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Hyper-NA lithography with polarized light illumination is introduced as the solution of 45nm or 32nm node
technology. In that case, consideration of new characteristics of mask materials and pellicle films has been required. In
order to analyze the influence of mask material's optical characteristics, we have proposed to use the AIMSTM system
measuring diffraction intensity balance in previous work. That was enabled by acquiring pupil plane images using the
Bertrand lens in the AIMSTM system to measure selected area's diffracted light.
In this study of mask material evaluation, we used same functionality of AIMSTM system, MonoPole illumination
and Bertrand lens, as previous work but other direction's pole is also used on the illumination aperture to cover total
diffraction orders of Cross-quad illumination because this illumination is more flexible for x and y patterns. In order to
get diffracted light of 45nm half-pitch, hyper-NA e.g. NA=1.35 was applied and the AIMSTM 45-193i Alpha system was
used for this evaluation. The examinations were performed with binary and half tone PSM with half pitch 40 to 150nm
on a 1x scale and fixed half pitch 45nm with various mask bias. We confirmed the relation between diffractions' intensity
balance and wafer printing performance for each material and we compared them to 3D simulation results.
Moreover, by using the same functionality of AIMSTM system, the transmission change by pellicle film was also
examined. We have prepared two different thickness pellicles to compare transmission change and printed CD on the
wafer. Intensity profile at pupil plane on the clear region of the mask was acquired with Bertrand lens and conventional
large sigma setting for both with and without pellicle film on the mask. By comparing transmission distribution change
between with and without pellicle, we could calculate transmission loss by pellicle at large incident angles. For this
experiment, NA=1.40 was applied and the AIMSTM 45-193i Alpha system was also used. The examinations were
performed with half tone PSM at half pitch 45nm and 65nm on a 1x scale on linear polarized DiPole illumination.
As a result, we have confirmed good agreement between AIMSTM measurement data and optical 3D simulations. In
conclusion, the AIMSTMsystem is a valuable tool for analyzing diffraction efficiency or intensity distribution on the
pupil plane and comparison to wafer printing performance.
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