摘要 :
Identical items are simultaneously subjected to stress and operate independently until failure. The authors observe the early failures and use the times of these failure to predict the times of later failures in the same sample. B...
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Identical items are simultaneously subjected to stress and operate independently until failure. The authors observe the early failures and use the times of these failure to predict the times of later failures in the same sample. Best linear invariant predictors are derived for location-scale families of failure time distributions, and two simplified predictors are developed. The relative behavior of the predictors is indicated in a table.
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摘要 :
Electron and negative ion densities have been measured in inductively coupled discharges containing C2F6 and CHF3. Line integrated electron density was determined using a microwave interferometer, negative ion densities were infer...
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Electron and negative ion densities have been measured in inductively coupled discharges containing C2F6 and CHF3. Line integrated electron density was determined using a microwave interferometer, negative ion densities were inferred using laser photodetachment spectroscopy, and electron temperature was determined using a Langmuir probe. For the range of induction powers, pressures and bias power investigated, the electron density peaked at 9 x 10(12) cm(-2) (line-integrated) or approximately 9 x 10(11) cm(-3). The negative ion density peaked at approximately 1.3 x 10(11) cm(-3). A maximum in the negative ion density as a function of induction coil power was observed. The maximum is attributed to a power dependent change in the density of one or more of the potential negative ion precursor species since the electron temperature did not depend strongly on power. The variation of photodetachment with laser wavelength indicated that the dominant negative ion was F(-) . Measurement of the decay of the negative ion density in the afterglow of a pulse modulated discharge was used to determine the ion-ion recombination rate for CF4, C2F6 and CHF3 discharges.
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摘要 :
Electron and negative ion density have been measured in a modfied Applied Materials DPS metal etch chamber using gas mixtures of BCl(sub 3), Cl(sub 2) and Ar. Measurements were performed for four different substrate types to exami...
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Electron and negative ion density have been measured in a modfied Applied Materials DPS metal etch chamber using gas mixtures of BCl(sub 3), Cl(sub 2) and Ar. Measurements were performed for four different substrate types to examine the influence of surface material on the bulk plasma properties; aluminum alumina, photoresist and 50 percent patterned aluminum / photoresist. Electron densities in the Cl(sub 2) / BCl(sub 3) mixtures varied from 0.25 to 4 x 10(sup 11) cm(sup -3). Photodetachment measurements of the negative ion density indicate that the negative ion density was smaller than the electron density and that the electron to negative ion density ratio varied between 1 and 6. The presence of photoresist had a dominant intluence on the electron and negative ion density compared to alumina and aluminum surfaces. In most cases, the electron density above wafers covered with photoresist was a factor of two lower while the negative ion density was a factor of two higher than the aluminum or alumina surfaces.
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