Apparatus For Delivering Gas and Illumination Source for Generating High Harmonic Radiation

摘要

A gas delivery system suitable for a harmonic generating (HHG) radiation source that can be used to generate measurement radiation for an inspection apparatus is disclosed. In such a radiation source, the gas delivery element delivers gas in a first direction. The gas delivery element has an optical input and an optical output defining an optical path running in a second direction. The first direction is disposed relative to the second direction at an angle that is not parallel or perpendicular. Also disclosed is a gas delivery element or a pair of gas delivery elements having a gas jet shaping device, one of which delivers a second gas, wherein the gas jet shaping device or the second gas has an abrupt number density of the gas. operable to modify the flow profile of the gas to fall