Improved graphene growth in UHV: Pit-free surfaces by selective Si etching of SiC(0001)-Si with atomic hydrogen

We present a novel technique of growing UHV graphene using atomic hydrogen etching of SiC(0001)-Si surfaces. Hydrogen atoms generated from a hot tungsten filament selectively etch silicon surface atoms thereby facilitating the Si-sublimation process at temperatures around 1000 °C according to Auger Electron Spectroscopy. This allows for separate, non-thermal control of the rate of formation of the interfacial buffer layer formation to yield reduced pit formation observed by scanning tunneling microscopy during subsequent UHV graphene growth.