A gas-liquid isolation device for immersion photolithography machine

Abstract

The invention discloses a projection objective lens group and a silicon wafer in an immersion photolithography machine, and a gas-liquid isolation device is installed between the projection objective lens group and the silicon wafer. The gas-liquid isolation device includes, from bottom to top, the surface block of the immersion unit, the lower end cover of the immersion unit, the main body of the immersion unit and the upper end cover of the immersion unit, which are integrally connected by screws. The first layer of the present invention is horizontal recovery, a large amount of liquid is recovered through the horizontal recovery structure, and the rapid update of the flow field is realized, while ensuring that the liquid level in the lens area maintains a certain height, and the liquid level will not exceed the immersion unit, overflow will occur, and the gas will not Therefore, it is brought into the submerged flow field with the horizontal injection, forming incomplete filling. The second layer is vertical recovery. The gas-liquid boundary of the slit flow field is preliminarily bound by the vertical small hole group structure evenly distributed along the circumference; the working method of hydrophilic and hydrophobic structures is adopted, and the liquid is used in the hydrophilic and hydrophobic structures. The tension characteristic of the hydrophobic junction strengthens the binding of the gas-liquid boundary to achieve an ideal sealing effect.

Description

technical field [0001] The invention relates to a flow field sealing and liquid injection recovery device, in particular to a gas-liquid isolation device for an immersion photolithography machine. Background technique [0002] The lithography machine is one of the core equipment for manufacturing VLSI. The modern lithography machine is mainly based on optical lithography. It uses the optical system to accurately project and expose the pattern on the mask to the silicon coated with photoresist. Chip. It includes a laser light source, an optical system, a projection mask composed of chip patterns, an alignment system and a silicon wafer coated with photosensitive photoresist. [0003] Immersion lithography (Immersion Lithography) equipment fills a liquid with a high refractive index between the last projection objective lens and the silicon wafer, which improves the numerical aperture of the projection objective lens ( NA), thereby improving the resolution and depth of focus...

AI Technical Summary

Problems solved by technology

During the high-speed movement of the substrate, once the external air or sealing liquid is involved or dissolved or diffused into the filling liquid, it will have a negative impact on the exposure quality

[0006] (2) The existing air sealing method uses an air curtain to apply around the filling fluid, resulting in instability at the edge of the flow field. During the high-speed stepping and scanning process of the silicon wafer, it may cause liquid leakage and entrainment of the sealing gas into the flow field ; At the same time, when the filling liquid and the sealing gas are recovered together, the gas-liquid two-phase flow will be intensified, which will cause vibration and affect the stable operation of the exposure system

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