Investigation of Sensor Performance in Accumulation- and Inversion-Mode Silicon Nanowire pH Sensors

Abstract

We investigate the performance of accumulation (ACC)-mode and inversion (INV)-mode silicon nanowire (SiNW) pH sensors that are electrically controlled by a liquid gate. The two sensing parameters of the changes of threshold voltage and current are explored in both types of SiNW pH sensors at different pH levels. As device dimensions and channel doping concentration increase, the performance of the ACC-mode biosensor degrades more rapidly than the performance of the INV-mode biosensor. Therefore, INV-mode SiNW pH sensors with a liquid gate could be robust to process variation and provide improved current sensitivity.