GAS SENSING CMOS TRANSISTORS BASED ON SOI SUBSTRATE

In recent years, the development of miniature gas sensors based on silicon technology is being increasingly emphasized. Most of the devices reported are based on micro-hot plates, but the materials they used are not fully compatible with CMOS and are therefore not suitable for massive production and co-integration with CMOS circuit. In addition, extra process steps are needed to form the sensing device and CMOS circuits separately. In this work, we demonstrate novel gas sensor devices directly based on the MOSFET transistors fabricated in the silicon-on-insulator (SOI) substrate. Both n-type and p-type devices are demonstrated showing opposite sensing polarity under the exposure to NO2 gas.