NL2014972B1 - Light source arrangement for an exposure system, and exposure system. - Google Patents

Light source arrangement for an exposure system, and exposure system. Download PDF

Info

Publication number
NL2014972B1
NL2014972B1 NL2014972A NL2014972A NL2014972B1 NL 2014972 B1 NL2014972 B1 NL 2014972B1 NL 2014972 A NL2014972 A NL 2014972A NL 2014972 A NL2014972 A NL 2014972A NL 2014972 B1 NL2014972 B1 NL 2014972B1
Authority
NL
Netherlands
Prior art keywords
light source
light sources
light
emission
source arrangement
Prior art date
Application number
NL2014972A
Other languages
Dutch (nl)
Inventor
Kaiser Paul
Original Assignee
Suss Microtec Lithography Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Suss Microtec Lithography Gmbh filed Critical Suss Microtec Lithography Gmbh
Priority to NL2014972A priority Critical patent/NL2014972B1/en
Application granted granted Critical
Publication of NL2014972B1 publication Critical patent/NL2014972B1/en

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70008—Production of exposure light, i.e. light sources
    • G03F7/7005—Production of exposure light, i.e. light sources by multiple sources, e.g. light-emitting diodes [LED] or light source arrays

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

A light source arrangement for an exposure system, in particular a photolithography exposure system, has a major axis and a plurality of light sources which each have an emission axis. At least one light source is radially spaced apart from the major axis and has an inclined emission axis so that the emission axis intersects the major axis at an angle of greater than 0° as seen from the light source in the emission direction. An exposure system is also shown.

Description

Light source arrangement for an exposure system, and exposure system
The invention relates to a light source arrangement for an exposure system having a plurality of light sources, and to an exposure system.
Exposure systems which are used to expose a photoresist to light in a photolithography method typically have a light source and optics which casts the light produced by the light source onto the photomask and the wafer, which is to be exposed to light, with an intensity as homogeneous as possible.
Typically, a gas discharge lamp is used as a light source. Gas discharge lamps have a high luminous flux but are difficult to handle and are expensive, and therefore an attempt is being made to replace them with light-emitting diodes (LEDs). However, the luminous flux of LEDs is considerably lower than that of gas discharge lamps which means a plurality of LEDs are always required to achieve comparable illumination intensities.
An arrangement of LEDs, also called an LED array, typically consists of a plurality of LEDs which are arranged next to each other in a plane perpendicular to the desired optical axis. The radiating surface of such an arrangement, i.e. the surface from which light is emitted, is larger than the radiating surface of a gas discharge lamp and the intensity is accordingly lower.
Owing to this different radiation characteristic, larger and thus more expensive optical components are required when using an LED array in the subsequent optics. The optics hereby requires more space, thus considerably enlarging the overall system. In particular, the structural length of the exposure system is increased.
Accordingly, it is the object of the invention to provide a light source arrangement for an exposure system and an exposure system itself, which allow the structural length and manufacturing costs of the exposure system to be reduced.
The object is achieved by a light source arrangement for an exposure system, in particular a photolithography exposure system, having a major axis and a plurality of light sources which each have an emission axis, wherein at least one light source is radially spaced apart from the major axis and has an inclined emission axis so that the emission axis intersects the major axis at an angle of greater than 0° as seen from the light source in the emission direction.
By virtue of the fact that the light source radially spaced apart from the major axis, emits light not in parallel with the major axis but slightly radially inwardly, the illuminated surface is reduced at the input of the optics, i.e. the optical component of the optics closest to the light source, and the intensity is increased. Therefore, radially smaller optical components can be used which are more cost effective. A lens having a shorter focal length can also now be used as the front lens of the optics whereby the structural length of the exposure system is reduced.
The major axis describes the optical axis of the entire light source arrangement and coincides with the optical axis of subsequent optics of the exposure system. An axis through a light source in the direction of the highest light intensity, i.e. the main light emission, of this light source is designated as the emission axis.
Preferably, the size of the angle is dependent upon the radial distance between the light source and the major axis, and therefore the size of the illuminated surface can be set in a precise manner.
For example, the light sources are arranged in a rotationally symmetrical manner in relation to the major axis, whereby the homogeneity of the intensity over the illuminated surface can be improved.
In one embodiment variant, a light source whose emission axis coincides with the major axis is arranged on the major axis, whereby the light emitted by this light source can be effectively used.
In one embodiment of the invention, the light sources are arranged in at least one ring around the major axis, wherein the light sources of the outermost ring have inclined emission axes. In this manner, it is ensured that the illuminated surface is reduced as compared to a light source arrangement without inclined emission axes.
In this case, the term "ring" is not necessarily to be understood as an arrangement of the light sources in a circle. Rather, a ring in terms of this invention can also have another geometric shape, wherein the radius of such a ring is then calculated as the average distance between the light sources of this ring and the major axis. The ring having the largest radius is understood to be the outermost ring.
Preferably, the light sources are arranged in a plurality of rings around the major axis, wherein the angles of the emission axes of the light sources of an inner ring are smaller than the angles of the emission axes of the light sources of the outermost ring, whereby the homogeneity can be further improved. A ring which has a radius smaller than the radius of the outermost ring is understood to be the inner ring.
For example, the rings are hexagons, whereby a particularly spacesaving arrangement of the light sources is permitted.
In one embodiment variant, a collimator is allocated to each light source and concentrates the light of the light source about the emission axis, whereby it is ensured that the emission angle of each light source is known and light is emitted along the emission axis.
In one embodiment of the invention, the angle is between 0° and 7°, particularly between 0° and 5°, and therefore it is ensured that the illuminated surface at the input of the optics is not increased owing to an excessive inclination of an emission axis of a light source. It is thereby guaranteed that all the light beams from the optics can be directed even as far as the wafer to be exposed to light.
Preferably, the light sources are LEDs, laser diodes and/or end facets of light-conducting fibres. As a result, space-saving and effective light sources are used at the level of the entire system.
In one embodiment variant of the invention, the angle can be adjusted, in particular separately for individual light sources or together for all the light sources of a ring, whereby the collimation angles of the entire exposure system can be adapted.
For example, for particular exposure tasks, the angle can be set to 0° so that the emission axis and the major axis extend in parallel with each other. This widens the region in which the collimation angles can be set.
The above object is further achieved by an exposure system, in particular a photolithography exposure system, having a light source arrangement described above.
Further features and advantages of the invention will be apparent from the following description and the enclosed drawings to which reference is made. In the drawings:
Figure 1 shows a schematic plan view along the major axis of a light source arrangement in accordance with the invention,
Figure 2 shows a sectional view of the light source arrangement of figure 1 together with a first optical component of an exposure system,
Figure 3 shows an enlarged section of figure 2,
Figure 4 shows a light source arrangement of figure 2 in which idealised peripheral beams of the individual light sources are indicated,
Figure 5 shows a sectional view of a further position of the light source arrangement of figure 4, and
Figure 6 shows a schematic sectional view of a part of an exposure system in accordance with the invention.
Figure 1 illustrates a plan view of a light source arrangement 10 for an exposure system 11 (figure 6), for example a photolithography exposure system.
The light source arrangement 10 comprises a plurality of light sources 12.
In the illustrated embodiment, 19 light sources 12 are provided. The light sources 12 are, for example, LEDs but they can also be laser diodes or end facets of light-conducting fibres, into which light was coupled. A collimator 14 is allocated to each light source 12 and concentrates the light exiting the light source 12 into a light beam having almost parallel beams. However, since the light sources 12 are relatively large compared with the collimator 14, a slightly divergent light cone is produced.
It is feasible that collimators 14 having different focal lengths are being used, and therefore the distances between the light sources 12 and the collimators 14 in each case allocated thereto are different. In this manner, the light sources 12 can be arranged more compactly.
Each light source 12 can emit light which propagates mainly along an emission axis E. The collimators 14 are arranged such that the optical axis thereof coincides with the emission axis E.
For example, the collimators 14 are lenses, wherein the light sources 12 are each arranged in the focal point of the lenses. A major axis H (figure 2) extends through the centre point of the light source arrangement 10 and corresponds to the optical axis of the light source arrangement 10.
One of the light sources 12, hereinafter referred to as central light source 12.0, is arranged on the major axis H so that the major axis H and the emission axis E of the central light source 12.0 coincide.
Further light sources 12 are arranged in an inner ring 16 and an outermost ring 18 around the central light source 12.0 and thus around the major axis H.
The term "ring" in this case is not to be understood to say that the light sources 12 are arranged in a circular path around the major axis H but rather the term "ring" is used to classify the light sources 12 in relation to their distance from the major axis H.
The rings 16, 18 can have other geometric shapes, and in the illustrated embodiment they are hexagons, for example. However, other polygons or other shapes are also feasible.
In the illustrated embodiment, the inner ring 16 consists of six light sources 12, hereinafter referred to as inner light sources 12.1, which are arranged at the corners of a regular hexagon around the major axis H.
The distance between the inner light sources 12.1 and the major axis H is considered to be the radius n of the inner ring 16.
In the illustrated embodiment, the outermost ring 18 is formed by 12 light sources 12, hereinafter referred to as outer light sources 12.2. Six of these light sources 12.2 are again arranged in a regular hexagon around the major axis H. The remaining six light sources 12.2 are arranged between the light sources 12.2 placed at the corners of the hexagon.
The radius r2 of the outermost ring 18 is now determined as the average distance between the light sources 12.2 and the major axis H.
The radius r2 of the outermost ring 18 is thus larger than the radius Π of the inner ring 16.
The minimum distance between the light sources 12 is determined by the diameter of the collimators 14. For a highest possible light intensity, the light sources 12 are arranged such that their collimators 14 adjoin each other.
This arrangement ensures that the light sources 12 are arranged in a rotationally symmetrical manner about the major axis H.
For ease of illustration, the structures which hold the light sources 12 and collimators 14 have not been illustrated in figure 1.
Figure 2 illustrates a sectional view of the arrangement of figure 1. In addition to the light sources 12 and collimators 14 of the light source arrangement 10, an optical component 20, closest to the light source arrangement 10, of optics of the exposure system 11 is illustrated, the light source arrangement 10 being provided therein.
The optical component 20 is, for example, an optical integrator and is also referred to as the input of the optics.
It can be seen that the emission axes E of the light sources 12 radially spaced apart from the major axis H do not extend in parallel with the major axis H. Rather, the emission axes E of these light sources 12.1, 12.2 intersect the major axis H in the emission direction R at an angle a or a‘ as seen from the light sources 12.
Figure 3 illustrates an enlarged view of figure 2 of the region in which the emission axes E intersect the major axis H. It can be clearly seen herein that the angles a, a‘ are greater than 0°.
For example, the angles a, a‘ are between 0° and 7°, in particular between 0° and 5°. The angle can be 3°, for example.
Moreover, the angles a, a‘ can be dependent upon the radial distance between the respective light source 12 and the major axis H.
In the illustrated embodiment, the inner light sources 12.1, i.e. of the inner ring 16, and also the outer light sources 12.2, i.e. of the outermost ring 18, have inclined emission axes E.
The emission axes E of the inner light sources 12.1 intersect the major axis H at an angle a which is smaller than the angle a‘ at which the emission axes E of the outermost light sources 12.2 intersect the major axis (cf. figure 3).
It is also feasible that only the emission axes E of the light sources 12.2 of the outer ring 18 intersect the major axis H at an angle a‘ and the emission axes E of the inner light sources 12.1 extend in parallel with the major axis H.
Of course, the emission axes E of the individual light sources 12 of a ring 16, 18 can also intersect the major axis H at different angles.
Also, the different emission axes E do not have to intersect the major axis H at the same point.
It is further feasible that the distances between the light sources 12 and the points of intersection of their respective emission axis E and the major axis H are different, whereby a compact design is possible by superimposing the light source arrangement 10.
Figure 4 illustrates the same view as figure 2 and additionally indicates the peripheral beams of the light bundles of the outer light sources 12.2 and the central light source 12.0. For reasons of clarity, the peripheral beams of the light bundles of the inner light sources 12.1 have been omitted and the indicated peripheral beams have been assumed to be ideal parallel beams.
It can be clearly seen that owing to the inclination of the emission axes E of the outer light sources 12.2, the area illuminated on the optical component 20 has a diameter D which is smaller than that in an arrangement having exclusively parallel emission and major axes (cf. figure 5).
The reduced diameter D of the illuminated surface on the optical component 20 means that the optics can be equipped with components which are smaller in the radial direction and are more cost-effective, in particular with a front lens having a shorter focal length.
The light sources 12.1 and 12.2 whose emission axis E is inclined can be arranged to be movable. For example, the light sources 12.1 and 12.2 can be inclined by piezo-actuators (not illustrated) or using a guide link and a corresponding drive (not illustrated) together with the collimators 14 allocated thereto. It is thereby possible to change the inclination of the emission axis E and thus vary the size of the angle a, a1.
The size of the angle a, a‘ can either be individually set for each light source 12 or simultaneously for all the light sources 12.1, 12.2 of a ring 16, 18. Owing to variably adjustable angles a, a‘, the collimation angle of the optics can be changed and can also be responsive to different distances between the photomask and the wafer to be exposed to light.
It is also feasible that the angle a, a‘ is set to 0° for individual, or all, light sources 12, and therefore the emission axis E and the major axis H are in parallel with each other. Such a situation is illustrated in figure 5. In this situation, the illuminated surface on the optical component 20 is very large which in some situations may be entirely intentional and helpful.
Figure 6 partly schematically illustrates an exposure system 11, in particular a photolithography exposure system, together with the light source arrangement 10 and the optics. It can be seen that the major axis H of the light source arrangement 10 coincides with the optical axis of the optics.

Claims (13)

1. Lichtbronopstelling voor een belichtingssysteem (11), in het bijzonder een fotolithografie-belichtingssysteem, met een hoofdas (H) en verschillende lichtbronnen (12), die elk een emissie-as (E) bezitten, waarbij ten minste één lichtbron (12.1, 12.2) radiaal op afstand van de hoofdas (H) is geplaatst en een hellende emissie-as (E) bezit, zodanig dat de emissie-as (E) de hoofdas (H) van de lichtbron (12.1, 12.2) gezien vanuit de emissierichting (R) onder een hoek (a, a’) groter dan 0° snijdt.A light source arrangement for an illumination system (11), in particular a photolithography illumination system, with a main axis (H) and different light sources (12), each having an emission axis (E), wherein at least one light source (12.1, 12.2) is arranged radially spaced from the main axis (H) and has an inclined emission axis (E), such that the emission axis (E) is the main axis (H) of the light source (12.1, 12.2) as seen from the emission direction (R) intersects at an angle (a, a ') greater than 0 °. 2. Lichtbronopstelling volgens conclusie 1, met het kenmerk, dat de grootte van de hoek (a, a’) afhankelijk is van de radiale afstand van de lichtbron (12) tot de hoofdas (H).Light source arrangement according to claim 1, characterized in that the magnitude of the angle (a, a ') depends on the radial distance of the light source (12) to the main axis (H). 3. Lichtbronopstelling volgens conclusie 1 of 2, met het kenmerk, dat de lichtbronnen (12) rotatiesymmetrisch met betrekking tot de hoofdas (H) zijn opgesteld.Light source arrangement according to claim 1 or 2, characterized in that the light sources (12) are arranged rotationally symmetrically with respect to the main axis (H). 4. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat op de hoofdas (H) een lichtbron (12.0) is opgesteld, waarvan de emissie-as (E) overeenkomt met de hoofdas (H).Light source arrangement according to one of the preceding claims, characterized in that a light source (12.0) is arranged on the main axis (H), the emission axis (E) of which corresponds to the main axis (H). 5. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat de lichtbronnen (12.1, 12.2) in ten minste één ring (16, 18) rond de hoofdas (H) zijn opgesteld, waarbij de lichtbronnen (12.2) van de buitenste ring (18) hellende emissie-assen (E) bezitten.Light source arrangement according to one of the preceding claims, characterized in that the light sources (12.1, 12.2) are arranged in at least one ring (16, 18) around the main axis (H), the light sources (12.2) of the outermost ring (18) have sloping emission axes (E). 6. Lichtbronopstelling volgens conclusie 5, met het kenmerk, dat de lichtbronnen (12.1, 12.2) in verschillende ringen (16,18) rond de hoofdas (H) zijn opgesteld, waarbij de hoeken (a) van de emissie-assen (E) van de lichtbronnen (12.1) van een binnenste ring (16) kleiner zijn dan de hoeken (a’) van de emissie-assen (E) van de lichtbronnen (12.2) van de buitenste ring (18).Light source arrangement according to claim 5, characterized in that the light sources (12.1, 12.2) are arranged in different rings (16, 18) around the main axis (H), the corners (a) of the emission axes (E) of the light sources (12.1) of an inner ring (16) are smaller than the angles (a ') of the emission axes (E) of the light sources (12.2) of the outer ring (18). 7. Lichtbronopstelling volgens conclusie 5 of 6, met het kenmerk dat de ringen (16, 18) hexagonen zijn.Light source arrangement according to claim 5 or 6, characterized in that the rings (16, 18) are hexagons. 8. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat bij elke lichtbron (12) een collimator (14) behoort, welke het licht van de lichtbron (12) rond de emissie-as (E) bundelt.Light source arrangement according to one of the preceding claims, characterized in that a collimator (14) is associated with each light source (12) which bundles the light from the light source (12) around the emission axis (E). 9. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat de lichtbronnen LED, laserdioden en/of eindfacetten van lichtgeleiders zijn.Light source arrangement according to one of the preceding claims, characterized in that the light sources are LED, laser diodes and / or end facets of light guides. 10. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat de hoek (a, a’) tussen 0° en 7°, in het bijzonder tussen 0° en 5° ligt.Light source arrangement according to one of the preceding claims, characterized in that the angle (a, a ') is between 0 ° and 7 °, in particular between 0 ° and 5 °. 11. Lichtbronopstelling volgens een van de voorgaande conclusies, met het kenmerk, dat de hoek (a, a’) instelbaar is, in het bijzonder separaat voor afzonderlijke lichtbronnen (12) en/of voor alle lichtbronnen (12.1, 12.2) van een ring (16, 18) tezamen.Light source arrangement according to one of the preceding claims, characterized in that the angle (a, a ') is adjustable, in particular separately for individual light sources (12) and / or for all light sources (12.1, 12.2) of a ring (16, 18) together. 12. Lichtbronopstelling volgens conclusie 11, met het kenmerk, dat de hoek (a, a’) op 0° kan worden ingesteld, zodanig dat de emissie-as (E) en de hoofdas (H) evenwijdig aan elkaar lopen.Light source arrangement according to claim 11, characterized in that the angle (a, a ') can be adjusted to 0 ° such that the emission axis (E) and the main axis (H) are parallel to each other. 13. Belichtingssysteem, in het bijzonder een fotolithografie-belichtingssysteem, met een lichtbronopstelling (10) volgens een van de voorgaande conclusies.An illumination system, in particular a photolithography illumination system, with a light source arrangement (10) according to one of the preceding claims.
NL2014972A 2015-06-16 2015-06-16 Light source arrangement for an exposure system, and exposure system. NL2014972B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NL2014972A NL2014972B1 (en) 2015-06-16 2015-06-16 Light source arrangement for an exposure system, and exposure system.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL2014972A NL2014972B1 (en) 2015-06-16 2015-06-16 Light source arrangement for an exposure system, and exposure system.

Publications (1)

Publication Number Publication Date
NL2014972B1 true NL2014972B1 (en) 2017-01-23

Family

ID=54011863

Family Applications (1)

Application Number Title Priority Date Filing Date
NL2014972A NL2014972B1 (en) 2015-06-16 2015-06-16 Light source arrangement for an exposure system, and exposure system.

Country Status (1)

Country Link
NL (1) NL2014972B1 (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006074812A2 (en) * 2005-01-14 2006-07-20 Carl Zeiss Smt Ag Illumination sytsem for a microlithographic projection exposure apparatus
US20140340665A1 (en) * 2013-05-14 2014-11-20 Taiwan Semiconductor Manufacturing Co., Ltd. Ultraviolet light emitting diode array light source for photolithography and method

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006074812A2 (en) * 2005-01-14 2006-07-20 Carl Zeiss Smt Ag Illumination sytsem for a microlithographic projection exposure apparatus
US20140340665A1 (en) * 2013-05-14 2014-11-20 Taiwan Semiconductor Manufacturing Co., Ltd. Ultraviolet light emitting diode array light source for photolithography and method

Similar Documents

Publication Publication Date Title
CN107614968B (en) Headlamp device and lighting device
TWI414896B (en) Illumination system for euv lithography as well as a first and second optical element for use in an illumination system of this type
JP6180527B2 (en) Headlight illuminator
EP2564111B1 (en) Ring light illuminator and beam shaper for ring light illuminator
US20100284201A1 (en) Illuminator using non-uniform light sources
JP6839648B2 (en) Vehicle lighting module
US9239144B2 (en) Light module
JP2010515214A (en) Floodlight with tiltable beam
JP2016212962A (en) Luminaire
WO2011132108A1 (en) Lighting device for variable spot illumination
JP2016110760A (en) Lighting fixture unit
JP2017003671A (en) Illumination device
JP2023153375A (en) Lighting fixture for vehicle
JP5951141B1 (en) Lighting device
EP3480518A1 (en) Light exiting structure and light exiting system comprising same
JP6816886B2 (en) Lighting device
NL2014972B1 (en) Light source arrangement for an exposure system, and exposure system.
JP6172540B2 (en) Light source device
JP6659707B2 (en) Color correction collimation of light from color overposition light source
JP2017500700A (en) Lighting device
US11359914B2 (en) Lighting system with pattern element
JP5465123B2 (en) High-incidence angle variable irradiation device for image measurement device
CN117916516A (en) Lighting device for a motor vehicle
US20080309888A1 (en) Stage projector structure
WO2019176876A1 (en) Lamp unit

Legal Events

Date Code Title Description
MM Lapsed because of non-payment of the annual fee

Effective date: 20180701