Westinghouse Electric

About: Westinghouse Electric is a company organization based out in Cranberry Township, Pennsylvania, United States. It is known for research contribution in the topics: Brake & Circuit breaker. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

Characterization of thin-oxide MNOS memory transistors

Abstract: A direct tunneling theory is formulated and applied to high-speed thin-oxide complementary metal-nitride-oxide-silicon (MNOS) memory transistors. Charge transport in the erase/write mode of operation is interpreted in terms of the device threshold voltage shift. The threshold voltage shift in the erase/write mode is related to the amplitude and time duration of the applied gate voltage over the full range of switching times. MNOS memory devices ( X_{o}=25 \Aring, X_{N} = 335 \Aring ) exhibit a \Delta V_{th} = \plusmn3 V for an erase/write t_{p} = 100 ns, which corresponds to an initial oxide field strength E_{ox}= 1.2 \times 10^{7} V/cm. The direct tunneling theory is applied to the charge retention or memory mode in which charge is transported to and from the Si-SiO 2 interface states. The rate of charge loss to interface states is influenced by electrical stress which alters the interface state characteristics. We discuss the fabrication of complementary high-speed MNOS memory transistors and the experimental test procedures to measure charge transport and storage in these devices.

Contact resistance: Its measurement and relative importance to power loss in a solar cell

Abstract: The concept of contact resistivity is discussed briefly and a technique for its measurement is presented. This technique allows for resistive contact material and for the possibility that the semiconductor sheet resistance beneath the contact differs from the semiconductor sheet resistance beside the contact. The test pattern is unique in that the effects of contact resistance are accumulated over the pattern, nearly unencumbered by voltage and current probes which might otherwise influence the current flow. Measurements of contact resistivities for typical solar cell metallizations using this technique are reported to be in the mid 10-6Ω-cm2range. The relative importance of contact resistance compared to other sources of power loss in a solar cell is determined for a typical contact system. Expressions derived in order to make this comparison are useful for evaluating and optimizing a solar cell contact system. Values of series resistance calculated using these expressions are compared with measured values.

Drift Velocities of Slow Electrons in Helium, Neon, Argon, Hydrogen, and Nitrogen

Abstract: The drift velocities of electrons in helium, neon, argon, hydrogen, and nitrogen have been measured for $\frac{E}{p}$ values between ${10}^{\ensuremath{-}4}$ and 10 volt/cm-mm Hg at temperatures between 77\ifmmode^\circ\else\textdegree\fi{}K and 373\ifmmode^\circ\else\textdegree\fi{}K. The data were obtained from measurements of electron transit time in an improved version of the double-shutter tube developed by Bradbury and Nielsen. By applying sufficiently small voltage pulses to the control grids, it was possible to eliminate end effects present in previous experiments. Values of the momentum transfer cross sections for electrons with energies between about 0.003 and 0.05 ev are obtained which are consistent with the measured drift velocities for thermal electrons in helium, argon, hydrogen, and nitrogen. The derived momentum transfer cross section for electrons in helium is found to be independent of electron energy and equal to 5.3\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$. The momentum transfer cross sections for argon, hydrogen, and nitrogen vary with electron energy.