Improving the pH Sensitivity of ISFET Arrays with
Reactive Ion Etching
Reactive Ion Etching
File(s)
Accepted version
Author(s)
Type
Conference Paper
Abstract
In this paper, we report a method to improve
sensitivity for CMOS ISFET arrays using Reactive Ion Etching
(RIE) as a post-processing technique. The process etches away
the passivation layers of the commercial CMOS process, using an
oxygen (O2) and sulfur hexafluoride (SF6) plasma. The resulting
attenuation and pH sensitivity are characterised for five dies
etched for 0 to 15 minutes, and we demonstrate that capacitive
attenuation is reduced by 196% and pH sensitivity increased
by 260% compared to the non-etched equivalent. The spread of
trapped charge is also reduced which relaxes requirements on the
analogue front-end. The technique significantly improves the performance
of the fully-integrated sensing system for applications
such as DNA detection.
sensitivity for CMOS ISFET arrays using Reactive Ion Etching
(RIE) as a post-processing technique. The process etches away
the passivation layers of the commercial CMOS process, using an
oxygen (O2) and sulfur hexafluoride (SF6) plasma. The resulting
attenuation and pH sensitivity are characterised for five dies
etched for 0 to 15 minutes, and we demonstrate that capacitive
attenuation is reduced by 196% and pH sensitivity increased
by 260% compared to the non-etched equivalent. The spread of
trapped charge is also reduced which relaxes requirements on the
analogue front-end. The technique significantly improves the performance
of the fully-integrated sensing system for applications
such as DNA detection.
Date Issued
2017-10-19
Date Acceptance
2017-08-11
Publisher
IEEE
Copyright Statement
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Source
BioCAS 2017
Publication Status
Accepted
Start Date
2017-10-19
Finish Date
2017-10-21
Coverage Spatial
Turin, Italy