1 / 14

Determining the Optical Constants of EUV Reflectors

Determining the Optical Constants of EUV Reflectors. Jedediah Johnson Dr. David Allred. Talk Outline. Background physics/applications Project Motivation Previous measurement techniques Current sputtered diode research. Reflectors in EUV range. EUV range is about 100-1000Å

caldwell-whitfield
Download Presentation

Determining the Optical Constants of EUV Reflectors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Determining the Optical Constants of EUV Reflectors Jedediah Johnson Dr. David Allred

  2. Talk Outline • Background physics/applications • Project Motivation • Previous measurement techniques • Current sputtered diode research

  3. Reflectors in EUV range • EUV range is about 100-1000Å • General Challenges: - hydrocarbon buildup - absorption - high vacuum needed • Complex index of refraction: ñ=n+ik

  4. EUV Reflectors • Light interacts principally with electrons. • More electrons = higher the theoretical reflectance. • High density desired.

  5. Applications of EUV Radiation Thin Film or Multilayer Mirrors EUV Lithography Soft X-ray Microscopes EUV Astronomy The Earth’s magnetosphere in the EUV Images from www.schott.com/magazine/english/info99/ and www.lbl.gov/Science-Articles/Archive/xray-inside-cells.html.

  6. Optical Constants • Precise optical constant data allows scientists to engineer reflectors for specific projects. • R+T+A=1

  7. Optical Constant Determination from Transmission Measurements • CXRO has compiled optical constants which were usually measured from transmission measurements and Kramers-Kronig analysis

  8. Kramers-Kronig Analysis • Integral evaluated from zero to infinity (approximations introduced) • Numerical methods or complex analysis required

  9. Computer and Measured Reflectance vs. Wavelength Differences in the measured reflectance of thorium and the reflectance computed from CXRO constants call into question the accuracy of currently published data.

  10. Simultaneous Reflection and Transmission Measurements

  11. First data acquired with new diodes

  12. Comparison with previous transmission window data

  13. Conclusions • We believe our methods will provide the most accurate optical constant measurements in the EUV. • Remainder of data taken in March 2005 must be analyzed and fit.

  14. Acknowledgments • BYU XUV Research Group colleagues • Dr. David D. Allred • Dr. R. Steven Turley • BYU Physics Department Research Funding

More Related