Development of Novel Positive-tone Photoresists for EUVL
a)Idemitsu
Kosan Co.,Ltd.
b)Semiconductor Leading Edge Technologies, Inc.
(Selete)
a)Takanori
Owada, Akinori Yomogita, Takashi Kashiwamura
b)Hiroaki Oizumi, Toshiro Itani
E-mail：[email protected]
Idemitsu Kosan Co.,Ltd.
Our concept for EUV resist
Low molecular weight amorphous materials have the advantage of having
definite structures and low molecular weights that would solve the current
serious problem of line-edge roughness (line width roughness).
Polymer
LER→large
LER→large
Low molecular
weight amorphous
LER→small
LER→small
Idemitsu Kosan Co.,Ltd.
Previous work (and in this study)
We had developed tetramethylcalix[4]-resorcinarene (C4-RA)
*H.Ishii et al.:J.Photopolym.Sci.Technol.,16(2003)685
calixarenes have unique characteristics such as …
→small molecular size
→excellent thermal stability
→many reactive groups such as hydroxyl groups and so on.
We found it shows good characters for resist and also it shows
bad characters (etching durability and so on.)
OHHO
HO
HO
HO
OH
OH
OH
C4-RA：Molecular weight=544
We focus on the NEW Cyclic low molecular Resists
in order to improve the performance of C4-RA.
Idemitsu Kosan Co.,Ltd.
Synthesis of Cyclic Low Molecular Resists(CLM-Resists)
HO
HO
OH
R-CHO
HO
R
R
resorcinol
OH
OH
HO
R
R
OH
HO
OH
HO
OH
HO
OH
OH
OH
HO
R
R
HO
OH
OH
OH
HO
R
R
HO
pyrrogarol
Protection Group
OH
OH
Cyclic Low Molecular Resists
Easy preparation of molecular resists (2 Steps)
We developed new platform, CLM-D resist.
Idemitsu Kosan Co.,Ltd.
Thermal Properties of CLM-Resist
Evaluated conditions
<1st heating>
N2 (200ml/min) flow
15℃/min
TG thermogram of CLM-D resist
Endo
Evaluated conditions
N2 (200ml/min) flow
10℃/min
0
20
40
60
80
100
120
140
Temp.（℃）
DSC thermogram of CLM-D resist
High decomposition temperature(above 170℃) and No Tg.
⇒This shows High Heat Resistance.
Idemitsu Kosan Co.,Ltd.
Evaluations of CLM-Resist
High-NA(NA=0.3) Small Field Exposure Tool (HiNA)
EUV imaging experiments were performed using the high-numerical-aperture
(NA=3), small field EUV exposure tool (HiNA) .
Idemitsu Kosan Co.,Ltd.
EUV exposure result (CLM-D resist)
Process Conditions
Substrate: Si
Thickness: 50nm
Exposure:HINA
Dev: TMAH 0.26N 30sec
SEM: S8840
Mag: 100k
Mask:MB24
45nm-hp
40nm-hp
35nm-hp
32nm-hp
30nm-hp
29nm-hp
[email protected]/cm2
28nm-hp
28nm L/S was resolved.
Idemitsu Kosan Co.,Ltd.
EUV exposure result (CLM-D resist with BARC)
Process Conditions
Substrate: BARC
Thickness: 50nm
Exposure:HINA
Dev: TMAH 0.26N 30sec
SEM: S8840
Mag: 100k
Mask:MB24
45nm-hp
40nm-hp
35nm-hp
32nm-hp
30nm-hp
29nm-hp
[email protected]/cm2
28nm-hp
Idemitsu Kosan Co.,Ltd.
Evaluation of Outgassing of CLM-D Resist by EUV Lithography
resist
CLM-D＋
PAG＋
quencher
CLM-D
film thickness
(nm)
79.0
84.0
out gas rate
(molecule/s/[email protected])
4.4E+17
9.0E+15
Resist outgassing analysis tool at Selete
To improve outgassing performance, we need to optimize the structure of
protection group, PAG and quencher.
Idemitsu Kosan Co.,Ltd.
Summary
・We have been investigating new CLM-Resist (CLM-D) for EUV.
・CLM-D resist was resolved sub-30nm L/S.
Future Work
・Optimization of Protecting group, PAG and quencher
in order to achieve the low outgassing and the other required performance.
・LER＆LWR：Making sure of the affects due to the molecular grass resists.
・We have been developing the new concept resists.
Idemitsu Kosan Co.,Ltd.
Acknowledgements
This work was partially supported by the New Energy and
Industrial Technology Development Organization (NEDO).
Idemitsu Kosan Co.,Ltd.