Cantilever-type microheater fabricated with thick silicon

In this paper, we present a cantilever-type silicon microheater operating at high temperature with low power consumption for the catalytic combustion methane sensor. The cantilever supported silicon microheaters were designed and fabricated with thick device silicon of silicon-on-insulator (SOI) wafer. The temperature dependence and electrical characteristic of the thick-silicon microheater resistor, including a key temperature corresponding to the twist point of temperature coefficient of resistance (TCR) were tested. A series of test microheaters was also designed in order to further investigate the influence of the length of support cantilever on power consumption. The twist point of TCR of the microheater was used as the reference point for the power evaluation. Experimental results demonstrated that the solid state heat conduction dominates the power losses and the total power consumption can be reduced to a satisfied minimum about 60 mW with the length-extension of the support cantilever for the thick silicon heater. Results also showed that the thick silicon heater is suitable for gas sensor operating at the high temperature with low power consumption, which is a particularly attractive quality for the use of battery-operated handheld methane gas monitoring.