KEYWORDS: Confocal microscopy, Modeling, Light sources and illumination, Microscopes, 3D modeling, Equipment, Optical surfaces, Electric fields, Objectives, 3D metrology
We present a unified electromagnetic modeling of coherence scanning interferometry, confocal microscopy, and focus variation microscopy as the most common techniques for surface topography inspection with micro- and nanometer resolution. The model aims at analyzing the instrument response and predicting systematic deviations. Since the main focus lies on the modeling of the microscopes, the light–surface interaction is considered, based on the Kirchhoff approximation extended to vectorial imaging theory. However, it can be replaced by rigorous methods without changing the microscope model. We demonstrate that all of the measuring instruments mentioned above can be modeled using the same theory with some adaption to the respective instrument. For validation, simulated results are confirmed by comparison with measurement results.
Coherence scanning interferometry is one of the most frequently used techniques for optical profiling due to its outstanding axial resolution. However, optical profilers suffer from systematic deviations caused by their transfer characteristics and diffraction effects occurring by means of light-surface interaction with measurement objects. In order to predict these deviations and to get better insight into the physical effects leading to their appearance, analytical and rigorous numerical models are applied. Usually, rigorous models provide higher accuracy whereas analytical models require less computational effort since the light-surface interaction is considered by a phase object approximation. We present a full vectorial three-dimensional modeling of coherence scanning interferometry based on the phase object approximation. Further, we compare three different common approaches using the phase object approximation, usually called Richards Wolf model, Foilmodel and Kirchhoff model. The comparison is validated with respect to rigorously simulated and measured results shown elsewhere.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.