Mass measurement of graphene using quartz crystal microbalances
Robin J. Dolleman (Kavli institute of nanoscience Delft, TU Delft - QN/Steeneken Lab)
Mick Hsu (Kavli institute of nanoscience Delft, Student TU Delft)
Sten Vollebregt (TU Delft - Electronic Components, Technology and Materials)
John E. Sader (University of Melbourne)
Herre S.J. Van Der Zant (TU Delft - QN/van der Zant Lab, Kavli institute of nanoscience Delft)
Peter G. Steeneken (Kavli institute of nanoscience Delft, TU Delft - Dynamics of Micro and Nano Systems, TU Delft - QN/Steeneken Lab)
Murali K. Ghatkesar (TU Delft - Micro and Nano Engineering)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Current wafer-scale fabrication methods for graphene-based electronics and sensors involve the transfer of single-layer graphene by a support polymer. This often leaves some polymer residue on the graphene, which can strongly impact its electronic, thermal, and mechanical resonance properties. To assess the cleanliness of graphene fabrication methods, it is thus of considerable interest to quantify the amount of contamination on top of the graphene. Here, we present a methodology for the direct measurement of the mass of the graphene sheet using quartz crystal microbalances (QCMs). By monitoring the QCM resonance frequency during removal of graphene in an oxygen plasma, the total mass of the graphene and contamination is determined with sub-graphene-monolayer accuracy. Since the etch-rate of the contamination is higher than that of graphene, quantitative measurements of the mass of contaminants below, on top, and between graphene layers are obtained. We find that polymer-based dry transfer methods can increase the mass of a graphene sheet by a factor of 10. The presented mass measurement method is conceptually straightforward to interpret and can be used for standardized testing of graphene transfer procedures in order to improve the quality of graphene devices in future applications.