Implementation and mechanical characterization of 2nm thin diamond like carbon suspended membranes

Abstract : Ultrathin diamond like carbon (DLC) layers with thickness down to 2 nm have been integrated into suspended membranes enabling their mechanical properties to be characterized. The goal of this study is the integration of a membrane with micrometric suspended area into operational MEMS. The early structure for feasibility study of a device is made of a membrane suspended above a micrometer sized cavity. Deflection is electrostatically induced by applying an electric potential between the membrane and the floor of the cavity. The thickness of the membrane determines at first order the amplitude of the deflection. Experimental measurements are presented and results obtained discussed. The experimental bending rigidity value is extracted and is shown to be a key parameter for modeling membrane's behavior in any other mechanical embodiment. DLC is identified as a suitable material for free standing over a micrometer large area, even when only a few nano-meters thick, and a promising candidate for MEMS integration.