Fast 3D thick mask model for full-chip EUVL simulations

I
Dark field thru -pitch thru -focus pattern shift of
12nm space at slit edge
2.5
2
E 15
c
t 0.5
tn c 0
-X Shift -FDTD
o X Shift -M3D+
-V Shift -FDTD
o V_Shift -M3D+
-2
0 80-4040 -d0 0 80-4040 -do 0 80-4040 -80 0 80-4040 -80 0 80-4040 -d0 0 80-4040
30 32 34 36 38 40 50 60 70 80 90 100
F Focus (nm)
F Pitch (nm)
Figure 12(c): Dark field thru-pitch thru-focus pattern shift of 12nm space at slit edge under the nominal dose condition
4.2 2D pattern case study
2D patterns of an actual design are much more diverse compared to 1D patterns. To make this study more relevant, we
adopted the 2D patterns previously investigated by a device manufacturer, which highlighted the need of 3D mask
modeling in EUV applications 11 . These patterns are shown in Figure 13.
EX1 (anchor)
00
D °° D
CC
0 0
0 0 0 0
0 0
0 0
° ° ° °
° ' °
0 0 00 0
O° 0 0 0 0 0
DC DO 0
x 14nm
0$ 22nm o 0 0
0 0 0 0
0 0 0
0 0
0 0
° ° °
EX2oo
o 0 0
0 0 2 nm x 14n
0 0 0 0 0
0 0 0
0 0 0 0 0
CC 0
00 0
° ° ° °
EX4A
EX16
0 0
0 0
D O C C
0 0
Do
13nmx26n,
] 0-9-0 0
0 0 0 0
1 0 0 0 0
Figure 13: 2D patterns used in simulation
l0000000
0 0 0 0 0
22nm x 14nm
0-12- o 0 0
O C C
0 0
O C O O
0 0 0
The size of the feature at the simulation domain center is labeled. In this work these patterns were directly used in
simulations without any OPC. Again, rigorous simulations were done first to generate reference data. The X- and Y-
CD’s of the first pattern (EX1) at the slit center under the nominal FEM condition were used to calibrate the M3D+
model and the thin mask model. Only threshold was calibrated for the M3D+ model. For the thin mask model, HV bias
was also calibrated in addition to threshold. Then the calibrated model was used to predict the printed contours of all
patterns and compared to rigorous results. The RMS of predicted CD delta to FDTD is shown in Figure 14.
Proc. of SPIE Vol. 8679 86790W-12
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