The Effect of Thermal Annealing Processes on Graphene

摘要

We present an in-depth investigation of the consequence of gas and vacuum annealing utilized to remove polymer (PMMA) residues on the electronic doping, strain, and morphology of chemical vapor deposition grown graphene. We demonstrate that annealing under gas or vacuum increases doping levels in graphene as residual PMMA is burned off, interfacial water is evaporated, and graphene conformally contacts the substrate. This is corroborated by AFM measurements, indicating a need for further research on graphene transfer or growth methods where substrate-induced doping is minimized. These results are significant for determining the extent of PMMA influence on graphene during the transfer process and/or device fabrication.