Room temperature multiplexed gas sensing using chemical-sensitive 3.5-nm-thin silicon transistors

Hossain Mohammad Fahad; Hiroshi Shiraki; Matin Amani; Chuchu Zhang; Vivek Srinivas Hebbar; Wei Gao; Hiroki Ota; Mark Hettick; Daisuke Kiriya; Yu-Ze Chen; Yu-Lun Chueh; Ali Javey

doi:10.1126/sciadv.1602557

Room temperature multiplexed gas sensing using chemical-sensitive 3.5-nm-thin silicon transistors

Sci Adv. 2017 Mar 24;3(3):e1602557. doi: 10.1126/sciadv.1602557. eCollection 2017 Mar.

Authors

Affiliations

¹ Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA 94720, USA.; Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, CA 94720, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
² Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA 94720, USA.; Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, CA 94720, USA.; Murata Manufacturing Co. Ltd., Nagaokakyo, Kyoto 617-8555, Japan.
³ Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA 94720, USA.
⁴ Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C.

Abstract

There is great interest in developing a low-power gas sensing technology that can sensitively and selectively quantify the chemical composition of a target atmosphere. Nanomaterials have emerged as extremely promising candidates for this technology due to their inherent low-dimensional nature and high surface-to-volume ratio. Among these, nanoscale silicon is of great interest because pristine silicon is largely inert on its own in the context of gas sensing, unless functionalized with an appropriate gas-sensitive material. We report a chemical-sensitive field-effect transistor (CS-FET) platform based on 3.5-nm-thin silicon channel transistors. Using industry-compatible processing techniques, the conventional electrically active gate stack is replaced by an ultrathin chemical-sensitive layer that is electrically nonconducting and coupled to the 3.5-nm-thin silicon channel. We demonstrate a low-power, sensitive, and selective multiplexed gas sensing technology using this platform by detecting H₂S, H₂, and NO₂ at room temperature for environment, health, and safety in the oil and gas industry, offering significant advantages over existing technology. Moreover, the system described here can be readily integrated with mobile electronics for distributed sensor networks in environmental pollution mapping and personal air-quality monitors.

Keywords: IoT; Multi-gas sensors; low power; nanoscale; room-temperature; selective; sensitive; silicon.