Bakshi V. EUV Lithography

Washington: SPIE, 2009. — 673 p.Extreme ultraviolet lithography (EUVL) is the principal lithography technology aiming to manufacture computer chips beyond the current 193-nm-based optical lithography, and recent progress has been made on several fronts: EUV light sources, optics, optics metrology, contamination control, masks and mask handling, and resists.
This comprehensive volume is comprised of contributions from the world's leading EUVL researchers and provides all of the critical information needed by practitioners and those wanting an introduction to the field.
Interest in EUVL technology continues to increase, and this volume provides the foundation required for understanding and applying this exciting technology.List of Contributors.
List of Abbreviations.
EUV Lithography: An Historical Perspective. Hiroo Kinoshita and Obert WoodThe Early Stage of Development—1981 to 1992.
The Second Stage of Development—1993 to 1996.
Other Developments in Japan and Europe.
The Development of Individual Technologies.
EUVL Conferences.EUV LLC: An Historical Perspective. Chuck Gwyn and Stefan WurmFormation of the LLC.
Program Structure.
Program Results.
Retrospective Observations.
Status of EUV Development at the End of LLC.Appendix A: Major Accomplishments of the EUV LLC Program.
Appendix B: EUV LLC Program Patents.EUV Source Technology. Vivek BakshiEUV Source Requirements.
DPP and LPP Source Technologies.
EUV Source Performance.
Summary and Future Outlook References.
Optics and Multilayer Coatings for EUVL Systems. Regina Soufli, SaSa Bajt, Russell M. Hudyma and John S. TaylorProperties of EUVL Systems.Projection Systems for Extreme Ultraviolet Lithography. Russell M. Hudyma and Regina Soufli
General EUVL Optical Design Considerations.
EUV Microsteppers.
Engineering Test Stand (ETS).
Six-Mirror EUVL Projection Systems.Specification, Fabrication, Testing, and Mounting of EUVL Optical Substrates. John S. Taylor and Regina SoufliSpecification.
Projection Optics.
Effect of Substrate Errors on Imaging Performance.
Low-Frequency (Figure) Errors.
Mid-Spatial-Frequency Errors.
High-Spatial-Frequency Errors.
Influence of Coatings on Roughness Specification.
Calculation of Surface Errors.
Uniformity.
Substrate Materials.
Fabrication.
Metrology.
Mounting and Assembly.
Alignment.
Condenser Optics.Multilayer Coatings for EUVL. Regina Soufli and SaSa Bajt
Overview and History of EUV Multilayer Coatings.
Choice of ML Materials and Wavelength Considerations.
Multilayer Deposition Technologies.
Theoretical Design.
High Reflectivity, Low Stress, and Thermal Stability Considerations.
Optical Constants.
Multilayer Thickness Specifications for Imaging and Condenser EUVL Mirrors.EUV Optical Testing. Kenneth A. GoldbergTarget Accuracy.
Techniques for Angstrom-scale EUV Wavefront Measurement Accuracy.
Intercomparison.
Future Directions.Optics Contamination. SaSa BajtFundamentals of Optics Contamination.
Optics Contamination Control.
Summary and Future Outlook References.
Grazing Angle Collector Contamination. Valentino RigatoCollector Lifetime Status and Challenges.Normal Incidence (Multilayer) Collector Contamination. David N. Ruzic and Shailendra N. SrivastavaOverview of Normal-Incidence Collector Mirrors.
Collector Performance.EUV Mask and Mask Metrology. Han-Кu Cho and Jinho AhnEUV Mask Structure and Process Flow.
Mask Substrate.
Mask Blank Fabrication.
Absorber Stack and Backside Conductive Coating.
Mask Patterning.
Mask Cleaning.
Advanced Mask Structure.
Summary and Future Outlook.Photoresists for Extreme Ultraviolet Lithography. Robert L. BrainardEarliest EUV Resist Imaging.
Absorption Coefficients of EUV Photoresists.
Multilayer Resists and Pattern Transfer.
Resist Types.
PAGs and Acids.
Line Edge Roughness.
Summary and Future Outlook.High-Resolution EUV Imaging Tools for Resist Exposure and Aerial Image Monitoring. Malcolm GowerEUV Tool Design Considerations.
EUV Microstepper.
Reticle Imaging Microscope.
Summary and Future Outlook.Fundamentals of EUVL Scanners. Kazuya OtaIllumination Optics.
Projection Optics.
Stages.
Sensors.
Handling Systems.
Vacuum and Environment System.
Budgets.EUVL System Patterning Performance. Patrick Naulleau, John E. Bjorkholmr and Manish Chandhok
Introduction: The Benefits of EUV Imaging.
Imaging with the 0.1 -NA ETS Optic.
Imaging with the 0.3-NA MET Optic.
System Contributors to Line Edge Roughness.
Flare in EUVL Systems.Lithography Cost of Ownership. Phil Seidel
Cost of Ownership Overview.
Lithography: Historical Cost and Price Trends.
Major Lithography CoO Parameter and Productivity Drivers.
General Observations on Lithography Cell and CoO Improvements (Past Decade).
CoO Considerations for Future Lithography Technologies.Appendix: Example Case Studies of Lithography CoO Calculations.Appendix. Reference Data for the EUV Spectral Region. Eric M. Gullikson and David AttwoodOptical constants and absorption data for extreme ultraviolet wavelengths.
Physical constants
Electron binding energies in electron volts for the elements in their natural forms.
Photon energies in electron volts of principal K- and L-shell emission lines.