Advanced Materials

Silica surface sensitization and chemical sensors

Authors

  • Prof. Paul Clechet,

    1. Laboratoire de Physicochimie des Interfaces, URA CNRS 404 Ecole Centrale de Lyon, BP 163, F-69131 Ecully Cedex (France)
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    • received his engineering degree from Ecole Supérieure de Chimie Industrielle de Lyon in 1958 and his Doctorate in 1965 from the University of Lyon. From 1961 until 1972 he worked on calorimetry and thermodynamics of solutions. Since 1972, he has been a Professor at the Ecole Centrale de Lyon and head of the Interfacial Physicochemistry Laboratory. The research activitie of this laboratory are mainly concerned with the surface chemistry of semiconductors and dielectrics.

  • Dr. Nicole Jaffrezic-Renault

    1. Laboratoire de Physicochimie des Interfaces, URA CNRS 404 Ecole Centrale de Lyon, BP 163, F-69131 Ecully Cedex (France)
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    • received her engineering degree from the Ecole Nationale Supérieure de Chimie, Paris, in 1971 and her Doctorat d'Etat ès Sciences Physiques from the University of Paris in 1976. Since 1971 she has been a research worker at the Centre National de la Recherche Scientifique. In 1984 she joined the Interfacial Physicochemistry Laboratory of the Ecole Centrale de Lyon, France, where shw is in charge of the Sensor Group. Her research activities include the preparation and physicochemical characterization of membranes for ISFET sensors.


Abstract

The surface modification of materials and its control now appear to be a challenge in many fields of technology, for example, composites, chromatography, and chemical sensors.

A well controlled engineering process for producing self-assembled long chain monolayers on a thin thermal silica layer has been perfected in our laboratory. The monolayers are covalently bonded to SiO2/Si(100) heterostructures and have been chemically (chemical analysis, pH sensitivity) and physically (spectroellipsometric and capacitance measurements) characterized.

The application of this process for sensitizing the surface of the silica insulator used in CHEMFET chemical sensors is presented using the example of an Ag® sensitive device. The main features of this sensor are its short response time(< 2 s) and its long lifetime (> 3 months).

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