High-brightness laser produced plasma source and methods for generating radiation and mitigating debris

A method for generating radiation from a laser-produced plasma, comprising:

• forming a target (4) by centrifugal force as a layer of molten metal on a surface (16) of an annular groove (11), implemented inside a rotating target assembly (3);
• sending a pulsed laser beam (7) through an input window (6)) of a vacuum chamber (1) into an interaction zone (5) while providing a line of sight between the interaction zone (5) and both the input and output windows (6), (8) particularly during laser pulses, irradiating a target (4) on a surface of a rotating target assembly (3) by a laser beam (7), and passing a generated short-wavelength radiation beam (9) through an output window (8) of a vacuum chamber (1).

A method for mitigating debris in a laser-produced plasma (LPP) source, characterized by irradiating a target (4) on a surface of a rotating target assembly (3) with a pulsed laser beam (7), while the laser beam (7) enters through the input window (6) and a generated short-wavelength radiation beam (9) exits through the output window (8) of a vacuum chamber (1), said method comprising:

• the target (4) formation by centrifugal force as a layer of molten metal on a surface (16) of an annular groove (11), implemented inside the rotating target assembly (3),
• and using an orbital velocity VR of the rotating target assembly (3) high enough for the droplet fractions of the debris particles exiting the rotating target assembly not to be directed towards the input and output windows (6) and (8).