Lithographic apparatus and device manufacturing method

• US 9,195,153 B2
• Filed: 12/03/2012
• Issued: 11/24/2015
• Est. Priority Date: 11/12/2002
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Lof, Joeri, De Smit, Joannes Theodoor, Ritsema, Roelof Aeilko Siebrand, Simon, Klaus, Modderman, Theodorus Marinus, Mulkens, Johannes Catharinus Hubertus, Meijer, Hendricus Johannes Maria, Loopstra, Erik Roelof
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): WILLIAMS, DON J
• Application Number:
  US13/692,865
• Publication Number:
  US 20130128256A1
• Time in Patent Office: 1,086 Days
• Field of Search: 250/548, 250/559.3, 250/559.33, 250/599.3, 356399-403, 355/30, 355/53, 355/67, 355 72- 76
• US Class Current: 1/1
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• 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
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment
• CPC Class Codes: G03F 9/7034 Leveling
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection

Abstract

A map of the surface of a substrate is generated at a measurement station. The substrate is then moved to where a space between a projection lens and the substrate is filled with a liquid. The substrate is then aligned using, for example, a transmission image sensor and, using the previous mapping, the substrate can be accurately exposed. Thus the mapping does not take place in a liquid environment.

Claims

1. A lithographic apparatus comprising:

an exposure station including a projection system configured to project a patterned beam of radiation through liquid onto a target portion of a substrate held on a first substrate table;

a measurement station configured to measure a substrate held on a second substrate table, wherein measurement of the substrate at the measurement station is not performed through said liquid adjacent the substrate; and

a positioning system configured to move the second substrate table from the measurement station to the exposure station so as to position the substrate held on the second substrate table into an optical path of the projection system.

2. The lithographic apparatus of claim 1, wherein the positioning system is configured to move the first substrate table from the exposure station to the measurement station.

3. The lithographic apparatus of claim 1, wherein measurement of the substrate at the measurement station is performed through a second liquid adjacent the substrate, the second liquid different from said liquid.

4. The lithographic apparatus of claim 1, wherein said liquid is in contact with a last element of the projection system and the substrate during projection of the patterned beam of radiation.

5. The lithographic apparatus of claim 1, wherein the measurement station is configured to measure a height, a tilt, or both, of each of a plurality of points on the substrate.

6. The lithographic apparatus of claim 1, wherein the measurement station is configured to measure the substrate held on the second substrate table in the absence of liquid adjacent the substrate.

7. The lithographic apparatus of claim 1, wherein the second substrate table comprises a reference and the measurement station comprises an alignment system configured to measure a location of the reference.

8. The lithographic apparatus of claim 7, comprising an alignment system configured to measure a location of the reference at the exposure station, wherein if the reference is not measured through liquid a correction is applied.

9. The lithographic apparatus of claim 1, wherein the exposure station comprises a liquid supply system configured to provide liquid onto the target portion of the substrate.

10. The lithographic apparatus of claim 1, wherein measurement of the substrate at the measurement station is performed at least partially overlapping in time with exposure of the substrate at the exposure station.