Study On Fabrication And Electrical Properties Of Graphene-based Electric Circuits

The fabrication of graphene electrical circuit is the basis of studying the electrical properties of graphene itself and applying it to various micro / nano electronic devices.Based on the mechanical peeling method,the electrical circuit of graphene was fabricated by various micro-nano-machining techniques.The fabrication of electrical circuit and the electrical properties of graphene were studied in depth.The electrical properties of graphene electrical circuit fabricated by different micro / nano processing technologies were studied.The main contents of this paper are as follows:(1)A few layers of graphene with a thickness of 1~3 and a size of about 100 ? m were prepared by the improved mechanical stripping method.The layer number and size of graphene were characterized by optical microscope,the position of graphene on the substrate was localized by labeling,and the morphology and thickness of graphene surface were characterized by atomic force microscope(AFM),and the surface morphology and thickness of graphene were characterized by atomic force microscopy(AFM).Finally,the layers and defects of graphene were characterized by the relative intensity between G peak and 2D peak and the height of D peak in Raman spectra.(2)The electrical circuit based on graphene was fabricated by Lift-off process with negative adhesive,photolithography and metal deposition in micro / nano machining technology.The problems of photoresist residue and graphene shedding in the process of lithography are studied.The electrical properties of graphene are measured and analyzed.Two kinds of source-drain current-gate voltage(Id-Vg)curves are obtained.Contains bipolar curves and unipolar curves.The influencing factors of the electrical properties of graphene electrical circuit are analyzed from three aspects: substrate,metal contact and graphene surface doping.(3)Lift-off process of positive adhesive was used to fabricate metal electrode for graphene electrical circuit based on dry transfer printing,on which the electrical circuit of graphene was fabricated by direct transfer printing and focused ion beam processing.The electrical properties of graphene electrical circuits under two different manufacturing methods were measured and analyzed.The electrical properties of two different types of graphene electrical circuits were obtained and the reasons for the difference in electrical properties were analyzed.(4)The effects of annealing and air adsorption on the electrical properties of graphene electrical circuit were studied,and the desorption of graphene surface was realized by annealing.