Electron scattering mechanisms in fluorine-doped SnO2 thin films

Polycrystalline fluorine-doped SnO2 (FTO) thin films have been grown by ultrasonic spray pyrolysis on glass substrate. By varying growth conditions, several FTO specimens have been deposited and the study of their structural, electrical, and optical properties has been carried out. By systematically investigating the mobility as a function of carrier density, grain size, and crystallite size, the contribution of each physical mechanism involved in the electron scattering has been derived. A thorough comparison of experimental data and calculations allows to disentangle these different mechanisms and to deduce their relative importance. In particular, the roles of extended structural defects such as grain or twin boundaries as revealed by electron microscopy or x-ray diffraction along with ionized impurities are discussed. As a consequence, based on the quantitative analysis presented here, an experimental methodology leading to the improvement of the electro-optical properties of FTO thin films is reported. FTO thin films assuming an electrical resistivity as low as 3.7 center dot 10(-4)Omega cm (square sheet resistance of 8 Omega/square) while retaining good transmittance up to 86% (including substrate effect) in the visible range have been obtained. (c) 2013 AIP Publishing LLC

Quasi-static capacitance measurements in pseudo-MOSFET configuration for D<inf>it</inf> extraction in SOI wafers

session posterInternational audienceWe investigate for the first time the quasi-static capacitance technique in pseudo-MOSFET configuration for the characterization of bare SOI wafers. We show the difference between the measurements performed with slow and fast ramp speed and compare them with split-CV characteristics. We discuss the impact of experimental parameters such as ramp speed, probe pressure and number of probes. Finally, we present an experimental procedure, based on an original physical model, to extract the interface trap density

Interface trap density evaluation on bare silicon-on-insulator wafers using the quasi-static capacitance technique

International audienceThis paper presents a detailed investigation of the quasi-static capacitance-voltage (QSCV) technique in pseudo-metal-oxide-semiconductor field effect transistor (pseudo-MOSFET) configuration for evaluating the interface quality of bare silicon-on-insulator (SOI) wafers, without processing dedicated metal-oxide-semiconductor (MOS) test devices. A physical model is developed that is capable of explaining the experimental results. In addition, frequency effects are used to validate the equations by a systematic comparison between experimental and calculated characteristics, as well as by a direct comparison with the standard high-low frequency approach. An extraction procedure for interface trap density based solely on QSCV experimental results is proposed, and limits of the procedure are discussed. The proposed experimental and analytical procedure is demonstrated by characterizing SOI structures with different geometries and with different qualities of surface passivation of the top silicon film

Study of the Functional Properties of ITO grown by Metalorganic Chemical Vapor Deposition from different Indium and Tin Precursors

International audienceFunctional properties of tin doped indium oxide (ITO) layers grown by MOCVD from different indium and tin precursors are investigated. Selected indium precursors are In(acac)3, In(tmhd)3 and InMe2OtBu, and tin precursors are DBTDA and Sn(acac)2. ITO layers are optically and electrically characterized to determine the better doping conditions. Differences in electrical properties of ITO layers are found when using InMe2OtBu, as compared to In(acac)3 and to In(tmhd)3. The best films present a resistivity of 2.5 × 10−4 Ω cm and a transmittance higher than 84% for high deposition temperatures (T ⩾ 600 °C). The nature of tin precursors modifies the optimal doping at which these characteristics are achieved. When doped by DBTDA optimal doping is 8 at.%, therefore close to the solubility limit of tin in In2O3 matrix; but when using Sn(acac)2, or In(acac)3/DBTDA combination, best functional characteristics are obtained for the maximal doping content obtained, i.e. 2.5 at.%. For optimized conditions, the resistivity decreases when deposition temperature increases except when using the couple InMe2OtBu/DBTDA without oxygen addition during deposition. For this combination of precursors a resistivity of 1 × 10−3 Ω cm is obtained at a deposition temperature of 350 °C and remains constant up to 600 °C. Only the films obtained from InMe2OtBu/DBTDA are crystalline state at a deposition temperature of 350 °C

“Hot Carrier Stress Effect on a CMOS 65 nm 60 GHz One Stage Power Amplifier” , vol. 31, no. 9, pp. 927-929, Sept. 2010.

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Characterization of Silicon-On-Insulator films with pseudo metal-oxide-semiconductor field-effect transistor: correlation between contact pressure, crater morphology and series resistance.

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"Hot Carrier Stress Effect on a CMOS 65 nm 60 GHz One Stage Power Amplifier"

International audienc

Characterization of Silicon-On-Insulator films with pseudo metal-oxide-semiconductor field-effect transistor: correlation between contact pressure, crater morphology and series resistance.

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Temperature dependence of the electromechanical characteristics of superconducting RF‐MEMS switches

International audienceMicro-electro-mechanical-system (MEMS) switches are very interesting for high frequency applications. These switches are electrostatically actuated micromechanical meanders-suspended bridges. In the field of millimeter wave radio astronomy, cryogenic circuits are frequently made of superconducting niobium and elements combining these circuits with MEMS devices of compatible technologies are of high potential for new applications. The initial profile of the bridge has been numerically simulated. This suggested the influence of possible residual stress in Nb thin films on the behavior of MEMS. A study of the capacitance variation as a function of the applied voltage has been performed for this type of MEMS at room and low temperatures down to 150K. It is associated with a mechanical study of the vibrating modes of the structure and with X-rays characterization of the Nb film. An identification of specific sets of geometric parameters to reach good performance and temperature stability was done