Detecting sp2 phase on diamond surfaces by atomic force microscopy phase imaging and its effects on surface conductivity

We show correlation of microscopic surface quality and morphology of nanocrystalline diamond films as a function of deposition temperature and post-growth acid treatment detected by atomic force microscopy in phase detection regime, X-ray photoelectron spectroscopy, X-ray induced Auger electron spectroscopy, Scanning Electron Microscopy, Raman spectroscopy, and the electrical conductivity of H-terminated diamond surfaces. The correlation reflects the decrease in sp2 amount and enhanced surface conductivity of the diamond surface after the chemical treatment. These results indicate that the AFM phase can detect clearly and microscopically carbon sp2 phase on facets and grain boundaries of nanocrystalline diamond films.