Lighting system of a microlithographic projection exposure system and method for operating such a lighting system

Patent metadata

Field	Value
Publication number	US-2016357113-A1
Application number	US-201615224954-A
Country	US
Kind code	A1
Filing date	Aug 1, 2016
Priority date	Feb 19, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

An illumination system of a microlithographic projection exposure apparatus includes a light source operated in a pulsed manner and a DMD (digital mirror device) or another array of optical elements, which are digitally switchable between two switching positions.

First claim

What is claimed is:

1 . A system, comprising:
a light source configured to generate a sequence of light pulses; an array of optical elements in a light path between the light source and a target surface, the optical elements being digitally switchable between two switching positions; an adjustable light-deflection optical unit arranged in the light path between the array and the target surface, the light-deflection optical unit being configured to deflect incident light with different deflection angles; and a control device configured to actuate the light-deflection optical unit to change deflection angles between two successive light pulses, wherein the system is an illumination system.

2 . The system of claim 1 , wherein the control device is configured to switch over at least one of the optical elements of the array between two light pulses.

3 . The system of claim 1 , wherein the light-deflection optical unit and the control device are configured so that a first light pattern, which is illuminable on the target surface via the array prior to a change in the deflection angles, does not overlap with a second light pattern, which is illuminable on the target surface by the array after a change in the deflection angles.

4 . The system of claim 3 , wherein the first and second light patterns are arranged on the target field so that envelopes of the first and second light patterns do not overlap.

5 . The system of claim 3 , wherein the first and second light patterns are entangled in one another.

6 . The system of claim 5 , wherein the distance between two adjacent optical elements of the array along a reference direction is greater than a maximum dimension of the two optical elements along the reference direction.

7 . The system of claim 1 , further comprising a lens in the light path between the array and the target surface, wherein the lens is configured to image the array onto the target surface.

8 . An apparatus comprising:
an illumination system according to claim 1 ; and a projection lens, wherein the apparatus is a projection exposure apparatus.

9 . A method of operating a projection exposure apparatus comprising an illumination system and a projection lens, the method comprising:
using the illumination system to illuminate patterns of a mask; and using the projection lens to project the illuminated patterns of the mask onto light-sensitive material, wherein the illumination system is an illumination system according to claim 1 .

10 . A system, comprising:
an array of optical elements upstream of a target surface along a path of light pulses, the optical elements being digitally switchable between two switching positions; an adjustable light-deflection optical unit arranged in the path of the light pulses between the array and the target surface, the light-deflection optical unit being configured to deflect incident light with different deflection angles; and a control device configured to actuate the light-deflection optical unit to change deflection angles between two successive light pulses, wherein the system is an illumination system.

11 . The system of claim 10 , wherein the control device is configured to switch over at least one of the optical elements of the array between two light pulses.

12 . The system of claim 10 , wherein the light-deflection optical unit and the control device are configured in such so that during use of the illumination system a first light pattern, which is illuminable on the target surface via the array prior to a change in the deflection angles, does not overlap with a second light pattern, which is illuminable on the target surface by the array after a change in the deflection angles.

13 . An apparatus comprising:
an illumination system according to claim 10 ; and a projection lens, wherein the apparatus is a projection exposure apparatus.

14 . A method of operating a projection exposure apparatus comprising an illumination system and a projection lens, the method comprising:
using the illumination system to illuminate patterns of a mask; and using the projection lens to project the illuminated patterns of the mask onto light-sensitive material, wherein the illumination system is an illumination system according to claim 10 .

15 . A method for operating an illumination system, the method comprising:
directing a sequence of light pulses onto an array of optical elements which are digitally switchable between two switching positions, wherein the array illuminates a target surface; and deflecting the light directed from the array to the target surface by different deflection angles via an adjustable light-deflection optical unit arranged in the light path between the array and the target surface, wherein a change in the deflection angles occurs between two successive light pulses.

16 . The method of claim 15 , wherein at least one of the optical elements of the array switches over between two light pulses.

17 . The method of claim 15 , wherein a first light pattern, which is illuminable on the target surface via the array prior to a change in the deflection angles, does not overlap with a second light pattern, which is illuminable on the target surface via the array after a change in the deflection angles.

18 . The method of claim 17 , wherein the first and second light patterns are arranged on the target field so that envelopes of the two light patterns do not overlap.

19 . The method of claim 17 , wherein the first and second light patterns are entangled in one another.

20 . The method of claim 19 , wherein a distance between adjacent optical elements of the array along a reference direction is greater than a maximum dimension of an optical element along the reference direction.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Deguenther Markus
• Davydenko Vladimir
• Korb Thomas
• Eisenmenger Johannes

Classifications

• G03F7/702 Primary

  Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems · CPC title

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G03F7/70041 Primary

  by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control · CPC title

• G03F7/70475

  Stitching, i.e. connecting image fields to produce a device field, the field occupied by a device such as a memory chip, processor chip, CCD, flat panel display · CPC title

• G03F7/70116

  Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets · CPC title