SEMATECH's EUVL Mask Blank Defect Reduction Program: ML ...
SEMATECH's EUVL Mask Blank Defect Reduction Program: ML ...
SEMATECH's EUVL Mask Blank Defect Reduction Program: ML ...
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Accelerating the next technology revolution<br />
<strong>SEMATECH's</strong> <strong>EUVL</strong> <strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong><br />
<strong>Reduction</strong> <strong>Program</strong>:<br />
<strong>ML</strong> Deposition <strong>Defect</strong> Sources and<br />
Mitigation Strategies<br />
Frank Goodwin 1 , Toshi Nakajima 2 , Patrick Kearney 1 ,<br />
Junichi Kageyama 2 , Vibhu Jindal 1 , Masahiro Kishimoto 2 ,<br />
C.C. Lin 1 , Andy Ma 1 , Milt Godwin 1 , Jenah Harris-Jones 1<br />
1 SEMATECH<br />
2 AGC Electronics America<br />
Oct, 2010<br />
Copyright ©2008<br />
SEMATECH, Inc. SEMATECH, and the SEMATECH logo are registered servicemarks of SEMATECH, Inc. International SEMATECH Manufacturing Initiative, ISMI, Advanced Materials Research Center<br />
and AMRC are servicemarks of SEMATECH, Inc. All other servicemarks and trademarks are the property of their respective owners.
EUV Readiness<br />
• <strong>Mask</strong> blank defects are the single most critical EUV<br />
technology gap.<br />
• <strong>Blank</strong> development has not kept pace with roadmap,<br />
especially progress with the multilayer deposition process.<br />
– There had not been sufficient progress with EUV mask blank defect<br />
reduction in 2008-2009.<br />
• <strong>Defect</strong> <strong>Reduction</strong> Roadmap<br />
• To improve performance SEMATECH formed the EUV<br />
<strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong> <strong>Reduction</strong> <strong>Program</strong>.<br />
2010 International Symposium on Extreme Ultraviolet Lithography<br />
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EUV <strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong> <strong>Reduction</strong><br />
<strong>Program</strong><br />
• <strong>Mask</strong> <strong>Blank</strong> Development Center<br />
– MBDC Strategy<br />
• Establish a facility and expertise to support metrology and evaluation of<br />
EUV mask blanks.<br />
• Continue to develop world class expertise on metrology and<br />
characterization of small (sub-100nm) defects.<br />
• Provide facilities for blank suppliers to develop and evaluate new<br />
processes for multi-layer deposition and metrology.<br />
• EUV Multi-layer Deposition<br />
– Deposition Strategy<br />
• Generate the fundamental understanding of the <strong>ML</strong> deposition process<br />
and particle generation.<br />
• Demonstrate feasibility of IBD multi-layer deposition to meet mask blank<br />
pilot line defect and reflectivity requirements.<br />
• Enable a supplier to successfully build the next generation multi-layer<br />
deposition tool.<br />
2010 International Symposium on Extreme Ultraviolet Lithography<br />
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Approach to EUV <strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong><br />
<strong>Reduction</strong><br />
• Resources<br />
– Increased headcount<br />
– Task force mode for the past 12 months<br />
• Data driven decisions<br />
– Improved metrology for defect classification<br />
• FIB/SEM (defects > 100nm)<br />
• Auger (defects down to 30nm)<br />
• TEM (defects down to
2010 International Symposium on Extreme Ultraviolet Lithography<br />
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<strong>Defect</strong> Classification<br />
• Current metrology, energy dispersive spectrometry (EDS), on FIB/SEM<br />
– EDS elemental mapping recently implemented to extract more information<br />
on the composition of defects<br />
– Does not provide quantifiable composition analysis or information on<br />
chemical state of the defect<br />
– Limited ability to characterize small core defects and distinguish these from<br />
the background material.<br />
• Auger and TEM analysis capability is ramping to support analysis of<br />
small core size defects.<br />
– Auger analysis availability increasing as experience base increases<br />
• Processes are being developed for defects of sizes down to 30nm.<br />
– TEM analysis is ramping up<br />
• Sample prep work on-going<br />
• Greater resolution for elemental analysis – morphology, EDS + EELS, defects<br />
EDS improvements to FIB/SEM:<br />
Elemental mapping<br />
• EDS mapping implemented to extract more information from multi-layer<br />
defects<br />
– AlOx+SS re-classified as Al<br />
– Same As Background (SAB) reclassified a Si rich defect<br />
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Recent Auger Results<br />
• <strong>Defect</strong> analysis on substrate<br />
is particularly challenging due<br />
to the charging issues<br />
– A carefully controlled conductive<br />
coating has been implemented<br />
as a countermeasure.<br />
– The coating is thin enough to<br />
allow Auger electrons to escape<br />
while being be thick enough to<br />
dissipate surface charge.<br />
• <strong>Defect</strong> size down to 30 nm<br />
have been identified<br />
successfully (Close to the<br />
resolution limits of the tool)<br />
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TEM Analysis<br />
• TEM Firsts<br />
– A native substrate defect at<br />
50 nm lateral size and > 5nm<br />
high has been imaged.<br />
– Film deposition over the<br />
defect characterized.<br />
– A native substrate pit type<br />
defect has been has also<br />
been imaged and<br />
characterized.<br />
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TEM Analysis<br />
• TEM analysis of crystalline defect<br />
– This defect was determined to be crystalline Si originating from the Si<br />
target.<br />
– On-going work to create 3D tomography to determine how defects on<br />
target could have been formed.<br />
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Fundamental Learning of Deposition<br />
Process<br />
• What has been characterized<br />
– Ion Source characteristics<br />
• Ion beam energy<br />
• Flux<br />
• Distribution of ions<br />
– Target characteristics<br />
• Material composition<br />
• Crystallinity<br />
• What is currently being worked on<br />
– Deposition characteristics on substrate<br />
• Decoration of pits and particles under different deposition conditions<br />
– Ion-target interaction<br />
• How defects form on the target surface<br />
– Plume/Ions/Sputtered atoms scattering and motion inside chamber<br />
• Study of gas phase scattering and motion in order to determine<br />
deposition rates on different areas of the chamber (chamber walls and<br />
substrate area)<br />
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Characterization of the Deposition<br />
Chamber<br />
• Film deposition, temperature and stress were measured<br />
across the process chamber.<br />
– Size of blue circles indicates thickness of deposition<br />
• Large circle > greater deposition rate.<br />
– Size and color of circles indicate size and direction of stress.<br />
• Red is compressive, Green tensile.<br />
• Large circle > greater stress levels<br />
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Comparison of Simulation to<br />
Experimental Data<br />
• Simulation run with 100,000 each of Mo and Si atoms into<br />
1.4e-4 Torr Argon.<br />
• Model matches the experimental data.<br />
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<strong>Defect</strong> Composition per Substrate<br />
Si Family<br />
<strong>Defect</strong>s<br />
Al Family<br />
<strong>Defect</strong>s<br />
SAB<br />
SiOx<br />
Si<br />
AlOx<br />
AlOx+SS<br />
Other<br />
<strong>Defect</strong><br />
Types<br />
Ru<br />
C<br />
0 1 2 3 4<br />
Average for all marathons<br />
M12<br />
M13<br />
• The advanced metrology and defect analysis capability<br />
enables development of a pareto graph by defect<br />
composition.<br />
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Targeted <strong>Defect</strong> <strong>Reduction</strong><br />
Absolute defect count per plate<br />
20<br />
15<br />
10<br />
5<br />
0<br />
Si family defects<br />
Al family controbutin<br />
Handling contribution<br />
M5 M6 M7 M8 M9 M10 M11 M12 M13<br />
• Identification of the composition and source of the defects<br />
enabled a targeted approach to reducing defects.<br />
– Elimination or mitigation of defect source or defect type.<br />
– Influence of process changes and conditions.<br />
• Performance obtained on the IBD tool supporting AGC<br />
Electronics America pilot line at the SEMATECH/CNSE MBDC<br />
facility.<br />
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Other<br />
Total defects
<strong>Defect</strong> <strong>Reduction</strong> Roadmap - Today<br />
• Over the past 12 months <strong>ML</strong> defects have been reduced from a average<br />
total defect level of 44 per mask-blank to a level of 18 defects per maskblank.<br />
Champion total defect results:<br />
• M1350@71nm: 6 defects<br />
• M7360@45nm: 51 defects<br />
• M7360@50nm: 30 defects<br />
• M7360@70nm: 7 defects<br />
Champion particle-type defect results:<br />
• M1350@71nm: 3 particle defects<br />
• M7360@45nm: 6 particle defects<br />
• M7360@50nm: 4 particle defects<br />
• M7360@70nm: 5 particle defects<br />
• Results were obtained in collaboration with our partner; AGC Electronics America<br />
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<strong>Defect</strong> <strong>Reduction</strong> Roadmap - Tomorrow<br />
defects/cm^2 @ 25nm<br />
sensitivity<br />
Jul-07<br />
15.7601<br />
Dec-07<br />
5.2534<br />
Dec-09<br />
3.9400<br />
Jul-10<br />
2.6267<br />
Dec-10<br />
0.5253<br />
Jul-11<br />
0.1051<br />
Dec-11<br />
0.0525<br />
Jul-12<br />
0.0210<br />
Dec-12<br />
0.0131<br />
Jul-13<br />
0.0053<br />
Dec-13<br />
0.0026<br />
# of defects (142X142 mm^2)<br />
@ 73 nm sensitivity<br />
120.98 40.33 30.25 20.16 4.03 0.81 0.40 0.16 0.10 0.04 0.02<br />
• Next Generation IBD Tool.<br />
– SEMATECH’s objective is to<br />
deliver a new tool concept by<br />
mid-2011.<br />
– Will likely be late 2013 before a<br />
new deposition tool will be<br />
available.<br />
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<strong>Defect</strong> <strong>Reduction</strong><br />
• At SEMATECH, little progress in defect reduction demonstrated in<br />
2008-2009.<br />
• With a refocused effort a 60% improvement in the defect levels of EUV<br />
<strong>Mask</strong> <strong>Blank</strong>s has been demonstrated over the past 12 months.<br />
– Tremendous improvement in failure analysis and characterization<br />
methodology has provided key understanding of defect modes.<br />
– Strong correlation between simulation of deposition process and<br />
experimental results.<br />
– Modulation of defectivity signal is proven.<br />
– First substantive improvement in defect level since December 2007.<br />
• Next Generation IDB Tool.<br />
– Needed to meet EUV mask blank defect requirements for pilot line<br />
production.<br />
– Concept design is being developed.<br />
– First tool potentially available in late 2013.<br />
• The achievements were obtained with the collaboration with our partner<br />
AGC Electronics America<br />
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More Details – Associated Posters<br />
• “Deposition Process for EUV <strong>Mask</strong> <strong>Blank</strong>s” - Junichi Kageyama (AGC<br />
Electronics America)<br />
• “SEMATECH’s Infrastructure for <strong>Defect</strong> Analysis and Failure Analysis of<br />
Small Size EUV <strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong>s to support EUV <strong>Mask</strong> <strong>Defect</strong><br />
<strong>Reduction</strong> <strong>Program</strong>” – C.C. Lin (SEMATECH)<br />
• “Modeling growth of defects during multilayer deposition of EUV blanks<br />
by level set method” – Vibhu Jindal (SEMATECH)<br />
• “Low defect <strong>EUVL</strong> mask blank deposition tool process characterization<br />
and modeling.” – Patrick Kearney (SEMATECH)<br />
• "<strong>EUVL</strong> <strong>Mask</strong> <strong>Blank</strong> <strong>Defect</strong> Inspection Capability at SEMATECH" – Andy<br />
Ma (SEMATECH)<br />
• “Implementing Dual-pod Handling Capability on a Film Deposition Tool<br />
for <strong>Defect</strong>-free <strong>EUVL</strong> <strong>Mask</strong> <strong>Blank</strong> Development” – Jae Sohn<br />
(SEMATECH)<br />
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Acknowledgements<br />
• Lithography<br />
– Bryan Rice, Stefan Wurm,<br />
• MBDC<br />
– Anne Rudack, Jon Underwood, Tim Owen, Cecilia<br />
Montgomery, Kristy Maxwell, Mark Maloney, Ed Maillet,<br />
Nancy Lethbridge, Chip Lethbridge, Dan Kraft, Butch<br />
Halliday, Len Gwenden, Chris Cirigilano.<br />
• Cleans Group<br />
– Abbas Rastegar, Matt House<br />
• ISMI Metrology<br />
– Chris Deeb, Brad Thiel<br />
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