Immersion lithographic apparatus and device manufacturing method detecting residual liquid

• US 8,319,939 B2
• Filed: 10/30/2008
• Issued: 11/27/2012
• Est. Priority Date: 07/07/2004
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Streefkerk, Bob, Baselmans, Johannes Jacobus Matheus, Donders, Sjoerd Nicolaas Lambertus, Hoogendam, Christiaan Alexander, Mertens, Jeroen Johannes Sophia Maria, Mulkens, Johannes Catharinus Hubertus
• Primary Examiner(s): Kim, Peter B
• Assistant Examiner(s): LIU, CHIA HOW MICHAEL
• Application Number:
  US12/289,591
• Publication Number:
  US 20090079949A1
• Time in Patent Office: 1,489 Days
• Field of Search: 355/30, 355/53, 355/67
• US Class Current: 355/30
• 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 7/70866 of mask or workpiece
• CPC Class Codes: G03F 9/7026 Focusing
• CPC Class Codes: G03F 9/7034 Leveling

Abstract

In immersion lithography after exposure of a substrate is complete, a detector is used to detect any residual liquid remaining on the substrate and/or substrate table.

Claims

1. A device manufacturing method comprising projecting, using a projection system of a lithographic apparatus, a patterned beam of radiation through a liquid onto a substrate while being held by a substrate table of the lithographic apparatus, and, after the projecting is complete, detecting whether there is presence of residual liquid (i) on the substrate table, (ii) on a further movable table of the lithographic apparatus, or (iii) both (i) and (ii).

2. The method according to claim 1, further comprising drying the substrate, the substrate table, and/or the further movable table in the event that the residual liquid is detected on the substrate table and/or the further movable table.

3. The method according to claim 1, wherein the detecting the residual liquid comprises measuring the position of a surface in a direction substantially parallel to an optical axis of the projection system, a tilt of a surface about axes substantially perpendicular to the optical axis of the projection system, or both.

4. The method according to claim 3, wherein the detecting of the residual liquid on the substrate table and/or the further movable table is effected by the measuring of the position, tilt, or both giving a measurement outside a normal operating range or varying significantly from a previous measurement or reference value.

5. The method according to claim 1, wherein the detecting the residual liquid comprises measuring the position of a marker, wherein the position measured is in a direction substantially perpendicular to an optical axis of the projection system.

6. The method according to claim 5, wherein the detecting of the residual liquid on the substrate table and/or the further movable table is effected by the measuring of the position giving a measurement outside a normal operating range or varying significantly from a previous measurement or reference value.

7. The method according to claim 1, wherein the projecting the patterned beam of radiation is performed at an exposure station and the detecting the residual liquid is performed at a measurement station, the measurement station being physically separate from the exposure station.

8. The method according to claim 1, further comprising generating, upon detection of the residual liquid, an alarm or error signal to instruct performance of a drying action.

9. A device manufacturing method comprising:

projecting, using a projection system of a lithographic apparatus, a patterned beam of radiation through a liquid onto a substrate while being held by a substrate table; and

detecting a property of a surface (i) of the substrate table, (ii) of a further movable table of the lithographic apparatus, or (iii) both (i) and (ii), in addition to or other than detecting a property of the liquid on the surface, after an exposure through the liquid is completed, wherein a measurement of the property that is outside a normal operating range or varies significantly from a previous measurement before application of the liquid to the surface is indicative of the presence of the liquid on the surface.

10. The method according to claim 9, wherein the detecting the property of the surface comprises measuring the position of the surface in a direction substantially parallel to an optical axis of the projection system, a tilt of the surface about axes substantially perpendicular to the optical axis of the projection system, or both.

11. The method according to claim 9, wherein the detecting the property of the surface comprises measuring the position of a marker on the surface, wherein the position measured is in a direction substantially perpendicular to an optical axis of the projection system.

12. The method according to claim 9, wherein the projecting the patterned beam of radiation is performed at an exposure station and the detecting the property of the surface is performed at a measurement station, the measurement station being physically separate from the exposure station.

13. The method according to claim 9, further comprising drying the substrate, the substrate table, and/or the further movable table in the event of the measurement of the property being outside the normal operating range or varying significantly from a previous measurement before application of the liquid to the surface.

14. The method according to claim 9, further comprising generating, upon the measurement of the property being outside the normal operating range or varying significantly from a previous measurement before application of the liquid to the surface, an alarm or error signal or to instruct performance of a drying action.

15. A device manufacturing method comprising:

projecting, using a projection system of a lithographic apparatus, a patterned beam of radiation through a liquid onto a substrate while being held by a substrate table;

detecting whether there is presence of residual liquid remaining (i) on the substrate table, (ii) on a further movable table of the lithographic apparatus, or (iii) both (i) and (ii); and

initiating drying of the substrate, the substrate table, and/or the further movable table in the event that the presence of the residual liquid is detected.

16. The method according to claim 15, wherein the detecting the residual liquid comprises measuring the position of a surface in a direction substantially parallel to an optical axis of the projection system, a tilt of a surface about axes substantially perpendicular to the optical axis of the projection system, or both, wherein detection of the residual liquid on the substrate table and/or the further movable table is effected by the measuring of the position giving a measurement outside a normal operating range or varying significantly from a previous measurement or reference value.

17. The method according to claim 15, wherein the detecting the residual liquid comprises measuring the position of a marker, wherein the position measured is in a direction substantially perpendicular to an optical axis of the projection system, and wherein detection of the residual liquid on the substrate table and/or the further movable table is effected by the measuring of the position giving a measurement outside a normal operating range or varying significantly from a previous measurement or reference value.

18. The method according to claim 15, wherein the projecting the patterned beam of radiation is performed at an exposure station and the detecting the residual liquid is performed at a measurement station, the measurement station being physically separate from the exposure station.

19. A device manufacturing method comprising:

projecting, using a projection system of a lithographic apparatus, a patterned beam of radiation through a liquid onto a substrate while being held by a substrate table;

directing a detection beam of radiation onto or adjacent a surface (i) of the substrate table, (ii) of a further movable table of the lithographic apparatus, or (iii) both (i) and (ii);

detecting reflected or refracted radiation from the detection beam in parallel with further projection of the patterned beam; and

determining, from the detection, presence of the liquid on the surface after exposure of the substrate through the liquid.