Some issues of traceability in the field of surface topography measurement

This paper highlights some of the reasons that surface topography measurements can have an ill-defined traceability route. Whereas the most common instruments on the shop floor are two-dimensional (2D) or profiling systems, there is a clear industrial trend towards three-dimensional (3D) surface topography instruments. Currently, there is no clear traceability route for three-dimensional measurements, and recent comparisons show alarming discrepancies between the various commercial instruments. This paper reviews these instrumental problems and highlights the need for unambiguous mathematical definitions for surface texture parameters and rigorous uncertainty evaluations. This paper also reviews some of the metrology issues that will be encountered when using three-dimensional surface texture measuring instruments to measure complex features on microsystems.