Subthreshold Operation of Schottky Barrier Silicon Nanowire FET
S.K. Yoo, J.Y. Ahn, S. Yang, J.H. Lee
Gwangju Institute of Science & Technology (GIST), KR
Keywords: Schottky barrier, FET, nanowire, sensitivity, biosensor
Abstract:This paper presents that the sensitivity of Schottky barrier silicon nanowires FET (SB-SiNWFET) is strongly modulated by the applied back gate voltage, and reveals that the operation in the subthreshold regime gives the significant enhancement in the sensitivity for biosensing. A simple structured SiNWFET biosensor was successfully developed using Schottky source/drain contact without complex doping process. The sensitivity versus back gate voltage characteristics was investigated in two ways. Firstly, an electrical potential is applied to the electrolyte through the Ag/AgCl reference electrode. The ratio of current variation in response to the potential difference shows that the high sensitivity is obtainable in the low back gate bias region although the differential current is small. Secondly, the sensitivity versus back gate voltage characteristics is inspected in the time domain. Likewise the first method, the sensitivity is increased in the low back gate voltage, although the differential current is decreased. The highest sensitivity was achieved at 1V of the back gate voltage, which is located in the subthreshold regime.