Elastomeric Stamp-Assisted Exfoliation and Transfer of Patterned Graphene Layers

Graphene with its mechanical strength and superior electrical and thermal conductivity is an interesting material for microelectronics. Despite its favorable properties, graphene has not fully transitioned as a mainstream electronic material due to challenges involved in its patterning and integration to standard device fabrication process flows. In this study, an elastomeric stamp-assisted exfoliation and transfer approach has been developed, where patterned graphene layers were seamlessly transferred by contact with a polydimethylsiloxane (PDMS) stamp with an applied weight of ~ 30 grams or less. With the approach presented herein, lengthy wet etching cycles to remove the underlying nickel or copper precursors during CVD-growth of graphene have been eliminated. Results indicate that the proposed technique is capable of direct, etch-free transfer of various graphene patterns up to ~ 50 µm in size and with high yield. Optical microscopy, SEM imaging, atomic force microscopy (AFM), and Raman spectroscopy characterization of transferred layers demonstrate retainment of the pristine graphene quality after the elastomeric stamp-assisted exfoliation and transfer process with no contamination or damage on the transferred graphene patterns.