Immersion self-adapting seal control device used for photo-etching machine

Abstract

The invention discloses an immersion self-adaptive sealing control device used in a lithography machine. The immersion self-adaptive sealing control device is arranged between a projection lens set and a substrate, and consists of a sealing element and a self-adaptive sealing member. When liquid forms the impact on the self-adaptive sealing member due to traction of the substrate, the device can absorb the impact formed by the high-speed moving liquid and converts the impact into power enhancing sealing; on the contrary, when the substrate draws the liquid away from the self-adaptive sealing member, the liquid prestored inside the device follows to enter a slit flow field to avoid gas bubble entrainment owing to the loss of the liquid at the boundary, meanwhile, the reduction of the liquid prestored inside the device reduces the sealing power of the self-adaptive sealing member, and the leaked liquid flows back to the inside of the slit flow field along with the substrate due to the reduction of obstruction. The liquid transmission mode of the immersion self-adaptive sealing control device adopts negative pressure recovery and free flow of a fluid injection end, which avoids the flow field fluctuation caused by the in-coordination between the injected fluid and the recovery pressure.

Description

technical field [0001] The invention relates to a liquid supply and recovery sealing device in an immersion lithography (Immersion Lithography) system, in particular to an immersion self-adaptive sealing control device for a lithography machine. Background technique [0002] Modern lithography equipment is based on optical lithography, which uses an optical system to accurately project and expose the pattern on the mask onto a substrate (such as a silicon wafer) coated with photoresist. It includes a laser light source, an optical system, a projection mask composed of chip patterns, an alignment system and a substrate covered with photosensitive photoresist. [0003] The immersion lithography system fills a certain liquid in the gap between the projection lens and the substrate, and increases the numerical aperture (NA) of the projection lens by increasing the refractive index (n) of the medium in the gap, thereby improving the resolution of lithography rate and depth of fo...

AI Technical Summary

Problems solved by technology

[0006] (1) Due to the use of positive pressure liquid supply and negative pressure recovery, the pressures of the two are not easy to coordinate, and it is easy to cause pressure fluctuations and interference forces in the filling flow field, and lead to turbulent flow in the liquid and some undesirable and unpredictable effects

[0007] (2) The positive pressure liquid supply method makes the liquid inside the gap flow field have a higher pressure, and this force acts on the sealing structure, which increases the possibility of liquid leakage and affects the reliability of the seal.

[0008] (3) When the substrate is moving at a high speed, due to the effect of molecular adhesion, the liquid close to the substrate will move along with the substrate, which will cause the boundary shape of the flow field to change rapidly; this change occurs at different boundary positions They are all different, and the commonly used pressure equalization sealing method cannot adaptively compensate the boundary of the flow field, so it is difficult to effectively avoid a series of problems caused by it

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

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