Airtight and two-level porous gas-liquid recycling device for immersion-type photoetching machine

Abstract

The invention discloses an airtight and two-level porous gas-liquid recycling device for an immersion-type photoetching machine. The airtight and two-level porous gas-liquid recycling device comprises an airtight and gas-liquid isolation device which is installed between a projection objective group and a silicon wafer and comprises an immersion unit lower end cover and a substrate; the immersion unit lower end cover is provided with a central taper hole, a lens injection port, a lens recycling port, a gas-liquid separation cavity, a second-level recycling cavity, a gas injection cavity, a flow-field multilevel buffer structure, a gas buffer groove, an inner sealing groove, an intermediate sealing groove and an outer sealing groove; the immersion unit substrate is provided with a central through hole, a lens injection cavity, a lens recycling cavity, a gas recycling cavity, a substrate second-level recycling cavity, a substrate gas injection cavity and a liquid recycling cavity. A great amount of waste liquid produced in the photoetching process can be recycled through the lens recycling structure, and the rapidness for updating a flow field can be realized; the liquid can be recycled through a two-level porous structure, the stability of the boundary of the flow field can be maintained, the gas-liquid separation is realized, and the primary sealing of the flow field is realized; the leakage of the liquid can be prevented by adopting the airtight structure.

Description

technical field [0001] The invention relates to a flow field sealing and liquid injection recovery device, in particular to an air seal and two-stage porous gas-liquid recovery 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. a. 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 re...

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, which causes 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, a gas-liquid two-phase flow will be formed, which will cause vibration and affect the stable operation of the exposure system

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