An Extended CMOS ISFET Model Incorporating the Physical Design Geometry and the Effects on Performance and Offset Variation
Author(s)
Liu, Y
Georgiou, P
Prodromakis, T
Constandinou, TG
Toumazou, C
Type
Journal Article
Abstract
This paper presents an extended model for the
CMOS-based Ion-Sensitive-Field-Effect-Transistor (ISFET), incorporating design parameters associated with the physical
geometry of the device. This can, for the first time, provide a good match between calculated and measured characteristics by
taking into account the effects of non-idealities such as threshold voltage variation and sensor noise. The model is evaluated through a number of devices with varying design parameters (chemical sensing area and MOSFET dimensions) fabricated in
a commercially-available 0.35μm CMOS technology. Threshold voltage, subthreshold slope, chemical sensitivity, drift and noise
were measured and compared to the simulated results. The first and second order effects are analysed in detail and it is shown that the sensors’ performance was in agreement with the proposed model.
CMOS-based Ion-Sensitive-Field-Effect-Transistor (ISFET), incorporating design parameters associated with the physical
geometry of the device. This can, for the first time, provide a good match between calculated and measured characteristics by
taking into account the effects of non-idealities such as threshold voltage variation and sensor noise. The model is evaluated through a number of devices with varying design parameters (chemical sensing area and MOSFET dimensions) fabricated in
a commercially-available 0.35μm CMOS technology. Threshold voltage, subthreshold slope, chemical sensitivity, drift and noise
were measured and compared to the simulated results. The first and second order effects are analysed in detail and it is shown that the sensors’ performance was in agreement with the proposed model.
Date Issued
2011-10-21
Citation
IEEE Transactions on Electron Devices, 2011, 58 (12), pp.4414-4422
ISSN
0018-9383
Publisher
IEEE
Start Page
4414
End Page
4422
Journal / Book Title
IEEE Transactions on Electron Devices
Volume
58
Issue
12
Copyright Statement
© 2011 IEEE. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible
Description
17/04/13 meb. Accepted version OK to pub.
Identifier
http://hdl.handle.net/10044/1/10999
Subjects
ISFET
CMOS
Chemical Sensor
Publication Status
Published