Design and Simulation of a High Temperature MEMS Micro-hotplate for Application in Trace Gas Detection

In this paper, we present the simulation results of a high temperature MEMS micro-hotplate. The electro-thermo-mechanical behaviors of micro- hotplates (MHP) have been simulated using CoventorWare. In the simulation, the effects of various thicknesses of the silicon nitride (Si3N4) membrane layer on the temperature, mechanical deflection and power consumption of the MHP are evaluated. The effect of the addition of a layer of silicon carbide (SiC) on the MHP temperature distribution is also investigated. Results show that as the thickness of the Si3N4 membrane is increased from 0.3 mu m to 3 mu m, the power consumption of the NHV increases from 7.1mW to 34.3mW while the displacement of the membrane remains constant at a value of about 5.8 mu m. It is also demonstrated that when the MHP is designed with a silicon carbide (SiC) heat distributing layer above the silicon oxide NOD insulating layer on top of the heater, the uniformity of the temperature on the MHP membrane is considerably improved as compared to a membrane without SiC.