Plasma-type X-ray generators encased in vacuum chambers exhibiting reduced heating of interior components, and microlithography systems comprising same
AssigneeNikon Corporation
InventorHiroyuki Kondo
Life of this patent
Estimating the term…
Abstract
X-ray generators are disclosed that produce X-ray radiation from a plasma and that exhibit reduced heating of certain components caused by proximity to the plasma. An embodiment of such an X-ray generator is encased in a vacuum chamber that exhibits reduced reflection and scattering of electromagnetic radiation from the inner walls thereof to components contained in the chamber. Since less reflected radiation reaches the components, the components experience less temperature increase during use. For example, the inner walls can be coated with a film of carbon black that absorbs incident radiation from infrared to ultraviolet.
Claims19
An X-ray generator, comprising:
- an X-ray source in which a plasma is produced from a target material and X-rays are emitted from the plasma;
- and
- a vacuum chamber defined by walls and containing the X-ray source, the walls including respective inner surfaces configured so that at least a portion of the inner surfaces absorbs incident electromagnetic radiation, produced by the plasma, in a wavelength range from infrared to X-ray radiation, the portion representing a location from which the electromagnetic radiation otherwise would reflect back into the vacuum chamber and heat a component situated inside the vacuum chamber.
An X-ray generator, comprising:
- an X-ray source in which a plasma is produced from a target material and X-rays are emitted from the plasma;
- and
- a vacuum chamber defined by walls and containing the X-ray source, at least a portion of the walls being made of a material that is transmissive to incident electromagnetic radiation, from the plasma, in a wavelength range from infrared to ultraviolet, the portion representing a location from which the electromagnetic radiation otherwise would reflect back into the vacuum chamber and heat a component situated inside the vacuum chamber.
Dependencies are inferred from the claim text.