Review of material measures for surface topography instrument calibration and performance verification

As the need for the manufacturing of complex surface topographies increases, traceable measurement with known uncertainties can allow a manufacturing process to remain stable. Material measures are the link in the chain that connects the surface topography measurement instrument's output to the definition of the metre. In this review, the use of material measures is examined for the purposes of instrument calibration and performance verification based on the metrological characteristics framework, as introduced in ISO 25178 part 600. The material measures associated with each metrological characteristic are investigated in terms of fabrication, geometry and functionality. Material measures for metrological characteristics are discussed in a sequential approach, focusing on material measures that have been developed for specific measurement technologies and optical surface topography measurement instruments. There remains a gap in the metrological characteristic framework for the characteristic, topography fidelity, and the review highlights current methods using reference metrology and alternative approaches using virtual instruments to quantify the effects of topography fidelity. The influence of primary instruments is also reviewed in the context of uncertainty propagation. In the conclusion, the current challenges are identified with regards to the scarcity of available material measures in the lower nanometre range, and the limitations in terms of cost, complexity, manufacturing time and industrial applicability.