Investigation of the utility of cellulose acetate butyrate in minimal residue graphene transfer, lithography, and plasma treatments

• CVD graphene is transferred using CAB and PMMA.
• Residues are analyzed using AES and FTIR spectroscopy.
• CAB is used as an under-layer under an EBL resist to reduce residues.
• CAB is used to protect graphene during plasma etching to remove residues.

Residues on graphene substrates from polymer-supported transfer and lithography can significantly degrade device performance. Using Fourier transform infrared (FTIR), Raman spectroscopy and Auger electron spectroscopy (AES), cellulose acetate butyrate (CAB) dissolved in ethyl acetate is shown to leave minimal polymer residue on graphene after substrate transfer. The polymer can also be used as a protective under-layer between an electron beam resist and the graphene during electron beam lithography, as well as a protective over-layer during inductively coupled plasma (ICP) etching to slow the etch rate of graphene and remove protruding polymer residues without etching the underlying graphene. CAB is therefore shown to be a useful material for the handling and processing of graphene.

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