阅读说明：本技术 照明光学系统、光刻机设备及曝光方法 (Illumination optical system, lithography apparatus, and exposure method ) 是由 康思睿 田毅强 储兆祥 于 2020-04-23 设计创作，主要内容包括：本发明提供了一种照明光学系统,包括照明光源和光束传播组件,所述光束传播组件包括中继镜组,所述中继镜组靠近照明像面设置,所述中继镜组包括至少一个可调节镜片,所述可调节镜片设置在所述中继镜组的入射端面和/或出射端面,用于调节光束入射至所述照明像面的照明远心度。基于照明光学系统,本发明还提供了一种光刻机设备和曝光方法。本发明提供的照明光学系统、光刻机设备和曝光方法,通过调整所述可调节镜片的倾斜姿态,从而实现实时调整光束的照明远心度,降低了光刻镜头设计难度,提高了曝光系统的性能。而且不会影响其他光学性能,从而实现光刻机设备的远心调整。(The invention provides an illumination optical system which comprises an illumination light source and a light beam propagation assembly, wherein the light beam propagation assembly comprises a relay lens group, the relay lens group is arranged close to an illumination image surface, the relay lens group comprises at least one adjustable lens, and the adjustable lens is arranged on the incident end surface and/or the emergent end surface of the relay lens group and is used for adjusting the illumination telecentricity of the light beam incident to the illumination image surface. The invention also provides a photoetching machine device and an exposure method based on the illumination optical system. According to the illumination optical system, the photoetching machine and the exposure method, the inclination posture of the adjustable lens is adjusted, so that the illumination telecentricity of the light beam is adjusted in real time, the design difficulty of a photoetching lens is reduced, and the performance of the exposure system is improved. And other optical performances cannot be influenced, so that the telecentric adjustment of the photoetching machine equipment is realized.)

1. The utility model provides an illumination optical system, includes illumination source and light beam propagation subassembly, the light that illumination source sent is through form images on image plane behind the light beam propagation subassembly, the light beam propagation subassembly includes relay lens group, relay lens group is close to illumination image plane setting, its characterized in that, relay lens group includes at least one adjustable lens, adjustable lens setting is in the incident terminal surface and/or the emergent terminal surface of relay lens group for adjust the light beam and incide to illumination telecentric degree on illumination image plane.

2. The illumination optical system according to claim 1, further comprising a reflection unit disposed between the illumination light source and the light beam propagation member along a light path propagation direction, the reflection unit being configured to change a propagation direction of the light beam emitted from the illumination light source.

3. The illumination optical system according to claim 2, further comprising a beam expander disposed between the illumination light source and the reflection unit along a propagation direction of the optical path, the beam expander being configured to expand and collimate the light beam emitted from the illumination light source.

4. The illumination optical system according to claim 2, wherein the light beam propagation assembly further includes a zoom lens group, a converging lens group, and a light uniformizing integrator in this order along the light path propagation direction, and the relay lens group is disposed between the light uniformizing integrator and the illumination image plane.

5. The illumination optical system according to claim 4, wherein the beam propagation assembly further comprises a first diffractive optical element disposed between the reflection unit and the zoom lens group along the optical path propagation direction, the first diffractive optical element being configured to diffract the beam into a predetermined angular distribution and configured to cooperate with the zoom lens group to form a predetermined pupil distribution on a pupil plane of the zoom lens group.

6. The illumination optical system according to claim 5, wherein the light beam propagation assembly further comprises a second diffractive optical element disposed between the zoom lens group and the converging lens group along the optical path propagation direction, and the second diffractive optical element is disposed on a pupil plane of the zoom lens group and is configured to cooperate with the converging lens group to form a light spot on an image plane of the converging lens group that matches the aperture of the integrator.

7. The illumination optical system according to claim 2, wherein the beam delivery assemblies are two each for receiving the light beam reflected by the reflection unit and for respectively imaging on the image plane; each light beam transmission assembly is used for adjusting the illumination telecentricity of the light beam transmission assemblies respectively incident to the illumination image surface.

8. The illumination optical system according to claim 2, wherein the adjustable angle range of the adjustable lens is ± 3 ° along a first coordinate axis, and the adjustable angle range of the adjustable lens is ± 3 ° along a second coordinate axis, wherein the first coordinate axis intersects the second coordinate axis perpendicularly in a plane perpendicular to the optical axis direction of the light beam.

9. A lithographic apparatus comprising the illumination optical system of any one of claims 1 to 8.

10. An exposure method, characterized in that a pattern on a reticle is exposed onto a substrate using the lithography apparatus according to claim 9.

Technical Field

The invention relates to the technical field of photoetching machines, in particular to an illumination optical system, photoetching machine equipment and an exposure method.

Background

The primary role of the illumination optics in a lithographic apparatus is to provide a correctly sized, shaped illumination field for the pattern on the mask. Among these, uniformity and telecentricity of the illumination light beam are the most important performance indexes for evaluating reliability of the illumination optical system, and the uniformity is a difference between edge brightness and center brightness of a field of view of the illumination light beam, and the telecentricity is a degree of parallelism between an optical axis and a main light beam. In transferring the pattern on the mask plate to the substrate, if telecentricity and uniformity are not satisfactory as the requirements of the working conditions, it is difficult in any case to faithfully transfer the pattern of the original plate to the substrate, and therefore, in the illumination optical system, adjustment of luminance uniformity and telecentricity is necessary.

Chinese patent application publication No. CN105629671A, entitled "illumination optical apparatus and device manufacturing method", published as 2016, 06 and 01, discloses an illumination optical apparatus in which a chief ray incident on a mask is made nearly parallel to a normal line of the mask by a method of additionally adding an adjustment unit to the outside of an image forming optical system. The device not only needs to add an additional adjusting unit to improve the manufacturing cost of the photoetching machine equipment, but also the additionally added wedge-shaped optical element has adverse effects on the uniformity and other optical performances of the light beam.

Therefore, it is necessary to provide an illumination optical system with simple operation and lower cost to solve the problems of difficult adjustment of illumination telecentricity and higher cost in the prior art.

It is noted that the information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention provides an illumination optical system, photoetching machine equipment and an exposure method, which are used for solving the problems that the illumination telecentricity of a light beam is difficult to adjust, other optical performances are adversely affected and the cost is high in the prior art.

In order to achieve the above object, the illumination optical system provided by the present invention is implemented by the following technical solutions: the utility model provides an optical lighting system, includes light source and light beam propagation subassembly, the light that light source sent is through form images on the illumination image plane behind the light beam propagation subassembly, the light beam propagation subassembly includes relay mirror group, relay mirror group is close to the setting of illumination image plane, relay mirror group includes at least one adjustable lens, adjustable lens sets up the incident terminal surface and/or the emergent terminal surface of relay mirror group for adjust the light beam and incide to illumination telecentric degree on illumination image plane.

Optionally, the illumination device further comprises a reflection unit, the reflection unit is disposed between the illumination light source and the light beam propagation assembly along the propagation direction of the light path, and the reflection unit is configured to change the propagation direction of the light beam emitted by the illumination light source.

Optionally, the illumination device further comprises a beam expander, the beam expander is arranged between the illumination light source and the reflection unit along a propagation direction of a light path, and the beam expander is used for expanding and collimating the light beam emitted by the illumination light source.

Optionally, along the light path propagation direction, the light beam propagation assembly further includes a zoom lens group, a converging lens group, and a light homogenizing integrator in sequence, and the relay lens group is disposed between the light homogenizing integrator and the illumination image plane.

Optionally, the light beam propagation assembly further includes a first diffractive optical element, and the first diffractive optical element is disposed between the reflection unit and the zoom lens group along a light path propagation direction, and is configured to diffract the light beam into a preset angle distribution, and is configured to cooperate with the zoom lens group to form a preset pupil distribution on a pupil plane of the zoom lens group.

Optionally, the light beam propagation assembly further includes a second diffractive optical element, along the light path propagation direction, the second diffractive optical element is disposed between the zoom lens group and the converging lens group, and the second diffractive optical element is disposed on a pupil plane of the zoom lens group and is configured to cooperate with the converging lens group to form a light spot matched with the aperture of the light homogenizing integrator on an image plane of the converging lens group.

Optionally, each of the two light beam propagation assemblies is used for receiving the light beam reflected by the reflection unit and respectively imaging on the image surface; each light beam transmission assembly is used for adjusting the illumination telecentricity of the light beam transmission assemblies respectively incident to the illumination image surface. .

Optionally, along a first coordinate axis, the adjustable lens has an adjustment range of ± 3 °, and along a second coordinate axis, the adjustable lens has an adjustment range of ± 3 °, wherein,

the first coordinate axis and the second coordinate axis are perpendicularly intersected and are positioned on a plane perpendicular to the direction of the optical axis of the light beam.

To achieve another object of the present invention, the present invention also provides a lithographic apparatus including the illumination optical system described in any one of the above.

In order to achieve another object of the present invention, the present invention also provides an exposure method for exposing a pattern on a reticle onto a substrate using the above-described lithography apparatus.

Compared with the prior art, the illumination optical system provided by the invention has the following beneficial effects:

the adjustable lens of the illumination optical system provided by the invention is arranged close to the illumination image surface of the illumination optical system, so that the problem of high telecentric adjustment difficulty is solved on the premise of not influencing other optical performances, no optical device is required to be additionally arranged in the light path propagation direction, the integral framework of the existing illumination optical system is not changed, and the illumination telecentric adjustment cost is reduced. Moreover, different illumination sources and beam spreading assemblies can be adapted.

Furthermore, the illumination optical system provided by the invention adjusts the inclination posture of the adjustable lens, so that the illumination telecentricity of the light beam can be adjusted in real time, the design difficulty of a photoetching lens is reduced, and the performance of an exposure system is improved.

The illumination optical system and the photoetching machine provided by the invention utilize the posture of the optical lens to influence the telecentricity, and other optical performances are not influenced, so that the telecentricity adjustment of the photoetching machine is realized.

Drawings

Fig. 1 is a schematic structural diagram of an illumination optical system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the adjustable lens of FIG. 1 in one of its tilted states;

FIG. 3 is a comparison graph of telecentricity of the adjustable lens of FIG. 1 before and after adjustment;

FIG. 4 is a comparison graph of field uniformity before and after adjustment of the adjustable lens of FIG. 1;

fig. 5 is a schematic structural diagram of an illumination optical system according to a second embodiment of the present invention;

fig. 6 is a schematic structural diagram of an illumination optical system according to a third embodiment of the present invention;

FIG. 7 is a schematic diagram of the adjustable lens of FIG. 6 in one of its tilted states;

wherein the reference numerals are as follows:

101-a laser light source, 102-a beam expander, 103-a reflector, 104-a first diffractive optical element, 105-a zoom lens group, 106-a second diffractive optical element, 107-a converging lens group, 108-a first light homogenizing integrator, 109-a first relay lens group, 109a, 109 b-a first adjustable optical lens, 110, 120-an image plane;

201-mercury lamp light source, 202-ellipsoid bowl, 203-zoom unit, 204-convergence unit, 205-second light homogenizing integrator, 206-second relay lens group, 206 a-second adjustable optical lens and 210-mask surface.

Detailed Description

The core idea of the invention is to provide an illumination optical system to solve the problem that the illumination telecentricity is difficult to adjust in the illumination optical system in the prior art.

In order to achieve the above idea, the present invention provides an illumination optical system, including an illumination light source and a light beam propagation assembly, where light emitted by the illumination light source forms an image on an illumination image plane after passing through the light beam propagation assembly, the light beam propagation assembly includes a relay lens group, the relay lens group is disposed near the illumination image plane, the relay lens group includes at least one adjustable lens, and the adjustable lens is disposed on an incident end surface and/or an exit end surface of the relay lens group and is used to adjust an illumination telecentricity at which the light beam enters the illumination image plane.

The relay lens group provided by the invention is arranged close to the illumination image surface of the illumination optical system, so that the problem of high telecentric adjustment difficulty is solved and the cost of telecentric illumination adjustment is reduced on the premise of not influencing other optical properties. Furthermore, according to the illumination optical system provided by the invention, the inclination posture of the adjustable lens of the relay lens group is adjusted, so that the illumination telecentricity of light beams is adjusted in real time, the design difficulty of a photoetching lens is reduced, and the performance of an exposure system is improved.

To make the objects, advantages and features of the present invention more apparent, the illumination optical system, the lithography apparatus and the exposure method according to the present invention will be described in further detail with reference to the accompanying drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. It should be understood that the drawings are not necessarily to scale, showing the particular construction of the invention, and that illustrative features in the drawings, which are used to illustrate certain principles of the invention, may also be somewhat simplified. Specific design features of the invention disclosed herein, including, for example, specific dimensions, orientations, locations, and configurations, will be determined in part by the particular intended application and use environment. In the embodiments described below, the same reference numerals are used in common between different drawings to denote the same portions or portions having the same functions, and a repetitive description thereof will be omitted. In this specification, like reference numerals and letters are used to designate like items, and therefore, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

< example one >

The illumination optical system provided by the present embodiment, as shown in fig. 1, includes an illumination light source and a light beam propagation assembly, the light beam propagation assembly includes a first relay lens group 109, the first relay lens group 109 is disposed near an illumination image plane 111, the first relay lens group 109 includes at least one first adjustable lens 109a, and the first adjustable lens 109a is disposed on an incident end surface and/or an exit end surface of the first relay lens group 109, and is configured to adjust an illumination telecentricity of a light beam incident on the illumination image plane. Preferably, in this embodiment, the adjustable lens is disposed at the exit end surface of the first relay lens group 109, close to the illumination image plane 111. Wherein the illumination light source of the present embodiment is a laser light source 101.

Preferably, in one exemplary embodiment, the illumination system further includes a reflection unit disposed between the laser light source 101 and the light beam propagation assembly along the propagation direction of the light path, and the reflection unit is configured to change the propagation direction of the light beam emitted from the laser light source 101. In the present embodiment, the reflecting unit is a mirror 103. In other embodiments, the reflecting unit may include two or more mirrors.

Preferably, the illumination system provided by the present invention further includes a beam expander 102, and along the propagation direction of the optical path, the beam expander 102 is disposed between the laser light source 101 and the reflector 103, and the beam expander 102 is configured to expand and collimate the light beam emitted by the illumination light source.

Preferably, along the propagation direction of the optical path, the light beam propagation assembly further includes a zoom lens group 105, a converging lens group 107 and a first light homogenizing integrator 108 in sequence, and the first relay lens group 109 is disposed between the first light homogenizing integrator 108 and the illumination image plane 111.

Preferably, the light beam propagation assembly further includes a first diffractive optical element 104, in the light path propagation direction, the first diffractive optical element 104 is disposed between the reflector 103 and the zoom lens group 105, and the first diffractive optical element 104 is configured to diffract the light beam into a predetermined angle distribution and is configured to cooperate with the zoom lens group 105 to form a predetermined pupil distribution on a pupil plane of the zoom lens group 105.

Preferably, the light beam propagation assembly further includes a second diffractive optical element 106, along the light path propagation direction, the second diffractive optical element 106 is disposed between the zoom lens group 105 and the converging lens group 107, and the second diffractive optical element 106 is disposed on a pupil plane of the zoom lens group 105 and is configured to cooperate with the converging lens group 107 to form a light spot matching with the aperture of the first light homogenizing integrator 108 on an image plane of the converging lens group 107.

In summary, with reference to fig. 1, the illumination optical system provided in this embodiment sequentially includes, along the propagation direction of the optical path, a laser light source 101, a beam expander 102, a reflector 103, a first diffractive optical element 104, a zoom lens group 105, a second diffractive optical element 106, a converging lens group 107, a first light homogenizing integrator 108, and a first relay lens group 109. The first adjustable lens 109a is close to the image plane 111, and is used for an illumination system of the lithography machine, and the image plane 111 may be a mask plane on the lithography machine. The first Diffractive Optical element 104 and the second Diffractive Optical element 106 are Diffractive Optical Elements (DOE), which are a series of movable Optical lenses mainly used for shaping and splitting laser beams in a high-efficiency manner. The second diffractive optical element 106 may be a microlens array.

Specifically, when the illumination optical system provided by this embodiment is used, the beam expander 102 can expand and collimate the light beam emitted by the laser light source 101; the mirror 103 redirects the expanded beam into the beam propagation assembly. Typically, depending on the position of the laser light source 101 and the beam propagation assembly, multiple mirrors are typically required. By adjusting the inclination of the mirror 103, the angle of the light beam entering the first diffractive optical element 104 can be adjusted. The first diffractive optical element 104 diffracts the collimated light beam to form a certain angle distribution, and the first diffractive optical element 104 and the zoom lens group 105 together form a certain pupil distribution on a pupil plane of the zoom lens group 105. The second diffractive optical element 106 is located on a pupil plane of the zoom lens group 105, and the second diffractive optical element 106 and the converging lens group 107 together form a light spot matched with the aperture of the first light homogenizing integrator 108 on an image plane of the converging lens group 107, so that light beams can completely enter the first light homogenizing integrator 108 without damaging the first light homogenizing integrator 108. The first light homogenizing integrator 108 is located on an image plane of the converging lens group 107, performs light homogenizing on the light beam, and forms a uniform illumination field at an outlet end of the first light homogenizing integrator 108. The object plane of the first relay lens group 109 is located at the exit end of the first light homogenizing integrator 108. The first relay lens group 109 enlarges the uniform field of view, and forms an illumination field of view of a certain wavelength with uniformity satisfying requirements on a relay image plane, that is, an illumination image plane 111.

In practical applications, due to assembly errors between the laser light source 101 and the light beam propagation assembly, and performance and wear of the optical device itself, when the light beam passing through the light beam propagation assembly from the laser light source 101 reaches the image plane 111, the telecentricity may not meet the requirements of the operating conditions. When the equipment applying the illumination optical system provided by the embodiment detects that the telecentricity of the image plane 111 does not meet the requirement of a working condition, the telecentricity of the light beam can be adjusted by adjusting the adjustable optical lens. Preferably, along a first coordinate axis, the adjustment range of the adjustable lens is ± 5 °, and along a second coordinate axis, the adjustment range of the adjustable lens is ± 5 °, wherein the first coordinate axis and the second coordinate axis intersect perpendicularly and are located on a plane perpendicular to the optical axis direction of the light beam. . In this embodiment, as shown in fig. 2, the first coordinate axis is an X-axis direction, the second coordinate axis is a Y-axis direction, and the optical axis direction is a Z-axis direction. As shown in fig. 3, when the adjustable optical lenses 109a in said first relay lens group 109 are tilted by-0.2 ° along said first coordinate axis (X-axis direction in the figure) and by 0.5 ° along said second coordinate axis (Y-axis direction in the figure), telecentricity adjustment from a maximum of 3mrad to less than 1mrad at full field and a deviation of the center position of the field of view of less than 100 μm is achieved throughout the field of view. Moreover, uniformity across the field of view is not only not adversely affected, but is also somewhat improved. As shown in fig. 4. Moreover, in a certain adjustment range, the diffuse spot of the first relay lens group does not change greatly with the positions before and after adjustment, as shown in table one below.

Table one: change of the diffuse spot of the first relay lens group before and after adjustment

When the optical lens in the relay lens group close to the object plane or the image plane 110 changes the inclined posture, the transmission angle of light is further changed, and the convergence position of light beams is changed, so that the telecentricity of the whole illumination optical system is adjusted.

< example two >

As shown in fig. 5, the illumination light source of this embodiment is a mercury lamp light source 201, the reflection unit is an ellipsoidal bowl 202, and the light beam propagation assembly of this embodiment is substantially the same as the first embodiment, and the light beam propagation assembly of this embodiment includes a zooming unit 203, a converging unit 204, a second light homogenizing integrator 205, a second relay lens group 206, and a second adjustable optical lens 206a located in the second relay lens group, where the second adjustable optical lens 206a is located close to an image plane of the second relay lens group 206, that is, located on an exit end surface of the second relay lens group 206, and close to a mask surface 210. The ellipsoid bowl 202 can form the light beam emitted by the mercury lamp light source 201 into a light beam with a certain divergence angle. Similar to the embodiment, along the propagation direction of the optical path, the zooming unit 203, the converging unit 204, the second light homogenizing integrator 205, and the second relay lens group 206 are arranged in sequence. The ellipsoid bowl 202 forms a certain angular distribution, and together with the zoom unit 203, a certain pupil distribution is formed on a pupil plane of the zoom unit 203. Light spots matched with the aperture of the second light homogenizing integrator 205 are formed on the image surface of the converging unit, so that light beams can completely enter the second light homogenizing integrator 205 and cannot damage the second light homogenizing integrator 205. The light homogenizing integrator 205 is located on an image plane of the converging unit 204, homogenizes light of the light beam, and forms a uniform illumination field at an outlet end of the second light homogenizing integrator 205. The object plane of the second relay lens group 206 is located at the exit end of the second light homogenizing integrator 205. The second relay lens group 206 enlarges the uniform field of view, and forms an illumination field of view with a certain wavelength, the uniformity of which meets the requirement, on the relay image plane, i.e. the mask plane 210.

Similar to the embodiment, when the second adjustable optical lens 206a in the second relay lens group 206 of the present embodiment is tilted along the first coordinate axis (X-axis direction in the drawing) by a certain angle (for example, -0.15 °), and is tilted along the second coordinate axis (Y-axis direction in the drawing) by a certain angle (for example, 0.6 °), similar technical effects can be achieved as shown in fig. 3 and 4 and table one, that is: under the condition that the telecentricity is adjusted to meet the preset working condition, the uniformity in the whole view field is not affected and is improved to a certain degree. Furthermore, the diffuse spot of the second relay lens group does not change greatly before and after adjustment.

The illumination optical system provided by the invention can be suitable for different illumination light sources and reflection units, has no limitation and requirement on the front-end optical device of the light beam transmission assembly, and has wider application range.

< example three >

The illumination optical system provided by the present embodiment is different from the first embodiment in that there are two light beam propagation assemblies, and each of the two light beam propagation assemblies is used for receiving the light beam reflected by the reflection unit and for respectively forming an image on the image plane; each light beam transmission assembly is used for adjusting the illumination telecentricity of the light beam transmission assemblies respectively incident to the illumination image surface. . As shown in fig. 6 and 7, the adjustable lenses in each of the beam spreading assemblies are independent of each other and are respectively used for adjusting the illumination telecentricity incident to the illumination image plane. Specifically, the optical path of the illumination optical system provided in this embodiment includes a laser light source 101, a beam expander 102, and a reflector 103, and the light beam propagation assembly of this embodiment includes a first light beam propagation assembly and a second light beam propagation assembly, in the direction shown in fig. 6, the first light beam propagation assembly is located below the light beam propagation assembly, and the second light beam propagation assembly is located below the light beam propagation assembly. The optical elements of the first light beam propagation assembly are similar to those in the first embodiment, and include, in order along the light path propagation direction, a first diffractive optical element 104, a zoom lens group 105, a second diffractive optical element 106, a converging lens group 107, a first light homogenizing integrator 108, and a first relay lens group 109, where the first relay lens group includes two adjustable optical lenses, i.e., a first adjustable optical lens 109a and a first adjustable optical lens 109 b. The first diffractive optical element 104, the zoom lens group 105, the second diffractive optical element 106, the converging lens group 107, and the first uniform light integrator 108 are the same as those in the first embodiment, and thus, the description thereof is omitted. In particular, the first relay lens group 109 in this embodiment is a generic term of the relay lens groups of the first light beam spreading component and the second light beam spreading component, and is only for convenience of description, and is not a limitation that the light beam spreading components of the illumination optical system provided by the present invention must share the relay lens group, and the relay lens groups of different light beam spreading components may be completely controlled in one or more combination forms of non-interference or mutual cooperation. In this embodiment, the object plane of the first relay lens group 109 of the first light beam propagation assembly and the object plane of the first relay lens group 109 of the second light beam propagation assembly are located at the exit end of the light uniformizing integrator, and the first relay lens group 109 of this embodiment enlarges the uniform field of view, and forms an illumination field with a certain wavelength and a uniformity satisfying the requirement on the relay image plane, that is, the illumination image plane. It is apparent that the present embodiment is merely an exemplary description of an illumination optical system having a plurality of beam spreading assemblies, and is not a limitation of the present invention. Although in the present embodiment, the optical devices of the first and second beam delivery assemblies are similar and do not constitute any limitation on the present invention, in other embodiments, the optical devices of the first and second beam delivery assemblies may be different, and there is no limitation on the number of beam delivery assemblies of the illumination optical system.

As shown in fig. 7, according to actual requirements, the first adjustable optical lenses 109a and 109b of the first relay lens group 109, which are close to the image plane 120, may be respectively tilted along the first coordinate axis and the second coordinate axis by different angles, and in a specific application scenario, under the condition that telecentricity adjustment is achieved to meet a preset working condition, uniformity within the whole field of view is not only not adversely affected, but also improved to a certain extent. Furthermore, the diffuse spot of the first relay lens group does not change greatly before and after adjustment.

In a further exemplary embodiment of the invention, a lithographic apparatus is also provided, which includes the illumination optical system according to any of the above embodiments, and the adjustable optical lens of the illumination optical system is disposed close to a mask plate of the lithographic apparatus.

In a further exemplary embodiment of the present invention, an exposure method is provided, which uses the above-mentioned lithography apparatus to expose a pattern on a mask plate of the lithography apparatus onto a substrate.

Obviously, the above description of the preferred embodiment is only in a manner understandable to those skilled in the art, and in other embodiments, a telecentricity adjustment control unit may be included to calculate the tilt of the adjustable lens in the first coordinate axis and the second coordinate axis, respectively, according to the telecentricity of the light beam incident on the image plane (mask plane), and to control the tilt of the adjustable lens.

In summary, in the technical solution of the present invention, the posture of the optical lens is used to affect telecentricity, and other optical properties are not affected, so that telecentric adjustment of the illumination optical system is realized.

The adjustable lens of the illumination optical system provided by the invention is arranged close to the illumination image surface of the illumination optical system, so that the problem of high telecentric adjustment difficulty is solved on the premise of not influencing other optical performances, no optical device needs to be additionally arranged in the light path propagation direction, the integral framework of the existing illumination optical system is not changed, and the illumination telecentric adjustment cost is reduced. Moreover, different illumination sources and beam spreading assemblies can be adapted.

Furthermore, the illumination optical system provided by the invention adjusts the inclination posture of the adjustable lens, so that the illumination telecentricity of the light beam can be adjusted in real time, the design difficulty of a photoetching lens is reduced, and the performance of an exposure system is improved.

A lithographic apparatus having an illumination optical system has the same advantageous effects as the illumination optical system.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

In summary, the above embodiments have been described in detail with respect to various configurations of the illumination optical system, the lithography apparatus and the exposure method, it is to be understood that the above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention.