Author(s): Woo-Chang Choi | Sung-Eun Kim
Journal: Transactions on Electrical and Electronic Materials
ISSN 1229-7607
Volume: 13;
Issue: 1;
Start page: 27;
Date: 2012;
Original page
Keywords: H2S | Gas sensor | SnO2-CuO | Multi-layer | MEMS
ABSTRACT
This paper proposes a micro gas sensor for measuring H2S gas. This is based on a SnO2-CuO multi-layer thin film. Thesensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layerin order to increase the temperature to an operating temperature. The SnO2-CuO multi layer film is prepared by thealternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace.To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers.The sensitivities are measured by applying H2S gas. It has a concentration of 1 ppm at an operating temperature of 270℃. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to thesensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of H2S gas is approximately 68%.This is approximately 12% more than that of a sensor with one-layer.
Journal: Transactions on Electrical and Electronic Materials
ISSN 1229-7607
Volume: 13;
Issue: 1;
Start page: 27;
Date: 2012;
Original page
Keywords: H2S | Gas sensor | SnO2-CuO | Multi-layer | MEMS
ABSTRACT
This paper proposes a micro gas sensor for measuring H2S gas. This is based on a SnO2-CuO multi-layer thin film. Thesensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layerin order to increase the temperature to an operating temperature. The SnO2-CuO multi layer film is prepared by thealternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace.To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers.The sensitivities are measured by applying H2S gas. It has a concentration of 1 ppm at an operating temperature of 270℃. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to thesensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of H2S gas is approximately 68%.This is approximately 12% more than that of a sensor with one-layer.
