EUV
Photodiodes
DepositedUranium
UraniumFilter
Filter
EUV
Photodiodes with
with Directly Deposited
Raj Korde*
International Radiation Detectrors, Inc.
2527 W. 237th St. Unit A
Torrance, CA 90505-5243
rajkorde@ird-inc.com
Phone:310-534-3661
Fax:310-534-3665
John F. Seely
Naval Research Laboratory
4555 Overlook Avenue S.W.
Washington DC 20375-5352 USA
John.seely@nrl.navy.mil
Phone:202-767-3529
Fax: 202-404-7997
Eric M. Gullikson
Lawrence Berkeley Laboratory
1 Cyclotron Road
Berkeley, CA 94720
EMGullikson@lbl.gov
Phone: 510-486-6646
Fax: 510-486-4550
Benjawan Kjornrattanawanich
Brookhaven National Laboratory
Upton, NY 11973
benjawan@bnl.gov
Phone:631-344-5683
David D. Allred
Department of Physics and Astronomy
Brigham Young University
Provo, UT 84602
dda@byu.edu
Phone:801-422-3489
Fax:801-422-0553
ABSTRACT
Silicon photodiodes with directly deposited Si/Zr and Mo/Si filters are used
presently to make dose measurements in EUV steppers and sources. Owing to
the inherent optical properties of Si, Zr, and Mo, passband of these coatings is
quite wide (6 to 10 nm) and the peak transmission does not occur at the
desired 13.5 nm wavelength. According to the CXRO, LBL optical constants,
uranium will be an excellent filter material because of the narrow EUV
passband and the peak transmission around 13.5 nm. Characteristics of the
fabricated AXUV photodiodes with directly deposited U/Zr/Si filter will be
presented here. Zirconium and silicon were added to the filter to get better
visible light blocking and surface passivation respectively. The fabricated
devices had a peak responsivity of .0124 C/J at 13.6 nm with 3 nm passband
and 3 orders of magnitude blocking for the visible light.
Keywords: Sensors and Diagnostics, EUV dose measurement
Fig: Structure of the AXUV/SXUV photodiode with directly
deposited filter
AXUV QE Com parison
Theoretical Ti/Zr/U/Si
10/130/200/200 nm
13
LBL Ti/Zr/U/Si
12
BNL Ti/Zr/U/Si
11
10
AXUV100 S/iZr
9
QE (Eph)
8
AXUV100 Mo/Si
7
6
5
4
3
2
1
0
-1 12
12.5
13
13.5
14
14.5
15
Wavelength (nm )
15.5
16
16.5
17
LBL Ti/Zr/U/Si
1.25
1.00
QE (Eph)
0.75
0.50
0.25
0
12
14
16
Wavelenght (nm)
18
BNL Ti/Zr/U/Si
1.00
QE (Eph)
0.75
0.50
0.25
0
12
14
16
Wavelength(nm)
18
200nmSi/130nmZr
200nmUO3/10nmTi
measured
Fig: The Simulated transmittance with 200nm UO3 instead of
200nm U matches with the measured values!