Lithographic apparatus and methods
AssigneeASML Netherlands B.V.
InventorsKoen Kivits, Hans Jansen, Vasco Miguel Matias Serrao
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Abstract
A system for cleaning a limited area of a top surface of a substrate table or an object positioned on a top surface of a substrate table is disclosed. The optical system used during normal imaging is adjusted to limit the cross-sectional area of a radiation beam to form a cleaning radiation beam which impinges on the limited area.
Claims25
A method of cleaning an area of a top surface of a table or of an object on a table in a lithography apparatus, the method comprising:
- providing a liquid between the area and an optical system of the lithography apparatus, which optical system is used in normal operation to generate and project a patterned beam of radiation onto a substrate;
- and
- projecting a cleaning radiation beam through the liquid using the optical system onto the area,
- wherein the projecting includes adjusting the optical system to limit a cross- sectional area of the cleaning radiation beam impinging on the area compared to the patterned beam of radiation.
A method of cleaning an area of a sensor on a table in a lithography apparatus, the method comprising:
- providing a liquid between the area and an optical system of the lithography apparatus, which optical system is used in normal operation to generate and project a patterned beam of radiation onto a substrate;
- and
- projecting a cleaning radiation beam through the liquid using the optical system onto only the sensor,
- wherein the cleaning radiation beam is substantially unpatterned.
A method of cleaning an area of a top surface of a table or of an object on a table in a lithography apparatus, the method comprising:
- providing a liquid between the area and an optical system of the lithography apparatus, which optical system is used in normal operation to generate and project a patterned beam of radiation onto a substrate;
- and
- projecting a cleaning radiation beam through the liquid using the optical system onto the area,
- wherein the projecting includes adjusting the optical system to adjust a cross- sectional dimension of the cleaning radiation beam impinging on the top surface so that the cleaning radiation beam is limited to the area.
A lithographic projection apparatus, comprising:
- a movable table;
- an optical system configured to project a patterned beam of radiation onto a substrate;
- and
- a controller configured to control the apparatus to clean an area of a top surface of the table or of an object on the table by causing provision of a liquid between the area and the optical system and projection of a cleaning radiation beam through the liquid using the optical system onto the area, wherein the projection includes adjustment of the optical system to limit a cross-sectional area of the cleaning radiation beam impinging on the area compared to the patterned beam of radiation.
Dependencies are inferred from the claim text.