Fabrication and Optimization of Graphene Membrane for Gas Sensor Applications

Graphene membranes over Si etched cavities are fabricated to form the sensing element for micro gas sensors. The repeatability and stability of the sensor is dependent on stress and stretch of the graphene membrane which is related to the conformal to non-conformal morphology of the graphene. This in turn depends on the surface roughness of the Si surface that anchors the graphene film. In this paper we present the results of the optimization of the cavity formation process to allow for a smooth surface that allows superior adhesion of the graphene without extra stretching or tears.