Correction of spatial instability of an EUV source by laser beam steering

摘要

A method to align a discharge axis of a discharge radiation source with respect to optics of the lithographic apparatus includes creating a discharge in a substance in a discharge space between an anode and a cathode to form a plasma so as to generate electromagnetic radiation. The discharge is triggered by irradiating an area on a surface proximate the discharge space with an energetic beam. The position of the area is controlled in response to a property of the radiation in the lithographic apparatus and/or the temperature of a collector of the lithographic apparatus. Controlling the position of the area which is irradiated improves alignment of the discharge axis with the different lithographic modules, such as the contamination barrier, the illumination system, the substrate table and/or the projection system.

主权项

1. A radiation system, comprising:
a radiation source; and a triggering device configured to initiate a discharge in a discharge material in a discharge space to form a plasma so as to generate electromagnetic radiation by irradiating an area on a surface of a predetermined material different from and proximate to the discharge material in the discharge space with an energetic beam, wherein the triggering device is configured to control a position of the area in response to an input signal received from a sensor positioned downstream from the radiation source relative to a propagation direction of the electromagnetic radiation.