Using the stylus method, the surface is scanned along a line with a fine diamond tip and a height profile is recorded. A variety of surface morphological parameters can be determined from the height profile, e.g. roughness, undulation, the height histogram, skew and steepness of the height distribution, mean local surface slope, percentage contact area, etc.
The IST has two stylus instruments at its disposal: the Dektak XT from Brucker (vertical resolution 0.5 nm, lateral resolution 0.2 or 1.25 µm) and the Talysurf from Taylor Hobson (vertical resolution 15 nm, lateral resolution 0.25 µm). Both devices can capture 3D as well as 2D scans. The Talysurf can also be used to characterize large components and complex geometries in terms of roughness and topography.
Layer thicknesses can be determined very quickly, easily and precisely by preparing a layer and using the profile.