Walter Scott, Jr. College of Engineering

Graduate Exam Abstract

Wei Li
Ph.D. Final
Jan 20, 2016, 10:30 am - 1:30 pm
ERC Electronic Classroom (A210)
Coherent lithography using a table-top EUV laser
Abstract: Nanotechnology has drawn a wide
variety of attention as interesting
phenomena occurs when the
dimension of the structures is in the
nanometer scale. The particular
characteristics of nanoscale
structures had enabled new
applications in different fields in
science and technology. Our
capability to fabricate these
nanostructures routinely for sure will
impact the advancement of
nanoscience. Apart from the high
volume manufacturing in
semiconductor industry, a small-scale
but reliable nanofabrication tool can
dramatically help the research in the
field of nanotechnology. This
dissertation describes alternative
extreme ultraviolet (EUV) lithography
techniques which combine table-top
EUV laser and various cost-effective
imaging strategies. Several alternative
techniques of EUV lithography is
described in this dissertation. For
each technique, numerical
simulations, system design,
experiment result and its analysis will
be presented. In chapter II, a brief
review of the main characteristics of
table-top EUV lasers will be
addressed concentrating on its high
power and large coherence radius
that enable the lithography application
described herein. After that, the
development of a Talbot EUV
lithography system which is capable
of printing 50nm half pitch
nanopatterns will be illustrated in
chapter III. A detailed discussion of its
defect tolerance limitation, fabrication
protocol for diffractive EUV mask,
development of X-Y-Z positioning
stage and pattern transfer using self-
developed ion beam etching will be
introduced. In addition, this
dissertation discusses how to
fabricate functional periodic
nanostructures using Talbot EUV
lithography. At the end of chapter III,
experiments results for displacement
Talbot EUV lithography together with
fractional Talbot EUV lithography,
which are capable of increasing
spacial frequencies, will be
demonstrated. Chapter IV will
describe a hybrid EUV lithography
which combines the Talbot imaging
and interference rendering a high
resolution interference pattern whose
lattice is modified by a custom
designed Talbot image. In other
words, this method enables filling the
arbitrary Talbot cell with ultra-fine
interference nanofeatures. Detailed
optics modeling, system design and
experiment results using He-Ne laser
and table top EUV laser are included.
The last part of chapter IV will analyze
its exclusive advantages over pure
Talbot or interference lithography.
Adviser: Mario Marconi
Co-Adviser: Carmen Menoni
Non-ECE Member: Mingzhong Wu, Physics
Member 3: Carmen Menoni
Addional Members: Diego Krapf, ECE
“Extreme ultraviolet Talbot interference lithography”, Wei Li and Mario C. Marconi, OPTICS EXPRESS, 23(20), p25532-25538, 2015
“Defect-free periodic structures using extreme ultraviolet Talbot lithography in a table-top system”, Wei Li, Victor Martinez Esquiroz, Lukasz Urbanski, Dinesh Patel, Carmen S. Menoni, Mario C. Marconi, Aaron Stein, Weilun Chao, Erik H. Anderson, JVSTB 31(6),06F604 (2013)
“Defect tolerant EUV lithography technique”, Lukasz Urbanski, Wei Li, Jorge J. Rocca, Carmen S. Menoni, Mario C. Marconi, Artak Isoyan, and Aaron Stein, JVSTB 30(6), 06F502 (2012)
“Hour-long continuous operation of a tabletop soft x-ray laser at 50-100 Hz repetition rate”, Brendan A. Reagan, Wei Li, Lukasz Urbanski, Keith A. Wernsing, Chase Salsbury, Cory Baumgarten, Mario C. Marconi, Carmen. S. Menoni, and Jorge J. Rocca, OPTICS EXPRESS, 21(23) 2013
“Fractional Talbot lithography with extreme ultraviolet light”, Kim HS, Li W, Danylyuk S, Brocklesby WS, Marconi MC, Juschkin L, Optics Letters, Vol. 39, Issue 24, pp. 6969-6972 (2014).
“Optical properties of 2D fractional Talbot patterns under coherent EUV illumination”, H Kim, W Li, S Danylyuk, WS Brocklesby, MC Marconi, L Juschkin, Journal of Physics D: Applied Physics, 48(37), p375101 (2015)
Program of Study:
ECE 642
PH 521
PH 641
ECE 641
ECE 673
ECE 795
ECE 799