Submerge liquid supplying recovery controlling device for photoetching machine

Abstract

The invention discloses an immersion liquid supply and recovery control device for a mask aligner. The immersion liquid supply and recovery control device is arranged between a projection lens group and a substrate to be exposed and consists of a liquid charging cover, a liquid charging disc, a flow control loop and a retainer ring. The external liquid charging and the internal liquid recovery are adopted. Liquid enters a slit flow field from the periphery with the fixed quantity and in the mode of high speed injection; and the balance and stability of the whole flow field is realized through coordination and control of the negative pressure acting on an internal recovery cavity. The mode of high speed liquid injection from outside to inside can not only effectively counteract the internal power of outward liquid leakage and reduce the infiltration of boundary air bubbles caused by a gas sealing device, but also quicken the updating rate of the flow field and consequently facilitate the timely removal of pollutants produced in the process of exposure.

Description

technical field [0001] The invention relates to an immersion liquid supply and recovery control device in an immersion lithography (Immersion Lithography) system, in particular to an immersion liquid supply and recovery control device for a photolithography 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 ...

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 existing air sealing method uses an air curtain to apply around the filling fluid, causing instability at the edge of the flow field. During the high-speed stepping and scanning process of the substrate, it may cause liquid leakage and entrainment of sealing gas to the flow field At the same time, gas-liquid two-phase flow will be formed when the filling liquid and sealing gas are recovered, which will cause vibration and affect the stable operation of the exposure system

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

[0009] (4) 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, and thus the receding contact angle opposite to the moving direction of the substrate will become smaller, making Boundary liquid is more likely to be pulled to the periphery of the flow field, causing liquid leakage, and thus forming a series of defects (such as: water marks)

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