Precision Profiling Method Insensitive to Vertical Vibrations (1st Report): A Proposition of an Optical Skid Method

摘要

A novel optical profiling method is proposed, which is nearly insensitive to vertical vibrations and able to measure the roughness of supersmooth surfaces on a long track. This method makes simultaneous height measurements of both a measurement position and its surroundings and perform subsequent digital subtraction of the latter from the former to obtain the roughness data. An instrument incorporated with this method is shown to have a height sensitivity of 0.1 nm under normal vibrational circumstance (0.4 cm/S2). Data obtained from measurements of a disk substrate, a mirror, an optical flat and a silicon wafer are included.