Permeated Porous Silicon Suspended Membrane as Sub-ppm Benzene Sensor for Air Quality Monitoring

• Published in: Journal of porous materials Vol. 7; no. 1-3; pp. 197 - 200
• Main Authors: Angelucci, R, Poggi, A, Dori, L, Tagliani, A, Cardinali, Gc, Corticelli, F, Marisaldi, M
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.01.2000
• Subjects: Porous materials
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1023/A:1009638821345

To realise advanced microsensors for a reliable monitoring of very low concentrations of pollutant species such as NO^sub x^, SO^sub 2^, CO, O^sub 3^ and aromatic hydrocarbons, the use of porous silicon (PS) permeated with semiconducting oxides has been explored. To reduce the power consumption and to make feasible the device to operate in a fast pulsed temperature mode, a novel sensor architecture has been designed. The main feature of the device is represented by a permeated suspended macroporous Si membrane, few tens of microns thick. In this paper the porous silicon formation through a suspended silicon membrane and the morphological characterization of the PS layer are reported. Moreover, the performance of a C^sub 6^H^sub 6^ gas sensor based on the suspended macroporous Si membrane (30 μm thick), permeated with the chemical precursor of Sn oxide is presented. The results have demonstrated the feasibility to realize a macroporous silicon suspended membrane with high specific surface area, efficient electrical insulation and negligible warpage. Furthermore, the permeation of the oxidized macroporous silicon membrane with SnO^sub 2^ has been proved to be a valuable approach to fabricate gas sensors suitable to detect aromatic hydrocarbons in a sub-ppm range.[PUBLICATION ABSTRACT]