In this study, we proposed a fast and effective technique to remove residual poly(methyl methacrylate) (PMMA) after its use as a supporting layer for transferring graphene films on a large scale with high productivity. We utilized a methyl isobutyl ketone (MIBK) solution, which is commonly used to develop PMMA layers, for an e-beam lithography process. This was done because MIBK molecules tend to inflate the PMMA layer, weakening the link between PMMA and the graphene surface. Field-effect transistors were fabricated on the transferred graphene, with which we addressed the Dirac points and their carrier motilities. We observed that due to the reduced p-doping effects, the Dirac points were located closer to the zero-gate bias compared to those obtained using the acetone treatment. Finally, the average device mobility reached 5400 and 3900 cm2/Vs for holes and electrons, respectively. These values are more than five times the values obtained using the conventional acetone treatment.
This work was supported by the Midcareer Researcher Program (2017R1A2B4009177) through a National Research Foundation grant funded by Korea Government (MSIP) and by Human Resources Program in Energy Technology (20184030202220) through a Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by Korea Government (MOTIE).This work was supported by the Midcareer Researcher Program (2017R1A2B4009177) through a National Research Foundation grant funded by Korea Government (MSIP) and by Human Resources Program in Energy Technology (20184030202220) through a Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by Korea Government (MOTIE).
