Title :
Nanowire hydrogen gas sensor employing CMOS micro-hotplate
Author :
Ali, S.Z. ; Santra, S. ; Haneef, I. ; Schwandt, C. ; Kumar, R.V. ; Milne, W.I. ; Udrea, F. ; Guha, P.K. ; Covington, J.A. ; Gardner, J.W. ; Garofalo, V.
Author_Institution :
Univ. of Cambridge, Cambridge, UK
Abstract :
In this paper we present a novel hydrogen gas sensor comprising a high temperature SOI-MOS micro-hotplate and employing zinc oxide nanowires as the sensing material. The micro-hotplates were fabricated at a commercial SOI foundry followed by a backside deep reactive ion etch (DRIE) at a commercial MEMS foundry. Particular care was taken in designing the heater shape using a systematic parametric approach to achieve excellent temperature uniformity (within 1-2%) as shown by both simulations and experimental infrared imaging results. Zinc oxide nanowires were grown on these devices and show promising responses to hydrogen with a response (Ra/Rh) of 50 at 100 ppm in argon. The devices possess a low D.C. power consumption of only 16 mW at 300°C and, being CMOS compatible, offer low unit cost in high volumes and full circuit integration. We believe that these devices have potential for application as a sub-$1 hydrogen sensor with sub-1mW (pulsed mode) power consumption.
Keywords :
gas sensors; infrared imaging; microfabrication; nanowires; sputter etching; CMOS microhotplate; MEMS foundry; deep reactive ion etch; full circuit integration; hydrogen sensor; infrared imaging; microhotplates; nanowire hydrogen gas sensor; pulsed mode power consumption; zinc oxide nanowires; Energy consumption; Etching; Foundries; Gas detectors; Hydrogen; Infrared heating; Micromechanical devices; Shape; Temperature sensors; Zinc oxide;
Conference_Titel :
Sensors, 2009 IEEE
Conference_Location :
Christchurch
Print_ISBN :
978-1-4244-4548-6
Electronic_ISBN :
1930-0395
DOI :
10.1109/ICSENS.2009.5398224