Contact resistance extraction of graphene FET technologies based on individual device characterization

•Contact resistances of graphene transistors are extracted with adapted Y-function methods.•Bias dependent and independent contact resistance values can be obtained.•No additional test structures are required for the extraction.•Results are in agreement with physics-based and other experimental approaches.•High-frequency performance highly degraded by non-optimal contacts. Straightforward contact resistance extraction methods based on electrical device characteristics are described and applied here to graphene field-effect transistors from different technologies. The methods are an educated adaptation of extraction procedures originally developed for conventional transistors by exploiting the drift–diffusion-like transport in graphene devices under certain bias conditions. In contrast to other available approaches for contact resistance extraction of graphene transistors, the practical methods used here do not require either the fabrication of dedicated test structures or internal device phenomena characterization. The methodologies are evaluated with simulation-based data and applied to fabricated devices. The extracted values are close to the ones obtained with other more intricate methodologies. Bias-dependent contact and channel resistances studies, bias-dependent high-frequency performance studies and contact engineering studies are enhanced and evaluated by the extracted contact resistance values.