Stair-type self-adaptive air sealing device used for immersed type photoetching machine

Abstract

The invention discloses a stair-type self-adaptive air sealing device used for an immersed type photoetching machine. The air sealing device is a device arranged between a projection lens group and a lining and is composed of an upper component, a lower component and a rotary component; in the photoetching scanning process, the boundary state of an immersed flow field can be changed rapidly along with the traction function of the high speed movement of the lining to the immersing liquid. The interior of the device adopts a multi-layer stair-type air sealing structure, the air sealing pressure is increased gradually from the center to outside, and the sealing pressure of air in each layer is adjusted in real time according to the movement direction and the speed of the lining, so that the leakage of the immersing liquid caused by insufficient periphery sealing pressure and the bubble entrainment caused by overhigh internal air sealing pressure are prevented, and thereby the self-adaptive air sealing of the liquid is realized; and meanwhile, by adopting spiral air flow auxiliary sealing outside the device, the reliability and the stability of the air sealing are further improved.

Description

technical field [0001] The invention relates to a sealing device for an immersion photolithography machine, in particular to a stepped self-adaptive gas sealing device for an immersion 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 an ultraviolet 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 (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 Photolithographic resolution and depth of focus. [0...

AI Technical Summary

Problems solved by technology

The larger the advancing contact angle, the easier it is for the outside gas to be entrained into the flow field to form bubbles, thereby affecting the uniformity of the flow field and the exposure imaging quality; the smaller the receding contact angle, the easier it is for the boundary liquid to be pulled to the periphery of the flow field. Leakage of liquid, and thus the formation of a series of defects (eg: water stains)

[0007] (2) The commonly used pressure-equalizing air seal method cannot adaptively compensate the boundary of the flow field, because a smaller air seal pressure will make it easier to leak at the receding contact angle, and a larger air seal pressure Will increase the possibility of liquid bubble entrainment at the advancing contact angle, the optimal seal gas pressure distribution changes instantaneously with the high-speed dynamic changes of the flow field boundary

However, there are also some sealing patents (for example, Chinese patents ZL200810164176.5 and ZL200910096971.X) that use non-uniform pressure air sealing or rotating to perform adaptive sealing of the gap flow field. Although the sealing effect is improved, there are still some shortcomings : During the high-speed and complex movement of the substrate, the slit flow field is in a turbulent state

As a result, the pressure and flow are unstable, and the pressure fluctuations caused by not being released effectively in time will continue to superimpose and cause vibration problems to the device, which will affect the exposure quality; in addition, these methods do not fully consider the extreme harshness of the substrate. Auxiliary remedial measures for serious consequences (such as droplet leakage) brought about by working conditions (such as instantaneous high acceleration and emergency stop conditions)

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