Lithographic Apparatus, Substrate Table, and Method for Enhancing Substrate Release Properties

• US 20100296073A1
• Filed: 08/13/2010
• Published: 11/25/2010
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Van De Ven, Johannes Theodorus Guillielmus Maria, Stam, Egbert Dirk, Gelinck, Edwin Robert Martin, PUYT, Michiel, Compen, Rene Theodorus Petrus, Bleeker, Arno Jan, Franssen, Johannes Hendrikus Gertrudis, Fischer, Rudolf Hartmut
• Granted Patent: US 8,792,085 B2
• Time in Patent Office: Days
• US Class Current: 355/72
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70708 being electrostatic; Electrostatically deformable vacuum chucks
• CPC Class Codes: H01L 21/6875 characterised by a plurality of individual support members, e.g. support posts or protrusions
• CPC Class Codes: H01L 21/68757 characterised by a coating or a hardness or a material

Abstract

A lithographic apparatus includes an illumination system constructed and arranged to condition a radiation beam, and a support constructed and arranged to support a patterning device. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. The apparatus also includes a substrate table constructed and arranged to hold a substrate, and a projection system constructed and arranged to project the patterned radiation beam onto a target portion of the substrate. The substrate table includes a chuck having a plurality of protrusions constructed and arranged to support corresponding parts of a bottom surface of a wafer. The top surface of at least one of the protrusions includes a plurality of elements that define a reduced contact area between the substrate and the top surface of the protrusion.

Claims

1. A substrate table for supporting a substrate, the substrate table comprising:

a chuck configured to clamp the substrate; and

a plurality of protrusions coupled to the chuck to support corresponding parts of a first surface of the substrate, wherein a first surface of at least one of the protrusions comprises micro elements, and wherein the first surface of at least one of the protrusions faces the first surface of the substrate when supporting the substrate.

2. A substrate table according to claim 1, wherein the protrusions are burls.

3. A substrate table according to claim 1, wherein the micro elements are elastic.

4. A substrate table according to claim 1, wherein the micro elements comprise chemically substantially non-reacting ends.

5. A substrate table according to claim 1, wherein the micro elements comprise a substantially regular pattern of local maxima and minima heights, such that at the maxima, the substantially regular pattern has substantially the same height.

6. A substrate table according to claim 1, wherein the micro elements are formed by a monolayer.

7. A substrate table according to claim 6, wherein the monolayer comprises bucky balls, glass pearls, polymeric molecules, or nano-tubes, or any combination thereof.

8. A substrate table according to claim 6, wherein the monolayer comprises organic, aromatic, aliphatic, polar, a-polar, halogenated, or fluorinated molecules, or any combination thereof.

9. A substrate table according to claim 6, wherein the monolayer comprises oxide, nitride, or Teflon molecules, or any combination thereof.

10. A substrate table according to claim 1, wherein the first surface of the at least one of the protrusions comprises a laser treated surface.

11. A substrate table according to claim 1, wherein the substrate table forms a part of a lithographic apparatus.

12. A substrate table according to claim 1, wherein the substrate table forms a part of an implanter or an etching device.

13. A method for enhancing substrate release properties of a protrusion in a substrate table that is configured to support a substrate, the method comprising:

coupling a plurality of protrusions to a chuck of the substrate table; and

disposing micro elements at a first surface of at least one of the plurality of protrusions of the substrate table.

14. A method according to claim 13, further comprising:

depositing or growing a monolayer to form the micro elements on the first surface of the at least one of the protrusions.

15. A method according to claim 13, further comprising:

applying a wet solution containing organic molecules to the first surface of the at least one of the protrusions; and

subsequently exposing the wet solution to an UV source or allowing the wet solution to chemically react with surface bonds to form a monolayer of the micro elements on the first surface of the at least one of the protrusions.

16. A method according to claim 13, further comprising:

applying a plasma enhanced chemical vapor decomposition (PE CVD) or filter high current arc (F-HCA) process to generate the monolayer on the first surface of the at least one of the protrusions.

17. A method according to claim 13, further comprising:

locally machining with a laser to form a defined pattern of the micro elements on the first surface of the at least one of the protrusions.

18. A method according to claim 17, wherein the locally machining with the laser fauns a defined pattern with height differences of an order of nanometers or an order of tens of nanometers.

19. A method according to claim 17, wherein the locally machining with the laser forms a defined pattern having convex or concave surfaces that are spherical, circular or elliptic.

20. A method according to claim 17, wherein the locally machining with the laser forms a defined pattern having edge structures.