Illuminating system

Abstract

The invention provides an illumination system which comprises a light source, a coupling unit, a dodging unit and a relay unit, the dodging unit comprises a first dodging element and second dodging elements, the second dodging elements are additionally arranged on the upper side and the lower side of the first dodging element, and under the condition that the original exposure view field size and illumination are not affected and an illumination light source does not need to be added, the illumination intensity is improved. The second dodging element fully utilizes unutilized light energy of the first image space view field part to independently provide uniform illumination energy for the alignment mark located on the outer edge of the exposure view field, the effective utilization rate of the light energy is improved, the second dodging element can be freely selected, and the degree of freedom of illumination view field selection is improved.

Description

Technical Field

[0001] The invention relates to the field of aiming lighting, and in particular to a lighting system. Background Art

[0002] In a photolithography machine, when coaxial alignment is required, the alignment marks on the mask are imaged onto the substrate surface through a projection objective lens, and the imaged marks are used for alignment. In this process, the alignment marks on the mask need to be provided with light energy of the required wavelength and energy, usually the illumination light source of the exposure area.

[0003] When the coaxial alignment mark is outside the exposure field of view, if the coaxial alignment mark is to be exposed, the illumination area needs to be expanded to cover the coaxial alignment mark. This will cause the light power of the same total energy to be dispersed to a larger area of ​​the illumination field of view, reducing the illumination and affecting the performance of the lithography machine. When additional optical fibers are used to increase the illumination, the optical fibers guide the light outside the illumination area to the top of the mask through the optical fibers to provide an illumination field of view for the alignment mark, but the uniformity of the illumination field provided under this operation is not enough. Summary of the invention

[0004] Therefore, in order to overcome the shortcomings of the above-mentioned prior art, the present application provides an illumination system, which makes full use of the unused light energy of the first image field of view without reducing the light intensity in the exposure area to provide a uniform illumination field for the alignment mark located outside the exposure field of view.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solution: an illumination system for providing an exposure field to a mask, characterized in that it comprises:

[0006] a light source for providing a light beam;

[0007] A coupling unit, used for modulating and transmitting the light beam, and providing a first image field of view of different sizes by changing the focal length of the coupling unit;

[0008] A light homogenization unit, used for performing light homogenization processing on the light beam in the first image field, and emitting a light beam of the same size as the exit end face at the exit end face of the light homogenization unit;

[0009] A relay unit, the relay unit is used to geometrically amplify the light beam emitted from the output end face of the light homogenizing unit, and obtain the exposure field of view and the illumination field of view after geometric amplification;

[0010] The light homogenizing unit includes a first light homogenizing element and two second light homogenizing elements, the first light homogenizing element and the second light homogenizing element are both rectangular parallelepipeds, and the two second light homogenizing elements are respectively arranged on the upper and lower sides of the first light homogenizing element; the incident end face of the first light homogenizing element is located in the first image field of view, and the exit end face of the first light homogenizing element is located in the second object field of view of the relay unit;

[0011] The light beam processed by the first light homogenizing element is proportionally magnified to obtain an exposure field of view, and the light beam processed by the second light homogenizing element is proportionally magnified to obtain the illumination field of view covering the alignment mark not within the exposure field of view.

[0012] Specifically, the diagonal length of the incident end surface of the first light homogenizing element is equal to the diameter length of the first image side field of view.

[0013] Specifically, the length of the long side of the incident end surface of the first light homogenizing element is consistent with the length of the long side of the incident end surface of the second light homogenizing element.

[0014] Specifically, endpoints of the incident end faces of the two second light homogenizing elements that are away from the first light homogenizing element both overlap with edges of the first image-side field of view.

[0015] Specifically, the connection method between the first light homogenizing element and the second light homogenizing element includes abutment connection, optical glue bonding and magnetic adsorption connection.

[0016] Specifically, the focal length of the coupling unit is changed by adjusting the relative positions of the lenses in the coupling unit and replacing the lenses in the coupling unit.

[0017] Specifically, the second light homogenizing element is formed by splicing a plurality of shorter light homogenizing rods.

[0018] Specifically, the incident end face and the emitting end face of the second light homogenizing element are plated with film layers with different transmittances.

[0019] Specifically, the incident end surface position of the at least one second light homogenizing element is inconsistent with the incident end surface position of the first light homogenizing unit, and is used to adjust the intensity of the incident light.

[0020] Specifically, the first light homogenizing element and the second light homogenizing element are made of a light-guiding material, including quartz or calcium fluoride.

[0021] Compared with the prior art, the advantages of the present application are: the lighting system of the present application adds a second light homogenizing element on the upper and lower sides of the first light homogenizing element. Without affecting the original exposure field size and illumination and without increasing the lighting light source, the second light homogenizing element fully utilizes the unused light energy of the first image field, and provides uniform lighting energy to the alignment mark located outside the exposure field separately, thereby improving the effective utilization rate of light energy, and the second light homogenizing element can be freely selected, thereby improving the freedom of selecting the illumination field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a schematic diagram of a lighting system in an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of the positional relationship between the first image field of view and the incident end surface of the first light homogenizing element in the embodiment of the present application;

[0025] Figure 3 is a schematic diagram of the relationship between the incident end face of the first light homogenizing element and the incident end face of the second light homogenizing element in the embodiment of the present application;

[0026] Figure 4 is a schematic diagram of the relationship between the first image field of view and the incident end surface of the first light homogenizing element and the incident end surface of the second light homogenizing element when the long side length of the exposure field of view is greater than the long side length of the illumination field of view in the embodiment of the present application;

[0027] Figure 5 It is a schematic diagram of the relationship between the first image field of view and the incident end surface of the first light homogenizing element and the incident end surface of the second light homogenizing element when the long side length of the exposure field of view is equal to the long side length of the illumination field of view in the embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0030] It should be noted that various aspects of the embodiments within the scope of protection of the present invention are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0031] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0032] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0033] The present application embodiment provides a lighting system, such as Figure 1 As shown, it includes: a light source 101, a coupling unit 102, a light homogenization unit 103 and a relay unit 104.

[0034] The light source 101 , the coupling unit 102 , the homogenizing unit 103 and the relay unit 104 are located on the same straight line. The illumination system finally provides a rectangular exposure field 11 with a length of L1 and a width of W2 , and an illumination field 12 covering the alignment mark outside the exposure field 11 .

[0035] The light source 101 may be a mercury lamp light source, a conventional light bulb light source, an LED light source or a laser light source, and is used to provide an illumination beam to the image coupling unit 102 .

[0036] The coupling unit 102 is located on the propagation path of the illumination beam, and is used to modulate and transmit the illumination beam provided by the light source 101, and convert the illumination beam into an imaging beam. The imaging beam surface intersecting with the incident end surface of the light homogenization unit 103 is a circular first image field 1021, that is, the cross section of the imaging beam is a circular light spot. The coupling unit 102 can change the size of the first image field 1021, that is, the size of the circular light spot, by adjusting its focal length.

[0037] The light homogenizing unit 103 includes a first light homogenizing element 1031 and two second light homogenizing elements 1032. The first light homogenizing element 1031 and the second light homogenizing element 1032 are both rectangular parallelepipeds. The two second light homogenizing elements 1032 are arranged on the upper and lower sides of the first light homogenizing element 1031. The first light homogenizing element 1031 and the two second light homogenizing elements 1032 are light homogenizing integrator rods, which can be specifically made of light-guiding materials such as quartz rods and calcium fluoride rods. The light homogenizing integrator rod is an optical device for controlling the propagation of light. Its working principle is to use refraction and total reflection to make the light reflect and refract multiple times in the rod to achieve the effect of evenly distributing the light.

[0038] The incident end face 1131 and the exit end face 1231 of the first light homogenizing element 1031 are both rectangles with a length of L1 / M and a width of W1 / M. The incident end face 1131 of the first light homogenizing element 1031 is located in the first image field of view 1021. A light beam with a rectangular cross section with a length of L1 / M and a width of W1 / M is emitted from the exit end face 1131 of the first light homogenizing element 1031, that is, a light beam with a rectangular light spot with a length of L1 / M and a width of W1 / M is provided. The incident end faces 1132 and the exit end faces 1231 of the two second light homogenizing elements 1032 are both rectangles with a length of L2 / M and a width of W2 / M. A light beam with a rectangular cross section with a length of L2 / M and a width of W2 / M is emitted from the exit end faces 1132 of the two second light homogenizing elements 1032, that is, a light beam with a rectangular light spot with a length of L2 / M and a width of W2 / M is provided.

[0039] The relay unit 104 provides a second object field of view 1041, and the exit end surface 1231 of the first light homogenizing element 1031 is located in the second object field of view 1041. The magnification of the relay unit 104 is M, and the light spot emitted from the exit end of the light homogenizing unit 103 is proportionally amplified. Specifically, the relay unit 104 amplifies the light spot emitted from the exit end of the first light homogenizing element 1031 by M times to obtain the exposure field of view 11, and the relay unit 104 amplifies the light spots emitted from the exit ends of the two second light homogenizing elements 1032 by M times to obtain the illumination field of view 12.

[0040] The illumination field of view 12 covers the alignment mark outside the exposure field of view 11. Light energy is provided to the alignment mark without introducing other light sources, which plays a role in maximizing the efficiency of light energy, integrating resources, and utilizing resources to the greatest extent.

[0041] The light source 101 emits a light beam, which enters the coupling unit 102. The coupling unit 102 modulates and transmits the light beam, and provides a circular first image field of view 1021 at the output end of the coupling unit 102. The diameter of the first image field of view 1021 provided by the coupling unit 102 is not less than (L1+M1) 0.5 / M. The diameter of the second object field of view 1041 of the relay unit 104 is not less than (L1+M1) 0.5 / M. The incident end face 1131 of the first light homogenizing element 1031 and the first image field of view 1021 are in the same plane, and the first light homogenizing element 1031 is located in the circular first image field of view 1021. The incident end face 1131 and the exit end face 1231 of the first light homogenizing element 1031 are both rectangular with a length of L1 / M and a width of W1 / M. The first light homogenizing element 1031 performs light homogenization transmission processing on the light beam overlapping with the first image field of view 1021, and provides a rectangular light spot with a length of L1 / M and a width of W1 / M at the exit end of the first light homogenizing element 1031. The exit end face 1231 of the first light homogenizing element 1031 is located in the second object field of view 1041 of the relay unit 104. The relay unit 104 magnifies the rectangular light spot with a length of L1 / M and a width of W1 / M provided by the output end of the first light homogenizing element 1031 by M times, and provides a rectangular exposure field of view 11 with a length of L and a width of W on the mask. The incident end faces 1132 and the output end faces 1232 of the two second light homogenizing elements 1032 are rectangles with a length of L2 / M and a width of W2 / M. The two second light homogenizing elements 1032 are arranged on the upper and lower sides of the first light homogenizing element 1031. By using part of the light energy outside the overlapping part of the circular first image field of view 1021 and the incident end face 1131 of the first light homogenizing element 1031, the two second light homogenizing elements 1032 perform light homogenization transmission processing on the light beam outside the overlapping part of the circular first image field of view 1021 and the incident end face 1131 of the first light homogenizing element 1031. A rectangular light spot with a length of L2 / M and a width of W2 / M is provided at the exit ends of the two second light homogenizing elements 1032. The relay unit 104 magnifies the rectangular light spot with a length of L2 / M and a width of W2 / M provided at the exit ends of the two second light homogenizing elements 1032 by M times, and provides two rectangular illumination fields of view 12 with a length of L2 and a width of W2 on the mask at the upper and lower sides of the exposure field of view 11. The illumination field of view 12 covers the alignment mark outside the exposure field of view 11.

[0042] In the above-mentioned illumination system, the first light homogenizing element 1031 remains unchanged, meets the original size requirement of the exposure field of view 11, provides the mask with a rectangular exposure field of view 11 with a length of L1 and a width of W1, and the illumination of the exposure field of view 11 is not affected and remains the same as before. Two second light homogenizing elements 1032 are added on the upper and lower sides of the first light homogenizing element 1031, without adding an illumination light source, and the two second light homogenizing elements 1032 fully utilize the unused light energy of the first image field of view 1021, and provide uniform illumination energy to the alignment mark outside the exposure field of view 11 separately, thereby improving the effective utilization rate of light energy, and the second light homogenizing element 1032 can be freely selected, thereby improving the freedom of selection of the illumination field of view 12.

[0043] In one embodiment, if Figure 2 As shown, the diameter length of the circular first image field 1021 is (L1+M1) 0.5 / M, at this time, the diagonal length of the incident end face 1131 of the first light homogenizing element 1031 is equal to the diameter length of the circular first image field of view 1021, that is, the four endpoints of the incident end face 1131 of the first light homogenizing element 1031 coincide with the edge of the circular first image field of view 1021, and the circular first image field of view 1021 is the circumscribed circle of the incident end face 1131 of the first light homogenizing element 1031. The first light homogenizing element 1031 has the highest light energy utilization rate in the circular first image field of view 1021, and transmits the light energy to the exposure field of view 11 to the greatest extent.

[0044] In one embodiment, if Figure 3 As shown, the length L2 / M of the long side of the incident end face 1132 of the second light homogenizing element 1032 is equal to L1 / M, that is, the length of the long side of the incident end face 1131 of the first light homogenizing element 1031 is consistent with the length of the long side of the incident end face 1132 of the second light homogenizing element 1032. At this time, the second light homogenizing element 1032 provides a rectangular light spot with a length of L2 / M and a width of W2 / M. After being magnified M times by the relay unit 104, the length of the long side of the rectangular illumination field of view 12 is L2, which is consistent with the length L1 of the long side of the rectangular exposure field of view 11. The alignment mark can be located anywhere on the upper and lower edges of the exposure field of view 11. The illumination field of view 12 has a large field of view, providing a maximum range of illumination field of view.

[0045] In one embodiment, the four endpoints of the incident end faces 1132 of the two second light homogenizing elements 1032 that are far from the first light homogenizing element 1031 overlap with the edge of the first image field of view 1021, and the incident end faces 1132 of the two second light homogenizing elements 1032 are entirely located within the first image field of view 1021, so that the utilization of the two second light homogenizing elements 1032 is maximized. Figure 4 As shown, when the diameter length of the circular first image field 1021 is (L1+W1 2 ) 0.5 / M, the length of the long side of the rectangular incident end face 1132 of the two second light homogenizing elements 1032 is less than the length of the long side of the rectangular incident end face 1131 of the first light homogenizing element 1031. At this time, when the first light homogenizing element 1031 has the maximum light energy utilization rate and provides the mask with an exposure field of view 11 with a length of L1 and a width of W1 after final processing, there is no need to add an additional light source, that is, the two additional second light homogenizing elements 1032 can provide the mask with an illumination field of view 12 covering the alignment mark. Figure 5 As shown, when the length L2 / M of the long side of the incident end surface 1132 of the second light homogenizing element 1032 is equal to L1 / M, that is, the length of the long side of the incident end surface 1131 of the first light homogenizing element 1031 is consistent with the length of the long side of the incident end surface 1132 of the second light homogenizing element 1032, at this time, the diameter length of the circular first image field of view 1021 is [L1+(W1+2×W2)] 0.5 / M, the rectangular incident end face 1131 of the first light homogenizing element 1031 and the rectangular incident end faces 1132 of the two second light homogenizing elements 1032 are both located within the first image field of view 1021, providing a large-size illumination field of view 12 for the mask.

[0046] In one embodiment, the connection between the first light homogenizing element 1031 and the second light homogenizing element 1032 includes abutment connection, optical glue bonding, and magnetic adsorption connection.

[0047] In one embodiment, the focal length of the coupling unit 102 is changed by adjusting the relative positions of the lenses in the coupling unit 102 and replacing the lenses in the coupling unit 102 .

[0048] In one embodiment, the second light homogenizing element 1032 is formed by splicing a plurality of shorter light homogenizing rods, which reduces the processing difficulty and cost of the second light homogenizing element 1032 with a longer length, and reduces the assembly difficulty during the integration process, thereby preventing the second light homogenizing element 1032 from being damaged by uneven stress during the assembly process caused by the excessive length of the rectangular second light homogenizing element 1032. In addition, both the incident end face and the exit end face of the light homogenizing unit 103 can be plated with the required spectral cutoff film layer according to the special requirements of the illumination field 12, and the light beam is spectrally modulated, so that the illumination field 12 with special requirements can be obtained.

[0049] In one embodiment, the incident end face 1132 and the emitting end face 1232 of the second light homogenizing element 1032 are coated with films with different transmittances, so that the illumination can be discretely adjusted. The intensity of the illumination field 12 can be adjusted separately, and the detector can be adapted and aligned, thereby increasing the degree of freedom of the system.

[0050] In one embodiment, the position of the incident end face 1132 of at least one end of the second light homogenizing element 1032 is inconsistent with the position of the incident end face 1131 of the first light homogenizing unit 1031, which is used to adjust the intensity of the incident light. According to the light intensity requirement of the illumination field 12, when the light intensity is too large, a film layer with a certain transmittance is plated on the incident end face 1132 or the exit end face 1232 of the second light homogenizing element 1032 to reduce the energy, thereby reducing the light intensity of the illumination field; when the light intensity is low, the position of the incident end face 1132 of the second light homogenizing element 1032 is adjusted, and the incident end face 1132 of the second light homogenizing element 1032 is moved toward the coupling unit 102 side, so as to increase the light intensity of the illumination field 12 within a certain range.

[0051] In one embodiment, the first light homogenizing element 1031 and the second light homogenizing element 1032 are made of light-guiding materials, including quartz and calcium fluoride.

[0052] Example 1

[0053] An illumination system provides a rectangular exposure field with a length of L1 and a width of W1, and rectangular illumination fields with a length of L2 and a width of W2 on the upper and lower sides of the exposure field, wherein L1=L2, and the magnification of the relay unit is M.

[0054] like Figure 5 As shown, the first image-side field of view 1021 is the circumscribed circle of the incident end face 1131 of the first light homogenizing element 1031 and the incident end face 1132 of the second light homogenizing element 1032; the second object-side field of view 1041 is the circumscribed circle of the first light homogenizing element 1031 and the exit end face 1232 of the second light homogenizing element 1032. The diameter of the first image-side field of view 1021 and the diameter of the second object-side field of view 1041 are both [L1+(W1+2×W2)] 0.5 / M.

[0055] The first light homogenizing element 1031 is a rectangular quartz rod, and the second light homogenizing element 1032 is a rectangular quartz rod. The incident end face 1131 and the exit end face 1231 of the first light homogenizing element 1031 are both rectangular with a length of L1 / M and a width of W1 / M, and the incident end face 1132 and the exit end face 1232 of the second light homogenizing element 1032 are both rectangular with a length of L2 / M and a width of W2 / M. L1=L2, that is, the long side length L1 / M of the rectangular incident end face 1131 and the exit end face 1231 of the first light homogenizing element 1031 is consistent with the long side length L2 / M of the rectangular incident end face 1132 and the exit end face 1232 of the second light homogenizing element 1032.

[0056] The four endpoints on the incident end face 1132 of the second light homogenizing element 1032 away from the first light homogenizing element 1031 all overlap with the edge of the first image-side field of view 1021 ; the four endpoints on the exit end face 1232 of the second light homogenizing element 1032 away from the first light homogenizing element 1031 all overlap with the edge of the second object-side field of view 1041 .

[0057] The light source emits a light beam, which enters the coupling unit. The coupling unit modulates and transmits the light beam, and provides a diameter length of [L1+(W1+2×W2)] at the output end of the coupling unit. 0.5 / M, the incident end face 1131 of the first light homogenizing element 1031 and the incident end face 1132 of the second light homogenizing element 1032 are located in the first image field of view 1021, the long side length L1 / M of the rectangular incident end face 1131 and the exit end face 1231 of the first light homogenizing element 1031 is consistent with the long side length L2 / M of the rectangular incident end face 1132 and the exit end face 1232 of the second light homogenizing element 1032, and the first image field of view 1021 is the circumscribed circle of the large rectangle formed by the incident end face 1131 of the first light homogenizing element 1031 and the incident end face 1132 of the second light homogenizing element 1032. The first light homogenizing element 1031 performs light homogenization on the light beam entering from the incident end face 1131, and emits a light beam with a rectangular spot of length L1 / M and width W1 / M at the exit end face 1231 of the first light homogenizing element 1031. The second light homogenizing element 1032 performs light homogenization on the light beam entering from the incident end face 1132, and emits a light beam with a rectangular spot of length L2 / M and width W2 / M at the exit end face 1232 of the second light homogenizing element 1032. The incident end of the relay unit provides a diameter length of [L1+(W1+2×W2)] 0.5 / M, the exit end face 1231 of the first light homogenizing element 1031 and the exit end face 1232 of the second light homogenizing element 1032 are located in the second object field of view 1041, and the second object field of view 1041 is the circumscribed circle of a large rectangle formed by the exit end face 1231 of the first light homogenizing element 1031 and the exit end face 1232 of the second light homogenizing element 1032. The relay unit magnifies the light beam of the rectangular light spot with a length of L1 / M and a width of W1 / M by M times to obtain a rectangular exposure field of view with a length of L1 and a width of W1; the relay unit magnifies the light beam of the rectangular light spot with a length of L2 / M and a width of W2 / M by M times to obtain a rectangular illumination field of view with a length of L2 and a width of W2.

[0058] The length L1 of the long side of the finally obtained rectangular exposure field is consistent with the length L2 of the long side of the rectangular illumination field, and the illumination field has a large range. The alignment mark can be located at any position on the upper and lower sides of the exposure field, and even if the alignment mark is located at the corner, the illumination field can cover the alignment mark, achieving a higher precision alignment effect.

[0059] Example 2

[0060] An illumination system provides a rectangular exposure field with a length of L1 and a width of W1, and rectangular illumination fields with a length of L2 and a width of W2 on the upper and lower sides of the exposure field, wherein L1>L2, and the magnification of the relay unit is M.

[0061] like Figure 4 As shown, the first image field of view 1021 is the circumscribed circle of the incident end face 1131 of the first light homogenizing element 1031; the second object field of view 1041 is the circumscribed circle of the exit end face 1231 of the first light homogenizing element 1031. The diameter of the first image field of view 1021 and the diameter of the second object field of view 1041 are both (L1+W1) 0.5 / M.

[0062] The incident end face 1131 and the output end face 1231 of the first light homogenizing element 1031 are both rectangles with a length of L1 / M and a width of W1 / M. The incident end face 1132 and the output end face 1232 of the second light homogenizing element 1032 are both rectangles with a length of L2 / M and a width of W2 / M.

[0063] The four endpoints on the incident end faces 1132 of the two second light homogenizing elements 1032 that are far from the first light homogenizing element 1031 overlap with the edge of the first image-side field of view 1021; the four endpoints on the exit end faces 1232 of the second light homogenizing element 1032 that are far from the first light homogenizing element 1031 overlap with the edge of the second object-side field of view 1041. That is, [L2+(W1+2×W2) 2 ] 0.5 / M=(L1+W1) 0.5 / M.

[0064] The light source emits a light beam, which enters the coupling unit. The coupling unit modulates and transmits the light beam, and provides a diameter length (L1+W1) at the output end of the coupling unit. 0.5The first image field of view 1021 of the first light homogenizing element 1031 is located in the first image field of view 1021, and the first image field of view 1021 is the circumscribed circle of the incident end face 1131 of the first light homogenizing element 1031. The first light homogenizing element 1031 performs light homogenization on the light beam entering from the incident end face 1131, and emits a light beam with a rectangular spot having a length of L1 / M and a width of W1 / M at the exit end face 1231 of the first light homogenizing element 1031. The four endpoints on the incident end faces 1132 of the two second light homogenizing elements 1032 that are far away from the first light homogenizing element 1031 overlap with the edge of the first image field 1021. The incident end faces 1132 of the two second light homogenizing elements 1032 are entirely located in the first image field 1021. The second light homogenizing element 1032 performs light homogenization on the light beam entering from the incident end faces 1132, and emits a light beam with a rectangular spot length of L2 / M and a width of W2 / M at the exit end face 1232 of the second light homogenizing element 1032. The incident end of the relay unit provides a diameter length of (L1+W1) 0.5 / M, the exit end face 1231 of the first light homogenizing element 1031 and the exit end face 1232 of the second light homogenizing element 1032 are located in the second object field of view 1041, and the second object field of view 1041 is the circumscribed circle of the exit end face 1231 of the first light homogenizing element 1031. The relay unit magnifies the light beam of the rectangular light spot with a length of L1 / M and a width of W1 / M by M times to obtain a rectangular exposure field of view with a length of L1 and a width of W1; the relay unit magnifies the light beam of the rectangular light spot with a length of L2 / M and a width of W2 / M by M times to obtain a rectangular illumination field of view with a length of L2 and a width of W2.

[0065] Finally, a rectangular exposure field of view with a length of L1 and a width of W1 and a rectangular illumination field of view with a length of L2 and a width of W2 are obtained. In this embodiment, the first light homogenizing element has the maximum utilization rate of light energy in the first image field of view. While ensuring the maximum utilization rate of light energy in the exposure field of view, the second light homogenizing element makes maximum use of the light energy in the first image field of view that is not utilized by the first light homogenizing element to provide an illumination field for the mask, thereby improving the effective utilization rate of light energy.

[0066] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be included in the protection scope of the present application.

Claims

1. An illumination system for providing an exposure field to a mask, characterized in that: include: A light source for providing a light beam; A coupling unit, used for modulating and transmitting the light beam, and providing a first image field of view of different sizes by changing the focal length of the coupling unit; A light homogenization unit, used for performing light homogenization processing on the light beam in the first image field, and emitting a light beam of the same size as the exit end face at the exit end face of the light homogenization unit; A relay unit, the relay unit is used to geometrically amplify the light beam emitted from the output end face of the light homogenizing unit, and obtain the exposure field of view and the illumination field of view after geometric amplification; The light homogenizing unit includes a first light homogenizing element and two second light homogenizing elements, the first light homogenizing element and the second light homogenizing element are both rectangular parallelepipeds, and the two second light homogenizing elements are respectively arranged on the upper and lower sides of the first light homogenizing element; the incident end face of the first light homogenizing element is located in the first image field of view, and the exit end face of the first light homogenizing element is located in the second object field of view of the relay unit; The light beam processed by the first light homogenizing element is proportionally magnified to obtain an exposure field of view, and the light beam processed by the second light homogenizing element is proportionally magnified to obtain the illumination field of view covering the alignment mark not within the exposure field of view.

2. A lighting system according to claim 1, characterized in that: The diagonal length of the incident end surface of the first light homogenizing element is equal to the circular diameter length of the first image-side field of view.

3. The lighting system according to claim 1, characterized in that: The length of the long side of the incident end surface of the first light homogenizing element is consistent with the length of the long side of the incident end surface of the second light homogenizing element.

4. A lighting system according to claims 1 to 3, characterized in that: End points of the incident end faces of the two second light homogenizing elements that are away from the first light homogenizing element both overlap with edges of the first image-side field of view.

5. The lighting system according to claim 1, characterized in that: The connection method between the first light homogenizing element and the second light homogenizing element includes abutment connection, optical glue bonding and magnetic adsorption connection.

6. The lighting system according to claim 1, characterized in that: The manner of changing the focal length of the coupling unit includes adjusting the relative positions of the lenses in the coupling unit and replacing the lenses in the coupling unit.

7. The lighting system according to claim 1, characterized in that: The second light homogenizing element is formed by splicing a plurality of light homogenizing rods of relatively short length.

8. The lighting system according to claim 1, characterized in that: The incident end face and the output end face of the second light homogenizing element are plated with film layers with different transmittances.

9. The lighting system according to claim 1, characterized in that: The incident end surface position of the at least one second light homogenizing element is inconsistent with the incident end surface position of the first light homogenizing unit, and is used to adjust the intensity of the incident light.

10. The lighting system according to claim 1, characterized in that: The first light homogenizing element and the second light homogenizing element are made of light-guiding material, including quartz or calcium fluoride.

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