Fabrication and Performance Research of Silicon Nanosheet Field Effect Transistor Biosensor

Silicon nanowire (SiNW) FET biosensor has made great contributions to chemical and bio-molecular sensing, and is considered to be one of the best candidates for biosensors. However, due to high sensitivity to pH changes of the buffer solution when detecting biomolecules and low binding rate to biomolecules for small area, SiNW FET biosensor still has the problems of high variation and long response time. To solve the problems, In this paper, we investigate the sensing performances of silicon nanosheets (SiNS) FET with different areas, and found that SiNS FET biosensor with large areas can reduce the sensitivity to pH effectively, thus reducing the detection error caused by pH changes and improving sensing accuracy. In addition, by COMSOL simulating, we also found that devices with wide SiNS show higher bonding rate than that of SiNW devices at low analyte concentrations, thereby decreasing the responding time for high-speed detecting.