ISTC project # 3857
description
Transcript of ISTC project # 3857
The two pulses two wavelength driver of EUV radiation LPP source and of 4M Bragg mirror
objective for laboratory EUV Lithography tool:Development of the ISTC project #3857
R.Seisyan, A.Zhevlakov, M.Sasin
A.F.Ioffe Physical Technical Institute of Russian Academy of Sciences, St.-Petersburg, Russia
e-mail: [email protected]
ISTC project # 3857
“Key Technologies of EUV-nanolithography System of Super high Resolution on the Base of High Effective LPP Source”
February 2009 – February 2012
Project Budget – 317,501 € = $492,700
executors:Ioffe Institute
and
Institute for Laser Physics,
both Saint-Petersburg, Russia
Collaborators of the Project
1. Gerry O’Sullivan,
2. John Costello,
3. Torsten Feigl,
4. Peter Choi,
5. Ladislav Pina,
all COST MP0601 participants
ISTC project #3857,the first year Work Plan
1. Calculation and design of dual-wavelength (λ = 1.06 μm and λ = 10.6 μm) laser- optical scheme forming focal spot on the target at double-pulse illumination.
2. Calculation and design of 4-mirror wide-aperture imaging objective with enlarged image area.
3. Precise mechanical and optical systems development providing for nanometric scale precision for adjustment and focusing of nanolithographer optical system.
4. Placing of the optical and mechanical systems in existing body of NL tool, designed and partly manufactured in the frame of ISTC project #0991.
Experimental
nanolithographer
of Ioffe Institute
in the making
(2006)
View of the experimental hall with the dustless room (center and right) and prototype excimer laser (on the left) used in
the Experimental Stand work
The main ideas of the industrial EUV LPP source
• The main ideas used in the SYMER source (as well as in GIGAPHOTON source) are the following.
• Target material should be Sn (liquid Sn droplets)• The main primary laser should be pulsed
powerful (about 15-20kW) CO2 laser• The main ways to solve debris mitigation
problem are the use of magnetic field and • The use of inert gas curtain
Advanced LPP source for NL tool
Cross-section of string source
Collector
mirrorMagnets
String
target unit
The “String” EUV Source cross-section
To an object
ive, sampl
es, etc..
String
Capillary
String covered with tinGas pulse for debris mitigation
Ionised Tin, “cold” plasma
UV laser pulse
10μ laser pulse: heating
Hot, radiating EUV plasma
“String” EUV target with different laser wavelength ignition and heating
YAG:Nd+3 , 1064 nm
1.5 J, 8 ns, 10 Hz
Optical delay line, 1-200 ns
2-nd harmonic generator
Optical parametrical oscillator
H2 cell
CO2 laserObjective
10 m
Objective1064 nm
1064 nm
532 nm
1930 nm
10 m
Former design of dual-wavelength (λ = 1.06 μm and λ = 10.6 μm) laser-optical scheme forming focal spot on the target at double-
pulse illumination.
Resulting dual-wavelength (λ = 1.06 μm and λ = 10.6 μm) laser-optical scheme forming focal spot on the target at double-pulse
illumination
Calculation of CO2 laser driver
• Possible amplification of 6 pass CO2 laser driver (1ns initial pulse)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10.01
0.1
1
10
Эффективный радиус пучка, см
Энергия, Дж
1
2
3
4
Multipass scheme of CO2 amplifier
Multipass scheme for amplifier based on CO2 laser “Fialka”
1
2
L
Rm
Experimental Lithographer (EN) made in Ioffe Institute
EN optical scheme
LensCollector
Plasm
First Mirror
CorrectionMirror
Mask
Second Objective Mirror
First Objective Mirror
Sample
Screen
EUV Spectrograph
EUV Detector & Filter
12
33
.66
mm
99
.9
12
56
.2 m
m
Coupling system
Bragg mirror imaging systems with high resolution
NA=0,06 – 0,09
NA=0,1 – 0,14
NA=0,36
NA=0,485
Image modeling
L&S 30 nm, contrast 60%L&S 45 nm, contrast 97%
L&S 15 nm, contrast 58%
Four mirror objective
Results of mathematical modeling of
microstructures.
The image of corners with
width of a line 10 nm in the
centre of a field
The specification of the objective
The numerical aperture 0.485
The resolution 10 nm with contrast 0.26
20 nm with contrast 0.35
The sizes of the field of the image 0.27x0.27 mm2 → 2.0x2.0mm2
The central shielding 0.407
The distance from a mask up to a plane of the image 829 mm
Root mean square wave aberration on the field of the image
0.0573 - 0.1181
The limiting resolution 68000 mm with contrast 0.02
The magnification of the objective 12
27
Scheme of nanolithograph
LensCollector
Plasm
First Mirror
CorrectionMirror
Mask
Second Objective Mirror
First Objective Mirror
Sample
EUV Spectrograph
EUV Detector & Filter
Coupling system
Third Objective Mirror
Fourth Objective Mirror
Grating pattern must be such that suppress the second order of diffraction.
grating 1
grating 0
O
d
a
grating 1
grating 0
O
d
Lens
0 order0 order
incoming
beam
incoming
beam
+1 order
-1 order
Base unit
Principal scheme of focusing and alignment system
1
wafer surface
(reflective)
mask surface(grating 0)
Focus system with single grating and reflecting wafer(single canal)
a 0z
a0 0
фото-детекторb
фото-детекторa
b0 0
b 0
регуляторb
источник излучения
модулятор
фото-детекторa0
фото-детектор
b0
регуляторс памятьюa- b
O
Z
x
X
Axis of the grating is perpendicular to the drawing plane
Plane of incoming beams is normal to the drawing plane
plan
e of
out
put
beam
s
plan
e of
inco
min
g
diffr
acte
d be
ams
plan
e o
f
inco
min
g be
ams
2=V1
wafer surface
(reflective)
mask surface(grating 0)
X
x
Z
O
• An original technology for photomask production is developed in the Ioffe Institute for the EN. It includes originally invented mask pattern and construction, and technologies for deposition both reflecting and absorbing structures on the mask surface. The focusing and alignment systems represent by itself multichannel interferometers using gratings and second harmonics solid state laser projection device.
Scheme of the focusing system realization
Vibroprotective table
• The EN modules are installed on massive granite plate of vibroprotective table. The table has been invented in the Baltic University (St. Petersburg) and later finished off in conformity with the EN needs. The table has high performance characteristics and provides both passive and active vibroprotection including infralow frequencies.
Piezopositioners
Phenomenological modelof the non-linear photoresist
Exposure (mJ/cm )2
0.54
0.48
0.42
120600
2=4mJ/cmH
-E 2=2mJ/cm
c2J/cm3=8.510c2J/cm4=1.710thI
/J3cm-3C=310
H
-E
Initial condition
Boundary condition
101 t
)()( 00tItI
z
1 - 2 mJ/cm2, 2 - 4 mJ/cm2
Estimated parameters of inorganic nonlinear
photoresists
Sensitivity: C = 3×10-3 cm3/J,threshold intensity: Ith = 1.7×104 W/cm2,
threshold diffusion width: δ = 8.5×103 W/cm2.Dose of H = h/C = 1.7 mJ/cm2 is sufficient for exposure of
a photoresist specimen h=50-nm thick. Pulse threshold dose (at 20 ns) is Hth = τIth = 0.34 mJ/cm2.Thus, the necessary dose is accumulated with 5 pulses at the
threshold intensity and 20 ns pulse duration.
Computer simulation of the enhancement of the contrast by means of inorganic non-linear
photoresist
The contrast enhancement U=(r1/x)/b (at r=r1s, b=1/Ip(I/x)) dependence on illumination intensity
where Ip, Tp - intensity and time of pulseIth - threshold intensity - smearing of threshold intensity
0 1 2 3 41
2
I/Ith
The best quality of image is reachedunder conditions:
0.10.9
0.10.9
0
00.1
0.9
0.9
50
50
50
50
50
0
00.9
Ip th
Ip=2 Ith
Ip=0.5 Ith
Ip=1.5IthIp=0.25Ith
100 200 3000
IP
1
0
I0
0
0
x (nm)
Ip=0.25IthIp=0.25Ith
Ip=0.5IthIp=0.5Ith
Ip=0.803IthIp=0.803Ith
Ip=1.5IthIp=1.5Ith
Ip=2Ith
Experiments on the EUV exposure have been carried out with synchrotron 13.4nm emission and, in a tentative form, on the Experimental Stand, the auxiliary setup of the Ioffe Institute, for λ = (13.4 ± 0.3) nm.
• The results obtained suggest that the EUV sensitivity should be some lower than that at λ = 193 nm.
• As2S3 films exposed on the synchrotron, after the chemical development, demonstrated distinct interferention structure with 30-40 nm stripes and space-stripe period about 50-100 nm thereby confirming good resolution ability of the material.
QDC(quantum
dot crystal)Interference
transistorSingle-electron
transistor
QD semiconduct
or laser
Мезоскопические элементы
d
GRIN waveguide
n-clad
n-GaAs substrate
p-clad
p-contact
SQW active
d
GRIN waveguide
n-clad
n-GaAs substrate
p-clad
p-contact
SQW active
DFB Laser systems Mesoscopic elements Photon
crystals