Metal electrode integration and Palladium nanoparticule functionalization on a miniaturized macroporous silicon chemiresistor

Porous silicon has a particularly large surface area available in a limited volume, tens or hundreds of square meters in a cubic centimeter. This attractive property is used to concentrate a large number of surface reactions (such as physico-chemical adsorption of gases) in a small volume. With a simple and cheap fabrication, the porous silicon is an ideal candidate for gas sensing applications. In this work, new gas sensor architecture in macroporous silicon is presented. The development of this new architecture, based on chemiresistor principle has led to several technological innovations. Three aspects were particularly studied: 1. Integration of miniaturized metal electrode on macroporous silicon to improve the sensitivity of measurement and to enable miniaturization of the sensor. The fabrication process has focused on standard microfabrication techniques to enables the transfer of the sensors to an industrial valorization. 2. A masking technique for localized formation of macroporous silicon to eliminate the mask underetching during the anodization of the porous silicon. 3. The functionalization by palladium nanoparticles of macroporous silicon with metal electrode integrated on the surface, to increase the sensitivity and selectivity of hydrogen sensing.(FSA - Sciences de l'ingénieur) -- UCL, 201