Patent ID: 9686846
Date: 2017-06-20
CPC Classifications: H01S,H05G

Claim:
1. An extreme ultraviolet light source device comprising: a disc-like rotating element having two side surfaces and an outer circumferential surface between said two side surfaces, each of the two side surfaces being flat; a rotation unit configured to cause the rotating element to rotate about a rotation center shaft, which is perpendicular to one of the two side surfaces of the rotating element; a cover-like structure configured to surround the rotating element with a gap; a first reserving vessel disposed in the cover-like structure and configured to reserve a liquid high temperature plasma raw material, with part of the rotating element being immersed in the high temperature plasma raw material reserved in the first reserving vessel; a raw material supplying mechanism configured to apply the liquid high temperature plasma raw material onto at least part of said one of the two side surfaces of the rotating element upon a rotating movement of the rotating element; an energy beam providing device configured to irradiate the high temperature plasma raw material with an energy beam; and a film thickness controlling mechanism provided in the cover-like structure, the film thickness controlling mechanism including a U-shaped structure, the U-shaped structure having two opposite sides and one connecting portion spanning the two opposite sides to define a U shape, each of the two opposite sides having a free end face, the U-shaped structure being biased by an elastic body in a direction against said one of the two side surfaces of the rotating element such that said free end faces of the two opposite sides of the U-shaped structure contact said one of the two side surfaces of the rotating element, a clearance between the rotating element and said one connecting portion of the U-shaped structure, which faces the rotating element, being set such that the liquid high temperature plasma raw material applied on the rotating element has a predetermined film thickness, the cover-like structure having an opening to expose a portion of said one of the two side surfaces of the rotating element and a portion of the outer circumferential surface of the rotating element such that the energy beam is directed to said one of the two side surfaces of the rotating element, on which the high temperature plasma raw material is applied, through the opening of the cover-like structure, and extreme ultraviolet light generated upon irradiation of the energy beam is released from the opening of the cover-like structure, the cover-like structure having a scattering preventing member extending in said opening of the cover-like structure, the scattering preventing member having a bending surface to oppose a direction of a centrifugal force acting on the rotating element, which is caused to rotate by the rotation unit, in said opening of the cover-like structure, the cover-like structure and the scattering preventing member being configured, in combination, to cover entirety of the outer circumferential surface of the rotating element.