Study on the Adhesion Properties of Graphene and Hexagonal Boron Nitride Monolayers in Multilayered Micro-devices by Scratch Adhesion Test.

The interlayer adhesion in the multilayered micro-devices is of significant importance for their electronic properties. The scratch adhesion test is applied here using a micro-blade sliding under a linearly increased load, combined with optical and SEM visualization, to study the Al₂O₃/GR/SiO₂/Si and Al₂O₃/hBN/GR/SiO2/Si stacks. The failure of the interlayers is determined by the critical load at which a sudden change in the coefficient of friction or a jump in the contact acoustic emission signal is observed during the scratch. It was found that the hBN/GR bilayer deposited on SiO₂ enhanced significantly (~30%) the critical load of the GR/SiO₂ interfacial failure compared to that of the GR monolayer. The adhesion at the upper Al₂O₃/hBN, hBN/GR and Al₂O₃/GR layers in the stack was improved by 11–15%, due to the thermal annealing, associated with enhanced solid-state diffusion at the interfaces. While the annealing has insufficient effect on the adhesion at the substrate SiO₂/Si layers. The scratch adhesion test was proven here as a suitable fast technique for control on the adhesion between layers in the multilayered structures, in order to be proposed for quality control on the fabrication process and the operational performances of micro-/nano-devices. [ABSTRACT FROM AUTHOR]