Monitoring and mapping imperfections in silane-based self-assembled monolayers by chemical amplification

This paper describes an innovative and simple technique for analyzing defects in silane-based self-assembled monolayers. The assembly of monolayers is a simple method for chemically modifying surfaces, which can be important for resisting chemical attack or adhesion of biomolecules. Measuring the molecular scale properties of monolayers and the reproducibility of their ability to uniformly modify a surface requires tools that provide limits of detection at the level of at least a few atoms per million with specificity to the top couple nanometers of the surface. To achieve this level of sensitivity a new technique is developed that combines spectroscopy and microscopy techniques (particularly atomic force microscopy) with chemical amplification of exposed silicon in self-assembled monolayers of silane molecules. This development is an important achievement for monitoring the quality of monolayers as a function of modifications to the method(s) used to deposit the silane molecules. Techniques presented here could be easily extended to assessing the molecular scale quality of other surface modifications.