Design and partial fabrication of low power Pt-based microheater for gas sensing application

The paper reports the design and simulation of double spiral shape Pt-based microheater using MEMS-CAD Tool COVENTORWARE. The structure consists with a thermal silicon dioxide suspended membrane, followed by a double spiral Pt heater. The hotplate membrane size and thickness were taken as 230 × 230 μm2 and 0.5 μm respectively. The simulation results show that for applied voltage, 0.2V to 0.8V, the maximum temperature of 364-1905K was obtained at center of the membrane. The heat is assumed to flow from the hotplate to the surrounding air at an ambient temperature of 300K by conduction. The power dissipation of less than 12 mW was obtained to reach 1905K membrane temperature. Based on simulation, the Pt heater was realized on an oxidized Si-substrate using lift-off technique. The resistance of the heater was measured as 86.4 ohm.