Lithographic apparatus, radiation beam inspection device, method of inspecting a beam of radiation and device manufacturing method

• US 20070002301A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Venema, Willem
• Granted Patent: US 7,307,694 B2
• Time in Patent Office: Days
• US Class Current: 355/69
• CPC Class Codes: G03F 7/70275 Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load

Abstract

A lithographic apparatus having a radiation beam inspection device comprising a barrier to the beam of radiation, the barrier having an aperture through which a portion of the beam of radiation passes; and a radiation sensor that determines the intensity of the radiation passing through the aperture and the position, relative to the aperture, of the point at which the radiation is incident on the radiation sensor.

Claims

1. A lithographic projection apparatus, comprising:

a patterning device that modulates a beam of radiation;

a projection system that projects the modulated beam onto a target portion of a substrate; and

a radiation beam inspection device that comprises,

a barrier to the radiation beam having an aperture that permits a portion of the radiation beam to pass through the barrier, and

a radiation sensor that detects intensity of the radiation passing through the aperture and a position, relative to the aperture, at which the radiation passing through the aperture is incident on the radiation sensor.

2. The lithographic projection apparatus of claim 1, further comprising:

an actuator constructed to move at least the barrier of the radiation inspection device relative to the beam of radiation, such that the aperture intersects the beam of radiation at a plurality of different locations within a cross-section of the beam.

3. The lithographic projection apparatus of claim 1, wherein the projection system comprises:

an array of focusing elements that each project a portion of the modulated beam of radiation onto the substrate, such that the modulated beam of radiation is projected as an array of sub-beams of radiation; and

a size of a largest dimension of the aperture is smaller than a separation between adjacent ones of the sub-beams of radiation in a plane at which the array of sub-beams are incident on the barrier.

4. The lithographic projection apparatus of claim 3, wherein the size of the largest dimension of the aperture is larger than a width of one of the array of sub-beams of radiation in the plane at which the array of sub-beams are incident on the barrier.

5. The lithographic projection apparatus of claim 1, wherein the aperture has an elongate shape.

6. The lithographic projection apparatus of claim 5, further comprising an actuator that rotates at least the barrier of the radiation inspection device relative to the projection system.

7. The lithographic projection apparatus of claim 5, wherein the lithographic apparatus comprises two radiation beam inspection devices, which are arranged such that the elongate directions of their apertures are not parallel to each other.

8. The lithographic projection apparatus of claim 7, wherein the radiation beam inspective devices are arranged such that the elongate direction of the apertures are perpendicular with respect to each other.

9. The lithographic projection apparatus of claim 1, further comprising:

a substrate table that supports the substrate, wherein the radiation beam inspection device is mounted to the substrate table.

10. The lithographic projection apparatus of claim 9, further comprising:

a substrate table actuator that moves the substrate table relative to the projection system, wherein the substrate table holds the substrate in a fixed position relative to the substrate table.

11. The lithographic projection apparatus of claim 10, wherein the radiation beam inspection device is mounted adjacent to the fixed position of the substrate.

12. The lithographic projection apparatus of claim 9, wherein:

the radiation beam inspection device is mounted to the substrate table such that, during exposure of the substrate, the substrate is located between the projection system and the radiation beam inspection device, and such that the radiation beam inspection device inspects at least a part of the beam of radiation when no substrate is located in a position to be exposed.

13. The lithographic projection apparatus of claim 12, wherein the substrate table comprises:

a substrate actuator that moves the substrate relative to the substrate table during a sequence of exposures of the substrate.

14. The lithographic projection apparatus of claim 1, further comprising:

a plurality of the radiation beam inspection devices arranged in fixed positions relative to each other; and

an actuator that moves the radiation beam inspection devices at a constant velocity relative to the projection system, such that the radiation beam is pulsed;

wherein the spacing of the radiation beam inspection devices, the velocity of the radiation beam inspection devices relative to the projection system, and the pulse rate of the beam are arranged such that successive radiation beam inspection devices inspect different parts of a given region of the beam of radiation during successive pulses of the beam of radiation.

15. The lithographic projection apparatus of claim 1, further comprising:

an actuator that moves at least the barrier at a constant velocity relative to the projection system;

wherein the radiation beam is pulsed;

wherein the barrier to the radiation in the radiation beam inspection device has a plurality of apertures; and

wherein the spacing of the apertures, the velocity of the barrier relative to the projection system, and the pulse rate of the beam are arranged such that successive apertures allow different portions of a given region of the beam of radiation to pass through the barrier to the radiation sensor during successive pulses of the beam of radiation.

16. A radiation beam inspection device, comprising

a radiation barrier having an aperture that permits a portion of a beam of radiation that is incident on the radiation beam inspection device to pass through the barrier;

and

a radiation sensor that detects an intensity of the radiation passing through the aperture and the position, relative to the aperture, at which the radiation passing through the aperture is incident on the radiation sensor.

17. The radiation beam inspection device according to claim 16, further comprising:

an actuator that moves at least the radiation barrier relative to a position of the beam of radiation, such that the aperture intersects the beam of radiation at a plurality of different locations within a cross-section of the beam.

18. A method of inspecting a beam of radiation, comprising:

inspecting at least a portion of the beam of radiation using a radiation beam inspection device that comprises a barrier to the radiation, the barrier having an aperture that permits a portion of the radiation beam to pass through the barrier, and a radiation sensor;

using the radiation sensor to detect an intensity of the beam of radiation passing through the aperture and a position, relative to the aperture, at which the beam of radiation passing through the aperture is incident on the radiation sensor.

19. The method of claim 18, wherein:

the beam of radiation is inspected a plurality of times to produce a plurality of radiation intensities, the aperture intersecting the beam of radiation at a different location within the cross-section of the beam on each of the plurality of inspection times; and

the plurality of radiation intensity readings are used to determine the intensity profile of at least a part of the beam of radiation and at least one of the position measurements is used to determine the direction of propagation of at least a portion of the beam of radiation.

20. The method of claim 19, further comprising:

using a lithographic apparatus to generate the beam of radiation;

using the lithographic apparatus to project a modulated beam of radiation onto a substrate;

wherein at least one setting of the lithographic apparatus is set, for the step of projecting a modulated beam of radiation onto the substrate, using the results of the inspection step.

21. A flat panel display manufactured according to claim 20.

22. An integrated circuit device manufactured according to claim 20.