Abstract
Persistent PMMA residue formed during a graphene transfer has been a culprit in the optimization of graphene device performance. We demonstrated a facile process to remove the PMMA residue using pulsed KrF laser annealing system at H2/Ar ambient. 10min laser annealing at 248nm could remove the PMMA residue as well as the methoxy and carboxyl function groups without causing noticeable damage to the graphene.
Highlights
Following the advancement in the large area graphene growth processes, various processes to transfer a large size graphene sheet to device substrates have been developed.[1,2,3,4,5,6,7] Wet transfer process is a most common transfer method utilized in the research lab environment.[1,2,3,4,5] The atomically thin graphene sheet grown on metal catalyst foils such as Cu or Ni are transferred using a supporting layer, typically polymer layers such as poly (PMMA), poly (PVA), polyimide or epoxy
After the metal wet etch step, the graphene/PMMA sheet is cleaned with deionized water or other wet cleaning step and transferred to the target substrate in the final wet cleaning solution
Supporting layer is deposited on graphene sheet and PDMS is stamped to the graphene sheet and directly detached from the catalyst metal
Summary
Following the advancement in the large area graphene growth processes, various processes to transfer a large size graphene sheet to device substrates have been developed.[1,2,3,4,5,6,7] Wet transfer process is a most common transfer method utilized in the research lab environment.[1,2,3,4,5] The atomically thin graphene sheet grown on metal catalyst foils such as Cu or Ni are transferred using a supporting layer, typically polymer layers such as poly (methyl methacrylate) (PMMA), poly (vinyl alcohol) (PVA), polyimide or epoxy. After the metal wet etch step, the graphene/PMMA sheet is cleaned with deionized water or other wet cleaning step and transferred to the target substrate in the final wet cleaning solution. In this case, it is difficult to avoid the ionic impurities, metallic residue, water molecules and oxygen contaminations at the interface between graphene and substrate, which will degrade the uniformity of mechanical and electrical properties of graphene. When the graphene sheet is stamped to a target substrate, it is detached from the PDMS stamp because van der Waals force between the graphene and the substrate is stronger than that with the PDMS mold This process is not applicable in large scale graphene. The PMMA residue is removed without noticeable damage to a graphene after the laser annealing at 248nm, 437.5mJ/cm[2] for 10 minutes in the H2/Ar
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
