Thermal analysis and design of a micro-hotplate for Si-substrated micro-structural gas sensor

There is considerable interest in decreasing the power consumption of available semiconductor metal oxide gas sensors. The low-voltage and low-power consumption metal oxide gas sensors can be easily produced by combining micromachining and thin-film technologies. The concept of micro-hotplate is one of the possible solutions. Considering of the thermal resistant and sensitive characteristics of metal platinum, as well as the heat and electricity insulating characteristics of SiO₂ and SiNx , a kind of the Si-substrated micro-hotplate gas sensor was designed. Platinum filament was used as heater and temperature sensor, including SiO₂ and SiNx was used as thermal and electricity insulation respectively. Then the temperature distribution of the Si-substrated micro-hotplate gas sensor was simulated and analyzed by the finite element analysis(FEA) tool ANSYS. In order to make the gas sensor obtain perfect properties of lower power and higher response speed, gas sensor was ameliorated by the result of analysis.