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.