/ 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

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Contents

Power of EUV sources for lithographySpecificationStatus

Debris mitigation: characterization status

Spectral Purity:SpecificationFiltering devices

Conclusions

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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

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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)

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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

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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

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Contents

Power of EUV sources for lithographySpecificationStatus

Debris mitigation: characterization status

Spectral Purity:SpecificationFiltering devices

Conclusions

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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

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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

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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