Surface Micromachining of Polyureasilazane Based Ceramic-MEMS Using SU-8 Micromolds

Abstract

We describe a novel surface micromachining process for the fabrication of ceramic-type MEMS devices, such as free-standing cantilevers, that is based on the use of high-aspect ratio micromolds of SU8 and aluminum as sacrificial layer. 250μm-high and 100-1000μm-wide molds were used to confine a liquid precursor of SiC/Si3N4 based ceramics on the sacrificial layer that enables the detachment of the green body before the pyrolysis step at 1000°C. The final ceramic cantilever has dimensions ranging from 100-500μm x 1-2mm x 50μm and a smooth surface. Details of the processing, structural and material characterization such as Dynamic Rheological and Thermogravimetric Analysis under UV will be presented and compared to those found in the literature.