Graphene Transfer with Favorable Electrical and Physical Characteristics on the Si / SiO2 Substrate

Graphene transfer from a metal substrate to the dielectric one is often the first step in graphene device fabrication. in order to achieve the proper performance of these devices surface cleanliness and maximum coverage of transferred graphene are crucial. In this paper wet transfer method and the effects of each stage of the process on transferred graphene quality have been investigated and also the reasons of tear formation and contamination during transfer process have been studied. In this research scanning electron microscopy images has been employed because of graphene surface morphology observation. by applying van der pauw method and measuring electrical resistance which itself depends on coverage percentage and contamination area , the quality of transferred graphene has been evaluated. The results are confirmed by raman spectroscopy in which spectra peaks display crystalline network defects and doping concentration. Finally an optimal process with 95% coverage level and 700 ± 50 ohm electrical resistance has been presented.