Impact of back-gate biasing on ultra-thin silicon-on-insulator-based nanoribbon sensors

For over 30 years, field effect transistors (FETs) have been used as ion sensors [1]. In the past, IonSensitive-FETs were based on bulk MOSFET designs and the reference electrode was used to bias the device [2]. Recently, functionalized silicon nanowires and nanoribbons have been used to detect a variety of species including proteins and single viruses [3-4]. These designs allow for gating of the device from the back, across the buried oxide of the wafer [3-4]. Careful consideration must be given to the interaction of the liquid media and coupling effects with the FET. This is paramount to the determination of the operating region of the sensor. In this work, we investigate the effects and advantages of applying a back gate bias on SOIFET-based chem-/biosensors. Further, we look at the different responses of dynamic and static DC measurements on pH and protein (biotin-streptavidin) sensors.