Comparison of atomic force microscopy imaging methods and roughness determinations for a highly polished quartz surface

Abstract

The morphology and microstructure of a polished quartz surface have been studied using atomic force microscopy (AFM) under ambient conditions, high vacuum and ultrahigh vacuum. The general features observed in air and vacuum environments are consistent, showing the existence of long corrugations, scratches, and holes. The root-mean-square surface roughness ranged from 0.2 to 0.4 nm. Imaging of hydrophilic surfaces, such as quartz, with contact-mode AFM can be problematic because of the presence of adsorbed water and contamination layers on the surface. Using tapping-mode AFM in air and noncontact mode AFM under vacuum, we are able to study the true structure of the surface; detection of more local features with higher resolution was achieved under ultrahigh-vacuum conditions.