Abstract:
A system for controlling convective flow in a light-sustained plasma includes an illumination source configured to generate illumination, a plasma cell including a bulb for containing a volume of gas, a collector element arranged to focus illumination from the illumination source into the volume of gas in order to generate a plasma within the volume of gas contained within the bulb. Further, the plasma cell is disposed within a concave region of the collector element, where the collector element includes an opening for propagating a portion of a plume of the plasma to a region external to the concave region of the collect element.
Abstract:
A plasma cell for controlling convection includes a transmission element configured to receive illumination from an illumination source in order to generate a plasma within a plasma generation region of the volume of gas. The plasma cell also includes a top flow control element disposed above the plasma generation, which includes an internal channel configured to direct a plume of the plasma upward, and a bottom flow control element disposed below the plasma generation region, which includes an internal channel configured to direct gas upward toward the plasma generation region. The top flow control element and the bottom flow control element are arranged within the transmission element to form one or more gas return channels for transferring gas from a region above the plasma generation region to a region below the plasma generation region.
Abstract:
The inspection of a sample with VUV light from a laser sustained plasma includes generating pumping illumination including a first selected wavelength, or range of wavelength, containing a volume of gas suitable for plasma generation, generating broadband radiation including a second selected wavelength, or range of wavelengths, by forming a plasma within the volume of gas by focusing the pumping illumination into the volume of gas, illuminating a surface of a sample with the broadband radiation emitted from the plasma via an illumination pathway, collecting illumination from a surface of the sample, focusing the collected illumination onto a detector via a collection pathway to form an image of at least a portion of the surface of the sample and purging the illumination pathway and/or the collection pathway with a selected purge gas.
Abstract:
A plasma cell for controlling convection includes a transmission element configured to receive illumination from an illumination source in order to generate a plasma within a plasma generation region of the volume of gas. The plasma cell also includes a top flow control element disposed above the plasma generation, which includes an internal channel configured to direct a plume of the plasma upward, and a bottom flow control element disposed below the plasma generation region, which includes an internal channel configured to direct gas upward toward the plasma generation region. The top flow control element and the bottom flow control element are arranged within the transmission element to form one or more gas return channels for transferring gas from a region above the plasma generation region to a region below the plasma generation region.