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P2 - A miniaturized thermopneumatic infrared detector with capacitive read-out circuit

Event
AMA Conferences 2013
2013-05-14 - 2013-05-16
Nürnberg
Band
Proceedings IRS² 2013
Chapter
IP - Poster Session
Author(s)
M. Schossig, V. Norkus, G. Gerlach - Technische Universität Dresden, Dresden (Germany)
Pages
95 - 99
DOI
10.5162/irs2013/iP2
ISBN
978-3-9813484-3-9
Price
free

Abstract

In this paper we present an improved design of a miniaturized thermopneumatic infrared detector with capacitive read-out circuit. The hybrid assembly basically consists of a sealed cavity and a capacitive displacement transducer fabricated with silicon micromachining. The IR absorber is placed on a thin, free-standing silicon nitride membrane centrally arranged in the cavity. The very small capacitance changes are measured with an extremely sensitive 24-bit sigma-delta converter capable of detecting capacitance changes of a few aF. As a result, a responsivity of 714 aF/μW and a specific detectivity of 1.3 · 106 cm Hz1/2 W-1 were attained. Further improvements in performance can mainly be achieved by reducing the electrode gap of the capacitive displacement transducer.

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