XUV and EUV Applications with EUV
Sources for Metrology
Rainer Lebert, Thomas Mißalla,
Azadeh Farahzadi, Christoph Phiesel, Urs Wiesemann, Wolfgang Diete
Bruker Advanced Supercon GmbH, Waltherstrasse 49-51,
51069 Köln-Dellbrück, Germany
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
History on EUV Sources: DPP & LPP !
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Studies on EUV metrology source stability, cleanliness,
integration: Paths to increased brightness sources
LPP source gold emission spectrum as supplied
from our partner LzH for
spectrophotometer
EUV-Lamp Platform prototype for up to 40 W EUV inband source from FhG-ILT
0
500
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1500
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2500
3000
3500
4000
4500
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9 10 11 12 13 14 15 16 17 18
Sig
na
l, a
rb.
Un
its
Wavelength, nm
Center
12 Uhr
3 Uhr
6 Uhr
9 Uhr
Isotropy of emission spectrum of Xenon
from EUV-Lamp under different angles
Targetchamber
Source Imaging Optics
Infinity Laser
CCD-Camera
Discharge Produced :
Laser Produced : EUV-Lamp < 1 W EUV ib EUV-Source > 10 W EUV ib
LPP < 10 mW EUV i.b. for spectr. PoC Set UP HB-LPP
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
DPP Source Systems
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
High Voltage
Power supply
Vacuum Chamber Beamline
Capacitor bank
Application
Hollow Cathode
EUV-Lamp Principle
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
EUV Discharge Lamp Operation Manual controlled cw 250 Hz Operation
0
5
10
15
20
0 5 10 15 20 25 30 35 40 45 50
Time, ms
Vo
lta
ge
, a
.u.
-20
-15
-10
-5
0
5
10
15
20
EU
V-I
nb
an
d S
ign
al,
a.u
.
Voltage at Source
EUV-Signal
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Spatial distribution (spectral resolved)
1mm
13,5 nm 10 nm
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
EUV Lamps emit mainly EUV ! But little inband EUV
Quantified distribution of emission over spectral channels as measured at EUV-Lamp.
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Pulse Statistics DPP
0
200
400
600
800
1000
1200
1400
0.035 0.04 0.045 0.05 0.055 0.06
Abu
ndan
ce N
-Tim
es p
er In
terv
al
Oscilloscope Signal, Volt
Seq. 1
Seq. 2
Seq. 3 @ 10 kV
FIT 3
FIT 2
FIT 1
Best-Fit : STDEV =4.3 %, 4.2% und 3.6 %
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
EUV-inband Open Frame Resist Exposer TEUVL
EUV-lamp inside
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
EUV, XUV & VUV Spectroscopy
EUV-
Spectro-
photometer
GI R&D EUV Reflectometer NI R&D EUV Reflectometer
EUV-
MBR
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Polychromatic
EUV-Reflectometer
2000 channels of 1.6 pm
Spot size:
< 0.1*0.5 mm²
Spot Exposure
< 20 second
Throughput
> 90 spots / hour
Precise Multilayer Metrology:
EUV-Reflectometer Mask Blank Reflectometer : MBR
14
Spectral resolution 1.6 pm
WL calibration ± < 2 pm
WL reproducibility ± < 1 pm
Spot Size < 50 µm × 1mm
Spectral range 12 to 15 nm
Spectral channel width 1.6 pm
Exposure time per spot 20 s
Evaluation time per spot 10 s
Angle of incidence 6° (5°-
10°)
Angle of incidence precision < 100 µrad
Dynamics > 15 bit
Min. reflectance capability < 0.01 %
EUV-Lamp
Service Port
EUV-
Lamp
CCD
PSD
Laser
EUV-Lamp: e.g. > 300 Mpulses
> 100 k spots (> 30M 10 pm Channels)
> 10.000 blanks with 9 spots
Load-Port
EUV-MBR: in tool reference parallel to sample
Ref 1 Ref 2 blind Ref 1 Ref 2 sample
250 µm*100 µm²
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
0
20
40
60
80
100
120
140
0 50 100 150
Reflektometrie Stand:
Vergleich Maskenblank vor und nach Reinigung
Vergleich der
Mittelwerte über
alle Messpunkte.
Beobachtet wurde
eine leichte
Erhöhung der
Spitzenreflektivität
um ca. 2 %, eine
leichte
Verschiebung der
CWL_50 um 5 pm
zur kurzwelligen
Seite und eine
Erhöhung der
FWHM um 0.1 pm
im Mittel.
0%
10%
20%
30%
40%
50%
60%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
10 10
15 15
20 20
25 25
30 30
35 35
40 40
45 45
50 50
55 55
60 60
65 65
70 70
73 73
74 74
75 75
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
77 77
77 77
78 78
79 79
80 80
85 85
90 90
95 95
100 100
105 105
0%
10%
20%
30%
40%
50%
60%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
10 10
15 15
20 20
25 25
30 30
35 35
40 40
45 45
50 50
55 55
60 60
65 65
70 70
73 73
74 74
75 75
76 76
76 76
76 76
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76 76
76 76
76 76
76 76
76 76
76 76
77 77
77 77
78 78
79 79
80 80
85 85
90 90
95 95
100 100
105 105-2.0%
-1.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
12 12.5 13 13.5 14 14.5 15
I
II
Delta
0%
10%
20%
30%
40%
50%
60%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
10 10
15 15
20 20
25 25
30 30
35 35
40 40
45 45
50 50
55 55
60 60
65 65
70 70
73 73
74 74
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76 76
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76 76
76 76
76 76
76 76
76 76
76 76
77 77
77 77
78 78
79 79
80 80
85 85
90 90
95 95
100 100
105 105
0%
10%
20%
30%
40%
50%
60%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
10 10
15 15
20 20
25 25
30 30
35 35
40 40
45 45
50 50
55 55
60 60
65 65
70 70
73 73
74 74
75 75
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
76 76
77 77
77 77
78 78
79 79
80 80
85 85
90 90
95 95
100 100
105 105
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
13.500
13.505
13.510
13.515
13.520
13.525
13.530
13.535
0 20 40 60 80 100 120 140
x,y, mm
CW
L_
50
, n
m
0.503
0.504
0.505
0.506
0.507
0.508
0.509
0.510
0.511
0.512
0.513
0.514
FW
HM
, n
m
CWL_50
FWHM
32 pm10 pm
MBR Sensitivity: Diagonal Scan over Mask Blank
(0.01 nm !)
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Stepping Measurement over Structured Mask Moving Measurement over structured mask
0%
10%
20%
30%
40%
50%
60%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
Wavelength, nm
Re
fle
cta
nc
eX014_000Y006_000
X014_000Y007_000
X014_000Y008_000
X014_000Y009_000
X014_000Y009_500
X014_000Y010_000
X014_000Y010_500
X014_000Y011_000
X014_000Y012_000
X014_500Y007_500
X014_500Y008_500
X014_500Y009_500
X014_500Y010_500
X014_500Y011_500
X014_500Y012_500
X014_500Y013_500
X014_500Y014_000
X014_500Y014_500
X014_500Y015_500
X015_000Y006_000
X015_000Y007_000
X015_000Y008_000
X015_000Y009_000
X015_000Y010_000
X015_000Y011_000
X015_000Y012_000
X015_000Y013_000
X015_000Y014_000
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Limit of Measurement: Reflection from Substrate
Dynamics of Measurement > 1 / 100,000 (> 16 bit)
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Improvements and extensions on actinic spectral metrology :
Concept for flexible spectral characterization of samples
Detector Sample stage
Collector
Main in-vacuum optical units of CXUVS collector
module, sample stage unit and detector unit.
Can Measure:
•Window / Foil transmission,
•Grazing Incidence down to < 1°
•Normal Incidence up to 85°
•Gas transmission
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Low Power Gold LPP Source (< 5 mW EUV inband) used
LPP < 5 mW EUV i.b. for spectr.
0
20
40
60
80
100
120
10 11 12 13 14 15 16 17 18 19 20
Inte
gral
ove
r C
CD
, ar
b.
Un
its
Wavelength, nm
58 Spectra within 21 minutes !TRANS_11_24_31
TRANS_11_24_43
TRANS_11_24_48
TRANS_11_25_02
TRANS_11_25_07
TRANS_11_25_25
TRANS_11_25_29
TRANS_11_25_34
TRANS_11_25_38
TRANS_11_25_43
TRANS_11_25_50
TRANS_11_25_55
TRANS_11_26_01
TRANS_11_26_06
TRANS_11_26_11
TRANS_11_26_16
TRANS_11_26_20
TRANS_11_26_36
TRANS_11_26_42
TRANS_11_27_04
TRANS_11_27_38
TRANS_11_27_57
TRANS_11_28_16
TRANS_11_28_21
TRANS_11_28_26
TRANS_11_28_31
TRANS_11_28_36
TRANS_11_28_40
TRANS_11_28_46
TRANS_11_28_50
TRANS_11_28_55
TRANS_11_29_01
TRANS_11_29_08
TRANS_11_29_13
TRANS_11_29_19
TRANS_11_29_43
TRANS_11_29_58
TRANS_11_30_09
TRANS_11_30_13
TRANS_11_30_18
TRANS_11_30_23
TRANS_11_30_27
TRANS_11_30_34
TRANS_11_30_52
after 7 minutes
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
GOLD LPP Spectral Fluctuations
0
20
40
60
80
100
120
10 11 12 13 14 15 16 17 18 19 20
Inte
gral
ove
r C
CD
, ar
b.
Un
its
Wavelength, nm
58 Spectra within 21 minutes !TRANS_11_24_31
TRANS_11_24_43
TRANS_11_24_48
TRANS_11_25_02
TRANS_11_25_07
TRANS_11_25_25
TRANS_11_25_29
TRANS_11_25_34
TRANS_11_25_38
TRANS_11_25_43
TRANS_11_25_50
TRANS_11_25_55
TRANS_11_26_01
TRANS_11_26_06
TRANS_11_26_11
TRANS_11_26_16
TRANS_11_26_20
TRANS_11_26_36
TRANS_11_26_42
TRANS_11_27_04
TRANS_11_27_38
TRANS_11_27_57
TRANS_11_28_16
TRANS_11_28_21
TRANS_11_28_26
TRANS_11_28_31
TRANS_11_28_36
TRANS_11_28_40
TRANS_11_28_46
TRANS_11_28_50
TRANS_11_28_55
TRANS_11_29_01
TRANS_11_29_08
TRANS_11_29_13
TRANS_11_29_19
TRANS_11_29_43
TRANS_11_29_58
TRANS_11_30_09
TRANS_11_30_13
TRANS_11_30_18
TRANS_11_30_23
TRANS_11_30_27
TRANS_11_30_34
TRANS_11_30_52
after 7 minutes
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
CEUVS example: 1 min exposed 50 µm diameter spot
Compared to PTB: MADT < 1 % absolute
ML Reflection and transmission of Si-nitride windows, compared with the measurement on
the same samples at PTB
The near normal reflection measurement for multilayer
samples, compared with the measurement on the same
sample at PTB
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
X-ray Microscopes
(“Water window” 2.4 < l < 4.4 nm)
• German Research Network (Coordinator: Bruker ASC)
• High brightness LPP and DPP sources
• Grazing incidence, multilayer, and diffractive (zone plate) optics
• Resolution ~30nm, ~20µm field
• Tomography, Cryo
Experience with the demands of Mask Metrology
(Source & Optics Integration and Alignment; Nanometer Sample Positioning,
UHV, Mechanical Stability; Vibration controlled architecture, Detectors etc.)
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Results from X-Ray Microscopy
M. Benk, K. Bergmann, D. Schäfer (2008)
Rayleigh resolution <40nm
1000 x magnified diatoms and 80 nm latex spheres
1000 x magnified diatoms
40 nm Rayleigh Resolution
demonstrated
Single Line (< 0.5 % bandwidth)
brightness of
7 W/mm²/sr with DPP
and
> 60 W/mm²/sr with LPP
achieved
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Imaging: EUV Transmission Microscopy Since 2005
CCD
Sample
Chamber
Beamline
EUV-Lamp
Collector
Objective
Designed for NA = 0,2 ;
i.e. < 100 nm resolution
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Dark Field Transmission EUV-Microscopy since 2007
Small structures below 250 nm exhibit significantly higher contrast in EUV dark field images
compared to 1 mm and 500 nm structures
Bright field Dark field E-Mik
SimulationCCD-Image SimulationCCD-Image
0th order 1st order
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Modification: Reflective Mode for Mask Blanks
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
First Results on “programmed” defects on ML
Structured pits on a multilayer mirror:
Stefan Herbert
26th European Mask and Lithography
Conference
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Actinic Defect Inspection fundamentals:
Result PoP Experiment
Fig. 2 : Profile of a dark field EUV image of ML mirror sample
(left) and the corresponding AFM scan (right). The equivalent
sphere diameter is 45 nm, the height is 7 nm.
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Actinic Defect Inspection fundamentals:
R&D Grade ABIT in Operation
Photo of the R&D ABIT as in operation
EUV source
Collector CCD camera
Schwarzschild
objective
Mask holder
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Instrument for the Measuring of EUV
Reflectance and Scattering - MERLIN
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Proof of concept for
Wide Angle XUV GI Scatterometry
Straight forward compact Proof of feasibility experiment set-up with available lab
components at BASC.
< 1mm² spot
>5° AOI
< 10 s per image
No beamstop
Wavelength and spectral
distribution flexibility of
EUV-Lamp with different
working gases
Achieved:
Accuracy of CD < ± 2 nm
Reproduc. < 0.06 nm rms
< 0.2 nm PV
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
CD-WA-XUV-Scatterometry: First results
Simulation of expected result is in agreement
Typical Result obtained with PoP set-up
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
PoC EUV Source with minimum pulse energy; flexible Laser
0.0E+00
2.0E+08
4.0E+08
6.0E+08
8.0E+08
1.0E+09
1.2E+09
1.4E+09
1.6E+09
1.8E+09
2.0E+09
7.0 9.0 11.0 13.0 15.0 17.0
Wavelength, nm
Yie
ld,
ph
oto
ns
/(p
uls
e*s
r)
150 ps 1.85%
900 ps 1.25%
2 ns 1.14%
Si-Edge
Liquid Tin Target (80:20 Sn:Pb)
+
R&D all solid state laser with
variable pulse length (25 W; 10 kHz; 2.5 mJ)
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Outlook: HB source Investigation:
Potential for > 300 W/mm²/sterad
9 times magnified inband EUV-Image of source and horizontal profile on
CCD with 20 µm pixel. Schema of set-up and in RAC-Lab as insert.
Multilayer Mirror
Spherical Multilayer
Mirror
Plasma
Image of Plasma Source
Targetchamber
Source Imaging Optics
Infinity Laser
CCD-Camera
Discussion of configurations matched to customer’s demands for actinic mask metrology
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
Summary : EUV Solutions with lab sources
Mask Tools
0%
10%
20%
30%
40%
50%
60%
70%
12.5 12.7 12.9 13.1 13.3 13.5 13.7 13.9 14.1 14.3 14.5
Wavelength, nm
Refl
ecta
nce
1
2
3
4
5
6
7
8
9
10
Nano Tools Resist Tools
GIXUVR on 5 nm layers 5 deg
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
6 7 8 9 10 11 12 13 14
Wavelength, nm
Re
fle
cta
nce LaLu 5 deg
LaSc 5 deg
GdSc 5 deg
DySc 5 deg
Si L-edge
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
10 11 12 13 14 15 16 17 18
Wavelength [nm]
Refl
ecti
vit
y
( ) Filter
Xenon
TT
Tl
Si with SiO2-Layer, Reflection Angle 4,5°
Experiment Fit
EUV-Sources
2012 International Workshop on EUV and Soft X-Ray Sources, Dublin, Ireland, October 8-11, 2012
www.bruker-asc.com
A Former ACCEL Instruments & AIXUV Business
ASCASC
Thank you for your attention
We gratefully acknowledge funding from the BMBF
In the framework of the Catrene (13N10572, CT301, EXEPT”)