A correlation for predicting film-pulling velocity in immersion lithography

By designing and implementing a new experimental method, we have measured the dynamic advancing and receding contact angles and the resulting hysteresis of droplets under electrowetting-on-dielectric (EWOD). Measurements were obtained over wide ranges of applied EWOD voltages, or electrowetting numbers (0 ≤ Ew ≤ 0.9), and droplet sliding speeds, or capillary numbers (1.4×10-5 ≤ Ca ≤ 6.9×10-3). If Ew or Ca is low, dynamic contact angle hysteresis is not affected much by the EWOD voltage or the sliding speed, i.e., the hysteresis increases by less than 50% with a two order-of-magnitude increase in sliding speed when Ca < 10-3. If both Ew and Ca are high, however, the hysteresis increases with either the EWOD voltage or the sliding speed. Stick-slip oscillations were observed at Ew>0.4. Data are interpreted with simplified hydrodynamic (Cox-Voinov) and molecular-kinetic theory (MKT) models; the Cox-Voinov model captures the trend of the data, but yields unreasonable fitting parameters. MKT fitting parameters associated with the advancing contact line are reasonable, but a lack of symmetry indicates that a more intricate model is required.

show abstract

“…This configuration is similar to a demonstrated method used to study wafer coating for immersion lithography. 41 …”

Section: Methodsmentioning

confidence: 99%

“…This configuration is similar to a demonstrated method used to study wafer coating for immersion lithography. 41 Experimental Setup and Procedure. Figure 2 illustrates the overall experimental setup.…”

Section: ' Experimental Sectionmentioning

confidence: 99%

Dynamic Contact Angles and Hysteresis under Electrowetting-on-Dielectric

2011

View full text Add to dashboard Cite

show abstract

“…In the 193i scanner, the water meniscus moves with the exposure head, as sketched in The dynamic model of the relation between dynamic contact angle and scan speed. 8,9 Figure 4(b). The static contact angle is insufficient to describe both the shape of the water meniscus and the water movement on resist surface: dynamic contact angles must therefore be introduced.…”

Section: Water Contact Angle Of Resist Stacksmentioning

confidence: 99%

“…The dynamics of the water meniscus have been investigated in a detail by a joint work of University of Wisconsin and Sematech. 8,9 The dynamic contact angles are related to the height of the water gap (h), velocity of the wafer stage (v), viscosity and surface tension of the water, and hydrophobicity of the resist surface. Figure 5 shows sketched results of the detailed calculations from the group.…”

Section: Water Contact Angle Of Resist Stacksmentioning

confidence: 99%