Plasma radiation source with axial magnetic field

Abstract

A patterned beam of radiation is projected onto a substrate. A reflective optical element is used to help form the radiation beam from radiation emitted from a plasma region of a plasma source. In the plasma source, a plasma current is generated in the plasma region. To reduce damage to the reflective optical element, a magnetic field is applied in the plasma region with at least a component directed along a direction of the plasma current. This axial magnetic field helps limit the collapse of the Z-pinch region of the plasma. By limiting the collapse, the number of fast ions emitted may be reduced.

Description

technical field [0001] The invention relates to a plasma radiation source, an apparatus for forming a radiation beam using a plasma radiation source (in an embodiment the apparatus is a lithographic apparatus), a method for forming plasma radiation and A device manufacturing method. Background technique [0002] A lithographic apparatus is a machine that applies a desired pattern to a substrate, usually a target portion of the substrate. For example, lithographic equipment may be used in the manufacture of integrated circuits (ICs). In this case, a patterning device, alternatively referred to as a mask or reticle, may be used to generate the circuit pattern to be formed on the individual layers of the IC. The pattern can be transferred onto a target portion (eg, comprising a portion, one or more dies) on a substrate (eg, a silicon wafer). Typically, the pattern is transferred by imaging the pattern onto a layer of radiation sensitive material (resist) provided on the subs...

AI Technical Summary

Problems solved by technology

Unfortunately, these fast ions can cause damage to reflective elements in lithographic equipment

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