Interference-Based Optical Testing Systems

To perform high-precision inspections of structured surfaces, which are commonly used in e.g. the semiconductor industry, optical testing systems based on interference effects can be used. A full simulation of these setups needs to include all physical optical effects, like diffraction at the structure, coherence and the resulting interference at the image plane. To help the optical engineer in this task, the fast physical optics software VirtualLab Fusion offers a series of tools to include diffraction and non-sequential modelling in the system.

With the release of the new version 2023.1 we also provide a new detector concept which allows the user to calculate any physical quantity that might be of interest, directly from the field information. To see all these tools in action, we showcase two examples below. In the first one, a high-NA objective is used to inspect an asymmetric micro-structured wafer, while in the second example we show the irradiance patterns from a classical Fizeau interferometer using differently shaped test surfaces.