Foil trap and extreme ultraviolet light source device using the foil trap

An extreme ultraviolet light source device, comprising:

• a vessel;
• an extreme ultraviolet radiating species supply means that feeds an extreme ultraviolet radiating species into the vessel;
• a discharge part that comprises a pair of discharge electrodes that heat and excite the extreme ultraviolet radiating species and generate a high-temperature plasma;
• a collector mirror that collects extreme ultraviolet radiation emitted from the plasma;
• a foil trap installed between the discharge part and the collector mirror;
• an extractor part formed in the vessel that extracts the extreme ultraviolet radiation collected;
• and
• an evacuation means that exhausts the vessel and regulates pressure within the vessel, wherein the foil trap includes:
• a plurality of foils extending radially from a main axis thereof, and configured to capture debris from the extreme ultraviolet light source, while allowing the emitted extreme ultraviolet radiation to pass through the foils to the collector mirror,
• wherein, in at least a portion of a region through which the extreme ultraviolet radiation passes through, a length of the foils in a direction parallel to the main axis and a direction of passage of the extreme ultraviolet radiation is shorter in positions close to the main axis than in positions distant from the main axis.