Sensors & Transducers (May 2014)
Design and Development of an Array of Dielectric Suspended Membranes for Microhotplate Applications
Abstract
The paper presents the design, fabrication and characterization of an array of suspended dielectric suspended membranes for microhotplate applications. A single cell membrane (100 µm ´ 100 µm) made of two different dielectric layers: SiO2 and Si3N4 separately, was designed and simulated using ANSYS 10.0. The simulation of stress generated in different dielectric membranes as a function of temperature is reported. The thickness of both layers was taken as 0.3 µm. The membranes of both SiO2 and Si3N4 dielectrics were fabricated on silicon substrate by bulk micromachining technique using TMAH solution. The buckling of the beam and breakage of membranes made of high-stress Si3N4 film are reported. The simulated results were verified by experiments. The membrane made of SiO2 layer was found to be more suitable in comparison to high-stress Si3N4 layer for microhotplate applications. The present approach provides high yield at low cost for fabrication of microhotplates for gas sensing applications.
