Characterization of SiO2/SiNx gate insulators for graphene based nanoelectromechanical systems

The structural and magnetotransport characterization of graphene nanodevices exfoliated onto Si/SiO2/SiNx heterostructures are presented. Improved visibility of the deposited flakes is achieved by optimal tuning of the dielectric film thicknesses. The conductance of single layer graphene Hall-bar nanostructures utilizing SiO2/SiNx gate dielectrics were characterized in the quantum Hall regime. Our results highlight that, while exhibiting better mechanical and chemical stability, the effect of non-stoichiometric SiNx on the charge carrier mobility of graphene is comparable to that of SiO2, demonstrating the merits of SiNx as an ideal material platform for graphene based nanoelectromechanical applications.