Development of Ellipsometric Microscope for High-Resolution Observation of Nanometer-Thick Lubricant Films

Abstract

Real-time visualization of the nm-thick liquid lubricants is useful to clarify the lubrication phenomena using liquid thin films, for example, the lubrication for hard disk drives. In this paper, we present a method of measuing the film thickness using a vertical-objective-based ellipsometric microscope, which is a microscope based on ellipsometry that widely used for the investigation for thin films. In this method, the intensity signal can be directly converted to the thickness and the calibration can also be done by a phase shift method without any other devices. Sub-nm thickness and the sub-μm lateral resolutions were experimentally achieved for the visualization of the nm-thick lubricant films.