International Journal of Engineering Trends and Technology- Volume3Issue4- 2012
A Emerging Technical Development in Next-Generation Low
Cost Mass Fabrication for Nanolithography
Sarita Singh1, Isha Arora2, Neha Jain3,
ECE Department, R. D. Engineering College, Ghaziabad, UP, India
Abstract - Emerging Trends provides an insight into the
developments
in
next-generation
low
cost
nanolithography techniques . The study focuses mainly
on the semiconductor market, which has the highest
requirement for resolution and cost. This research paper
covers key developments taking place in nanolithography
required for fabricating future nanoscale semiconductor
devices. In particular, potential technologies for
fabricating smaller transistors is looked into, with leading
extreme ultraviolet (EUV) Lithography, electron beam
(E-Beam) direct writing, nanoimprinting and EOL
Technique. An analytical overlook on research pipelines
and market requirements is done to highlight the possible
scenario in the coming years. The paper is written in a
manner easily understood and allows the reader to assess
different technologies from a top level view, while
simultaneously providing comprehensive degree of
information.
Illuminating the photoresist drives a chemical cross
linking reaction and, depending on the type of
photoresist, is washed away in a developer step,
leaving a negative or positive image of the original
master pattern. Advances in nanolithography
techniques have been a fundamental driver to
supplying high-technology markets such as laptop
computers and smart cell phones with customized,
rapidly mass-produced semiconductor microchips,
each with millions of finely patterned integrated
circuits (ICs) onboard. However, as ICs’ feature
sizes shrank to the nanometer scale, new techniques
had to be developed to overcome the diffraction
limit of visible light sources.
Keywords
Electronics
and
Optoelectronics
Laboratories(EOL), Optical Pickup Heads, Phase
Transition Mastering (PTM) Technology, Blu-ray Disc
read only memory (BD-ROM)
The
Research
centre
Electronics
and
Optoelectronics Laboratories (EOL) in Hsinchu,
Taiwan. The EOL already had considerable
experience in developing organic and inorganic
dyes and optical pickup heads (OPHs) for DVDbased consumer electronics. These unique dyes led
to the development of innovative dry, in organic
photoresists that would allow these researchers to
exceed the diffraction limit of their light source.
I. INTRODUCTION
The Countless innovations and progress in this
field will continue to drive technological
development in the semiconductor industry
Semiconductor chip manufacturers use many
different types of equipment in the making of
integrated circuits. There are 300 to 500 process
steps, utilizing over 50 different types of process
tools, required in the making of a single device like
a
microprocessor.
Semiconductor
chip
manufacturers seek efficiency improvements
through
increased
throughput,
equipment
utilization and higher manufacturing yields.Their
should be develop a nanolithography- based
mastering process that can be transferred to
commercial mass production. By the way, it must
be low cost so we shall use a visible light instead of
an electron beam (e-beam) or extreme ultraviolet
(EUV) as an exposure light source, and hence we
might need to circumvent some laws of physics
along the way.’’
Lithography was originally a printing method to
transfer a master pattern to another surface. The
master pattern, usually a metal or dielectric mask,
is transferred to a substrate by using a photoresist.
ISSN: 2231-5381
II. T ECHNOLOGY ADVANCEMENT
Recalling from freshman physics, the Rayleigh
criterion sets the resolution limit between two point
sources and is proportional to the wavelength of the
illumination source. In practice, it is difficult to
resolve objects less than half the size of the
illumination wavelength using far-field optical
techniques. Thus, using a 405-nm blue-laser diode,
one would expect to only be able to create
structures greater than 200 nm in diameter. Today,
most nanopatterning is done using e-beam
lithography, which can produce line widths on the
order of 10 nm or smaller. However, e-beam
lithography requires very expensive, bulky
equipment, and the writing process can take up to
12 h per wafer-sized master, which makes it
unsuitable for mass production. Other alternatives
such as deep UV-based and EUV systems are also
restricted by optical diffraction limits and slow
throughput on the scale of 20–30 wafers per hour.
This low-cost nanolithography technique was
enabled by two technical achievements, namely,
first, developing dry photoresist. Second,
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International Journal of Engineering Trends and Technology- Volume3Issue4- 2012
nanopositioning systems that could be integrated
with the OPHs to realize a compact, nanopatterning
exposure system.
OPH like, blue-laser module is used to traverse the
surface and exposes the photoresist via a directwrite action.
The OPH-like, direct-write module contains a 405nm laser and an objective lens with a numerical
aperture of 0.85. The module is able to traverse
over an x–y range of _300 lm with a dynamic tilt of
less than 1 arc-min, resulting in a positioning
accuracy of _30 nm [1]. There is also an electrooptical focusing error- signal feedback mechanism
to the servo controller for additional positioning
stability. The laser optics of the module generates a
260-nm diameter exposure beam.
Figure 1Far-field optics using a 405-nm blue laser to generate
(a) a BD-ROM master disk with (b) 180
The result is a miniaturized, OPH-like, precision
exposure system based on a blue laser (405-nm
wave- length) that is capable of patterning a
proprietary dry photoresist with features less than
180 nm in width. Almost all previous low-cost but
accurate positioning systems were only capable of
r–θ translation.
The EOL technique is based on the phase
transition mastering (PTM) technology in replacing
the traditional laser beam recorder in the mastering
process for BD-ROM disks. Using inorganic
photoresists and by controlling laser parameters
such as the pulse frequency, duty cycles, and peak
power, patterned spot sizes and line widths less
than 100 nm have been demonstrated using much
larger industrial systems. Furthermore, PTM
technology has three major advantages: 1) it can be
implemented in air, 2) any arbitrary pattern can be
created using third-party pattern generation
software, and 3) it is the lowest cost solution for
patterning nanometer scale features.
Figure 3 The EOL nanolithography and nanostructuredpatterning fabrication process to make a master BD-ROM stamp
Exposure of the dry photoresist is via a thermal
mechanism at powers greater than 0.3 mW, which
allows for the patterning of 180-nm pillars in the
resulting nickel master stamper. Furthermore, the
electroforming process has an ultralow (less than 2
nm) surface roughness. This system is currently
being tested with a dual-wavelength OPH-like
module so that it can be used to expose both
organic and inorganic photoresists [2] (Figure 4).
Figure 2 Low-cost nanolithography is realized by using far-field
optical techniques to generate a precise, narrower thermal
profile to locally expose the special dry photoresist. This yields
results comparable to near-field mastering techniques where the
spot size can be less than half the illumination wavelength
By RF sputtering a 70-nm thick layer of inorganic
photoresist onto a silicon or glass substrate. The
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International Journal of Engineering Trends and Technology- Volume3Issue4- 2012
Figure 4 Hand-sized prototype OPH-like module with integrated
precision positioners and 405-nm blue laser used to expose the
inorganic photoresist
III. MARKET TRENDS
A low-cost nanolithography platform is a ‘‘game
changer that is
currently actively being
investigated. They include improving the
efficiencies of solar cells, light-emitting diodes
(LEDs), and touch panels for portable consumer
electronics’’ in that it extends these devices along
their respective technology development roadmaps,
at times exceeding their projected target
performance parameters and efficiencies a few
years ahead of schedule. This nanolithography
platform was also envisioned as a basis for a new
profitable industry to supply nano patterned
surfaces to these growth industries. The optical
reflectance of a silicon solar cell can be greatly
reduced by using a specially designed nano
patterned surface structure. effectively act as
nanolenses to enhance light transmission toward
the
semiconductor
p–n
junction
while
simultaneously reducing losses due to reflected
light at angles away from the surface. These are
significant improvements considering that the
highest reported efficiencies of crystal siliconbased solar cells. With the switch to LED-based
backlights for computer monitors and flat panel
televisions, Nanopatterned, sapphire-substrate
surfaces of LEDs have been demonstrated to
decrease the dislocation intensity of the epitaxial
layer and to affect the critical angle for light
emission, which improve both the internal and
external efficiencies of an LED. Driven by glossy
smart phone and tablet designs from companies
such as Apple, HTC, and Samsung, antireflective
and antismudge transparent protective coatings are
another area of application for nanopatterned
surfaces.This technology platform that improves
the power consumption efficiency of LEDs, while
increasing overall brightness is a must- have
solution for companies to remain competitive
internationally.
with industry players heading towards EUV. This
will however be dependent also on tooling cost for
EUV. The industry is still not prepared for mass
volume production; scanners are targeted to be
ready around 2020.
REFERNCES
[1]
[2]
[3]
[4]
[5]
[6]
C.-T. Yang, C.-Y. Chen, C.-C. Huang, Y.-C. Lee, S.-C.
Chen, and C.-T. Cheng, ‘‘Single wavelength blue-laser
optical head-like optomechanical system for turnable
thermal mode lithography and stamper fabrication,’’
IEEE Trans. Magn., vol. 47, no. 3, pp. 701–705, Mar.
2011.
Y.-C. Lee, S. Chao, C.-C. Huang, and C.-T. Yang,
‘‘Design of a dual-wavelength optical
head for
submicron-scale nano-scale lithography,’’ IEEE Trans.
Magn., vol. 47, no. 3, pp. 696–700, Mar. 2011.
Kee-Bong Choi ; Gee-Hong Kim ; Seung Woo Lee ;
Hyun Taek Cho “The UV-Nanoimprint Lithography with
Multi-head Nanoimprinting Unit for Sub-50nm Half-pitch
in SICE-ICASE, 2006. International Joint Conference 1821 Oct. 2006.
Chang, T.M. ; Chiu, K.P. ; Tsai, D.P None-touched
Near-field Optical Nanolithography in Numerical
Simulation of Semiconductor Optoelectronic Devices,
2006. NUSOD '06. International Conference.
Broers,
A. N. ; Koch, R. H. ; Willson, C.
G. ; Laibowitz, R. B. “Nanolithography with a highresolution STEM”IBM Research Division, T. J. Watson
Research Center, P.O. Box 218, Yorktown Heights, New
York 10598, USA”.
Pease, R. F. W. “Nanolithography and its prospects as a
manufacturing technology” Journal of Vacuum Science &
Technology B: Microelectronics and Nanometer
Structures in Jan 1992.
IV. CONCLUSION
The study will benefit existing manufacturers for
low cost nanolithography fabrication equipment
that seek to expand revenues and market
opportunities by expanding and diversifying the use
of their equipment in manufacturing most powerful
microprocessors and memory chips for computers,
electronic devices and other applications and the
challenge to fabricate fault-free masks. The
industry is considered critical to continued
economic development in the U.S. as well as Japan,
China, Korea and the member states of the
European Union. Alternatives for future nanolithography tools such as e-beam (electron-beam)
and nanoimprinting faces a big challenge ahead
ISSN: 2231-5381
http://www.internationaljournalssrg.org
Page 494