TY  - JOUR
A1  - Molinnus, Denise
A1  - Iken, Heiko
A1  - Johnen, Anna Lynn
A1  - Richstein, Benjamin
A1  - Hellmich, Lena
A1  - Poghossian, Arshak
A1  - Knoch, Joachim
A1  - Schöning, Michael Josef
T1  - Miniaturized pH-Sensitive Field-Effect Capacitors with Ultrathin Ta₂O₅ Films Prepared by Atomic Layer Deposition
JF  - physica status solidi (a) applications and materials science
N2  - Miniaturized electrolyte–insulator–semiconductor capacitors (EISCAPs) with ultrathin gate insulators have been studied in terms of their pH-sensitive sensor characteristics: three different EISCAP systems consisting of Al–p-Si–Ta2O5(5 nm), Al–p-Si–Si3N4(1 or 2 nm)–Ta2O5 (5 nm), and Al–p-Si–SiO2(3.6 nm)–Ta2O5(5 nm) layer structures are characterized in buffer solution with different pH values by means of capacitance–voltage and constant capacitance method. The SiO2 and Si3N4 gate insulators are deposited by rapid thermal oxidation and rapid thermal nitridation, respectively, whereas the Ta2O5 film is prepared by atomic layer deposition. All EISCAP systems have a clear pH response, favoring the stacked gate insulators SiO2–Ta2O5 when considering the overall sensor characteristics, while the Si3N4(1 nm)–Ta2O5 stack delivers the largest accumulation capacitance (due to the lower equivalent oxide thickness) and a higher steepness in the slope of the capacitance–voltage curve among the studied stacked gate insulator systems.
KW  - atomic layer deposition
KW  - capacitive field-effect sensors
KW  - pH sensors
KW  - ultrathin gate insulators
Y1  - 2022
U6  - http://dx.doi.org/10.1002/pssa.202100660
SN  - 1862-6319
VL  - 219
IS  - 8
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Karschuck, Tobias
A1  - Schmidt, Stefan
A1  - Achtsnicht, Stefan
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Multiplexing system for automated characterization of a capacitive field-effect sensor array
JF  - Physica Status Solidi A
N2  - In comparison to single-analyte devices, multiplexed systems for a multianalyte detection offer a reduced assay time and sample volume, low cost, and high throughput. Herein, a multiplexing platform for an automated quasi-simultaneous characterization of multiple (up to 16) capacitive field-effect sensors by the capacitive–voltage (C–V) and the constant-capacitance (ConCap) mode is presented. The sensors are mounted in a newly designed multicell arrangement with one common reference electrode and are electrically connected to the impedance analyzer via the base station. A Python script for the automated characterization of the sensors executes the user-defined measurement protocol. The developed multiplexing system is tested for pH measurements and the label-free detection of ligand-stabilized, charged gold nanoparticles.
KW  - Capacitive field-effect sensor
KW  - Gold nanoparticles
KW  - Label-free detection
KW  - Multicell
KW  - Multiplexing
Y1  - 2023
U6  - http://dx.doi.org/10.1002/pssa.202300265
SN  - 1862-6300 (Print)
SN  - 1862-6319 (Online)
N1  - Corresponding author: Michael Josef Schöning
VL  - 220
IS  - 22
PB  - Wiley-VCH
CY  - Weinheim
ER  -