Utilities transfer system in a lithography system

Abstract

Techniques for transferring utilities to and from a reticle or wafer stage in a lithography system while minimizing physical disturbances that affect the stage are described. These techniques involve transferring utilities to and from the stage without making physical contact with the stage. Alternatively, utilities are transferred by making physical contact with the stage while the stage is in a stationary position. In addition to transferring utilities to and from the stage, devices such as processing devices, buffers (storage mediums), electrical components, and mechanical components can be placed within the stage to use and / or control the transferred utilities.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to lithography systems, and more specifically to techniques for minimizing physical disturbances and contamination of wafer or reticle stages when transferring utilities to such stages. BACKGROUND OF THE INVENTION [0002] Lithography systems are used to manufacture semiconductor devices by exposing semiconductor wafers to specific patterns of light. This is typically done by shining light, through a patterned reticle, onto the wafers. A reticle is supported within a reticle stage, which is in turn supported by a frame. The reticle stage is supported in a way that it can be precisely moved with respect to the frame and thereby with respect to the wafer. The reticle stage can be supported through mechanical devices such as actuators or through resistance-free techniques that employ air pressure or electromagnetic forces. In some lithography systems, a wafer stage, which supports a wafer, can also be precisely moved w...

AI Technical Summary

Benefits of technology

[0007] The present invention is directed to techniques for transferring utilities to and from a reticle or wafer stage in a lithography system while minimizing physical disturbances that affect the stage. These techniques involve transferring utilities to and from the stage without making physical contact with the stage. Alternatively, utilities are transferred by making physical contact with the stage while the stage is in a stationary position.

[0012] Yet another aspect of the invention pertains to a lithography system having a stage suitable for supporting a reticle or wafer, a stage port located on a surface of the stage, a frame for supporting the stage, a frame port located on a surface of the frame wherein the stage port and the frame port are suitable for making a connection with each other so that gas and / or fluids can be transferred between the stage and the frame, and a frame vacuum pump within the frame, the frame vacuum pump having vacuum passageways that extend to the surface of the frame at positions around a perimeter of the frame port, whereby the frame vacuum pump can evacuate any gas and / or fluids that leak from the connection between the stage port and the frame port.

Problems solved by technology

Unfortunately, typical problems with such transfer techniques include vibration transmission between the stage and the frame, particle generation by the connecting hoses and cables, and leaks by the hoses and cables.

This causes a reduction in stage positioning performance.

Particle generation is problematic because moving cables and hoses can generate particles as they bend, flex, and rub on fixed surfaces.

These particles can reduce performance of lithographic processes if they should migrate to the reticle, optics, wafer, or metrology devices.

Finally, leakage is always a risk since flexible hoses can break.

The solutions to reduce risk of such problems have led to stiff, bulky, or high bend-radius cables and hoses, which consume space or worsen vibration transmission.

Other solutions to reduce these risks include limiting coolant material to one, which is less effective than water, but evaporates quickly and is non-corrosive to system components.

These problems are especially problematic with Next Generation Lithography (NGL) systems, which require extremely high tolerances.

In addition to the already discussed problems, EUV systems have additional problems that are associated with flexible cables and hoses.

For one, out gassing of water and hydrocarbons from the flexible hoses can have adverse affects on the life of optical elements.

For example, water can corrode optical elements and such damage is irreparable.

Also, hydrocarbons reduce optical reflectivity over time, which will reduce system throughput.

Out gassing also adversely affects the time to reach operating vacuum levels.

The possible solution of baking-out cables and hoses only makes them stiffer which in turn exacerbates certain problems.

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