Assembly method for lithographic objective lens, and lithographic objective lens

Abstract

Provided in the present application are an assembly method for a lithographic objective lens, and a lithographic objective lens. The lithographic objective lens comprises a lens, which has a first light-transmitting surface and a second light-transmitting surface which are arranged opposite each other, and an outer wall surface circumferentially arranged. The lithographic objective lens further comprises a lens frame which carries the lens, wherein the lens frame has an annular configuration; and an inner wall surface of the lens frame is provided with an annular protrusion for abutting against the first light-transmitting surface or the second light-transmitting surface of the lens, and a plurality of dispensing grooves. The lens assembly steps include: determining the number and specification of the dispensing grooves and the dispensing amount by means of simulation software; and fixing the lens to the dispensing grooves by means of an adhesive, thereby reducing the usage amount of the adhesive, and reducing the shrinkage stress of the adhesive after curing. Moreover, the lens frame is prevented from directly generating circumferential stress on the lens, such that while the assembly stress requirements of the lithographic objective lens are met, the assembly cost of the lithographic objective lens can be greatly decreased, and the assembly efficiency can be improved.

Description

A method for assembling a photolithography objective and the photolithography objective itself. Technical Field

[0001] This application relates to the field of lithography equipment technology, and in particular to an assembly method for a lithography objective lens and the lithography objective lens itself. Background Technology

[0002] Optical lens systems are widely used in camera equipment, microscopic equipment, telescopes, and various precision instruments. Their performance and stability directly affect image quality and equipment reliability. Traditional optical lens assembly technology mainly relies on physical fixing methods such as mechanical clamps, fasteners, and washers. While these methods can secure the lens, they also bring some technical challenges, such as lens deformation caused by mechanical stress, obstruction of the optical path by fixing components, limited assembly accuracy, and complex assembly processes.

[0003] For lithography objectives, the requirements for lens deformation caused by mechanical stress are even more stringent, demanding near-zero applied stress. Internationally, there are many mechanical pressure ring designs to reduce stress. This increases design difficulty and manufacturing costs from a design perspective, and requires manual control of applied stress, resulting in extremely demanding requirements for assembly personnel.

[0004] In another approach, most lithography objectives are also mounted and fixed using UV-cured adhesive based on acrylic. However, as the lens NA (numerical aperture) and exposure power increase, the lens size and thickness become larger and larger, and the amount of adhesive used also increases significantly. This causes the adhesive to generate stress on the lens when it cures and shrinks, exceeding the design requirements.

[0005] Therefore, how to reduce the assembly cost and improve the assembly efficiency of lithography objectives while ensuring that they meet the assembly stress requirements is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this application is to address the problem in the prior art of how to reduce the assembly cost and improve the assembly efficiency of lithography objectives while ensuring that they meet the assembly stress requirements. Therefore, this application provides an assembly method and a lithography objective, which maintains a first assembly gap between the outer wall surface of the lens and the inner wall surface of the lens frame to avoid the lens frame directly generating circumferential stress on the lens. Furthermore, a dispensing groove is provided so that the outer wall surface of the lens is bonded and fixed to the dispensing groove with adhesive, thereby only experiencing shrinkage stress in the circumferential direction after the adhesive cures. This method can significantly reduce the assembly cost and improve the assembly efficiency of the lithography objective while meeting the assembly stress requirements.

[0007] This application provides a method for assembling a photolithography objective lens, including a lens having a first light-transmitting surface and a second light-transmitting surface disposed opposite to each other, and an outer wall surface disposed circumferentially, and also including a lens frame for supporting the lens, the lens frame being arranged in annular shape; the inner wall surface of the lens frame is provided with annular protrusions for abutting against the first light-transmitting surface or the second light-transmitting surface of the lens, and a plurality of adhesive dispensing grooves;

[0008] The assembly steps of the lens include:

[0009] Based on the lens size, determine the first assembly gap between the inner wall surface of the frame and the outer wall surface of the lens;

[0010] The quantity and specifications of the dispensing tanks, as well as the dispensing volume, are determined using simulation software.

[0011] The lens is installed into the frame, with the first or second light-transmitting surface of the lens abutting against the annular protrusion; at the same time, the outer wall surface of the lens corresponds to the inner wall surface of the frame, with the first assembly gap remaining.

[0012] Adhesive is dripped into the dispensing groove, and the lens assembly is completed after the adhesive has cured.

[0013] By adopting the above technical solution, a first assembly gap is maintained between the outer wall surface of the lens and the inner wall surface of the frame to avoid the frame directly generating rigid stress on the lens. Furthermore, multiple adhesive grooves are provided on the inner wall surface of the frame. At this time, the multiple adhesive grooves can be interconnected through the first assembly gap. The lens is fixed to the frame by dripping adhesive into the adhesive grooves. When the adhesive in the adhesive groove cures, the shrinkage in the circumferential direction is greater, thereby reducing the shrinkage stress of the adhesive in the radial direction, so as to reduce the stress generated on the lens when the adhesive cures.

[0014] In some embodiments, the plurality of adhesive grooves are located on the same side of the annular protrusion and are connected to the annular protrusion; and the plurality of adhesive grooves on the inner wall of the frame are evenly distributed in the circumferential direction.

[0015] By adopting the above technical solution, the stress caused by the shrinkage of multiple dispensing grooves can be evenly distributed in the circumferential direction of the lens, thereby ensuring uniform stress in the circumferential direction of the lens and thus ensuring the optical performance of the lens.

[0016] In some embodiments, the specifications of the dispensing groove include a first length of the dispensing groove in the circumferential direction and a second length of the dispensing groove recessed relative to the inner wall surface;

[0017] Simulation software was used to simulate the assembly of the lens and the frame, and the simulated stress on the lens was calculated.

[0018] When the simulated stress exceeds a first threshold, the simulated stress is reduced by increasing the number of dispensing grooves, increasing the first length of the dispensing grooves, and decreasing the second length.

[0019] By adopting the above technical solution, reducing the second length can minimize the thickness of the adhesive in the second length direction within the dispensing groove, thereby reducing the shrinkage amplitude of the adhesive in the second length direction and thus reducing the shrinkage stress of the adhesive.

[0020] Meanwhile, increasing the number of dispensing grooves and increasing the first length of the dispensing grooves can increase the adhesive bonding area, thereby reducing the amount of adhesive used, reducing the volume of adhesive, and thus reducing the shrinkage stress of adhesive.

[0021] In some embodiments, the frame is arranged in a circular shape and has a first thickness; the second length is less than 1 / 10 to 1 / 5 of the first thickness;

[0022] The sum of the first lengths of the plurality of dispensing grooves is less than 1 / 2 to 2 / 3 of the circumference of the inner wall of the frame.

[0023] By adopting the above technical solution, the second length of the adhesive groove is avoided from being too large, which would cause defects in the rigidity of the frame. At the same time, the thickness of the adhesive in the second length direction of the adhesive groove is avoided from being too large, which would generate excessive shrinkage stress.

[0024] Furthermore, avoid having an excessively short second length in the dispensing groove, which would make it difficult to fully dispense the adhesive, resulting in uneven bonding, poor fixation, and uneven stress on the lens.

[0025] Furthermore, it is important to avoid an excessively large sum of the first lengths of the multiple dispensing grooves, which would lead to a significant increase in the amount of adhesive used, thereby making it impossible to control the stress on the lens to meet design requirements.

[0026] In some embodiments, the first thickness is set to 10–30 mm;

[0027] The upper limit of the second length is set to 2-6 mm.

[0028] In some embodiments, the diameter of the lens is 150-500 mm; the first assembly gap is set to 3-8 mm.

[0029] In some embodiments, the adhesive is configured as a silicone-based adhesive;

[0030] The silicone adhesive has a viscosity of 30,000; a hardness of SHORE A 29.0; a shrinkage rate of 1%; and an elongation at break of 13%.

[0031] By adopting the above technical solution, the adhesive has a high viscosity, which ensures that it will not flow outside the dispensing groove after being dripped into the adhesive, such as in the first assembly gap; and the extremely low hardness allows the adhesive to play a vibration isolation role to protect the lens; the extremely low shrinkage rate and elongation at break can greatly reduce the stress on the lens after the adhesive has cured.

[0032] In some embodiments, after determining the number and specifications of the dispensing grooves and the dispensing amount using simulation software, corresponding scale lines are marked in the dispensing grooves according to the number and specifications of the dispensing grooves and the dispensing amount.

[0033] This application also provides a photolithography objective lens, including a lens and a frame, wherein the lens and the frame are assembled using the assembly method described in any of the above embodiments;

[0034] The lens has a first light-transmitting surface and a second light-transmitting surface arranged opposite to each other, and an outer wall surface arranged circumferentially;

[0035] The frame is arranged in a ring shape, and the inner wall of the frame is provided with a ring-shaped protrusion and multiple glue grooves.

[0036] The lens is fixed inside the frame, and the first or second light-transmitting surface of the lens abuts against the annular protrusion of the frame. A first assembly gap is left between the outer wall surface of the lens and the inner wall surface of the frame.

[0037] The outer wall surface of the lens is bonded and fixed to the multiple adhesive grooves of the frame using silicone adhesive.

[0038] Using the above technical solution, a first assembly gap is maintained between the outer wall surface of the lens and the inner wall surface of the frame to avoid the frame directly generating rigid stress on the lens. Furthermore, multiple adhesive grooves are provided on the inner wall surface of the frame, and these grooves can be interconnected through the first assembly gap. The outer wall surface of the lens is bonded and fixed to the multiple adhesive grooves of the frame with silicone adhesive. As a result, when the silicone adhesive cures, the circumferential shrinkage is greater, thereby reducing the radial shrinkage stress of the silicone adhesive and reducing the stress generated on the lens when the silicone adhesive cures.

[0039] Other features and corresponding beneficial effects of this application will be described in the latter part of the specification, and it should be understood that at least some of the beneficial effects will become obvious from the description in this application. Attached Figure Description

[0040] Figure 1 is a three-dimensional structural diagram of the photolithography objective lens according to an embodiment of this application;

[0041] Figure 2 is a cross-sectional view of the structure of the photolithography objective lens according to an embodiment of this application;

[0042] Figure 3 is a top view of the structure of the photolithography objective lens according to an embodiment of this application;

[0043] Figure 4 is a partial top view of the frame of the photolithography objective lens according to an embodiment of this application;

[0044] Figure 5 shows the stress simulation results of the photolithography objective lens with three dispensing grooves in an embodiment of this application;

[0045] Figure 6 shows the stress simulation results of the photolithography objective lens with six dispensing grooves in an embodiment of this application.

[0046] Explanation of reference numerals in the attached drawings: 1. Lens; 2. Frame; 21. Adhesive groove; 22. Annular protrusion; 23. Scale line; 3. First assembly gap; L. First length; H. Second length. Detailed Implementation

[0047] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application is presented in conjunction with preferred embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details will be included in the following description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0048] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0049] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0053] Please refer to Figures 1 to 4. Figure 1 is a three-dimensional structural schematic diagram of the photolithography objective lens of the present application embodiment. Figure 2 is a structural cross-sectional view of the photolithography objective lens of the present application embodiment. Figure 3 is a structural top view of the photolithography objective lens of the present application embodiment. Figure 4 is a partial structural top view of the lens frame of the photolithography objective lens of the present application embodiment.

[0054] As shown in Figures 1 to 4, this application provides an assembly method for a photolithography objective lens, including a lens 1, which has a first light-transmitting surface and a second light-transmitting surface disposed opposite to each other, and an outer wall surface disposed circumferentially, and also includes a lens frame 2 for supporting the lens 1, which is arranged in an annular shape; the inner wall surface of the lens frame 2 is provided with an annular protrusion 22 for abutting against the first light-transmitting surface or the second light-transmitting surface of the lens 1, and a plurality of adhesive grooves 21;

[0055] The assembly steps for lens 1 include:

[0056] Based on the size of lens 1, determine the first assembly gap 3 between the inner wall surface of frame 2 and the outer wall surface of lens 1;

[0057] The quantity and specifications of the dispensing tank 21, as well as the dispensing volume, were determined using simulation software.

[0058] The lens 1 is installed into the frame 2, and the first or second light-transmitting surface of the lens 1 abuts against the annular protrusion 22; at the same time, the outer wall surface of the lens 1 corresponds to the inner wall surface of the frame 2, and a first assembly gap 3 is left.

[0059] Adhesive is dripped into the dispensing tank 21. After the adhesive has cured, the assembly of lens 1 is completed.

[0060] It should be noted that during the assembly process of the lithography objective lens, the stress generated by assembly methods such as clamping or bonding can affect the surface accuracy of lens 1, thereby affecting the resolution and imaging quality of the lithography. Specifically, stress may cause slight deformation or displacement of lens 1, which in turn changes the propagation path and focusing characteristics of light, ultimately affecting the accuracy and uniformity of the lithography.

[0061] Therefore, by placing the first or second light-transmitting surface of the lens 1 against the annular protrusion 22, the greater supporting force of the annular protrusion 22 can be uniformly applied to the axial direction of the lens 1. On the one hand, this greatly reduces the impact of the supporting force of the annular protrusion 22 on the lens 1. On the other hand, since the annular protrusion 22 is a rigid support, the influence of the supporting force of the annular protrusion 22 can be predicted and controlled.

[0062] Furthermore, it should be noted that in the field of photolithography objective lens assembly, the main function of the adhesive is to limit the position of lens 1 and prevent it from shifting or sliding due to slight vibrations. Therefore, the adhesive only needs to provide adhesion between the frame 2 and lens 1, and the adhesive strength requirement is relatively low. At the same time, since the shrinkage stress of the adhesive is difficult to control precisely, and lens 1 is extremely sensitive to stress, when using adhesive to assemble lens 1, it is necessary to minimize the stress generated by the adhesive on lens 1, preferably to no longer generate stress, and only generate force when lens 1 shifts, in order to limit the displacement of lens 1.

[0063] In the circumferential direction of the lens 1, a first assembly gap 3 is maintained between the outer wall surface of the lens 1 and the inner wall surface of the frame 2 to avoid the frame 2 directly generating rigid stress on the lens 1. Furthermore, multiple adhesive grooves 21 are provided on the inner wall surface of the frame 2. At this time, the multiple adhesive grooves 21 can be interconnected through the first assembly gap 3. The lens 1 and the frame 2 are fixed by dripping adhesive into the adhesive grooves 21. When the adhesive in the adhesive grooves 21 cures, the shrinkage in the circumferential direction is greater, thereby reducing the shrinkage stress of the adhesive in the radial direction, so as to reduce the stress generated on the lens 1 when the adhesive cures.

[0064] Furthermore, the cured adhesive can act as a shock absorber and buffer, thus protecting lens 1.

[0065] In one embodiment, multiple adhesive grooves 21 are located on the same side of the annular protrusion 22 and are connected to the annular protrusion 22; and the multiple adhesive grooves 21 on the inner wall of the lens frame 2 are evenly distributed in the circumferential direction. This ensures that the stress from the contraction of the multiple adhesive grooves 21 is evenly distributed in the circumferential direction of the lens 1, thereby ensuring that the lens 1 is subjected to uniform force in the circumferential direction and thus ensuring the optical performance of the lens 1.

[0066] In one embodiment, a plurality of dispensing grooves 21 are provided in eight locations and are evenly distributed in the circumferential direction.

[0067] In one embodiment, the specifications of the dispensing groove 21 include a first length L in the circumferential direction and a second length H in which the dispensing groove 21 is recessed relative to the inner wall surface.

[0068] Simulation software was used to simulate the assembly of lens 1 and frame 2, and the simulated stress on lens 1 was calculated.

[0069] When the simulated stress exceeds the first threshold, the simulated stress is reduced by increasing the number of dispensing grooves 21, increasing the first length L of the dispensing grooves 21, and decreasing the second length H.

[0070] By reducing the second length H, the thickness of the adhesive in the dispensing groove 21 in the second length H direction can be reduced as much as possible, thereby reducing the shrinkage amplitude of the adhesive in the second length H direction and reducing the shrinkage stress of the adhesive.

[0071] At the same time, increasing the number of dispensing grooves 21 and increasing the first length L of the dispensing grooves 21 can increase the adhesive bonding area, thereby reducing the amount of adhesive used, reducing the volume of adhesive, and thus reducing the shrinkage stress of adhesive.

[0072] It should be noted that increasing the number of dispensing grooves 21 will lead to an increase in the dispensing process and the processing cost of the frame 2; increasing the first length L of the dispensing grooves 21 will lead to a decrease in the rigidity and structural strength of the frame 2.

[0073] In one embodiment, a lower limit and an upper limit are preset for the number of dispensing grooves 21; a lower limit and an upper limit are preset for the first length L; and the lower limit of the number of dispensing grooves 21 and the lower limit of the first length L are preset values.

[0074] The preset value of the second length H is 5mm; wherein, the preset value of the second length H is determined according to the precision of the dispensing process and the viscosity of the adhesive to ensure that the adhesive can be fully filled; at the same time, it ensures that the preset value of the second length H will not cause strength defects in the frame 2.

[0075] In one embodiment, when the simulated stress is greater than the first threshold, the number of dispensing grooves 21 is increased first. After reaching the upper limit of the number of dispensing grooves 21, the first length L is increased. At this time, with the amount of adhesive remaining unchanged, the bonding area of ​​the adhesive can be increased while the height of the adhesive is reduced, so that the shrinkage stress of the adhesive is more dispersed, thereby reducing the stress on the lens 1.

[0076] In one embodiment, while keeping the height of the dispensing amount constant, the second length H is reduced. On the one hand, this reduces the thickness of the adhesive in the dispensing groove 21 in the direction of the second length H, thereby reducing the shrinkage amplitude of the adhesive in the direction of the second length H and reducing the shrinkage stress of the adhesive. On the other hand, it can reduce the dispensing amount and reduce the use of adhesive.

[0077] In one embodiment, after determining the number and specifications of the dispensing grooves 21, as well as the dispensing amount, using simulation software, corresponding scale lines 23 are marked within the dispensing grooves 21 according to the number and specifications of the dispensing grooves 21 and the dispensing amount. This facilitates accurate control of the amount of adhesive dispensed into the dispensing grooves 21.

[0078] Please refer to Figures 5 and 6. Figure 5 is a stress simulation result diagram of the photolithography objective lens with three dispensing grooves in an embodiment of this application, and Figure 6 is a stress simulation result diagram of the photolithography objective lens with six dispensing grooves in an embodiment of this application.

[0079] In one example, as shown in Figures 5 and 6, when the number of adhesive grooves 21 is 3, the surface deformation of lens 1 under stress ranges from +0.0249 wave to -0.0310 wave, and the distribution of deformation under stress is extremely uneven. When the number of adhesive grooves 21 is 6, the surface deformation of lens 1 under stress ranges from +0.00125 wave to -0.00473 wave, and the extreme values ​​of its deformation are significantly reduced, indicating that the stress distribution of lens 1 is more uniform at this time.

[0080] It should be noted that acrylic-based adhesives have high viscosity, dry quickly, and cure rapidly, typically within milliseconds. They also offer good transparency and strong adhesion, making them suitable for applications requiring high transparency. Furthermore, they can firmly bond various materials and possess a certain degree of shear resistance.

[0081] Therefore, in another example, when the dispensing groove 21 is not provided, the prior art usually uses acrylic adhesive to bond the lens 1; at this time, when acrylic adhesive is used for bonding and the dispensing groove 21 is not provided, after the lens 1 is directly bonded to the frame 2, the surface deformation of the lens 1 caused by stress is in the range of +0.0513 wave to -0.0845 wave, which is significantly higher than +0.0249 wave to -0.0310 wave;

[0082] In one embodiment, the frame 2 is arranged in a circular shape and has a first thickness; the second length H is less than 1 / 10 to 1 / 5 of the first thickness;

[0083] The sum of the first length L of the multiple glue-dispensing grooves 21 is less than 1 / 2 to 2 / 3 of the circumference of the inner wall of the frame 2.

[0084] This avoids the second length H of the glue groove 21 being too large, which would cause defects in the rigidity of the frame 2. At the same time, it avoids the adhesive in the glue groove 21 being too thick in the second length H direction, which would generate excessive shrinkage stress.

[0085] Furthermore, to avoid the second length H of the dispensing groove 21 being too small, which would make it difficult to fully dispense the adhesive, resulting in uneven bonding, poor fixing effect, and uneven stress on the lens 1, etc.

[0086] Furthermore, to avoid the sum of the first length L of multiple dispensing grooves 21 being too large, which would lead to a significant increase in the amount of adhesive used, thus making it impossible to control the stress on the lens 1 to meet the design requirements.

[0087] In one embodiment, the first thickness is set to 10–30 mm;

[0088] The upper limit of the second length H is set to 2-6 mm.

[0089] In one embodiment, the diameter of the lens 1 is 150-500 mm; the first assembly gap 3 is set to 3-8 mm.

[0090] In one embodiment, the diameter of lens 1 is 150 mm; the first assembly gap 3 is set to 4 mm; the first thickness is set to 15 mm; and the second length H is set to 3 mm.

[0091] In one embodiment, the adhesive is configured as a silicone-based adhesive;

[0092] The silicone adhesive has a viscosity of 30,000; a hardness of SHORE A29.0; a shrinkage rate of 1%; and an elongation at break of 13%.

[0093] By adopting the above technical solution, the adhesive has a large viscosity, which ensures that after the adhesive is dripped in, it will not flow into areas other than the dispensing groove 21, such as the first assembly gap 3; and the extremely low hardness allows the adhesive to play a vibration isolation role to protect the lens 1; the extremely low shrinkage rate and elongation at break can greatly reduce the stress on the lens 1 after the adhesive is cured.

[0094] This application embodiment also provides a photolithography objective lens, including a lens 1 and a frame 2, wherein the lens 1 and the frame 2 are assembled using the assembly method in any of the above embodiments;

[0095] The lens 1 has a first light-transmitting surface and a second light-transmitting surface that are disposed opposite to each other, and an outer wall surface that is disposed circumferentially;

[0096] The frame 2 is arranged in a ring shape, and the inner wall surface of the frame 2 is provided with a ring-shaped protrusion 22 and multiple glue grooves 21;

[0097] The lens 1 is fixed inside the frame 2, and the first or second light-transmitting surface of the lens 1 abuts against the annular protrusion 22 of the frame 2. A first assembly gap 3 is left between the outer wall surface of the lens 1 and the inner wall surface of the frame 2.

[0098] The outer wall of the lens 1 is bonded and fixed to the multiple adhesive grooves 21 of the frame 2 using silicone adhesive.

[0099] In the photolithography objective lens, a first assembly gap 3 is maintained between the outer wall surface of the lens 1 and the inner wall surface of the frame 2 to avoid the frame 2 directly generating rigid stress on the lens 1. Furthermore, multiple dispensing grooves 21 are provided on the inner wall surface of the frame 2. At this time, the multiple dispensing grooves 21 can be interconnected through the first assembly gap 3. And the outer wall surface of the lens 1 and the multiple dispensing grooves 21 of the frame 2 are bonded and fixed with silicone adhesive. Thus, when the silicone adhesive cures, the shrinkage in the circumferential direction is greater, thereby reducing the shrinkage stress of the silicone adhesive in the radial direction, so as to reduce the stress generated on the lens 1 when the silicone adhesive cures.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

An assembling method of a lithography objective lens, comprising a lens having a first light-transmitting surface and a second light-transmitting surface arranged oppositely, and a circumferentially arranged outer wall surface, characterized in that, It also includes a frame for supporting the lens, the frame being arranged in a ring shape; the inner wall of the frame is provided with a ring-shaped protrusion for abutting against the first or second light-transmitting surface of the lens, and a plurality of adhesive grooves; The assembly steps of the lens include: Based on the lens size, determine the first assembly gap between the inner wall surface of the frame and the outer wall surface of the lens; The quantity and specifications of the dispensing tanks, as well as the dispensing volume, are determined using simulation software. The lens is installed into the frame, with the first or second light-transmitting surface of the lens abutting against the annular protrusion; at the same time, the outer wall surface of the lens corresponds to the inner wall surface of the frame, with the first assembly gap remaining. Adhesive is dripped into the dispensing groove, and the assembly of the lens is completed after the adhesive has cured. The plurality of adhesive grooves are located on the same side of the annular protrusion and are connected to the annular protrusion; and the plurality of adhesive grooves on the inner wall of the frame are evenly distributed in the circumferential direction. The specifications of the dispensing groove include a first length of the dispensing groove in the circumferential direction and a second length of the dispensing groove that is recessed relative to the inner wall surface. Simulation software was used to simulate the assembly of the lens and the frame, and the simulated stress on the lens was calculated. The lower and upper limits of the number of dispensing grooves and the lower and upper limits of the first length are preset; and the lower limit of the number of dispensing grooves and the lower limit of the first length are used as preset values; When the simulated stress exceeds the first threshold, the number of dispensing grooves is increased first. Once the upper limit of the number of dispensing grooves is reached, the first length is increased. The adhesive is configured as a silicone-based glue; The silicone adhesive has a viscosity of 30,000; a hardness of SHORE A 29.0; a shrinkage rate of 1%; and an elongation at break of 13%. After determining the number and specifications of the dispensing grooves and the dispensing amount using simulation software, corresponding scale lines are marked in the dispensing grooves according to the number and specifications of the dispensing grooves and the dispensing amount. The method of assembling a lithography objective according to claim 1, characterized in that The frame is arranged in a circular shape and has a first thickness; the second length is less than 1 / 10 to 1 / 5 of the first thickness; The sum of the first lengths of the plurality of dispensing grooves is less than 1 / 2 to 2 / 3 of the circumference of the inner wall of the frame. The assembly method of the photolithography objective lens according to claim 2 is characterized in that: The first thickness is set to 10–30 mm; The upper limit of the second length is set to 2-6 mm. The method of assembling a lithography objective according to claim 1, characterized in that The diameter of the lens is 150-500mm; the first assembly gap is set to 3-8mm. Lithographic objective, characterized in that It includes lenses and frames, and the lenses and frames are assembled using the assembly method described in any one of claims 1 to 4; The lens has a first light-transmitting surface and a second light-transmitting surface arranged opposite to each other, and an outer wall surface arranged circumferentially; The frame is arranged in a ring shape, and the inner wall of the frame is provided with a ring-shaped protrusion and multiple glue grooves. The lens is fixed inside the frame, and the first or second light-transmitting surface of the lens abuts against the annular protrusion of the frame. A first assembly gap is left between the outer wall surface of the lens and the inner wall surface of the frame. The outer wall surface of the lens is fixed by silicon-based glue between the multiple dispensing grooves of the frame.

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