Conference Agenda

TOM10 S01: Frontiers in Optical Metrology: Scatter techniques
Wednesday, 14/Sept/2022:
2:30pm - 4:00pm

Session Chair: Juergen Czarske, TUD, Germany
Location: B031

Ground floor, 60 seats

2:30pm - 3:00pm
ID: 265 / TOM10 S01: 1
TOM 10 Frontiers in Optical Metrology

Practical limits and opportunities with speckle metrology

Mikael Sjödahl

Luleå University of Technology, Sweden

In this presentation, the role of speckles as a carrier of information in phase-based optical metrology is re-visited. Starting with the fundamental mechanisms for speckle decorrelation it is shown that information about the state of an object is transferred through the modified mutual coherence function and can be detected either through the phase, speckle movement, speckle decorrelation or as a combination. The presentation is focusing on practical scale laws that set the limit for what is possible to achieve with present day technology and is demonstrated with a few examples incorporating measurements of microstructural changes, strain, shape, lenses and other refractive index objects.

3:00pm - 3:15pm
ID: 111 / TOM10 S01: 2
TOM 10 Frontiers in Optical Metrology

Influence of displacement gradients on laser speckle photography

León Schweickhardt1, Andreas Tausendfreund1, Dirk Stöbener1,2, Andreas Fischer1,2

1University of Bremen, Bremen Institute for Metrology, Automation and Quality Science (BIMAQ), Germany; 2University of Bremen, MAPEX Center for Materials and Processes, Germany

The influence of first and second order displacement gradients on laser speckle photography is investigated in a simulative study that is supported with experimental data. The systematic error is found to scale linearly with the second order gradient, while the random error scales with the first order gradient. The gradient-based error dominates the uncertainty budget of an in-process measurement during single tooth milling close to the machined surface.

3:15pm - 3:30pm
ID: 217 / TOM10 S01: 3
TOM 10 Frontiers in Optical Metrology

Coherent Fourier scatterometry for particle detection on structured surfaces

Anubhav Paul, Dmytro Kolenov, Silvania F. Pereira

TU Delft, Netherlands, The

We demonstrate the detection of particles/contamination present on a structured surface using Coherent Fourier scatterometry (CFS) by applying Fourier filtering to the scanned maps, which eliminates background effects due to the electronic noise as well the structure itself. We show that by using filters in the Fourier space we can significantly improve the detection capabilities of the particles present on the structure.

3:30pm - 3:45pm
ID: 257 / TOM10 S01: 4
TOM 10 Frontiers in Optical Metrology

Coherent Fourier Scatterometry for defect detection on SiC samples

Jila Rafighdoost, Dmytro Kolenov, Silvania F. Pereira

Delft University of Technology (TU Delft), Netherlands, The

Coherent Fourier Scatterometry (CFS) is a scatterometry technique that has been applied for grating and nanoparticle detection. Here, it has been challenged to verify the detectability of the so-called killer defects on SiC samples for power electronic applications. It has been shown that CFS is able to precisely recognize these defects regardless of their shape or size. CFS could be considered as a possible alternative for this purpose.

3:45pm - 4:00pm
ID: 197 / TOM10 S01: 5
TOM 10 Frontiers in Optical Metrology

Characterisation of nanowire structures with scatterometric and ellipsometric measurements

Jana Grundmann, Tim Käseberg, Bernd Bodermann

Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany

Nanowire structures arranged in a hexagonal lattice are to be characterized in terms of their diameter, height and pitch. A scatterometer and an imaging Mueller matrix ellipsometer, which is a combination of a commercial Mueller matrix ellipsometer and a microscope, have been used as measurement tools. These measurements are supported by numerical simulations using the finite element method to characterize the structure parameters.