A light source apparatus according to an embodiment includes: a target material capable of generating EUV light when being irradiated with laser light; a collector mirror configured to reflect the EUV light; an exhaust case including an outer cover disposed between the target material and the collector mirror, and an exhaust port communicating with an exhaust space formed on a target material side of the outer cover; a cylindrical optical-path cover a diameter of an opening another end being larger than that of an opening at one end; and a filter that is disposed at the other end of the optical-path cover or inside thereof, and configured to let the EUV light pass therethrough.

A radiation source includes a fuel supply, a collector, a debris mitigation system, and a temperature control system. The fuel supply device supplies fuel. The excitation device excites the fuel into a plasma. The collector collects radiation emitted by the plasma and directs the radiation to a beam exit. The debris mitigation system collects debris generated by the plasma and has a first component having a first conduit passing therethrough and a second component having a second conduit passing therethrough. The temperature control system increases or decreases temperatures of the first component and the second component by selectively heating or cooling a thermal transfer fluid circulating through the respective conduit. The temperature control system cools the first component to a first temperature that is below the melting point of the fuel and heats the second component to a second temperature that is above the melting point of the fuel.

Some implementations described herein incorporate a heating system to heat a cover of a bucket. A liquified target material, collected by vanes and/or a transport ring within a vessel of an extreme ultraviolet (EUV) radiation source, flows through a drain port of the transport ring and through a conduit that provides the liquified target material to the bucket through an opening of the cover. By heating the cover, the heating system prevents the liquified target material from solidifying at or near the opening before the liquified target material can flow into the bucket. By preventing the solidifying of the liquid target material, a likelihood of a blockage within the conduit and/or the drain port is reduced.

The disclosed embodiments include a vacuum chamber that may include a vacuum chamber wall having a first wall layer and a second wall layer defining a gap therebetween, where the first wall layer is subjected to a heat source and the second wall layer is subjected to a cooling source. Also, the vacuum chamber may include a gas supply device connected to the gap and configured to supply a gas thereto. Furthermore, the vacuum chamber may include a controller connected to the gas supply device and configured to control pressure of the gas in the gap so as to control heat flow across the vacuum chamber wall.