Investigation of the Salt Concentration Dependence of Water-Gated Field Effect Transistors (WG-FET) Using 16-nm-Thick Single Crystalline Si Film

Ozan Ertop,Bedri Gurkan Sonmez,Senol Mutlu

doi:10.3390/proceedings1040486

Abstract

This paper presents the effect of NaCl concentration on the operation of a water-gated field effect transistor (WG-FET) that uses 16-nm-thick single crystalline silicon (Si) film. In WG-FET, electrical double layer (EDL) formed at the water/silicon interface behaves as gate dielectric and this fluidic interface makes WG-FET a suitable device for sensing applications. Characteristics of EDL and the threshold voltage of WG-FET depend on the molarity of solution. Increasing the molarity of NaCl solution from 0.5 to 65 mM changes the threshold voltage from 360 to 465 mV. Accordingly, drain current of the WG-FET device changes with NaCl concentration.

Highlights

Water-gated field effect transistors (WG-FET) that use 16-nm-thick mono-Si films as channel layers promise a new platform where chemical/biological sensors and their read-out circuits can be integrated together
Characteristic IDS-VDS curves of the WG-FET with de-ionized (DI) water are presented in Figure 4, showing the typical transistor characteristics of the WG-FET used in this work
Applied voltages are limited to 0.6 V to eliminate any electrochemical reaction in NaCl solution, which keeps electrical double layer (EDL)

Summary

Introduction

Water-gated field effect transistors (WG-FET) that use 16-nm-thick mono-Si films as channel layers promise a new platform where chemical/biological sensors and their read-out circuits can be integrated together. Ultrathin and high mobility characteristics of the channel layer result in high surface sensitivity in sensor applications and on-site amplification in their read-out circuits. This accumulation type device contains no p-n junctions, which reduces the fabrication cost and light sensitivity.

Materials and Methods

Results and Discussion

Conclusions