To implement low-power gas sensors with low component costs, the principle
of work-function read out via a hybrid suspended gate FET (SGFET) is being
pursued, whereby a freely selectable sensor film undergoes a reversible wor
k-function change corresponding to the buildup of a potential difference on
the surface in response to gas adsorption/reaction. This is read out via a
n ISFET structure. An innovative design which allows cheap manufacturing wi
ll be described for the principle that has already been successfully demons
trated. The starting point of the design is a ceramic Al2O3 substrate coate
d with conductor patterns and sensitive materials onto which the FET is mou
nted in flip-chip technology. By means of the freely selectable sensor film
and its preparation method, a wide range of applications can be opened up.
(C) 2001 Elsevier Science B.V. All rights reserved.