Lithographic apparatus and device manufacturing method

Patent metadata

Field	Value
Publication number	US-2018039188-A1
Application number	US-201715694537-A
Country	US
Kind code	A1
Filing date	Sep 1, 2017
Priority date	Oct 18, 2004
Publication date	Feb 8, 2018
Grant date	—

Abstract

A lithographic apparatus is disclosed including a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, an outlet configured to remove a mixture of liquid and gas passing through a gap between a liquid confinement structure of the liquid supply system and the substrate, and an evacuation system configured to draw the mixture through the outlet, the evacuation system having a separator tank arranged to separate liquid from gas in the mixture and a separator tank pressure controller, connected to a non-liquid-filled region of the separator tank, configured to maintain a stable pressure within the non-liquid-filled region.

First claim

1 . A lithographic apparatus comprising:
an illuminator configured to condition a radiation beam; a support constructed to hold a patterning device, the patterning device configured to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table constructed to hold a substrate; a projection system configured to project the patterned radiation beam onto a target portion of the substrate; a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, the liquid supply system comprising a liquid confinement structure configured to at least partly confine the liquid within the space; an outlet configured to remove a mixture of liquid and gas passing through a gap between the liquid confinement structure and the substrate; and an evacuation system configured to draw the mixture through the outlet, the evacuation system comprising a separator tank arranged to separate liquid from gas in the mixture and a separator tank pressure controller, connected to a non-liquid-filled region of the separator tank, configured to maintain a stable pressure within the non-liquid-filled region.

2 . The lithographic apparatus according to claim 1 , wherein the evacuation system further comprises:
a purge tank, situated lower than the separator tank and connected thereto via an opening in a lower portion of the separator tank and an opening in an upper portion of the purge tank, the connection being controllable via a purge valve; and a pressure equalization connection, controllable by a pressure equalization valve, configured to connect respective upper portions of the separator and purge tanks to facilitate flow of separated liquid from the separator tank to the purge tank without a change in pressure in the separator tank, wherein the purge tank is configured so that liquid can be removed therefrom, during a liquid removal phase, by closing the purge valve, closing the pressure equalization valve and opening the purge tank to a liquid sink via a liquid sink valve.

3 . The lithographic apparatus according to claim 2 , wherein the evacuation system further comprises a high pressure gas source connectable to the purge tank and configured to force liquid from the purge tank to the liquid sink at an increased rate.

4 . The lithographic apparatus according to claim 3 , wherein the evacuation system further comprises a liquid pump configured to pump liquid from the separator tank to the liquid sink, the liquid pump comprising a gas jet pump powered by the high pressure gas source.

5 . The lithographic apparatus according to claim 2 , wherein the purge valve, the liquid sink valve, or both comprises a check valve configured to prevent backflow.

6 . The lithographic apparatus according to claim 1 , wherein the evacuation system further comprises:
a purge tank, situated lower than the separator tank and connected thereto via an opening in a lower portion of the separator tank and an opening in an upper portion of the purge tank, the connection being controllable via a purge valve; and a limited flow connection configured to connect respective upper portions of the separator and purge tanks and comprising a flow restriction device arranged to provide a flow impedance, wherein the purge tank is configured so that liquid can be removed therefrom, during a liquid removal phase, by closing the purge valve and opening the purge tank to a liquid sink via a liquid sink valve, and the flow impedance is selected to equalize the pressures of the separator and purge tanks, after the liquid removal phase, without causing a fluctuation of the pressure in the separator tank that exceeds a threshold value.

7 . The lithographic apparatus according to claim 6 , wherein the flow impedance is also selected to allow liquid to flow from the separator tank to the purge tank at a rate above a minimum transfer rate.

8 . The lithographic apparatus according to claim 6 , wherein the evacuation system further comprises a high pressure gas source connectable to the purge tank and configured to force liquid from the purge tank to the liquid sink at an increased rate.

9 . The lithographic apparatus according to claim 6 , wherein the purge valve, the liquid sink valve, or both comprises a check valve configured to prevent backflow.

10 . The lithographic apparatus according to claim 1 , wherein the evacuation system further comprises:
a purge tank, situated lower than the separator tank and connected thereto via an opening in a lower portion of the separator tank and an opening in an upper portion of the purge tank, the connection being controllable via a purge valve; a limited flow connection configured to connect respective upper portions of the separator and purge tanks and comprising a flow restriction device arranged to provide a flow impedance; and a pressure equalization connection, controllable by a pressure equalization valve, configured to connect respective upper portions of the separator and purge tanks to facilitate flow of separated liquid from the separator tank to the purge tank without a change in pressure in the separator tank, wherein the purge tank is configured so that liquid can be removed therefrom, during a liquid removal phase, by closing the purge valve and opening the purge tank to a liquid sink via a liquid sink valve, and the flow impedance is selected to equalize the pressures of the separator and purge tanks, after the liquid removal phase, without causing a fluctuation of the pressure in the separator tank that exceeds a threshold value.

11 . The lithographic apparatus according to claim 10 , wherein the evacuation system further comprises a high pressure gas source connectable to the purge tank and configured to force liquid from the purge tank to the liquid sink at an increased rate.

12 . The lithographic apparatus according to claim 10 , wherein the purge valve, the liquid sink valve, or both comprises a check valve configured to prevent backflow.

13 . The lithographic apparatus according to claim 1 , wherein the evacuation system further comprises a liquid pump configured to pump liquid from the separator tank to the liquid sink.

14 . The lithographic apparatus according to claim 1 , wherein the separator tank pressure controller comprises:
a main pumping line connected to a two-phase compatible pump configured to pump a the mixture; and a backup line connectable to a shared vacuum facility configured to pump gas only, wherein the main pumping and backup lines are connected to the separator tank, and the two-phase compatible pump being configurable to provide a deeper vacuum than the shared vacuum facility.

15 . The lithographic apparatus according to claim 14 , wherein the main pumping line is connected to a lower, predominantly liquid filled portion of the separator tank, and the backup line is connected to an upper, predominantly gas filled portion of the separator tank.

16 . The lithographic apparatus according to claim 14 , wherein the main and backup pumping lines are each fitted with check valves to prevent one pumping line from drawing on the other pumping line.

17 . The lithographic apparatus according to claim 14 , wherein the backup line comprises a hydrophobic filter configured to prevent liquid from reaching the shared vacuum facility.

18 . The lithographic apparatus according to claim 14 , wherein the main pumping line, the backup line, or both, comprise a back-pressure regulator configured to control the pumping pow

Assignees

• Asml Netherlands Bv

Inventors

• Mertens Jeroen Johannes Sophia Maria
• Donders Sjoerd Nicolaas Lambertus
• De Graaf Roelof Frederik
• Hoogendam Christiaan Alexander
• Van Der Net Antonius Johannus
• Teunissen Franciscus Johannes Herman Maria
• Tinnemans Patricius Aloysius Jacobus
• Verhagen Martinus Cornelis Maria
• Verspay Jacobus Johannus Leonardus Hendricus
• Van Gompel Edwin Augustinus Matheus

Classifications

• G03F7/70341 Primary

  Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply (chemical composition of immersion liquids G03F7/2041) · CPC title

• G03F7/70716 Primary

  Stages · CPC title

• G03F7/70808

  Construction details, e.g. housing, load-lock, seals or windows for passing light in or out of apparatus · CPC title

• G03F7/2041

  in the presence of a fluid, e.g. immersion; using fluid cooling means · CPC title