Fraunhofer Institute for Integrated Systems and Device Technology IISB
Fraunhofer Institute for Integrated Systems and Device Technology IISB

Computational Lithography and Optics

The computational lithography and optics group develops physical and chemical models, numerical algorithms, and software for the simulation of lithographic processes and for the fabrication and characterization of nanophotonic components. This covers the process steps pre-bake, exposure, post-exposure bake, and chemical development of the photoresist.

Our lithography simulation algorithms are available in the software Dr.LiTHO of Fraunhofer IISB. Additional modules of Dr.LiTHO are used for the evaluation and optimization of lithographic processes and for the simulation of non-standard lithographic exposures such as interferometric exposures.

Models from the field of artificial intelligence are used in various areas such as prediction of lithographic imaging performance, resist pattern collapse, and defect detection.

Besides from model and software development, the lithography group offers support for industrial and governmental partners in process development and feasibility studies.

Leadership Change at Fraunhofer IISB's Computational Lithography and Optics Group

As of 2026, Christian Schwemmer has taken over as head of the Computational Lithography and Optics Group at Fraunhofer IISB in Erlangen. The group focuses on developing physical and chemical models, numerical algorithms, and software for simulating lithographic processes, as well as on the fabrication and characterization of nanophotonic components.

We extend our sincere thanks to Dr. Andreas Erdmann for leading the group for over two decades. Under his leadership the group established an outstanding reputation in computational lithography.

Moving forward, our main research directions will be:

  • Rigorous simulation of light diffraction from advanced masks, including pristine and defective EUV masks.
  • Modeling chemically amplified and novel EUV resists, including model calibration using local and global optimization methods.
  • Evaluation and optimization of lithographic imaging, mask design, and source configuration using genetic algorithms.
  • Modeling nanophotonic devices such as metasurfaces, waveguides, couplers, and resonators.
  • Modeling two‑photon lithography for the fabrication of optical metasurfaces.
  • Application of AI methods to EUV lithography and two‑photon lithography.

We look forward to building on this strong foundation and advancing our research under Christian Schwemmer’s leadership.

SPIE Advanced Lithography + Patterning 2026

Meet us at the "SPIE Advanced Lithography + Patterning 2026", February 22 to 26, San Jose, United States.

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Andreas Erdmann (center, in striped shirt) and the members of the Computational Lithography and Optics Group at Fraunhofer IISB.

Frits Zernike Award 2026 for Andreas Erdmann

Dr. Andreas Erdmann, former head of the Computational Lithography and Optics Group at Fraunhofer IISB and a pioneer in lithography simulation, was awarded the 2026 Frits Zernike Award for Microlithography. The award recognizes his contributions to understanding and modeling image formation and resist patterning in deep and EUV lithography, particularly the 3D effects of photomasks, and his commitment to lithography education.

The SPIE Frits Zernike Award for Microlithography is presented for outstanding accomplishments in microlithographic technology, especially for advancing semiconductor lithographic imaging and patterning solutions.

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© Fraunhofer IISB
Andreas Erdmann (standing in the middle, holding the wafer) and the Fraunhofer IISB Computational Lithography and Optics Team at the IISB Lithography Simulation Workshop 2025

Fraunhofer IISB Lithography Simulation Workshop

Our 21st Fraunhofer IISB lithography simulation workshop will take place in Behringersmühle from May 28 to 30, 2026.

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Projects

Major previous projects