Gate decorated Field Effect Transistors for high sensitivity pH sensing

Hajmirzaheydarali, Mohammadreza; . Sadeghipari, Meharnosh; Soleimani-Amiri, Samana; Akbari, Mahdi; Shahsafi, Alireza; Hajhosseini, Hosen; Salehi, Fhatama; Mohajerzadeh, Shamsedin

Gate decorated Field Effect Transistors for high sensitivity pH sensing

Authors

M. Hajmirzaheydarali ¹

M. . Sadeghipari ¹

S. Soleimani-Amiri ¹

M. Akbari ¹

A. Shahsafi ²

H. Hajhosseini ¹

F. Salehi ¹

S. Mohajerzadeh ¹

¹ Nano-electronics Lab, Nano-electronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran.

² Nano-electronics Lab, Nano-electronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran

Abstract

We present a micro/nano-machining process to introduce nanostructured poly-silicon layer on the gate region of the pH-sensitive field effect transistors. Decoration of the gate of the field effect transistors by nanostructures plays an important role to improve the sensitivity of the pH-sensitive FETs. Electron beam lithography was exploited to realize the poly-Si nanopillars on the gate surface. Comparison between different micro and nanostructures demonstrates the potential of nanopillars to be utilized on the gate of this device rather than micro-conical structures (different size and shapes) and vertically carbon nanotubes. A high sensitivity of 500 mV/pH has been achieved, through the incorporation of silicon based nanopillars.

Keywords

micro/nano-machining process

poly-Si nanostructure

pH-sensitive FET

nanopillar