Comeback of epitaxial graphene for electronics: large-area growth of bilayer-free graphene on SiC

摘要

We present a new fabrication method for epitaxial graphene on SiC whichenables the growth of ultra-smooth defect- and bilayer-free graphene sheetswith an unprecedented reproducibility, a necessary prerequisite for wafer-scalefabrication of high quality graphene-based electronic devices. The inherent butunfavorable formation of high SiC surface terrace steps during high temperaturesublimation growth is suppressed by rapid formation of the graphene bufferlayer which stabilizes the SiC surface. The enhanced nucleation is enforced bydecomposition of polymer adsorbates which act as a carbon source. With most ofthe steps well below 0.75 nm pure monolayer graphene without bilayer inclusionsis formed with lateral dimensions only limited by the size of the substrate.This makes the polymer assisted sublimation growth technique the most promisingmethod for commercial wafer scale epitaxial graphene fabrication. Theextraordinary electronic quality is evidenced by quantum resistance metrologyat 4.2 K with until now unreached precision and high electron mobilities on mmscale devices.