/ Slide 1
Vadim Banine
Extreme ultraviolet sources for lithography applications
Vadim Banine
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Contents
Power of EUV sources for lithographySpecificationStatus
Debris mitigation: characterization status
Spectral Purity:SpecificationFiltering devices
Conclusions
/ Slide 3
Contents
Power of EUV sources for lithographySpecificationStatus
Debris mitigation: characterization status
Spectral Purity:SpecificationFiltering devices
Conclusions
/ Slide 4
Throughput dependence
Power of the sourceOptical efficiency of the systemStage performance and overheadResist performance
Joint Requirement for EUV Source up to now
SOURCE CHARACTERISTIC REQUIREMENTWavelength 13.5 [nm] EUV Power (in-band) in IF 115 [W]
For 5 mJ/cm2 of resist sensitivity
Collector
FilterSource
Debris mitigation
Aperture (IF)
Vacuum chamber
/ Slide 5
Main challenges for the HVM EUV sources related to high power operation
For DPP based sources:Heat load (electrodes close to the place of heat release) or how much power can be inserted in the system
For LPP based sources:Required laser power (CoO)
For all sources:High debris production
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Solutions for the HVM EUV source power
• Step from the current Xe based solutions with low CE (0.5-1%) to high CE (>3 %) materials, such as Sn and Li
• Source multiplexing
• Both of above
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Laser triggered multiplexed Sn sourceLaser triggered single
pseudo sparkLaser triggered multiplexed pseudo spark
10-100 temporally multiplexed elementary sources ! -> Distributed Heat load (theoretical limit for
power load 120 kW)
No significant electrode erosion
Trigger laserRotating electrodes with
Sn - surface
EUV
Achieved:• 2 % CE• 1 kW in20 W in 2p in-band (about 1-2 W IF)
Achieved:• 2 % CE• 18 kW (Continuous)360 W in 2p in-band (about 18-36 W IF)
2001-2004 20052000
Achieved:• 3.1 % CE (Phystex-tool)• 50 W in1-2 W in 2p in-band (about < 0.2 W IF)
/ Slide 8
Will be updated
Philips Extreme UV
+
laser
tin supply
cooling channel
Philips‘ EUV Lamp: Sn-based rotating electrodes
- 200W/2π continuous operation (scalable to >600W /2π)- very small pinch (<1mm)- >>1 bln shots electrode life- commercial product
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MNE RotterdamSep2004
Here will be a new slide of Xtreme
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Here will be a new slide of Cymer
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0.1
1.0
10.0
100.0
1000.0
2001 2002 2003 2004 2005 2006 2007 2008 2009
EU
V p
ower
at I
F [W
]
Sn
Xesupplier 2supplier 1
supplier 3
Need 27 W for alpha demo
tool, 10 wph at 5 mJ/cm2
Actual measured data Planned performance
Source power progress has been increasing
supplier 4
Need 180+ W for HVM,
100+ wph at 10 mJ/cm2
Spread of latest results
Roadmaps conform to requirements
/ Slide 12
Conclusion for the power specifications and scaling
Due to uncertainty in the resist development >180 W EUV source to support 100+ wph throughput tool is neededSources working with alternative materials and/or multiplexing show that power scaling (20-50 W already now) is feasible and roadmaps conform to required power level
/ Slide 13
Contents
Power of EUV sources for lithographySpecificationStatus
Debris mitigation: characterization status
Spectral Purity:SpecificationFiltering devices
Conclusions
/ Slide 14
Debris characterization
Total amount produced debrisMicro particles -> non-uniform collector surface coverage
Fast ions -> surface sputtering
Atomic/ ionic debris -> uniform collector surface coverage
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Suppression of Sn micro-particles
ConclusionSn particulates (>100nm) can be suppressed to desired values from reaching the collector
no mitigation: a mess!
with mitigation: 1 particulate!
0.1
1.0
10.0
100.0
1000.0
10000.0
0 100 200 300 400 500 600 700
Micro-particle stopping factor [a.u.]
Supp
ress
ion
fact
or [a
.u.]
micro-particles target
limited by accuracy of meas.10 µm
10 µm
Particle count
0 5 10 15 20 25 30 35 40 4520
0
20
40
60
80
100
120
140
160
180
Particle size, um
Num
ber d
ensi
ty -
bare
leve
l num
ber d
ensi
.
Without mitigation
With mitigation
Part
icle
cou
nt d
ensi
ty, A
U
0 5 10 15 20 25 30 35 40 45Size, µm
No mitigation With mitigation
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Sn deposition and cleaning1. micro-particle debris (droplets >100 nm): absorption2. fast ionic/neutral debris: causing sputtering/etching of
collector surface (reflection degradation)3. atomic/ionic debris: causing ‘uniform’ layer deposition
(absorption)
ConclusionMTBC is demonstrated to be several hours of operation, and improvements are identified **. Sn cleaning is required.
0.1
1.0
10.0
100.0
1000.0
10000.0
0 0.5 1 1.5 2Background gas factor [a.u.]
Supp
ress
ion
fact
or [a
.u.]
etching target
deposition target
deposition
etching limited by accuracy of meas.
cleaning Cleaning of a Sn-deposited mirror*
0%
20%
40%
60%
80%
100%
0 10 20 30Grazing angle, deg
Ref
lect
ivity
, %
Before handlingAfter cleaningBefore cleaning
* see poster M. van Herpen (This symposium)** see presentation J. Pankert (This symposium),
/ Slide 17Philips Extreme UV
0 5 10 15 20 25 300
20
40
60
80
100
Ref
lect
ivity
/%
Angle /°
Ru Ref NL5CXRO (Sn=0nm; RuO2=0.8nm)
Ru050714a (18MS, GI)CXRO (Sn=0.1nm; RuO2 = 0.8nm)
Advanced Mitigation and Cleaning
GI-sample, 18 Ms exposure:Very little degradation
0 5 10 15 20 25 300
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
Reflectivity recovery due to cleaning
Ru reference mirror sample
Ru sample covered by Sn
refle
ctiv
ity (%
)angle (°)
Cleaning of Ru surface:Almost 100% recovery
/ Slide 18
Collector lifetime combining a number of methodsProduction system (10 kHz)
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1.0E+05
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Col
lect
or li
fetim
e [e
xpos
. hrs
]XeSn
Combinationof methods
Target for production if collector is:
Consumable 3000 hr
Non-consumable 15000 hr
Combination of methods demonstrate projected lifetime of ∼0.5 year
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Remarks on debris mitigation
Experiments with debris mitigation show no collector damage based on the accuracy of the measurements (up to about 108
shots)Combination of a number of debris mitigation methods results in the projected collector lifetime of ∼0.5 yearA path to achieve the target of HVM seems feasible
/ Slide 20
Contents
Power of EUV sources for lithographySpecificationStatus
Debris mitigation: characterization status
Spectral Purity:SpecificationFiltering devices
Conclusions
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Spectral purity (DUV)•DUV is defined here as non-EUV resistsensitive radiation•Factors which influence the spectral purity specification :
• non-EUV resist sensitive radiation @at wafer (not well known and different for different resists)• non-EUV ML reflectivity (depends on wavelength, 11 mirrors!)• non-EUV source output (different per source
Joint spec: 1% DUV relative to in-band EUV
@ wafer
RDUV ∼ 0.5 NMLM = 11
Collector
FilterSourceIF
Mitigation system
<3-7% DUV @ IF
Spectral Purity Filter might be needed
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Results of the mechanical filter fabrication, solution once and for all (Transmission @13.5 nm 78%)
Mesh-less filters of 30 mm in diameter are fabricated.which can withstand high mechanical and thermal stress at high transmission
Uniformity about 0.5%
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.20.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0.016
0.018
0.020
0.022
0.024
Tran
smis
sion
Wavelength ( µ m)
>1000x in DUV
About 50x in IR
No mechanical damage after load for 52 hours at 2 W/cm2 (conform HVM)
0.2 Wavelength, µm 2.2
Tran
smis
sion
See presentation of L. Smaenok @ EUV SWS Thursday
Typical transmission in DUV and IR
6 7 8 9 10 11 12 13 14 15 16 17 18 1976,076,276,476,676,877,077,277,477,677,878,078,278,478,678,879,079,279,479,679,880,0
Tran
smiti
on c
oeffi
cien
t, %
Sample coordinate, mm
Zr/Si - filter with 23 periods Zr/Si - filter with 37 periods
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Gradual solution: Results of special coating ML MirrorCoating Normal cap layer
ML Mirror
For higher suppression in DUV a numberof mirrors can be coated
FOMFOM
Per mirror: DUV suppression 3-5 x
with 4.5% EUV loss
0
0.1
0.2
0.3
0.4
0.5
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
wavelength (Angstrom)
Ref
lect
ance
See presentation of F. Bijkerk @ EUV SWS ThursdayAnd van de Kruijs, Poster session 2 Wednesday
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Remarks on SPF
In case if SPF is needed there are 2 proven solutions1000x in DUV suppression and 50x suppression in IR is achieved for 22% EUV loss in the absorptive filter solution (under HVM conditions)3-5 x DUV suppression for 4% EUV loss is shown in the coating solution. The absorptive filter can be applied if DUV and IR is significantly out of specificationThe coating solution can be applied gradually thus optimizing EUV losses
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Concluding remarks
Due to uncertainty in the resist development >180 W EUV source to support 100+ wph throughput tool is needed
• Sources working with alternative materials and/or multiplexing show that power scaling (20-50 W already now) is feasible and roadmaps is conform required power level
• Experiments with debris mitigation show no collector damage based on the accuracy of the measurements (up to about 108 shots) Combination of a number of debris mitigation methods results in the projected collector lifetime of ∼0.5 year2 viable solution for spectral purity are demonstrated (5-1000 x DUV suppression for 4-22% EUV loss)
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People contributed to the presentation
ASML: J. Benschop, N. Harned, H. Meiling, H. MeijerISAN: K. Koshelev and teamFOM: F. Bijkerk and teamTUE: K. GielessenPhilips Research: D. Klunder, M. van Herpen
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Acknowledgements
Thanks for help at…ASMLPhilipsXtreme TechnologiesCymerPhystex…and many others
with support from national governments, More Mooreand European Commission