Characterization of Silicon Oxide-Based Materials in an Atomic Force Microscope

Abstract

Silicon oxides are widespread in microelectronics and microelectromechanical systems (MEMS) applications. One form of this material that has been suggested as a dielectric in MEMS applications is a carbon-doped form of silicon oxide that can be produced in thin coatings. However, the mechanical properties and wear resistance of these coatings is unknown, and coatings of interest are difficult to characterize because they are very thin. A test methodology has been previously described using extremely sharp diamond tips on a stainless steel cantilever in an atomic force microscope, and this method allows direct calculation of an effective material flow strength at penetration depths as small as twenty nanometers. A number of forms of carbon-doped and undoped silicon dioxide have been evaluated using this methodology. Size effects on material properties are evaluated, and correlations between test methods are presented.