Transfer of preheat-treated SnO 2 via a sacrificial bridge-type ZnO layer for ethanol gas sensor

Abstract
The progress in developing the microelectromechanical system (MEMS) heater-based SnO2 gas sensors was hindered by the subsequent heat treatment of the tin oxide (SnO2), nevertheless it is required to obtain excellent sensor characteristics. During the sintering process, the MEMS heater and the contact electrodes can be degraded at such a high temperature, which could reduce the sensor response and reliability. In this research, we presented a process of preheating the printed SnO2 sensing layer on top of a sacrificial bridge-type ZnO layer at such a high temperature, followed by transferring it onto the contact electrodes of sensor device by selective etching of the sacrificial ZnO layer. Therefore, the sensor device was not exposed to the high sintering temperature. The SnO2 gas sensor fabricated by the transfer process exhibited a rectangular sensing curve behavior with a rapid response of 52 s at 20 ppm ethanol concentration. In addition, reliable and repeatable sensing characteristics were obtained even at an ethanol gas concentration of 5 ppm.

Citation
Lee DH, Kang SK, Pak Y, Lim N, Lee R, et al. (2018) Transfer of preheat-treated SnO 2 via a sacrificial bridge-type ZnO layer for ethanol gas sensor. Sensors and Actuators B: Chemical 255: 70–77. Available: http://dx.doi.org/10.1016/j.snb.2017.08.025.

Acknowledgements
This work was supported by the Materials & Devices Advanced Research Institute of LG Electronics Inc. in Seoul, Korea, and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2061494).

Publisher
Elsevier BV

Journal
Sensors and Actuators B: Chemical

DOI
10.1016/j.snb.2017.08.025

Additional Links
http://www.sciencedirect.com/science/article/pii/S0925400517314478

Permanent link to this record