Design and simulation of Pt-based microhotplate, and fabrication of suspended dielectric membrane by bulk micromachining

摘要

The paper presents the design and simulation of double spiral Pt-based microhotplate (MHP) for gas sensing application. A platinum resistor of 52 Ω has been designed and simulated on a 0.3 micron thick SiO_2 suspended membrane of size 40 × 40 μm~2 using ANSYS. The SiO_2 membrane of size 40 × 40 μm~2 and thickness 0.3 micron has been fabricated successfully by bulk micromachining in <100> orientation P-type silicon using 25% tetra methyl ammonium hydroxide (TMAH) solution. The simulated temperature and transit time response of microhotplate were obtained as 600.5 °C and 0.2 ms respectively at 4.8 mW power consumption.