Multi-mirror adaptive optics for control of thermally induced aberrations in extreme ultraviolet lithography

Michel Habets, Joni Scholten, Siep Weiland, Wim Coene

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

2 Citations (Scopus)
531 Downloads (Pure)


The imaging quality of the projection optics of an extreme ultraviolet lithography scanner degrades under the influence of thermally induced deformations of its mirrors. Wavefronts of different reticle points encounter different parts of the deformed mirrors, resulting in a field dependent wavefront error. This paper presents how ideas from multi-conjugate adaptive optics can be used to reduce these thermally induced aberrations. To this end a generic deformable mirror model is implemented. Linear actuator sensitivities are derived directly, based on nominal ray locations and directions, enabling fast prototyping. An integrated opto-thermo-mechanical mirror heating model is used to determine the evolution of thermally induced abberations over time. This transient simulation is used to analyze four different adaptive optics configurations and two different control algorithms. It is shown that by employing the multi-objective goal-attainment method, it is possible to improve the optical performance significantly when compared to minimizing the ℓ2-norm of the total residual wavefront error vector.

Original languageEnglish
Title of host publicationExtreme Ultraviolet (EUV) Lithography VII
EditorsEric M. Panning, Kenneth A. Goldberg
ISBN (Electronic)978-1-510600119
Publication statusPublished - 2016
EventExtreme Ultraviolet (EUV) Lithography VII - San Jose, United States
Duration: 22 Feb 201625 Feb 2016

Publication series

NameProceedings of SPIE
ISSN (Print)0277-786X


ConferenceExtreme Ultraviolet (EUV) Lithography VII
CountryUnited States
CitySan Jose


  • Aberration control
  • Adaptive optics
  • Deformable mirrors
  • EUV Lithography
  • Mirror heating
  • Thermally induced aberrations

Fingerprint Dive into the research topics of 'Multi-mirror adaptive optics for control of thermally induced aberrations in extreme ultraviolet lithography'. Together they form a unique fingerprint.

Cite this