The stylus profiler is a contact profiler in which a sharp stylus is moved horizontally over the sample surface. The vertical displacement of the stylus due to the surface roughness is measured as a function of the position. The Dektak 150 Stylus profiler, available at our lab, is an advanced step height measurement tool capable of measuring steps below 100Å. It can be used to profile surface topography and waviness, as well as to measure surface roughness in the nanometer range.