View
2
Download
0
Category
Preview:
Citation preview
EUV Lithography and EUVL sources: from the beginning to
NXE and beyond.
V. Banine
Slide 2 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 3 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 4 | Public
EUV has come a long way in last 25 years
'85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '08 '09 '10
NL:
5 µµµµm
USA:
40 nm hp
70nmL&S
1st papers soft X-ray for lithography(LLNL, Bell Labs)
ASML start EUVL research program
•ASML has active program since 1997. •Currently >1000 people work on pre-production systems are shipped 2010-11.
Japan:
80nm
160nm
ASML ships pre-production tools
ASML ships 2 alpha tools to IMEC (Belgium) and CNSE (USA)
NL:
40 nm hp28 nm Lines and spaces
Japan:
Kinoshita et al
11
NL:
40 nm hp28 nm Lines and spaces
18 nm Lines and spaces
Slide 5 | Public
EUV and BEUV product roadmap spans >10 years
Under study
6/8M6/8M6M6M6M6MLens mirrors
>350035003300C3300B3100ADTProduct
New λ13.5 nm13.5 nm13.5 nm13.5 nm13.5 nmWavelength
flex OAI
2018
3502501053Source (W)
1515105Dose (mJ/cm2)
150 wph125 wph60 wph4 wphThroughput (wph)
3.0 nm3.5 nm4.5 nm7.0 nmOverlay (SMO)
flex OAIOAI0.2-0.90.80.5Sigma
11 nm18 nm22 nm27 nm32 nmResolution (hp)
20162013201220102006Introduction year
>0.40 NA0.33 NA0.25 NA
Slide 6 | PublicSlide 6 |
• Imaging• Resolution 27nm
• NA=0.25
• σ=0.8
• Overlay• DCO=4.0 nm
• MMO=7.0 nm
• Productivity• 60wph
• 10mJ/cm2 resist
Next step in EUV Manufacturing integration:4 NXE:3100 shipped, 1st operational at customer site
Slide 7 | Public
Further Resolution extension with 0.25NAsupports resist and process development for NXE:3300
21p42 20p40 19p38
• dipole-60, inorganic negative tone resist
• further reduction of resolution with smaller poles possible
in collaboration with IMEC, resist Inpria
18p36
Slide 8 | Public
NXE:3100 and source challenges
Challenges:•To produce enough power (Plasma source)•To protect collection optics from the debris produced by the source (Plasma sputtering and deposition)
Slide 9 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 10 | Public
Definition of clean photon spot at intermediate focus (IF)
Collector
FilterSource
Debris mitigation
Source specifications are defined at intermediate focus (IF)
which is illuminator entrance
Aperture (IF)
Vacuum chamber
illuminator
Slide 11 | Public
Joint Requirements for EUV Source till not long ago (2008)
SOURCE CHARACTERISTIC REQUIREMENT
•Wavelength 13.5 [nm]
•EUV Power (in-band) 115 [W]
•Etendue of Source Output max 1 - 3.3 mm2sr•Collector lifetime (to 10% loss) > 15000 hours
•Source Cleanliness at IF ≥≥≥≥ 30,000 hours•Max. solid angle input to illuminator 0.03 - 0.2 [sr] •Repetition Frequency > 6000 Hz
•Integrated Energy Stability ±±±±0.3%, 3σσσσ over 50 pulses
•Spectral purity:
130-400 [nm] (DUV/UV) ≤≤≤≤ 3 - 7%≥≥≥≥ 400 [nm] (IRVis) at Wafer TBD
Slide 12 | Public
Historical perspective: Production power requirement,achieved power, productivity
0.01
0.1
1
10
100
1000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Year
Po
wer
@ I
F,
W
Power desired, W IF
Power achieved, W IF
Age of Xe Age of SnAge of choice
ADT
Averaged and independent on supplier
Age of industrialization
NXE-3100
Produc
tivity
Gap in productivity is being bridged, in reliable power is still 10x to go.
Pro
du
ctiv
ity, w
ph
Slide 13 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 14 | Public
Synchrotron wiggler, undulator , FEL
Principle:
1. Relativistic electrons traversing a periodic
magnetic structure are being bent;
2. Being bent, electrons emit EUV.
Prospects before 2000:
1. No debris;
2. Good dose repeatability;
3. High maturity (1999!);
4. High uptime
Issues:
1. High CoO;
2. Non-flexible configuration.
3. Not enough power (2005!)
4. Current update: 0.2 W with FLASH (250 m
installation)
e-
EUV
Never made it
See for further reference eg: DC Ockwell et al J. Vac. Sci. Technol. B 17, 3043 (1999)
Slide 15 | Public
Plasma focus (Cymer)
Principle:
1. Voltage is applied between anode
and cathode;
2. Interaction of magnetic field with current
pushes the current to the anode top;
3. Very hot Xe plasma cluster (PF) is formed;
4. EUV is emitted
Prospects before 2000 :
1. Low CoO.
Issues:
1. Debris (solution is forseen);
2. Heat load;
3. Component erosion;
4. Pulse to pulse repeatability.
EUV
Cathode
Anode
Pinch
B
B
F
RIP 2004
See for further reference eg: Fomenkov et al, Sematech International workshop on EUVL, 1999
Slide 16 | Public
Z-pinch
Principle:
1. Xe is puffed into the system;
2. Diffused preionization is applied;
3. Voltage is applied between anode and cathode;
4. Azimuthal magnetic field is generated by the
current;
5. Magnetic field contracts discharge into a thin
thread,
which is called Z-pinch;
6. This produces high temperature and thus EUV.
Early prospects:
1. Low CoO;
Issues:
1. Debris (solution is foreseen);
2. Heat load;
3. Component erosion;
4. High rep. rate.
EUV
AnodeCathode
Pinch
Puff Xe injection
Ceramic plugDiffuse preionization
Changed but still alive
See for further reference eg:Bakshi V, EUV Sources for Lithography, SPIE Press, Bellingham, Washington, USA, 2006
Slide 17 | Public
Capillary discharge
EUV
AnodeCathode
XeInsulator
Capillary
Principle:
1. Xe is being pumped through the system;
2. Voltage is applied between anode and cathode;
3. Geometrically current is driven to flow
through a narrow capillary;
4. Due to Joule dissipation Xe is being heated and
emits EUV;
Prospects before 2000 :
1. Low CoO.
Issues:
1. Debris;
2. Heat load;
3. Component erosion;
4. High rep. rate. ( >1000 Hz)
Never made it
See for further reference eg: F. Jin. and M. Richardson., Applied Optics 34, p.5750, 1995
Slide 18 | Public
LPP plasma
Laser
Nozzle
Xe clusters
Collection mirror
Principle:
1. An intense pulsed laser is focused on
targets, which are jet produced Xe clusters;
2. Xe is highly ionized by heating and emits
EUV.
Prospects before 2000 :
1. High maturity;
2. Good dose repeatability.
Issues:
1. CoO;
2. Debris;
3. MoBe optics (11 nm) (1999!).
Changed but still alive
See for further reference eg:Bakshi V, EUV Sources for Lithography, SPIE Press, Bellingham, Washington, USA, 2006
Slide 19 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 20 | Public
Plasma Focus of Cymer HCT of Philips
EUV
Cathode
Anode
Pinch
B
B
F
Bergmannet al., Microel .eng. 57-58, 2000, pp. 71-77
Cathode
Anode
Bergmannet al., Microel .eng. 57-58, 2000, pp. 71-77Bergmannet al., Microel .eng. 57-58, 2000, pp. 71-77
Cathode
Anode
Slide 21 | Public
EUV pictures of plasma pinching for Philips source (5ns frame)
Measured:
CE = 0.4%
0 -10 ns
15 -25 ns
30 -40 ns
45 -55 ns
60 -70 ns
75 -85 ns
Sheet type pinching
Slide 22 | Public
Xtreem (Lambda) LPP Z-pinch
EUV emission
Slide 23 | Public
End of Xe age
• Too low conversion efficiency 0.5-1.1% (in-band in 2π)
• Not high enough projected maximum power (30-40 W @IF)
• Short lifetime of electrodes (DPP) (several hours of operation)
• Too high CoO for LPP at such CE
• Emerging alternative: Sn and Li (up to 3.5-5 % CE) and potential multiplexing (early trials at ASML-ISAN, Cymer et al)
Slide 24 | Public
Emerging alternative
•Spectra•CE•cleanliness
2 % BW @ 14.32 % BW @ 13.5
InSn
Li
Ein= 3 J
CE (2% BW,
2π):
in 13.5nm:Li = 0.5%Sn = 2 - 3.5 %(best ever)in 14.3 nm:In = 1 %
Concern: Potentially increased debris production with respect to gaseous materials
•Spectra•CE•cleanliness
2 % BW @ 14.32 % BW @ 13.5
InSn
Li
•Spectra•CE•cleanliness
2 % BW @ 14.32 % BW @ 13.5
InSn
Li
Ein= 3 J
CE (2% BW,
2π):
in 13.5nm:Li = 0.5%Sn = 2 - 3.5 %(best ever)in 14.3 nm:In = 1 %
Concern: Potentially increased debris production with respect to gaseous materials
Laser
Cathode
AnodeLaser
Cathode
AnodePseudo spark (ASML-Troitsk) 2000
Achieved:
• 2 % CE
• 100 Hz (ignition laser limited)
10 W in 2π in-band (1-2 W in IF)
Prospect:
• 2-3%
• 1000 Hz
>100 W in IF
Multiplexing
Slide 25 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn – the beginning
• Age of industrialization
• … and beyond
• Conclusions
Slide 26 | Public
Will be updated
Philips Extreme UV
++++
lasertin supplycooling channel
Philips‘ EUV Lamp: Sn-based rotating
electrodes
- 200W/2π continuous operation (scalable to >600W /2π)- very small pinch (>1 bln shots electrode life
- commercial product
2005
Slide 27 | Public
MNE Rotterdam
Sep2004
Here will be a new slide of Xtreme
2005
Slide 28 | Public
Here will be a new slide of Cymer
Development of one of the first LPP with Sn was started
Slide 29 | Public
Collector lifetime (DPP) combining a number of methods
Production 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
Co
lle
cto
r life
tim
e [
ex
po
s. h
rs]
Xe
Sn
Combination
of methods
Consumable 3000 hr
Non-consumable 15000 hr
Combination of methods demonstrate lifetime of ∼∼∼∼0.5 year
Price to pay:
Slide 30 | Public
Debris characterization
• Total amount produced debris
• Micro particles -> non-uniform collector surface coverage
• Fast ions -> surface sputtering
• Atomic/ ionic debris -> uniform collector surface coverage
Slide 31 | Public
Suppression of Sn micro-particles
Conclusion• Sn 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.]
Su
pp
ressio
n f
acto
r [a
.u.]
micro-particles target
limited
by accuracy
of meas.10 µµµµm
10 µµµµm
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
den
sity
- b
are
level
num
ber
den
si
.
Without mitigation
With mitigation
Part
icle
co
un
t d
en
sit
y,
AU
0 5 10 15 20 25 30 35 40 45Size, µµµµm
No mitigationWith mitigation
~ 2005
Slide 32 | Public
Ionic debris characterization
Source
PumpPump
multi
channel
plate
z= 1z=2z=3
z=4
z=5
z=10
z=9
z=8
E/Z=290 eV
Ionic Energy Analyzer
Ions form z=1 to z=10 are present
in the ionic debris
~ 2005
Slide 33 | Public
No mitigation applied
Z=1, Sn
2
3
Mitigation applied
Current
Voltage
Ion spectra
4
8
Z=1, W
Z=2, W
Ionic debris mitigation
Ionic debris can be successfully stopped by applied mitigation
Ion spectra
As measured with witness samples no fast ion induced damage has occurred with an equivalent 107-108 pulses of lifetime (determined by the detection limit)
~ 2005
Slide 34 | Public
Sn deposition and cleaning
Cleaning of a Sn-deposited mirror*
0%
20%
40%
60%
80%
100%
0 10 20 30
Grazing angle, deg
Re
fle
cti
vit
y, %
Before handling
After cleaning
Before cleaning
If Sn deposition would limit the collector lifetime it is proven to be cleanable
~ 2005
Slide 35 | Public
Collector lifetime must be ensured also at higher power levels
Lifetime demonstration of 1000x is needed
Maintaining debris suppression with power scaling of up to 100x is necessary
~ 2008
Slide 36 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 37 | Public
Historical perspective: Production power requirement,achieved power, productivity
0.01
0.1
1
10
100
1000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Year
Po
wer
@ I
F,
W
Power desired, W IF
Power achieved, W IF
Age of Xe Age of SnAge of choice
ADT
Averaged and independent on supplier
Age of industrialization
NXE-3100
Produc
tivity
Gap in productivity is being bridged, in reliable power is still 10x to go.
Pro
du
ctiv
ity, w
ph
Slide 38 | Public
Source roadmap activities driven by 3 itemspower scaling, debris and stability
power scaling
2-3x more power needed for volume production (250W)
duty
cyc
le
Lifetime/debris
Degradation and thermal load
of parts close to plasma
test time Stability
tin management
start up issues of new H/W
stable co
nfig
uratio
ns
Slide 39 | Public
4 Cymer LPP sources integrated to NXE:310011W expose power being implemented at scanner
Demonstration
80W expose power at 3% duty cycle
99%
Fie
lds
Slide 40 | Public
30min
+/- 0.2% dose control
0 20 40 60 800
400
800
1200
1600
po
we
r a
t p
lasm
a [
W/2
pi]
input power [kW]
0.2 sec on0.8 sec off
1st Ushio source integrated and exposing wafers9 shell collector, 7W integrated, 12W (61W, 20%) demonstrated
61W expose powerat 20% duty cycle
Slide 41 | Public
GPI demonstration source assembly completed20 W expose power at 5% duty cycle and 3.6 kW CO2
Source vessel Drive Laser
0
5
10
15
20
25
30
0 1 2 3 4 5 6 7 8time [hr]
EU
V p
ow
er
@ I
F c
lean
[W
]
Slide 42 | Public
Source industrialization is progressing3 suppliers committed for volume manufacturing with NXE:3300B
0.1
1
10
100
1000
Q1/2009 Q1/2010 Q1/2011 end/2012
timeline
250W
125wph
15mJ/cm2
~10W
5wph
10mJ/cm2
~1W
0.5wph
10mJ/cm2
end/2011
~105W
60wph
10mJ/cm2
So
urc
e p
ow
er
[W]
op
era
tio
nal
so
urc
es
for
NX
E:3
x00
0
5
10
Slide 43 | Public
Content
• EUV lithography: History and status
• EUV sources- historical perspective:
• Age of choice
• Age of Xe
• Age of Sn
• Age of industrialization
• … and beyond
• Conclusions
Slide 44 | Public
EUV and BEUV product roadmap spans >10 years
Under study
6/8M6/8M6M6M6M6MLens mirrors
>350035003300C3300B3100ADTProduct
New λ13.5 nm13.5 nm13.5 nm13.5 nm13.5 nmWavelength
flex OAI
2018
3502501053Source (W)
1515105Dose (mJ/cm2)
150 wph125 wph60 wph4 wphThroughput (wph)
3.0 nm3.5 nm4.5 nm7.0 nmOverlay (SMO)
flex OAIOAI0.2-0.90.80.5Sigma
11 nm18 nm22 nm27 nm32 nmResolution (hp)
20162013201220102006Introduction year
>0.40 NA0.32 NA0.25 NA
Possible new wavelength = 6.x nm
Slide 45 | Public
Source: materials and spectraSource: Churilov etc
• Gd and Tb are the main potential materials of choice for 6.x lithography• Simultaneous optimization of ML band and emission spectral power is required
Optical throughput optimized for the coating (10 mirrors)Optical throughput optimized for the maximum emission spectrum
Slide 46 | Public
0
0.4
0.8
1.2
1.6
2
Dec-08 Feb-09 Mar-09 May-09 Jul-09 Aug-09 Oct-09
CE
in
2ππ ππ
in
ba
nd
, %
Investigating Conversion efficiency (CE) for 6.77 nmwith LPP
CE is defined as usual in 2ππππ in bandwidthBut bandwidth is not 2% as for 13.5 nm but 0.6%
Power density scaling
(Nd-Yag)
Target optimization(CO2)
In-band CE for 6.x nm (1.8% vs theoretical 3-5%) is
already comparable with that of 13.5 nm Sn
Gd
Slide 47 | Public
Summary: First 4 NXE:3100 systems shipped1st system operational in the field
• Full wafer imaging of 27nm L/S demonstrated
• Resolution down to 18nm demonstrated
• 7nm Matched Machine Overlay demonstrated
• Platform roadmap in place for cost effective EUV production
• Significant source power scaling > 100x is achieved In last 10 years
• Source showed a significant progress in reliability (10x)
• Source suppliers are committed to support volume manufacturing needs
Slide 48 | Public
Acknowledgements
The work presented today, is the result of hard
work and dedication of teams at ASML and many technology partners worldwide
including our customers
ASML is grateful for the support of the EAGLE and EXEPT projects, as well as the MEDEA+ and CATRENE organizations of
the European Union
Recommended