Graphene field-effect transistor properties modulation via mechanical strain induced by micro-cantilever

This work presents a new method, which enables the electrical characterization of graphene monolayer with induced mechanical strain. The device is a combination of two dimensional field effect transistor (2DFET) and a MEMS cantilever, both of which can be used to alter graphene properties. The first method applies external electric field to the graphene monolayer. The second method is based on mechanical bending of the cantilever by external force, which induces mechanical strain in the characterized layer. By sweeping the gate voltage (VGS) in range from – 50 V to + 50 V and measuring the current between drain and source (IDS) with fixed drain source voltage (VDS) at 1 V, Dirac point of graphene is found at ≈ 9.3 V of VGS. After bending of the cantilever, the sweep is performed again. The induced strain shifts the position of the Dirac point by ≈ 1.3 V to VGS = 8 V. Because the fabrication process is compatible with silicon technology, this method brings new possibilities in graphene strain engineering.