Extreme UV radiation source device and method for eliminating debris which forms within the device
To suppress the adherence of debris as a result of a radiating fuel, such as tin or the like, within a vessel for forming high density and high temperature plasma of an extreme UV radiation source device, and to eliminate deposited tin and/or tin compounds with high efficiency, hydrogen radical producing parts are provided in the vessel; and hydrogen radicals are produced in the vessel so that deposition of tin and/or a tin compound is suppressed in the area with a low temperature of the device, such as a focusing mirror or the like, and the deposited tin and/or tin compound is eliminated.
1. Extreme UV radiation source device, comprising:
a vessel for forming high density and high temperature plasma;
a raw material supply means which supplies a raw material which contains at least one of tin and a tin compound to the vessel as an extreme UV radiating fuel;
a heating/excitation means for heating and exciting the raw material supplied to the vessel to produce high density and high temperature plasma;
an evacuation means which is connected to the vessel;
an exit part for extreme UV radiation from which the extreme UV radiation which has been emitted by the high density and high temperature plasma emerges, and
a means for feeding hydrogen radicals provided in the vessel, wherein said means for feeding hydrogen radicals includes a radical producing part which is arranged such that the emission direction of the hydrogen radicals which have been emitted by the radical producing part crosses an outlet flow containing debris including tin and/or a tin compound which is formed in the extreme UV radiation source device.
2. Extreme UV radiation source device as claimed in claim 1 , further comprising a focusing mirror disposed in an area of an optical path defined between a part where high density and high temperature plasma is formed and an exit part for extreme UV radiation and wherein the means for feeding hydrogen radicals supplies hydrogen radicals to an area between a reflection surface of the focusing mirror and an area in which the high density and high temperature plasma is formed.
3. Process for eliminating debris which forms in an extreme UV radiation source device, comprising the steps of:
supplying a raw material which contains at least one of tin and a tin compound to a vessel of an extreme UV radiation source device as an extreme UV radiation radiating fuel for forming a high density and high temperature plasma;
producing a high density and high temperature plasma by heating/excitation of the raw material supplied to the vessel, and
supplying hydrogen radicals to debris which forms in said vessel of the extreme UV radiation source device and that contains at least one of tin and a tin compound for eliminating said debris,
wherein a hydrogen radical producing part for supplying hydrogen radicals emits hydrogen radicals in such a way that said radicals cross an outlet flow which contains debris including tin and/or a tin compound.