Library

X
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
    Detection of particulates in a rf plasma by laser evaporation and subsequent discharge formation (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 2959-2961 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nd:YAG-laser-induced evaporation of particulates formed in an Ar-CCl2F2 rf plasma and the subsequent discharge in the vapor have been investigated in situ by means of optical emission spectroscopy. The estimated threshold for discharge formation is 5×106 W/cm2. The maximum laser-induced emission intensity is observed when the laser is operated in the long-pulse mode (about 200 μs pulse duration) at the fundamental frequency. The wavelength integrated intensity of this continuum emission has been compared with light scattering intensity at the same laser energy. It has been found that the laser-induced emission intensity can be more than ten times higher than the scattering intensity, especially for particulates with a diameter much smaller than the wavelength of the laser. Therefore, this effect provides a sensitive particulate detection method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Depth profiling of the Ge concentration in SiGe alloys using in situ ellipsometry during reactive-ion etching (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 8017-8026 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The complex refractive index of SiGe alloys at 632.8 nm has been measured as a function of the Ge concentration using in situ ellipsometry while the material is slowly removed from a silicon substrate using reactive-ion etching (RIE). Homogeneous, strained epitaxial SiGe films on silicon substrates were used. The Ge concentration was obtained by Rutherford backscattering. If an unknown SiGe structure is etched with RIE, in situ ellipsometry yields combinations of the ellipsometric angles Ψ and Δ with time. Starting at the Si substrate, these points are, on a point-to-point basis, converted into combinations of complex refractive index and depth in a numerical procedure. For this inversion of the ellipsometry equations, the known relation between the real and the imaginary part of the refractive index of SiGe is used. Finally the refractive indices are converted into Ge concentrations. Thus the depth profile of the Ge concentration in an unknown epitaxial SiGe structure can be inferred from an in situ ellipsometric measurement during RIE of the unknown structure. The obtained resolutions in depth and Ge concentration are 0.3 nm and 0.3%, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353916
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nonintrusive wafer temperature measurement using in situ ellipsometry (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 3390-3392 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown that in situ HeNe laser ellipsometric measurements performed during and after rf plasma exposure of a Si wafer with or without oxide can be used to obtain the wafer temperature during plasma exposure. The method utilizes either the temperature coefficient δn/δT of the refractive index of Si or the linear thermal expansion coefficient δl/lδT of SiO2. The values of these parameters have been redetermined in this work.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348517
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Measurements of negative ion densities in 13.56-MHz rf plasmas of CF4, C2F6, CHF3, and C3F8 using microwave resonance and the photodetachment effect (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 3472-3480 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The high-power density of a frequency quadrupled pulsed Nd-YAG laser has been used to photodetach electrons from negative ions in rf plasmas generated within a microwave cavity. Negative ion densities have been determined by measuring the frequency shift of the resonance transmission, the shift being caused by the photoelectrons created by irradiating the plasma with the laser pulse. By measurement of the shape of the resonance curve as a function of time and of microwave frequency, and consecutive fitting of a parabola to the top of the resonance curve, the negative ion density has been determined as a function of gas pressure, rf power, and position in the plasma. Measurements were performed in plasmas of CF4, C2F6, CHF3, and C3F8. The results indicate that the negative ion densities are about one order of magnitude larger than the electron density, which is in good agreement with a fluid model calculation. The pressure and power dependence of the electron density and of the negative ion density gives insight in the relation between the electron temperature and the macroscopic plasma parameters. Measurements as a function of the laser wavelength, using a pulsed dye laser, show that in CF4 the negative ions mainly consist of F−, whereas in C2F6 significant densities of other negative ions may occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350346
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Temporal behavior of the electron and negative ion densities in a pulsed radio-frequency CF4 plasma (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 2939-2946 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electron and negative ion densities in the afterglow and in the plasma initiation phase of a 13.56-MHz rf discharge in CF4 were measured by using a microwave cavity method and a laser photodetachment technique. Measurements were carried out at low rf powers ((approximately-less-than)10 W) and in the pressure range from 100 to 300 mTorr. The electron density in the afterglow showed an enhanced decay rate due to the presence of negative ions. Electrons originating from negative ions through associative collisional detachment with neutral radicals were also detected in the afterglow. Decay curve analysis of the negative ion density gave an ion–ion (presumably CF+3−F−) recombination rate constant of (5±2)×10−13 m3 s−1, and showed that, in the active plasma, the negative ion loss rates by associative detachment and ion–ion recombination are of the same order of magnitude. The behavior of the electron and negative ion densities in the plasma initiation phase indicates that molecules and radicals that slowly accumulate in the plasma do not play a significant role in the production of negative ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Thomson scattering in a low-pressure neon mercury positive column (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 3720-3725 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electron density and the electron temperature in a low-pressure neon mercury positive column are determined using Thomson scattering. Special attention has been given to the stray light reduction in the Thomson scattering setup. The results are obtained in a discharge tube with a 26 mm diam, 10 mbar of neon, a mercury pressure inbetween 0.14 and 0.85 Pa, and an electric current ranging from 100 to 400 mA. The systematic error in the electron density is 15%–45%, the statistical error is 25%–35%. The total error in the electron temperature is 15%–35%. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1390497
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Energy distribution of ions and fast neutrals in microdischarges for display technology (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 2240-2245 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this work we present simple theoretical predictions as well as full Monte Carlo calculations of the energy distribution of the ion and fast neutral fluxes impinging on the materials that surround the microdischarges in plasma display panels and plasma addressed liquid crystal displays. We consider various rare gas ion species in different microdischarge designs. Often simple theoretical distribution functions are in good agreement with the results of Monte Carlo calculations. Under the influence of symmetric charge transfer collisions the ion energy distribution is essentially different from a Maxwellian distribution, and the ion motion is strongly orientated along the electric field. The flux of the fast neutrals formed by symmetric charge transfer is usually even larger than the ion flux itself. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1287758
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Emission spectrum of a depleted neon–mercury positive column (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 1733-1741 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Under certain discharge conditions, radial cataphoresis causes significant mercury depletion in a low-pressure neon–mercury positive column. This depletion can result in the addition of neon radiation to the emission spectrum of the column. The addition of neon radiation can be used to change the color of fluorescent lamps. In order to investigate the radial cataphoresis process, we performed spatially resolved emission measurements. For the relevant spectral lines of mercury and neon, the emission coefficient is determined, along with the density of the upper state of the corresponding transition. Absorption measurements are performed to check the amount of self-absorption of the spectral lines. We present emission and density profiles for various discharge conditions. The obtained results can be understood using an approximate description of the radial cataphoresis process. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1305843
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Modeling of the microdischarges in plasma addressed liquid crystal displays (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 2252-2262 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Plasma addressed liquid crystal (PALC) is a promising technology for large size flat display devices, which uses gas discharges as electrical switches for the addressing of a liquid crystal (LC) layer. This work presents a comprehensive two-dimensional fluid model, that we developed for the simulation of the microdischarges occurring in PALC displays. The model comprises continuity equations and drift-diffusion equations for plasma particle species, a balance equation for the electron energy, and Poisson's equation for the electric field. Using this model, we succeeded in simulating the full PALC operation, reproducing a series of discharge pulses and afterglows in three consecutive PALC discharge channels. Results are presented for helium and helium–hydrogen mixtures. The results include: calculated particle densities, current–voltage curves, plasma decay times, surface charges, and LC transmission profiles. The influence of electrical crosstalk between adjacent channels is demonstrated.© 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1287529
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Thomson scattering using an atomic notch filter (2000)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 71 (2000), S. 2007-2014 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: One of the biggest problems in performing Thomson scattering experiments in low-density plasmas is the very high stray light intensity in comparison with the Thomson scattering intensity. This problem is especially present in fluorescent lamps because of the proximity of the glass tube. We propose an atomic notch filter in combination with a dye laser and an amplified spontaneous emission (ASE) filter as a way of reducing this stray light level. The dye laser produces 589 nm radiation which is guided through the ASE filter that increases the spectral purity. The beam is then guided in the fluorescent lamp, where the Thomson scattering process takes place. The scattered light is collected and guided through a sodium vapor absorption cell, where the stray light is absorbed because it is resonant to the D2 transition of sodium. The spectral width of the Thomson scattering light is large enough to be transmitted through the absorption cell. In this way we only measure the Thomson scattering light. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1150569
    Library Location Call Number Volume/Issue/Year 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...