(539d) Aging of Self-Assembled Monolayers for Anti-Stiction Coatings Studied by near Edge X-Ray Absorption Fine Structure

Near edge x-ray absorption fine structure (NEXAFS) is a powerful technique to study elemental composition, bonding, and orientation on the surface of organic films. NEXAFS is especially relevant to the study of self-assembled monolayers (SAMs) used to decrease stiction effects in microelectromechanical systems. SAMs typically form highly oriented structures on surfaces, and although failure of SAMs has been studied, the route to failure through deorientation, wear, and organic decomposition has not been clearly established. Here we utilize NEXAFS to obtain the bonding structure and orientation of SAMs after aging at temperatures from 100 degrees C to 600 degrees C, under dry nitrogen, dry air, and humid air. The fraction of SAMs remaining on the surface, the orientation of the SAMs, and the mechanism of decomposition were determined from the carbon and oxygen K-edges for each aging condition.