Characterization of SiO_2/SiN_x gate insulators for graphene based nanoelectromechanical systems

摘要

The structural and magnetotransport characterization of graphene nanodevices exfoliated onto Si/SiO_2/SiN_x 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 Hallbar nanostructures utilizing SiO_2/SiN_x 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 SiN_x on the charge carrier mobility of graphene is comparable to that of SiO_2, demonstrating the merits of SiN_x as an ideal material platform for graphene based nanoelectromechanical applications.