1840 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The influence of the lattice defects induced by silicon-ion implantation on the B, P, As, and Sb diffusivities is investigated after annealing between 700 and 900 °C. The nature and depth position of the residual implantation defects in undoped samples is determined by the analysis of the rocking curves obtained by triple-crystal x-ray diffraction and transmission electron microscopy. In particular, besides the interstitial dislocation loops and clusters below the original amorphous-crystal interface, the epitaxial regrowth of the amorphized silicon leaves a vacancy-rich surface layer and a deeper region enriched in interstitials. These regions correspond to those where Monte Carlo simulations of defect production foresee excess point defects. Accordingly, as the dopant is located in correspondence with the vacancy or interstitial clusters, different behaviors of anomalous diffusion are observed. In the deep region where an interstitial excess is present, B and P show marked enhanced diffusion, while only a small enhancement is exhibited by As and Sb. On the contrary, retarded diffusivity for B and light enhancement for As and Sb are observed in the surface layer. These different trends are consistent with the different accepted contributions of vacancies and interstitials to the diffusion mechanisms of the investigated dopants.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 7223-7227 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The appearance of an elastic strain relief in narrow mesalike patterned Si1−xGex heteroepitaxial layers is shown. A Si1−xGex layer was deposited on a mesalike patterned Si(001) substrate by molecular-beam epitaxy. The germanium concentration was x=14%, the layer thickness h=96 μm was several times larger than the critical thickness hc. The layers on top of the mesas were investigated by Raman microscopy. The Raman line shifts of the wider mesas and their dislocation densities agree with the predicted strain reduction by generation of misfit dislocations. On the narrow mesas an additional shift of the Raman lines toward the unstrained alloylike Raman frequency was measured. It is caused by an elastic strain relief on top of the narrow mesas. An estimation of the expected Raman line shifts is given assuming an uniaxially strained SiGe layer. The calculated line shifts agree sufficiently with the measured values. The elastic strain relief reduces the free energy of the layer-substrate system, reduces the stress in the pseudomorphic layer, and stabilizes the structure. The effect arises if the mesas are narrower than 2 μm. It is therefore of interest in all submicrometer technologies.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 231-235 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We show that the formation of self-organized pseudosuperlattices during homogeneous epitaxial growth of Si1−yCy on Si(001) is a fundamental phenomenon not limited to special growth techniques. For samples grown at higher temperatures, and therefore, with higher concentration of nonsubstitutional carbon, we find contrast variations in cross-sectional transmission electron microscopy, roughly periodic in the growth direction in epitaxial Si1−yCy alloy layers. The periodicity is a monotonic function of growth temperature and growth rate. Although the final explanation of this phenomenon remains an open question, we are able to rule out several possible effects. These structures do not reflect a modulation in the substitutional C content, the formation of the C-rich SinC phases, or the segregation of nonsubstitutional C-containing defect complexes up to a certain saturation level. Rather, we show that the layers formed during the different growth processes contain different amounts of carbon. There is no critical size of the C-containing defect complexes independent of growth conditions that could lead to the formation of the observed structures. The variation of the periodicity with growth rate and temperature is similar to surface diffusion processes with an activation energy of 0.94±0.04 eV, close to the value for Si adatom diffusion on a Si(001) surface. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 6134-6140 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The annealing behavior of pseudomorphic Si0.603Ge0.397/Si and Si0.597Ge0.391C0.012/Si superlattice structures was studied in the temperature range between 750 °C and 900 °C. Carbon incorporation of 1.2% changes the thermal stability of SiGe structures significantly. It suppresses plastic relaxation due to an effective dislocation pinning. No relaxation of the SiGeC sample was observed during annealing up to 875 °C for 3 h. For comparison the SiGe sample relaxed at 800 °C. Carbon strongly increases the interdiffusion of Ge and Si. The activation energy of this diffusion process for a Ge content of 40% decreases from about 4.8 eV for the pure SiGe to about 2.0 eV with an additional C content of 1.2% assuming a neglectable diffusion of the carbon. This leads to a distinct modification of the Ge profile in the investigated temperature range. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3177-3180 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Epitaxial Si1−xGex layers, grown by molecular beam epitaxy (MBE) and by chemical vapor deposition (CVD) on Si(001) substrates, with thicknesses between 20 and 50 nm and Ge contents from 4% to 23% were investigated by micro Raman backscattering, x-ray double crystal diffractometry, and transmission electron microscopy. A quite simple phenomenological model was developed to derive the Raman shift of the Si–Si mode as a function of the germanium content for the two limiting cases, the pseudomorphically strained layer, and the alloy-like stress-free layer. A measure for the degree of relaxation can be obtained from the measured Raman shift and from the independently determined germanium content, using the results of the model. The degree of relaxation was determined for a number of CVD- and MBE-grown Si1−xGex layers. The as-grown pseudomorphic layers relax partially after annealing at 900 °C. The Raman scattering allows the monitoring of the development of relaxation during the semiconductor device processing.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...