Markets and Industrialisation of Low-Power Gas Sensors Based on Work Function Measurements

Abstract

Several sensor principles for gas sensors have been successfully established in the market. This are mainly sensors characterised by high power consumption and low costs (heated metaloxide gas sensors) or sensors characterised by low power consumption and high costs (Electrochemical cells). A combination of the features Low Power Consumption and Low Costs will open up new fields of applications, especially if it allows the incorporation of the majority of the already developed sensor materials. Besides the conventional markets for gas sensors new markets segments will be opened up due to the possibility of personal portable devices in personal security and consumer applications. Such sensors may be realised on the basis of the workfunction readout of a big variety of sensor materials using suspended gate FETs. The hybrid construction of such sensors already successfully investigated will allow the use of a maximum amount of different material classes as sensor materials. To come to a design which has the potential for quick industrialisation, a Flip-Chip technique using ceramic carrier is proposed and investigated. Design criteria are discussed. To arrive at usable systems drawbacks in terms of scattering and drifts have to be successfully resolved. Two strategies for this are discussed.