Fabrication of 3C-silicon carbide membranes: Towards development of novel microdevices for biomedical applications

Abstract

3C-SiC is currently under intense study as a potential material for implantable low power blood pressure sensing due to its biocompatibility. In this work, we present and discuss the fabrication processes for n-type 3C-SiC membranes using epitaxial SiC layers with thicknesses of 0.285 and 0.95 μm on Si substrates (650 μm). Membranes of n-type SiC with dimensions of 0.5×0.5 cm2 were successfully fabricated using the described method for both thicknesses. We also report the fabrication of larger area membranes (1.5× 1.0 cm2) using the 0.95 μm epitaxial layer. The thicker membrane was able to flex when probed using a micromanipulator electrical probe, however, the 0.285 μm membrane could not support the same small force. The ability to fabricate patterns of aluminum on the surface of the thicker membrane suggests future applications of large 3C-SiC membranes in microfabrication technology for biomedical microdevices. For electrical characterization, arrays of metal patterns were made on the 3C-SiC. Surface modification due to reactive ion etching (RIE) process had significant impact on the electrical properties of the sample. X-Ray Photoelectron Spectroscopy (XPS) was used to investigate surface modification due to RIE. The effect of reactive ion etching is expected to modify the biocompatibility of the 3C-SiC as a potential biomaterial.