Nanoscale silicon ion-sensitive field-effect transistors for pH sensor and biosensor applications

Introduction: Increased demand for point-of-care diagnostics has provided a strong motivation for the development of lab-on-a chip systems. The most important part to develop the system is to realize sensing components with high sensitivity, high reliability, low power consumption, low noise and small size in a cost-effective way. The Si-nanowire (Si-NW) ion-sensitive field effect transistor (ISFET) has been considered as one of the most promising devices because of the well-established fabrication techniques taking advantage of the low-cost wafer-scale top down methods [1–2]. In this work, the Si-NW ISFETs with embedded Ag/AgCI electrode have been demonstrated. The DC characteristics and the pH response of the Si-NW ISFET were measured and analysed. In addition, the low-frequency noise measurement was performed in order to investigate noise characteristics of the Si-NW ISFETs.