Vertical-objective-based ellipsometric microscope for backside illuminated real-time visualization of nm-thick lubricant films

The vertical-objective-based ellipsometric microscope (VEM) is presented which can be used for real-time visualization of nm-thick lubricant films with high lateral resolution. The performance of hard disk drives (HDDs) depends on the dynamics of the nm-thick liquid lubricant films due to decrease of head-disk gap to 2 to 3 nm. The contact or near-contact head disk interface is needed to increase the recording intensity. However, meniscus formation or lubricant pick-up will occur. Therefore, real-time visualization of shearing nm-thick liquid lubricant films plays an important role in the analysis of these phenomena. However, the current VEM can not provide this contact or near-contact situation due to the short working distance (WD) of the high magnification objective lens. In this report, we propose a backside illuminated VEM, whose illumination system and objective lenses are set on the opposite of the sliding probe to solve this problem, and the feasibility of the method is discussed.