Detection of hydrocarbon species using silicon MOS capacitors operated in a non-stationary temperature pulse mode

The paper reports on the detection of hydrocarbon species using silicon metal-oxide-semiconductor (Si-MOS) capacitors operated in a non-stationary temperature pulse mode. In this mode of operation, high-temperature chemical interaction of analyte gases with a catalytically active electrode and low-temperature electrical read-out of the CV characteristic is performed in a time-sequential way. Due to this kind of sequencing, hydrocarbon species could be detected with narrow-bandgap Si devices, which previously has only been possible using MOS devices fabricated on wide-bandgap materials such as silicon carbide (SiC) or gallium nitride (GaN). In order to successfully implement a time-sequential sensor operation, the Si-MOS capacitors were integrated into a micromachined hotplate-array fabricated from silicon-on-insulator (SOI) wafers.