Stamp stress analysis with low temperature nanoimprint lithography
High temperature nanoimprint lithography has the drawback of long process cycle, demoulding difficulty, polymer degradation, thermal stress. Low temperature nanoimprint lithography (LTNIL) can avoid these problems. LTNIL is also ideal for manufacturing biological compatibility samples since the samp...
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| Cite this: | Stamp stress analysis with low temperature nanoimprint lithography / Hongwen Sun, Xiaochao Ma, Chenhui Hu // Functional Materials. — 2016. — Т. 23, № 3. — С. 517-520. — Бібліогр.: 11 назв. — англ. |
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Hongwen Sun Xiaochao Ma Chenhui Hu 2017-06-14T12:52:36Z 2017-06-14T12:52:36Z 2016 Stamp stress analysis with low temperature nanoimprint lithography / Hongwen Sun, Xiaochao Ma, Chenhui Hu // Functional Materials. — 2016. — Т. 23, № 3. — С. 517-520. — Бібліогр.: 11 назв. — англ. 1027-5495 DOI: dx.doi.org/10.15407/fm23.03.517 https://nasplib.isofts.kiev.ua/handle/123456789/121489 High temperature nanoimprint lithography has the drawback of long process cycle, demoulding difficulty, polymer degradation, thermal stress. Low temperature nanoimprint lithography (LTNIL) can avoid these problems. LTNIL is also ideal for manufacturing biological compatibility samples since the samples do not sustain high temperature. However, LTNIL need to optimize the press parameters in order to fully transfer patterns. Finite Element Method (FEM) is an excellent approach to examine the filling process. The stamp stress was simulated from four points of view, imprint pressure, imprint temperature, stamp pattern and stamp material. It was found that the stress in the stamp corners is especially bigger than other areas, the stress increases with the stamps aspect ratio increases, and stress distribution is more uniform for dense pattern stamp. en НТК «Інститут монокристалів» НАН України Functional Materials Technology Stamp stress analysis with low temperature nanoimprint lithography Article published earlier |
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Stamp stress analysis with low temperature nanoimprint lithography |
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Stamp stress analysis with low temperature nanoimprint lithography Hongwen Sun Xiaochao Ma Chenhui Hu Technology |
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Stamp stress analysis with low temperature nanoimprint lithography |
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Stamp stress analysis with low temperature nanoimprint lithography |
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Stamp stress analysis with low temperature nanoimprint lithography |
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Stamp stress analysis with low temperature nanoimprint lithography |
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stamp stress analysis with low temperature nanoimprint lithography |
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Hongwen Sun Xiaochao Ma Chenhui Hu |
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Hongwen Sun Xiaochao Ma Chenhui Hu |
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High temperature nanoimprint lithography has the drawback of long process cycle, demoulding difficulty, polymer degradation, thermal stress. Low temperature nanoimprint lithography (LTNIL) can avoid these problems. LTNIL is also ideal for manufacturing biological compatibility samples since the samples do not sustain high temperature. However, LTNIL need to optimize the press parameters in order to fully transfer patterns. Finite Element Method (FEM) is an excellent approach to examine the filling process. The stamp stress was simulated from four points of view, imprint pressure, imprint temperature, stamp pattern and stamp material. It was found that the stress in the stamp corners is especially bigger than other areas, the stress increases with the stamps aspect ratio increases, and stress distribution is more uniform for dense pattern stamp.
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Stamp stress analysis with low temperature nanoimprint lithography / Hongwen Sun, Xiaochao Ma, Chenhui Hu // Functional Materials. — 2016. — Т. 23, № 3. — С. 517-520. — Бібліогр.: 11 назв. — англ. |
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AT hongwensun stampstressanalysiswithlowtemperaturenanoimprintlithography AT xiaochaoma stampstressanalysiswithlowtemperaturenanoimprintlithography AT chenhuihu stampstressanalysiswithlowtemperaturenanoimprintlithography |
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Functional materials, 23, 3, 2016 517
ISSN 1027-5495. Functional Materials, 23, No.3 (2016), p. 517-520
doi:http://dx.doi.org/10.15407/fm23.03.517 © 2016 — STC “Institute for Single Crystals”
Stamp stress analysis with low temperature
nanoimprint lithography
Hongwen Sun,� ���o���o ��,� ��en�u� Hu ���o���o ��,� ��en�u� Hu���o���o ��,� ��en�u� Hu
College of Internet of Things Engineering, Hohai University, Changzhou,
Jiangsu, 213022, P.R. China
Received March 22, 2016
High temperature nanoimprint lithography has the drawback of long process cycle, demoulding
difficulty, polymer degradation, thermal stress. Low temperature nanoimprint lithography
(LTNIL) can avoid these problems. LTNIL is also ideal for manufacturing biological compatibility
samples since the samples do not sustain high temperature. However, LTNIL need to optimize the
press parameters in order to fully transfer patterns. Finite Element Method (FEM) is an excellent
approach to examine the filling process. The stamp stress was simulated from four points of view,
imprint pressure, imprint temperature, stamp pattern and stamp material. It was found that the
stress in the stamp corners is especially bigger than other areas, the stress increases with the
stamp’s aspect ratio increases, and stress distribution is more uniform for dense pattern stamp.
Keywords: Hot embossing lithography, nanoimprint lithography,low temperature, stamp,
stress, finite element method.
Высокотемпературная нанопечатная литография имеет такие недостатки как длитель-
ный цикл процесса, сложность деформации, деградация полимера, термические напряже-
ния. Низкотемпературная нанопечатная литография (LTNIL) может помочь преодолеть эти
проблемы. LTNIL также идеальная для производства биологически совместимых образцов,
потому что образцы не испытывают влияния высокой температуры. Однако, LTNIL требует
оптимизации параметров печати, чтобы достичь полной передачи рисунка. Метод конечных
элементов (FEM) - прекрасный метод для исследования процесса нагрузок. Напряжения в
штампе были промоделированы с четырех точек зрения: давление печати, температура пе-
чати, рисунок штампа и материал штампа. Было найдено, что напряжения в углах штампа
значительно выше, чем в других областях, напряжения растут с ростом соотношения сторон
штампа, распределение напряжений более однородно для плотного рисунка штампа.
Аналіз напруги, що виникає при низкотемпературой нанодрукарської літогра-
фії. Хонгвэн Сан, Сяочао Ma, Чэнху Ху
Високотемпературна нанопечатная літографія має такі недоліки як тривалий цикл
процесу, складність деформування, деградація полімеру, термічні напруги. Низькотемпе-
ратурна нанопечатная літографія (LTNIL) може допомогти подолати ці проблеми. LTNIL
також ідеальна для виробництва біологічно сумісних зразків, тому що зразки не зазнають
впливу високої температури. Однак, LTNIL вимагає оптимізації параметрів друку, щоб до-
сягти повної передачі малюнка. Метод кінцевих елементів (FEM) - прекрасний метод для
дослідження процесу навантаження. Напруження в штампі були промодельовані з чотирь-
ох точок зору, тиск друку, температура друку, малюнок штампа і матеріал штампа. Було
знайдено, що напруги в кутах штампа значно вище, ніж в інших областях, напруги зроста-
ють зі зростанням співвідношення сторін штампа, розподіл напруг більш однорідний для
щільного малюнка штампа.
518 Functional materials, 23, 3, 2016
Hongwen Sun et al. / Stamp stress analysis with low temperature ...
1. Introduction
Hot embossing lithography (HEL), one of
the common nanoimprint lithography (NIL)
technique, has the advantage of high resolu-
tion, high uniformity and low cost [1]. Howev-
er, high temperature the process needed leads
to many disadvantages, such as long process
cycle, demoulding difficulty, polymer degrada-
tion, thermal stress and not suitable for part
of substrates heating [2]. Low temperature na-
noimprint lithography (LTNIL) can avoid the
above drawbacks [3,4]. LTNIL can be widely
used in the area of biology, medical science, and
organic light-emitting because the polymers
applied in these areas cannot sustain high tem-
perature [5,6].
There are some researchers conducted the
study of LTNIL. Scheer et al. researched the
polymer time constants during LTNIL [7].
Chen et al. imprited metal films by NIl with
both low temperature and low pressure [8].
They imprinted SU-8 at 45°C and NEB-22
at 60°C. Lu et al. even patterned poly(acrylic
acid)/Poly(allylamine hydrochloride) multilay-
er films by room temperature imprinting [9]. To
save cost and time, it is necessary to study the
LTNIL process by modeling and simulation.
Kim et al. used a viscoelastic model to simulate
low temperature NIL with temperature range
Tg < T < Tg + 40°C [10]. Song et al. researched
room temperature NIL by simulating different
imprinting speeds and patterns [11]. However,
there are few references studying the stamp
stress by simulation. This contribution applied
Finite Element Method (FEM) to research the
stress of nanoimprint stamp at low tempera-
ture.
2. Modeling
The FEM software ANSYS was used to set
up modeling. The element type of stamp is
Plane42 and element type Hyper56 for the re-
sist. Fig. (1) shows one of our models. The length
of the groove is 300nm and depth is 50nm. The
thickness of the resist is 100nm.
The common used resist Poly(methyl meth-
acrylate) (PMMA) was taken as the resist in
the simulation. For stamps, different materi-
als, silicon (Si) and nickel (Ni) was used for
comparison purpose. The parameters of them
were shown in Table 1.
3. �e�ult� �nd �i�cu��ion. �e�ult� �nd �i�cu��ion�e�ult� �nd �i�cu��ion
3.1 I��rint �re��ure ��ri�tion.1 I��rint �re��ure ��ri�tionI��rint �re��ure ��ri�tion
Firstly, 5GPa was applied to the above mod-
el. The stress distribution under 400K was giv-
en in Fig. (2). From the figure, it can be found
that the resist filled the stamp well. The stress
in the borders between the stamp and the re-
sist are obviously larger than the inner area.
The stress in the corners is especially bigger
than other areas. The central area has the low-
est stress.
To further lower the stress, it is necessary
to find the minimum pressure needed to help
the resist fully fill the stamp cavities. After sev-
eral simulation, we found 1.7GPa is the proper
pressure for the combination of Ni stamp and
PMMA resist at 400K. Although, the stress
distribution is similar to the above 5GPa situ-
Fig. 1. Typical FEM Model (above is the stamp
with one groove and the bottom is the resist).
Table 1. Parameters of �ifferent Nanoimprint StampsParameters of �ifferent Nanoimprint Stamps
Material Elastic
modulus, GPa
Poisson’s
ratio
�ensity,
kg/m3
Thermal conductivity
coefficient
Specific heat
capacity, J/kg
Ni 207 0.29 8900 71.4 460
Si 190 0.30 2330 149.0 700
Fig. 2. Stamp stress distribution with 5GPa
pressure and 400K.
Functional materials, 23, 3, 2016 519
Hongwen Sun et al. / Stamp stress analysis with low temperature ...
ation, the imprint time increases when the im-
print force decreases.
3.2 I��rint Te��er�ture ��ri�tion
To simulate the stress of the stamp in NIL
with different temperatures, we analyzed the
stamp stress with temperature at 390K, 400K
and 410K. Fig. 3 shows the stress change dur-
ing the imprint for four different points in the
stamp under 390K.
For three temperatures, the stress distribu-
tion shows little variation. Therefore, it can be
concluded that the temperature has little effect
on the stamp stress when imprint is conducted
under low temperature, which is still greater
than the glass transition temperature of the
resist.
3.3 I��rint Te��er�ture ��ri�tion.3 I��rint Te��er�ture ��ri�tion3 I��rint Te��er�ture ��ri�tion I��rint Te��er�ture ��ri�tionI��rint Te��er�ture ��ri�tion
Another three grooves pattern structure was
designed and simulated for further research
the relationship between the stamp's pattern
structure and the stress after imprinting. Fig-
ure 4 gives the three grooves model. The length
of each groove is 100 nm and depth is still
50 nm. The thickness of the resist is 100 nm.
Fig.. 4 also shows the stress distribution with
the imprint condition of temperature 400 K
and pressure 5 GPa.
From Fig. 4, it can found that the mini-. 4, it can found that the mini-4, it can found that the mini-
mum and maximum stress is 0.472´108 Pa
and 0.124´1011 Pa, respectively, which is both
larger than the minimum and maximum stress
in one groove stamp situation. It means that
when the stamp's aspect ratio increases, the
stress will increase corresponding.
For comparison, the typical four points were
chosen again to show the stress change with
imprint time. These four points are at the same
place as in Section 3.2. Fig. (5) shows the cor-
responding stress change with imprint time. It
can be noticed that stress distribution is more
uniform for three groove stamp, which means
the stress of different places does not vary too
much.
3.�� �t��� M�teri�l ��ri�tion.�� �t��� M�teri�l ��ri�tion�� �t��� M�teri�l ��ri�tion �t��� M�teri�l ��ri�tion�t��� M�teri�l ��ri�tion
For analyzing the stress after NIL using dif-
ferent stamp materials, the first model with one
groove was chosen. In general, the stress distri-
bution of Ni and Si stamp has similar charac-
teristics. However, when finding the minimum
pressure in order to fully fill the cavity of the
stamp, we found 1.5G Pa is the proper pres-
sure for the Si stamp and PMMA resist at 400K,
which is lower than the situation of Ni stamp.
This can be explained by that the hardness of
Si is larger than Ni.
��. Conclu�ion�
Low temperature nanoimprint lithography
can reduce thermal cycle and stress. They can
be widely used in different areas, especially in
the medical and organic lighting areas since
the sample substrate needn't suffer high tem-
perature. Analyzing LTNIL by Finite Element
Method can save time and cost. The stamp
stress was simulated from four points of view,
that is Imprint Pressure, Imprint Tempera-
ture, Stamp Pattern and Stamp Material. The
Fig. 3. Stress change during the imprint for four
typical points in the stamp under 390K.
Fig. 4. Three grooves stamp model and stress
distribution with the imprint condition of tem-
perature 400K and pressure 5 GPa.
Fig. 5. Four points’ stress change with imprint
time using three grooves stamp.
520 Functional materials, 23, 3, 2016
Hongwen Sun et al. / Stamp stress analysis with low temperature ...
stress in the borders of the stamp is obviously
larger than the inner stamp area. When the
stamp's aspect ratio increases, the stress will
increase corresponding. The stress distribution
is more uniform for dense stamp patterns. The
stress distribution of Ni and Si stamp is simi-
lar. However, the Si stamp has smaller mini-
mum pressure in order to fully fill the cavity of
the stamp.
Acknowledge�ent�
This research was supported by “the Funda-
mental Research Funds for the Central Univer-
sities” with project No. 2015B22514.
�eference�
1. S.Y. Chou, P. R. Krauss, P. J. Renstrom, Chou, P. R. Krauss, P. J. Renstrom,Chou, P. R. Krauss, P. J. Renstrom, Krauss, P. J. Renstrom,Krauss, P. J. Renstrom, �enstrom,�enstrom,, Appl.
Phys.Lett., 67, 3114, 1995.3114, 1995., 1995.1995..
2. C.M. Sotomayor Torres, S. Zankovych, et al.,,
Mater. Scie. Engin., 23, 23, 2003.2003.
3. M.M. Alkaisi, R.J. Blaikie, S. J. McNab, J. McNab,J. McNab, Micro-
electron. Eng., 57–58, 367, 2001. 367, 2001., 2001.
4. N.Ikutame, K. Kawaguchi, H. Ikeda, et al.,N.Ikutame, K. Kawaguchi, H. Ikeda, et al.,Ikutame, K. Kawaguchi, H. Ikeda, et al.,K. Kawaguchi, H. Ikeda, et al.,Kawaguchi, H. Ikeda, et al.,H. Ikeda, et al.,Ikeda, et al.,et al., J.
Appl. Phys., 114, 083514, 2013.083514, 2013., 2013.2013..
5. A.Pepin, P. Youinou, �. Studer, et al.,. Youinou, �. Studer, et al., Youinou, �. Studer, et al.,�. Studer, et al.,Studer, et al., Microelec-
tron. Eng.. Eng. Eng.., 61-62, 927, 2002.927, 2002., 2002.2002..
6. J. Kettle, S. Whitelegg, A. M. Song, et al.,. Kettle, S. Whitelegg, A. M. Song, et al., Kettle, S. Whitelegg, A. M. Song, et al.,. Whitelegg, A. M. Song, et al., Whitelegg, A. M. Song, et al.,. M. Song, et al., M. Song, et al.,. Song, et al., Song, et al., Nano-
technology, 21, 075301, 2010.075301, 2010., 2010.2010..
7. H.C. Scheer, N. Bogdanski, M. Wissen, et al.,7. H.C. Scheer, N. Bogdanski, M. Wissen, et al., J.
Vac. Sci. Technol. B: Microelectron. Nanomet.
Struct., 23, 2963, 2005.
8. H.L. Chen, S. Y. Chuang, H. C. Cheng, et al.,8. H.L. Chen, S. Y. Chuang, H. C. Cheng, et al.,. H.L. Chen, S. Y. Chuang, H. C. Cheng, et al., Y. Chuang, H. C. Cheng, et al.,Y. Chuang, H. C. Cheng, et al., C. Cheng, et al.,C. Cheng, et al.,, et al.,et al.,
Microelectro. Eng. Eng.Eng., 83, 893, 2006.893, 2006., 2006.2006..
9. Y. Lu, J. Sun, J. Shen,,9. Y. Lu, J. Sun, J. Shen,,. Y. Lu, J. Sun, J. Shen,,. Lu, J. Sun, J. Shen,, Lu, J. Sun, J. Shen,, J. Sun, J. Shen,,J. Sun, J. Shen,,. Sun, J. Shen,, Sun, J. Shen,, J. Shen,,J. Shen,,. Shen,, Shen,,, Langmuir, 24, 80�0,80�0,,
2008.
10. N.W. Kim, K.W. Kim, H.C. Sin,. N.W. Kim, K.W. Kim, H.C. Sin,.W. Kim, K.W. Kim, H.C. Sin,W. Kim, K.W. Kim, H.C. Sin,. Kim, K.W. Kim, H.C. Sin, Kim, K.W. Kim, H.C. Sin,.W. Kim, H.C. Sin,W. Kim, H.C. Sin,. Kim, H.C. Sin, Kim, H.C. Sin, H.C. Sin,H.C. Sin,.C. Sin,C. Sin,. Sin, Sin,, Microelectron.
Eng., 85, 1858, 2008.1858, 2008., 2008.2008..
11. J.H. Song, H. Huh, S.H. Kim, H.T. Hahn,. J.H. Song, H. Huh, S.H. Kim, H.T. Hahn,J.H. Song, H. Huh, S.H. Kim, H.T. Hahn, Mater.
Sci. Forum, 505-507, 85, 2006.
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