3C-SiC hetero-epitaxial films for sensor fabrication

Silicon Carbide (SiC) is a very promising material for the fabrication of a new category of sensors and devices, to be used in very hostile environments (high temperature, corrosive ambient, presence of radiation, etc.). The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC microfabrication. This approach puts together the standard silicon bulk microfabrication methodologies with the robust mechanical properties of 3C-SiC. Using this approach we were able to fabricate SiC cantilevers for a new class of pressure sensor. The geometries studied were selected in order to study the internal residual stress of the SiC film. X-Ray Diffraction polar figure and Bragg-Brentano scan analysis were used to check to crystal structure and the orientations of the film. SEM analysis was performed to analyze the morphology of the released MEMS structures. © 2008 Trans Tech Publications, Switzerland.