ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
Your search history is empty.
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Analysis and modeling of the base currents of Si/Si1−xGex heterojunction bipolar transistors fabricated in high and low oxygen content material (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 2823-2829 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A comparison is made of the dc electrical characteristics of Si/Si1−xGex heterojunction bipolar transistors (HBTs) fabricated on high oxygen content material grown using molecular beam epitaxy and low oxygen content material grown using chemical vapor deposition. The base currents of Si/Si0.85Ge0.15 HBTs with a high oxygen content are significantly higher than those of comparable devices with a low oxygen content and the base currents of both are higher than those of silicon homojunction devices. In addition the base current in the low oxygen content devices increases significantly when the germanium concentration is increased from 15% to 23%. The roles of the lifetime in the base and the out-diffusion of the boron from the Si1−xGex base are investigated using a two-dimensional drift-diffusion device simulator. It is shown that the increased base currents in the HBTs are caused by recombination in the neutral base, and that the lifetime in the Si1−xGex is an important parameter in determining the base current. Modelling of the measured base currents indicates that the lifetime in the high oxygen content Si0.85Ge0.15 is reduced by a factor of approximately 15 compared with silicon, but in the low oxygen content Si0.77Ge0.23 by a smaller factor of approximately 4. Boron out-diffusion from the base is present in both the high and low oxygen content HBTs, but it appears to be significantly less in the former. A high oxygen content in Si1−xGex HBTs therefore has the disadvantage of decreasing the lifetime, but the advantage of decreasing the boron out-diffusion from the base. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spectroscopic ellipsometry characterization of strained and relaxed Si1−xGex epitaxial layers (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 239-250 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Spectroscopic ellipsometry has been used to study thick, relaxed and thin, strained epilayers of Si1−xGex on Si in the range 0.1〈x〈0.25. Dielectric functions of relaxed Si0.87Ge0.13 and Si0.8Ge0.2 have been obtained and long-wavelength absorption coefficient values, required for interference fringe fitting, shown to be higher than measured previously. The dielectric function of strained Si0.78Ge0.22 has been measured for the first time and the effects of strain on the critical points shown to be consistent with deformation potential theory. An interpolation procedure has been developed for the fitting of layer composition and thickness, and excellent agreement with conventional techniques obtained for a series of uncapped single epilayers. The surface roughness of Si1−xGex epilayers has been studied as a function of time and deposition temperature and shown to play an important role in the modeling. The application of the technique to the characterization of buried strained layers is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353896
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Near-band-gap photoluminescence from pseudomorphic Si1−xGex single layers on silicon (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 1407-1414 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The systematic study of band-edge luminescence in pseudomorphic Si/Si1−xGex/Si double-heterostructure layers is reported for a wide composition range, 0.12〈x〈0.24, for the first time. An analytical expression for the exciton energy gap at 4.2 K valid for x〈0.24 is derived from the no-phonon line energies: ESX(x) = 1.155−0.874x+0.376x2 eV. Addition of an expression for the exciton binding energy provides an approximation for the energy difference between the alloy valence band and the lowest conduction-band edge at low temperature. An exciton upshift of 16.9 meV due to quantum confinement is observed in a 6.3-nm Si0.83Ge0.17 alloy well. This is consistent with either type-I or type-II band alignment for which the conduction-band offset has a magnitude ||ΔEc|| ≤ 10 meV. The excitonic hole is closely confined in the alloy but the spectra suggest that the electron density in the silicon barriers is increased for the thin layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A model for heterogeneous growth of Si1−xGex films from hydrides (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 3729-3732 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Growth rates for Si1−xGex films (0≤x≤0.19) have been measured between 610–750 °C using low pressure H2/SiH4/GeH4 mixtures and at different temperatures these rates show different dependencies on composition x. A model attributes this complex behavior to competition between an increasing rate for desorption of surface hydrogen and a decreasing sticking probability for the reactive hydrides as x increases. The latter effect is explicitly reported for the first time. GeH4 is found to be ∼4.7 times more reactive than SiH4, and relative surface hydrogen coverages on Si and Si0.87Ge0.13 films measured by secondary ion mass spectroscopy are compared with the model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Surface-emitting two-dimensional coherent semiconductor laser array (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 331-333 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We describe a new surface-emitting semiconductor structure, its fabrication, and its performance. Phase-locked emission takes place from a region much larger than the wavelength in two dimensions; therefore we term this device a two-dimensional coherent array. The key feature of our device is that the radiation is coupled directly from the active region using a nonresonant grating coupler, i.e., the grating is of noninteger order.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101899
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    1.3-μm light-emitting diode from silicon electron irradiated at its damage threshold (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1509-1511 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report 77-K electroluminescence from an irradiated carbon-rich silicon diode that has an internal quantum efficiency more than 103 times higher than that of band-to-band recombination in an unirradiated, but otherwise identical diode. This is achieved by creating optically active Cs-SiI-Cs complexes with room-temperature electron bombardment at an energy between the displacement thresholds for single vacancy and divacancy formation. Under these irradiation conditions, it is possible to create a high concentration of radiative defects without gross degradation of the diode's electrical characteristics. The technique could provide very large scale integration-compatible silicon light-emitting diodes for 1.3–1.6 μm all-silicon integrated optics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.98618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Using a hydrogen ambient to eliminate interfacial boron spikes in reduced temperature silicon epitaxy (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 1229-1231 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We show that the concentration of boron at the interface between a silicon epitaxial layer and an n-type Si substrate can be reduced to 109–1010 atoms cm−2, near the detection limit of secondary-ion mass spectrometry, when passivating oxide is desorbed from the substrate surface in a hydrogen ambient. Interfacial boron contamination is found to be much higher when the substrate surface oxide is desorbed in ultrahigh vacuum prior to growth, consistent with previous studies of Si molecular beam epitaxy. The hydrogen ambient is effective in removing boron only during the decomposition of the surface oxide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101663
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Long-wavelength SiGe/Si resonant cavity infrared detector using a bonded silicon-on-oxide reflector (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 544-546 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Resonant-enhanced detection of long wavelength infrared radiation using a SiGe/Si multiquantum well device grown on a bonded silicon-on-insulator substrate reflector is reported. A low refractive index in the wavelength region below the 9.2 μm absorption peak in SiO2 gives high Si/SiO2 reflectivities between 7 and 9 μm. Comparison with a control device grown on a p+-Si substrate shows a fivefold enhancement in the peak responsivity at 7.2 μm, which is the resonant wavelength of the cavity formed between the buried Si/SiO2 and the Si/air interfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.116394
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Absorption in p-Si1−xGex quantum well detectors (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 1512-1514 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The normal incidence absorption between 2 and 14 μm in a pseudomorphic p-Si0.81Ge0.19/Si multiple quantum well sample with doping 5×1012 cm−2 per well is described by a Drude conductivity characteristic of free carriers, with an in-plane mobility of 32 cm2/V s and a relaxation time of 5.5 fs at 77 K. When the absorption is scaled with dopant concentration these parameters predict quantum efficiencies for quantum well infrared photodetectors in reasonable agreement with experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Electroluminescence from a pseudomorphic Si0.8Ge0.2 alloy (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 1350-1352 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electroluminescence due to recombination of electrons and holes at the band edges of strained Si1−xGex alloy is reported for the first time. This is demonstrated by comparison of the luminescence energy with the photoconductivity threshold of a p-i-n diode incorporating Si0.8Ge0.2, and with the calculated energy gap for the pseudomorphic alloy. The luminescence is strong at low temperature and persists to 220 K. The high intensity of the no-phonon line relative to the momentum-conserving phonon replica in the spectrum shows the scattering in the random alloy is a practical and effective mechanism for enhancing the recombination probability in this indirect semiconductor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...