Asymmetric fluid-structure dynamics in nanoscale imprint lithography

The feature sizes are typically on the order of 100-200 nm. Precalibrationof the template orientation stages can align the template and wafer towithin two interference fringes across a one-inch template, which is equivalent toa wedge height of approximately 340 - 440 nm. The wedge can be computed asW = L tanθ[5.5]where W is the wedge height (m), L is the length of the template (0.025 m), and θis the angle between the template and the wafer (rad). Thus through careful precalibration,the initial angle between the template and wafer is about 2 × 10 -5 rad.Being slightly less conservative, a wedge of 2.5 × 10 -5 rad was used. Table 5.2summarizes the initials conditions and the system parameters used in thenumerical simulation.Parameter Description Symbol ValueMass M 1.5 kgStiffness constant in the axial direction K Z 1.3 × 10 8 N/mDamping constant in axial direction C Z 1400 N⋅s/mInertia I 5 × 10 -6 kg⋅m 2Stiffness constant in the torsional direction K θ 64 N⋅m/radDamping constant in the torsional direction C θ 2 × 10 -3 N⋅m⋅s/radTemplate width L 2 cmViscosity of the etch barrier µ 1 cpSurface tension of the etch barrier γ 28 dynes/cmInitial base layer thickness h i 2 micronInitial angular misalignment θ 0 2.5 × 10 -5 radInitial boundary x α,β ± 1 mmTable 5.2 Simulation Parameters Reflecting Experimental Setup69