Sub-Nanometre Surface Texture and Profile Measurement with NANOSURF 2

Abstract A surface texture and profile-measuring stylus instrument, developed at NPL and called ‘NANOSURF 2’, which has a continuous dynamic horizontal range of 50 nm to 50 mm, is being used for sub-nanometre surface texture and profile measurement on a wide range of engineering, optical and semi-conductor surfaces. The paper presents a selection of results on such specimens. Built almost entirely of near-zero thermal expansivity materials, with a tight measurement loop and minimum interfaces, the instrument exhibits very low susceptibility to thermal and mechanical disturbances. Some features of the instrument are incorporated in a novel, ultra-high precision machine tool under development, which is briefly mentioned in the paper.