Combining Chemical Functionalization and FinFET Geometry for Field Effect Sensors as Accessible Technology to Optimize pH Sensing

Publication year: 2021
Authors: D.Rani 1, S.Rollo 1,2, W.Olthuis 2, S.Krishnamoorthy 1, C.P.García 1
1 - Nano-Enabled Medicine and Cosmetics Group, Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg
2 - BIOS Lab on Chip Group, MESA+ Institute for Nanotechnology, University of Twente, 7522 NB Enschede, The Netherlands
Published in: Chemosensors 2021, Vol. 9(2), 20
doi: 10.3390/chemosensors9020020

Field Effect Transistors (FETs) have led the progress of applications measuring the acidity in aqueous solutions thanks to their accuracy, ease of miniaturization and capacity of multiplexing. The signal-to-noise ratio and linearity of the sensors are two of the most relevant figures of merit that can facilitate the improvements of these devices. In this work we present the functionalization with aminopropyltriethoxysilane (APTES) of a promising new FET design consisting of a high height-to-width aspect ratio with an efficient 2D gating architecture that improves both factors. We measured the transistor transfer and output characteristics before and after APTES functionalization, obtaining an improved sensitivity and linearity in both responses. We also compared the experimental results with a site-biding model of the surface buffering capacity of the APTES functionalized layers.

MP-SPR keywords: layer thickness, SiO2 sensor slide