Transferring Few-Layer Graphene Sheets on Hexagonal Boron Nitride Substrates for Fabrication of Graphene Devices

Abstract

We have developed a dry transfer method that allows graphene to be transferred from polymerthyl-methacrylate (PMMA)/Si (silicon) substrates on commercially available hexagonal boron nitride (hBN) crystals. With this method we are able to fabricate graphene devices with little wrinkles and bubbles in graphene sheets, but that do not degrade the electronic quality more than the SiO2 substrate does. For hBN to perform the function described above substrate cleanliness is critical to get high quality graphene devices. Using hBN as a substrate, graphene exhibits enhanced mobility, reduced carrier inhomogeneity, and reduced intrinsic doping compared to graphene on SiO2 substrate.

Transfer of monolayer TMD WS2 and Raman study of substrate effects

“…1 , combines aspects of previous methods, used for both WS 2 and other two dimensional materials, with some new aspects. The previously reported aspects are specifically the etching of SiO 2 32 37 45 46 to remove the flakes from the growth substrate and the use of micromanipulation of flakes on PMMA under a microscope 44 47 48 49 50 . The flakes are CVD grown on a SiO 2 /Si graphics, Fig.…”

“…In this study, facilitated by an easy and fast transfer method, we present a focused study on the effects of transfer and substrates on the resulting material properties as determined with Raman spectroscopy. We demonstrate a flake transfer and positioning method based on previously published methods 32 37 44 45 46 47 48 49 50 . Our method is most similar to that used for graphene by Zomer et al .…”

PMMA-Etching-Free Transfer of Wafer-scale Chemical Vapor Deposition Two-dimensional Atomic Crystal by a Water Soluble Polyvinyl Alcohol Polymer Method

“…Therefore, with the PMMA/PVA assisted transfer method, which has all the advantages of the conventional PMMA transfer method such as simplicity, large area, and high degree of freedom, we can easily transfer 2D materials of different morphologies onto arbitrary target substrates with controlled transfer orientation while minimum contamination. There are a few studies that use a similar method for the crystal transfer 9 10 11 12 . However, it should be clearly noted that in this dry-transfer method, the 2D material is mechanically transferred onto the top of PMMA/PVA and 2D/PMMA layer is released from the substrate by dissolving PVA in water and then transferred to a target substrate for device fabrication.…”

From Diffusive to Ballistic Transport in Etched Graphene Constrictions and Nanoribbons

“…Most graphene nanodevices fabricated from graphene that rest directly on SiO 2 suffer from inherent substrate induced disorder in the form of dangling bonds, substrate roughness, charge puddles and surface phonons which cause serious limitations to the mobility of charge carriers in such devices. Recently, hBN has received a great deal of attention as an alternative substrate for graphene owing to its atomically smooth surface that suppresses rippling in graphene, a lattice constant similar to that of graphene and planar structure that is expected to be free of any dangling bonds or surface charge traps . Scanning tunneling microscopy studies also confirmed that graphene on hBN has significantly less pronounced electron‐hole puddles as compared to SiO 2 …”