Tip-based graphene etching for MEMS resonator frequency trimming

We report the first-ever demonstration of ultra precise MEMS resonator frequency trimming by atomic-level graphene removal using tip-based electrolytic etching. We placed the graphene films over the electrodes defined over lows-stress Si_xN_y membranes using a film transfer method. In this method, the graphene film is polycrystalline with a grain size in the range 50-800 nm, and can be two or three layers thick. Removing nanometers of graphene film, results in atomic-scale mass control. Using the graphene removal method, we report frequency shifts as low as 7.6 ppm by etching graphene films through STM based anodic reaction.