In situ spectroscopic ellipsometry, deep UV ellipsometry, and imaging ellipsometry were employed to study the
absorption of liquid by photoresist(PR) used for 193 nm immersion lithography. When 140 nm thick PR was soaked in
water over a period of >70 minutes, ~7% increase in thickness was observed. From the analysis of ellipsometric spectra
covering from near infrared to deep UV, we could estimates less than 2 vol. % uptake of water by PR after completion of
soaking. This resulted in very small decrease in refractive index of PR (~0.4%). When imaging ellipsometry was used,
the absorption of water by PR in much shorter periods could be detectible. In imaging ellipsometry, the microscopic
images of (Δ,Ψ ) in small area are obtained thanks to two dimensional multi-channel detection systems such as CCD.
Using imaging ellipsometry, we could observe the interaction of PR with water even upon 1 s of contact. Also, we found
that the water absorption or interaction was not uniform over surface. More studies are required for the implication of
this observation. Obviously, imaging ellipsometry is a good technique to inspect water mark in immersion lithography.
We also repeated similar experiments for high reflective index liquid (JSR HIL-001) but to find negligible change by
A design for an equivalent electric circuit of three-layered piezoelectric bimorph is presented. The piezoelectric bimorph is modeled as a beam in which only bending deformation can be induced; thus, its end deflections and rotations are considered the ports of the equivalent electric circuit. The electromechanical impedance parameters of the equivalent electric circuit, which has a single electrical and four mechanical ports, are found.