Calibration of the scales of areal surface topography measuring instruments: part 3. Resolution

TLDR

Calibration of areal surface topography instruments requires resolution testing, yet existing artefact designs lack standardized analysis methods for comparable results. The paper presents a novel method to determine the lateral resolution of areal surface topography instruments. The method employs a star‑shaped ASP material measure and applies ISO lateral period limit criteria to assess the resolution of a phase‑shifting interferometer. It allows quantitative estimation of instrument resolution from ASP material measures, replacing qualitative judgments.

Abstract

Calibration of the scales of areal surface topography measuring instruments requires testing of the resolution. Several designs of artefact that allow testing of the resolution of such instruments are currently available; however, analysis methods need to be developed to provide comparable results. A novel method for determining the lateral resolution of areal surface topography measuring instruments is presented. The method uses a type ASP (star-shaped) material measure. To demonstrate the validity of the method, the resolution of a phase shifting interferometer was determined based on the ISO definition of the lateral period limit. Using the proposed method, the type ASP material measure, which is often used to judge qualitatively an instrument's resolution, can be used to quantitatively estimate the resolution of instruments using the topography data.