Silica surface sensitization and chemical 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).