Lithographic apparatus and device manufacturing method

Abstract

A system and method are used to direct a radiation beam to illuminate non-perpendicularly a patterning array of individually controllable elements used for patterning the radiation beam. The individually controllable elements can change a telecentricity of the radiation beam. Projection of the radiation beam onto the individually controllable elements can be by a concave mirror or use a folding mirror placed in an object field of the individually controllable elements. Alternatively, the individually controllable elements can change the optical axis of the radiation beam.

Description

BACKGROUND [0001] 1. Field of the Invention [0002] The present invention relates to a lithographic apparatus and a device manufacturing method. [0003] 2. Related Art [0004] A lithographic apparatus is a machine that applies a desired pattern onto a target portion of a substrate. The lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs), flat panel displays, and other devices involving fine structures. In a conventional lithographic apparatus, a patterning means, which is alternatively referred to as a mask or a reticle, can be used to generate a circuit pattern corresponding to an individual layer of the IC (or other device), and this pattern can be imaged onto a target portion (e.g., comprising part of one or several dies) on a substrate (e.g., a silicon wafer or glass plate) that has a layer of radiation-sensitive material (e.g., resist). Instead of a mask, the patterning means can comprise an array of individually controllable elements t...

AI Technical Summary

Benefits of technology

[0010] In one example, the individually controllable elements can change the telecentricity of the radiation beam. This can be done by providing a folding mirror or prism in the object field of the individually controllable elements or a concave optical element to project the radiation beam onto the individually controllable elements.

Problems solved by technology

Use of the polarization to control the direction of the radiation beam means that the cross section of the radiation beam has a uniform polarization, and thus different polarizations cannot be used to create different effects during the exposure.

Also, beam splitters are inefficient and can be difficult to thermally control.

A non-polarizing beam splitter, with a half silvered mirror, can be used instead of a polarizing beam splitter to avoid polarization issues, but with two passes through such a device about 75% or more of the radiation is lost, substantially reducing throughput.

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