Radiation source and method for lithographic apparatus for device manufacture
First Claim
1. A radiation source having a fuel droplet generator configured to provide a stream of droplets of fuel at least one laser configured to vaporize at least some of said droplets of fuel, whereby radiation is generated, the fuel droplet generator comprising:
- a nozzle;
a fuel feed line;
a reservoir;
a pumping device configured to supply a flow of molten metal fuel from the reservoir through the fuel feed line and out of the nozzle as a stream of droplets; and
a replaceable filter assembly in the fuel feed line and configured to filter said molten metal fuel in use, the replaceable filter assembly having a rigid support plate having first and second opposed faces, with one or more channels, each extending from a respective first aperture in the first face through a respective second aperture in the second face, and supporting a filter membrane on the first face and extending over each first aperture of the first face,wherein the filter membrane comprises mutually spaced holes therein, with each first aperture aligned with a plurality of the holes to provide fluid connection between the plurality of holes and the respective channel.
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Accused Products
Abstract
A radiation source for generating EUV from a stream of molten metal fuel droplets by LPP (Laser Produced Plasma) or (Dual Laser Plasma) has a fuel droplet generator arranged to provide a stream of droplets of fuel and at least one laser configured to vaporise at least some of said droplets of fuel, whereby radiation is generated. The fuel droplet generator has nozzle, fuel supply line, and reservoir, with a pumping device arranged to supply a flow of molten metal fuel from the reservoir through the fuel feed line and out of the nozzle as a stream of droplets. The fuel droplet generator has a replaceable filter assembly in the fuel feed line, arranged to filter the molten metal fuel in use, to deter nozzle blockage by solid particulate impurities in the fuel.
18 Citations
20 Claims
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1. A radiation source having a fuel droplet generator configured to provide a stream of droplets of fuel at least one laser configured to vaporize at least some of said droplets of fuel, whereby radiation is generated, the fuel droplet generator comprising:
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a nozzle; a fuel feed line; a reservoir; a pumping device configured to supply a flow of molten metal fuel from the reservoir through the fuel feed line and out of the nozzle as a stream of droplets; and a replaceable filter assembly in the fuel feed line and configured to filter said molten metal fuel in use, the replaceable filter assembly having a rigid support plate having first and second opposed faces, with one or more channels, each extending from a respective first aperture in the first face through a respective second aperture in the second face, and supporting a filter membrane on the first face and extending over each first aperture of the first face, wherein the filter membrane comprises mutually spaced holes therein, with each first aperture aligned with a plurality of the holes to provide fluid connection between the plurality of holes and the respective channel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A fuel droplet generator for providing a stream of droplets of fuel for use in a radiation source for device lithography, the fuel droplet generator comprising a nozzle, a fuel feed line, a reservoir, and a pumping device arranged to supply a flow of molten metal fuel from the reservoir through the fuel feed line and out of the nozzle as a stream of droplets,
wherein the fuel droplet generator has a filter assembly in the fuel feed line, arranged to filter said molten metal fuel in use, the filter assembly comprising a rigid support plate having first and second opposed faces, with one or more channels, each extending from a respective first aperture in the first face through a respective second aperture in the second face, and supporting a filter membrane bonded to the first face and extending over each first aperture of the first face, wherein the filter membrane comprises mutually spaced holes therein, with each first aperture aligned with a plurality of the holes to provide fluid connection between the plurality of holes and the respective channel.
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12. A method for filtering a molten metal fuel supply for a fuel droplet generator for providing a stream of droplets of molten metal fuel to provide a radiation source, by laser excitation, for device lithography, the fuel droplet generator comprising a nozzle, a fuel feed line, a reservoir, and a pumping device arranged to supply a flow of molten metal fuel from the reservoir through the fuel feed line and out of the nozzle as a stream of droplets, the method comprising:
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inserting and retaining a replaceable filter assembly in the fuel feed line, arranged to filter the molten metal fuel in use, the replaceable filter assembly comprising a rigid support plate having first and second opposed faces, with one or more channels, each extending from a respective first aperture in the first face through a respective second aperture in the second face, and supporting a filter membrane on the first face and extending over each first aperture of the first face, wherein, the filter membrane comprises mutually spaced holes therein, with each first aperture aligned with a plurality of the holes to provide fluid connection between the plurality of holes and the respective channel. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification