title: Silicon nanowire ion sensitive field effect transistor with integrated Ag/AgCl electrode: pH sensing and noise characteristics.
abstract: We have fabricated Si nanowire (SiNW) based ion-sensitive field effect transistors (ISFETs) for biosensing applications. The ability to prepare a large number of sensors on a wafer, the use of standard silicon microfabrication techniques resulting in cost savings, and potential high sensitivity are significant advantages in favor of nanoscale SiNW ISFETs. The SiNW ISFETs with embedded Ag/AgCl reference electrode were fabricated on a standard silicon-on-insulator wafer using electron-beam lithography and conventional semiconductor processing technology. The current-voltage characteristics show an n-type FET behavior with a relatively high on/off current ratio, reasonable sub-threshold swing value, and low gate-leakage current. The pH responses of the ISFETs with different pH solutions were characterized at room temperature which showed a clear lateral shift of the drain current vs. gate voltage curve with a change in the pH value of the solution and a sensitivity of 40 mV pH(-1). The low frequency noise characteristics were investigated to evaluate the signal to noise ratio and sensing limit of the devices.
authors: Department of Electrical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea.
authors: Sungho
authors: S
authors: Kim
authors: Taiuk
authors: T
authors: Rim
authors: Kihyun
authors: K
authors: Kim
authors: Unsang
authors: U
authors: Lee
authors: Eunhye
authors: E
authors: Baek
authors: Hojoon
authors: H
authors: Lee
authors: Chang-Ki
authors: CK
authors: Baek
authors: M
authors: M
authors: Meyyappan
authors: M Jamal
authors: MJ
authors: Deen
authors: Jeong-Soo
authors: JS
authors: Lee
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D055616:Microtechnology; D053770:Nanowires / Q000737:chemistry*; D012825:Silicon; D018030:Silver Compounds
chemical_list: D018030:Silver Compounds; C037548:silver chloride; D012825:Silicon