The Dektak 8 profilometer measures the vertical profile of developed or etched patterns by lightly dragging a sharp stylus across the surface and detecting its vertical movement. This allows users to determine resist thickness, etch depth, and general step height distances. Vertical sensitivity is in the fractions of an Angstrom (0.01 nano-meters). It uses a general purpose stylus with a 12.5 micron radius. This system is highly automated but quite user friendly, and can measure features anywhere on a substrate up to 8 inches in diameter.