Lithographic apparatus and device manufacturing method

• US 20050083496A1
• Filed: 08/25/2004
• Published: 04/21/2005
• Est. Priority Date: 08/29/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Kemper, Nicolaas Rudolf, Van Der Schoot, Harmen Klaas, Cornelissen, Sebastiaan Maria Johannes, Cox, Henrikus Herman Marie, Van Diesen, Robert Johannes Petrus, Dansberg, Michel Pieter, Jansen, Rob, Munnig-Schmidt, Robert-Han
• Granted Patent: US 7,359,032 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: G03F 7/70933 Purge, e.g. exchanging fluid or gas to remove pollutants
• CPC Class Codes: G03F 7/7095 Materials, e.g. materials for housing, stage or other support having particular properties, e.g. weight, strength, conductivity, thermal expansion coefficient

Abstract

A lithographic projection apparatus is disclosed. The apparatus includes a radiation system for providing a beam of radiation, a first support structure for supporting a patterning device, a second support structure for supporting a substrate, and a projection system. At least one of the first and second support structures includes a planar base, a movable stage that can be moved over the planar base, and an actuator for moving the stage. The apparatus also includes a contactless position measuring device for measuring a position of the stage, and a first pump for generating a conditioned gas flow in a volume between the measuring device and the stage. The base includes a plurality of gas channels that provide a path for the conditioned gas to flow through the base.

Claims

1. A lithographic projection apparatus comprising:

a radiation system for providing a beam of radiation;

a first support structure for supporting a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern;

a second support structure for supporting a substrate,

at least one of said first and second support structures comprising a planar base, a movable stage that can be moved over said planar base, and an actuator for moving said stage;

a projection system for projecting the patterned beam onto a target portion of the substrate;

a contactless position measuring device for measuring a position of said stage; and

a first pump for generating a conditioned gas flow in a volume between said measuring device and said stage;

wherein said base comprises a plurality of gas channels that provide a path for said conditioned gas to flow through said base.

2. A lithographic projection apparatus according to claim 1, wherein said gas channels are connected to a second pump for removing gas from said channels and/or wherein said stage is provided with a third pump, for removing gas from between said stage and said base.

3. A lithographic projection apparatus according to claim 2, wherein any of said pumps are arranged to provide a gas flow speed between said stage and said base that is higher than the maximum speed of the stage on said base.

4. A lithographic projection apparatus according to claim 2, wherein said gas channels in said base are provided with valves arranged to close due to suction of said third pump.

5. A lithographic projection apparatus according to claim 2, wherein any of said pumps are so connected as to provide a closed-loop air shower.

6. A lithographic projection apparatus according to claim 5, wherein said base and said stage are contained in a closed environment, and wherein cooling and/or purifying devices are coupled between any of said pumps.

7. A lithographic projection apparatus according to claim 1, wherein said gas channels are provided in a regular pattern across substantially the whole planar base.

8. A lithographic projection apparatus according to claim 1, wherein the gas flow is oriented perpendicular to said base.

9. A lithographic projection apparatus according to claim 1, wherein said measuring device is an interferometer providing a measuring beam parallel to said base.

10. A lithographic projection apparatus according to claim 1, wherein said actuator comprises a planar electro magnetic motor.

11. A lithographic projection apparatus according to claim 10, wherein said planar magnetic motor comprises a stator coupled to said base, and a translator movable relative to said stator and coupled to said stage in order to provide a movement of the stage by electromagnetic forces, wherein at least one of said stator and said translator comprises a grid of magnets and/or electric wiring, and wherein said gas channels are provided on preselected corners of said grid.

12. A lithographic projection apparatus according to claim 1, wherein said stage is provided with a further pump in order to provide an air bearing between said stage and said base.

13. A planar magnetic motor comprising:

a stator; and

a translator movable relative to said stator in order to provide a relative movement of said translator to said stator by electromagnetic forces,

wherein gas channels are provided in said stator and/or said translator, in order to provide a gas flow path for removing heated air from between said stator and said translator, the gas channels being connectable to a pump.

14. A device manufacturing method comprising:

patterning a beam of radiation with a patterning device supported by a first support structure;

projecting the patterned beam of radiation onto a target portion of a substrate supported by a second support structure;

measuring a position of a movable stage of said first support structure and/or said second support structure with a measuring device; and

pumping a conditioned gas flow in a volume between said measuring device and said stage and through a plurality of gas channels in a base of said first support structure and/or said second support structure.

15. A stage assembly and measuring device therefor for a lithographic projection apparatus, comprising:

a base;

a movable stage that can be moved across said base;

a contactless position measuring device for measuring a position of said stage; and

a pump for generating a conditioned gas flow in a volume between said measuring device and said stage;

wherein said base comprises a plurality of gas channels that provide a path for said conditioned gas to flow through said base.