Efficient Improvement of Sensing Performance Using Charge Storage Engineering in Low Noise FET-type Gas Sensors

A novel charge storage engineering (CSE) using program/erase (P/E) operation for improving the sensing performance of FET-type gas sensors with floating-gate is proposed for the first time. The responses of the sensors to NO2 and H2S gases are significantly improved when the sensors are set at programmed (holes stored) and erased (electrons stored) states, respectively. The sensor, fabricated simply using 6 masks, has a 1/f noise (SID/ID²) that is ~10³ times lower than that of resistor-type gas sensor fabricated on the same substrate, and is resistant to P/E F-N stress. The proposed CSE not only improves the response and limit of detection, but also allows selectivity for NO2 and H2S gases up to 5 and 6 times, respectively.