Plasma generating apparatus and method for extreme-ultaviolet laser

Abstract

A plasma generating apparatus for an extreme-ultraviolet laser that can generate high temperature plasma at high efficiency, and can form long plasma to be recombined by rapid cooling of the high temperature plasma. A shield plate including a narrow slit is disposed adjacent to a high temperature plasma source, and the high temperature plasma is discharged through the slit. Both high efficiency plasma generation and rapid expansion thereof can be simultaneously achieved by discharging high temperature plasma through the narrow slit. The rapid expansion makes it possible to form a long plasma having a large gain in an extreme-ultraviolet region. The high temperature plasma source can be readily realized by irradiating it with an exciting laser beam from behind the opposite side of the slit with regard to the high temperature plasma source directly or through a transmitting window. A closure provided in front of the slit can prevent a liquid or gas from flowing out of the slit before it is changed into plasma. This makes it possible to use a liquid or gas as a plasma source material.

Dependencies are inferred from the claim text.