Lithographic apparatus and device manufacturing method

• US 20050012912A1
• Filed: 07/01/2004
• Published: 01/20/2005
• Est. Priority Date: 07/01/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Houkes, Martijn, Draaijer, Evert Hendrik Jan, Cuijpers, Martinus Agnes Willem, Van Donkelaar, Edwin Teunis, Breukers, Marcus Joseph Elisabeth Godfried, Fien, Menno
• Granted Patent: US 7,148,950 B2
• Time in Patent Office: Days
• US Class Current: 355/52
• CPC Class Codes: G03F 7/70733 Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask

Abstract

A lithographic apparatus that includes an exposure system and a measurement system, is presented. The exposure system projects a patterned beam onto a target portion of a first substrate, while the measurement system projects a measurement beam on a target portion of a second substrate. Movement of a movable part of the apparatus generates a disturbance in a position of another movable part of the apparatus, e.g. due to displacement of air. This error can be compensated by calculating a compensation signal which is a function of states of one or both of the movable parts.

Claims

1. A lithographic apparatus, comprising:

(a) an exposure system comprising;

a radiation system configured to condition a beam of radiation;

a support structure configured to support a patterning device that imparts a desired pattern to the beam of radiation;

a substrate holder configured to hold a first substrate; and

a projection system that projects the patterned beam onto a target portion of the first substrate, the projection system comprising a projection controller configured to control the projection onto the target position of the first substrate; and

an exposure system controller configured to move a movable part of the exposure system such that the patterned beam is movable relative to the first substrate;

(b) a measurement system comprising;

an optical measurement device that projects a measurement beam to measure a surface property of a target portion of a second substrate;

a second substrate holder configured to hold the second substrate; and

a measurement system controller configured to move a movable part of the measurement system such that the measurement beam is movable relative to the second substrate;

(c) a correction determination mechanism configured to generate a correction signal that at least partly corrects an error of a position of the exposure system movable part or the measurement system movable part in which the error is respectively caused by a movement of the measurement system movable part or exposure system movable part; and

(d) a signal feeder configured to supply the correction signal into the exposure system controller and/or measurement system controller for at least partly correcting the position of the respective exposure system controller and/or measurement system controller.

2. The apparatus of claim 1, wherein the correction determination mechanism is configured to determine the correction signal from the exposure system movable part and/or the measurement system movable part.

3. The apparatus of claim 1, wherein the correction determination mechanism is configured to calculate the correction signal based on information from the exposure system movable part and/or the measurement system movable part and on a distance between the exposure system movable part and the measurement system movable part.

4. The apparatus of claim 3, wherein:

the information comprises an acceleration of the exposure system movable part and/or the measurement system movable part, the acceleration being provided by an acceleration detector employed by exposure system controller and/or measurement system controller, and

the distance between the exposure system movable part and the measurement system movable part is calculated from respective positions of the the exposure system movable part and/or the measurement system movable part, the respective positions being provided by respective position detectors employed by the exposure system and the measurement system.

5. The apparatus of claim 3, wherein the correction determination mechanism is further configured to:

determine an x-correction signal in order to correct an error in the position of the exposure system movable part or the measurement system movable part along an x-axis from an x-axis component of the information, and

determine a y-correction signal in order to correct an error in the position of the movable part of the exposure system movable part or the measurement system movable part along a y-axis from an y-axis component of the information,

wherein an x axis and a y axis is defined in a plane in which the exposure system movable part or the measurement system movable part are movable,

6. The apparatus of claim 5, wherein the exposure system controller and the measurement system controller are configured to generate the correction signal based on the formula:

$F_{x,y}=\frac{C*{\mathrm{Acc}}_{x,y}}{D_{\mathrm{xy}}^2}$

wherein F_x,y is the correction signal in x and y direction respectively, C is a constant, Acc_x,y is the acceleration in x and y direction respectively, and D_xy is the distance between the movable parts of the exposure system and the measurement system.

7. The apparatus of claim 5, wherein the correction determination mechanism is further configured to:

determine an x-to-y correction signal in order to correct an error in the position of the exposure system movable part or the measurement system movable part along the x-axis from an y-axis component of the information, and

determine a y-to-x correction signal in order to correct an error in the position of the exposure system movable part or the measurement system movable part along the y-axis from an x-axis component of the information.

8. The apparatus of claim 7, wherein the exposure system controller and the measurement system controller are configured to generate the x-to-y correction signal or the y-to-x-correction signal based on the formula:

$F_{x<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{to}<br><br>\text{\hspace{1em}<br><br>}<br><br>y,y<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{to}<br><br>\text{\hspace{1em}<br><br>}<br><br>x}=\frac{C*D_x*{\mathrm{Acc}}_{x,y}}{D_y^2}$

wherein F_{x to y, y to x} is the x to y and the y to x correction signal respectively, C is a constant, Acc_x,y is the acceleration in x and y direction respectively, D_x is the distance between the movable parts of the exposure system and the measurement system in x direction, and D_y is the distance between the movable parts of the exposure system and the measurement system in y direction.

9. The apparatus of claim 8, wherein the signal feeder comprises a delay for delaying at least one of the x-correction signal, the y-correction signal, the x-to-y correction signal, and the y-to-x correction signal.

10. The apparatus of claim 8, wherein the signal feeder is configured to add at least one of the x-correction signal, the y-correction signal, the x-to-y correction signal, and the y-to-x correction signal to a control signal at an output of a regulator in a closed loop feedback control loop.

11. A device manufacturing method, comprising:

providing a first substrate that is at least partially covered by a layer of radiation-sensitive material;

conditioning a beam of radiation;

configuring the conditioned beam of radiation with a desired pattern in its cross-section;

projecting the patterned beam of radiation onto a target portion of the first substrate;

moving the patterned beam relative to the first substrate;

providing a second substrate;

projecting a measurement beam onto a target portion of the second substrate to measure a surface property;

moving the measurement beam relative to the second substrate;

determining a correction signal for at least partly correcting an error of a position of the patterned beam or the measurement beam relative to the respective first substrate or second substrate, wherein the error is caused by a movement of a device that moves the other of the patterned beam or the measurement beam relative to the other one of the first substrate or second substrate; and

correcting the position of the patterned beam or the measurement beam relative to the respective first or second substrate based on the correction signal.