-0.5 0.0 0.5
0.2 0.4
Defocus [痠]
0.5 0.4 0.3 0.2 0.1 0.0
Cross Section: X Parallel, Y = 0.000
(b)
Fig 4-16 aerial image for (a) Atten-NPS =25％ (b) equal binary mask (dark line=67nm, pitch=140nm)
SOLID-C ®
Average Sidewall Angle (CS) [財 85.000-92.000 Thickness Loss (CS) [%]
inf.-10.000
0.8087 7.00%
best Defocus [痠]: -0.196, best Dose [mJ/cm^2]: 56.668
(a)
Average Sidewall Angle (CS) [財 85.000-92.000 Thickness Loss (CS) [%]
inf.-10.000
0.8698 7.00%
best Defocus [痠]: -0.165, best Dose [mJ/cm^2]: 51.616
(b)
Fig 4-17 process window for (a) Atten-NPS =25％ (b) equal binary mask (dark line=67nm, pitch=140nm
Chapter 5
Conclusion
5-1 Conclusion
It is found that the dark line between a bright lines pair can decrease the iso-focal intensity so to gain a better line pattern. But because in the pair bright lines mask undesirable dark line is formed between adjacent pairs, so it needs double exposure to erase the undesirable dark line.
In order to decrease the time of exposure step, so we change the dark lines between the pair of bright lines with non-phase shifting mask to increase the aerial image intensity of the place. So the original aerial image intensity which is low and can not be resolved will become high enough and can resolve.
Finally, we change the non-phase-shifting mask to a set of line patterns. The line patterns have small width that is below the resolution limit so will not be resolved and the patterns have the similar transmission behavior as non-phase-shifting mask so can be the replaced mask of non-phase-shifting mask.
The schemes of the three methods are shown in figure 5-1. And the simulated results are shown in figure 5-2. From the simulation results can improve our conclusion of above.
Fig 5-1 scheme of the three methods
SOLID-C ®
Cross Section: X Parallel, Y = 0.000
SOLID-C ® Average Sidewall Angle (CS) [財 85.000-92.000
Cross Section: X Parallel, Y = 0.000
SOLID-C ® Average Sidewall Angle (CS) [財 85.000-92.000 Thickness Loss (CS) [%]
inf.-10.000
0.8087 7.00%
best Defocus [痠]: -0.196, best Dose [mJ/cm^2]: 56.668
image=90nm
Cross Section: X Parallel, Y = 0.000
SOLID-C ® Average Sidewall Angle (CS) [財 85.000-92.000
(c) binary line equal to Att-NPS
Fig 5-2 process window and aerial image for three methods
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