Ultraviolet lithography projection objective

Abstract

The application belongs to the technical field of maskless lithography, and particularly relates to a kind of ultraviolet lithography projection objective lenses for high-density PCB, LCD and MEMS design and manufacture. It is applied to the projection of mixed or monochromatic ultraviolet lithography light source, including the first lens group G1, aperture diaphragm, second lens group G2, third lens group G3 and fourth lens group G4 consistent with the optical axis from the object plane to the image plane; the first lens group G1 has positive focal power; the second lens group G2 has positive focal power; the third lens group G3 has negative focal power; the fourth lens group G4 has positive focal power; wherein the ultraviolet lithography projection objective lens is object, image double-telecentric structure and does not include aspheric surface. The application proposes a kind of ultraviolet lithography projection objective lens for ultraviolet SLM lithography with simple structure and good performance, which can work in 365nm-405nm mixed or monochromatic light source, and has the advantages of simple structure, low lens processing cost, good aberration and no aspheric surface.

Description

Technical Field

[0001] This invention belongs to the field of maskless lithography technology, specifically relating to an ultraviolet lithography projection lens for the design and manufacturing of high-density PCBs, LCDs and MEMS. Background Technology

[0002] The basic principle of spatially modulated light (SLM) lithography in maskless lithography is similar to that of traditional projection lithography. Its exposure and imaging principles are also similar to traditional projection lithography. The difference lies in that SLM lithography uses a digital spatial light modulator instead of a traditional mask. The spatial light modulator modulates the incident light to generate the desired pattern for projection exposure. Maskless lithography can be used to manufacture a range of structures such as PCBs, liquid crystal displays (LCDs), and microelectromechanical systems (MEMS). Over the past few decades, exposure equipment technology has continuously developed, meeting the demands for smaller line sizes, larger exposure areas, higher reliability and yield, and lower costs. Furthermore, the design quality of the ultraviolet lithography projection lens directly affects the quality of the exposed pattern.

[0003] Existing ultraviolet lithography projection lens systems used for the design and manufacturing of high-density PCBs, LCDs, and MEMS are complex in structure, have a large number of lenses, and contain aspherical surfaces. Summary of the Invention

[0004] In view of this, the present invention provides a simple and high-performance ultraviolet lithography projection lens that can be used for ultraviolet SLM lithography. This lens can operate in a mixed or monochromatic light source in the range of 365nm to 405nm and has advantages such as simple structure, low lens processing cost, good aberrations, and no aspherical surfaces.

[0005] To achieve the above-mentioned technical objectives, the specific technical solution adopted by the present invention is as follows:

[0006] An ultraviolet lithography projection lens, used for projection of mixed or monochromatic ultraviolet lithography light sources, includes a first lens group G1 with an optical axis aligned from the object plane to the image plane, an aperture stop, a second lens group G2, a third lens group G3, and a fourth lens group G4.

[0007] The first lens group G1 has positive optical power; the second lens group G2 has positive optical power; the third lens group G3 has negative optical power; and the fourth lens group G4 has positive optical power.

[0008] The ultraviolet lithography projection lens is a telecentric structure on both the object and image sides and does not include aspherical surfaces.

[0009] Furthermore, the first lens group G1 includes: a plano-concave positive lens L1, a biconvex positive lens L2, a meniscus negative lens L3, and a biconvex positive lens L4;

[0010] The second lens group G2 includes: a biconvex positive lens L5, a biconcave negative lens L6, and a biconvex positive lens L7;

[0011] The third lens group G3 includes a biconvex positive lens L8, a biconcave negative lens L9, a meniscus negative lens L10, and a meniscus negative lens L11.

[0012] The fourth lens group G4 includes a biconvex positive lens L12.

[0013] Furthermore, the ultraviolet lithography projection lens uses a low-dispersion material for the lens with positive optical power and a high-dispersion material for the lens with negative optical power.

[0014] Furthermore, the first lens group G1 contains at least one flint glass material and one crown glass material; wherein the crown glass material is wrapped around the biconvex positive lens L2 and / or the biconvex positive lens L4;

[0015] In the second lens group G2, the three lenses contain at least two crown glass materials; wherein the lens containing the crown glass material is a biconvex positive lens L5 and / or a biconvex positive lens L7;

[0016] The third lens group G3 contains at least one flint glass material and one crown glass material; wherein the lens containing the flint glass material is a biconcave negative lens L9, a meniscus negative lens L10 and / or a meniscus negative lens L11, and the lens containing the crown glass material is a biconvex positive lens L8.

[0017] Furthermore, the first lens group G1, the aperture stop, the second lens group G2, the third lens group G3, and the fourth lens group G4 satisfy the following relationship:

[0018] 0.72 < |f1 / f2| < 1.12

[0019] 0.83 < |f2 / f3| < 1.23

[0020] 0.26 < |f3 / f4| < 0.66

[0021] 0.23 < |f1 / f4| < 0.63

[0022] 0.03 < |f1 / fL| < 0.09

[0023] 1.67 <VL2 / VL4<2.61

[0024] 1.93 <VL5 / VL6<2.23

[0025] 1.93 <VL8 / VL9<1.93

[0026] Wherein: f1: focal length of the first lens group G1; f2: focal length of the second lens group G2; f3: focal length of the third lens group G3; f4: focal length of the fourth lens group G4; fL: overall system focal length of the ultraviolet lithography projection lens; VL2: Abbe number of the material of the biconvex positive lens L2; ​​VL4: Abbe number of the material of the biconvex positive lens L4; VL5: Abbe number of the material of the biconvex positive lens L5; VL6: Abbe number of the material of the biconcave negative lens L6; VL8: Abbe number of the biconvex positive lens L8; VL9: Abbe number of the material of the biconcave negative lens L9.

[0027] Furthermore, the first lens group G1 includes a biconvex positive lens L1, a biconvex positive lens L2, a meniscus negative lens L3, a meniscus positive lens L4, a meniscus negative lens L5, and a biconcave negative lens L6;

[0028] The second lens group G2 includes a biconvex positive lens L7, a biconcave negative lens L8, a biconvex positive lens L9, and a biconvex positive lens L10;

[0029] The third lens group G3 includes a biconcave negative lens L11;

[0030] The fourth lens group G4 includes a meniscus positive lens L12, a meniscus negative lens L13, and a biconvex positive lens L14.

[0031] Furthermore, the ultraviolet lithography projection lens uses a low-dispersion material for the lens with positive optical power and a high-dispersion material for the lens with negative optical power.

[0032] Furthermore, the first lens group G1 contains at least two flint glass materials and two crown glass materials, with the crown glass materials on the biconvex positive lens L1 and the biconvex positive lens L2;

[0033] The second lens group G2 contains at least one flint glass material and two crown glass materials; the lens containing the crown glass material is a biconvex positive lens L7, a biconvex positive lens L9 and / or a biconvex positive lens L10; the lens containing the flint glass material is a biconcave negative lens L8.

[0034] The fourth lens group G4 contains at least one piece of flint glass material.

[0035] Furthermore, the first lens group G1, the aperture stop, the second lens group G2, the third lens group G3, and the fourth lens group G4 satisfy the following relationship:

[0036] 2.41 < |f1 / f2| < 2.81

[0037] 0.86 < |f2 / f3| < 1.26

[0038] 0.05 < |f3 / f4| < 0.45

[0039] 0.03 < |f5 / fL| < 0.08

[0040] 1.67 <VL2 / VL4<2.65

[0041] 0.35 <VL6 / VL7<0.70

[0042] 0.25 <VL13 / VL14<1.00

[0043] in:

[0044] f1: Focal length of the first lens group G1; f2: Focal length of the second lens group G2; f3: Focal length of the third lens group G3; f4: Focal length of the fourth lens group G4; fL: Overall system focal length of the ultraviolet lithography projection lens; VL2: Abbe number of the material of the biconvex positive lens L2; ​​VL4: Abbe number of the material of the meniscus positive lens L4; VL6: Abbe number of the material of the biconcave negative lens L6; VL7: Abbe number of the material of the biconvex positive lens L7; VL13: Abbe number of the material of the meniscus negative lens L13; VL14: Abbe number of the material of the biconvex positive lens L14.

[0045] By adopting the above technical solution, the present invention can bring the following beneficial effects:

[0046] The ultraviolet lithography projection lens of this invention can operate in a mixed or monochromatic light source in the range of 365nm to 405nm, and has advantages such as simple structure and good performance. The ultraviolet lithography projection lens provided by this invention has a total length of no more than 700mm, a magnification of -3.0, an object-side numerical aperture of 0.14, and an image-side field-of-view diameter greater than 75.0mm. The object-side working distance of the ultraviolet lithography projection lens of this invention is greater than 65mm, and the image-side working distance is greater than 205mm. In order to reduce the magnification error and alignment error caused by the position change of the object and image planes, a dual telecentric structure of object and image planes is adopted, which can achieve better overlay accuracy. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a system structure diagram of an embodiment 1 of an ultraviolet lithography projection lens according to a specific implementation of the present invention;

[0049] Figure 2The field curvature, astigmatism, and distortion of a system in Example 1 of an ultraviolet lithography projection lens according to a specific embodiment of the present invention are shown in the figure;

[0050] Figure 3 The MTF curve of an ultraviolet lithography projection lens in Example 1 of this invention is shown in the specific embodiment. Figure 3 ;

[0051] Figure 4 This is an example 1 of the telecentric angle diagram of the object and image sides of an ultraviolet lithography projection lens according to a specific embodiment of the present invention;

[0052] Figure 5 This is a system structure diagram of Embodiment 2 of an ultraviolet lithography projection lens according to a specific embodiment of the present invention;

[0053] Figure 6 The field curvature, astigmatism, and distortion of a system in Example 2 of an ultraviolet lithography projection lens according to a specific embodiment of the present invention are shown in the figure;

[0054] Figure 7 The MTF curve of Example 2 of an ultraviolet lithography projection lens in a specific embodiment of the present invention is shown. Figure 3 ;

[0055] Figure 8 This is an example 2 of the telecentric angle diagram of the object and image sides of an ultraviolet lithography projection lens according to a specific embodiment of the present invention. Detailed Implementation

[0056] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0057] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0058] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one 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 of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0059] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0060] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0061] Example 1

[0062] This embodiment provides an ultraviolet lithography projection lens for projection of mixed or monochromatic ultraviolet lithography light sources, including a first lens group G1, an aperture stop, a second lens group G2, a third lens group G3, and a fourth lens group G4 with the optical axis aligned from the object plane to the image plane.

[0063] The first lens group G1 has positive optical power; the second lens group G2 has positive optical power; the third lens group G3 has negative optical power; and the fourth lens group G4 has positive optical power.

[0064] The ultraviolet lithography projection lens is a telecentric structure on both the object and image sides and does not include aspherical surfaces.

[0065] like Figure 1 As shown, the first lens group G1 includes: a plano-concave positive lens L1, a biconvex positive lens L2, a meniscus negative lens L3, and a biconvex positive lens L4.

[0066] The second lens group G2 includes: a biconvex positive lens L5, a biconcave negative lens L6, and a biconvex positive lens L7;

[0067] The third lens group G3 includes a biconvex positive lens L8, a biconcave negative lens L9, a meniscus negative lens L10, and a meniscus negative lens L11.

[0068] The fourth lens group G4 includes a biconvex positive lens L12.

[0069] like Figure 1 As shown, the lens with positive optical power in the ultraviolet lithography projection lens is made of low dispersion material, while the lens with negative optical power is made of high dispersion material.

[0070] like Figure 1 As shown, the first lens group G1 contains at least one flint glass material and one crown glass material; wherein the crown glass material is wrapped around the biconvex positive lens L2 and / or the biconvex positive lens L4;

[0071] In the second lens group G2, the three lenses contain at least two crown glass materials; wherein the lens containing the crown glass material is a biconvex positive lens L5 and / or a biconvex positive lens L7;

[0072] The third lens group G3 contains at least one flint glass material and one crown glass material; wherein the lens containing the flint glass material is a biconcave negative lens L9, a meniscus negative lens L10 and / or a meniscus negative lens L11, and the lens containing the crown glass material is a biconvex positive lens L8.

[0073] like Figure 1 As shown, the first lens group G1, the aperture stop, the second lens group G2, the third lens group G3, and the fourth lens group G4 satisfy the following relationship:

[0074] 0.72 < |f1 / f2| < 1.12

[0075] 0.83 < |f2 / f3| < 1.23

[0076] 0.26 < |f3 / f4| < 0.66

[0077] 0.23 < |f1 / f4| < 0.63

[0078] 0.03 < |f1 / fL| < 0.09

[0079] 1.67 <VL2 / VL4<2.61

[0080] 1.93 <VL5 / VL6<2.23

[0081] 1.93 <VL8 / VL9<1.93

[0082] Wherein: f1: focal length of the first lens group G1; f2: focal length of the second lens group G2; f3: focal length of the third lens group G3; f4: focal length of the fourth lens group G4; fL: overall system focal length of the ultraviolet lithography projection lens; VL2: Abbe number of the material of the biconvex positive lens L2; ​​VL4: Abbe number of the material of the biconvex positive lens L4; VL5: Abbe number of the material of the biconvex positive lens L5; VL6: Abbe number of the material of the biconcave negative lens L6; VL8: Abbe number of the biconvex positive lens L8; VL9: Abbe number of the material of the biconcave negative lens L9.

[0083] The photolithography ultraviolet lithography projection lens of this embodiment includes 12 optical elements, one object plane, one aperture stop, and one image plane. The designed ultraviolet lithography projection lens has seven parts arranged sequentially from the beam incident direction: object plane, first lens group G1, aperture stop, second lens group G2, third lens group G3, fourth lens group G4, and image plane.

[0084] The relationship between lens groups further established the basis for object image quality optimization, corrected the aberrations of the system, and defined the relationship between the aberrations of the system and the optical structure. Lenses with positive optical power used low dispersion materials, while lenses with negative optical power used high dispersion materials. The combination of high and low dispersion materials corrected axial chromatic aberration.

[0085] In this embodiment of the ultraviolet lithography projection lens, the aperture stop is located between the first lens group G1 and the second lens group G2. The effective light-passing diameter of the ultraviolet lithography projection lens can be adjusted by changing the diameter of the aperture stop; that is, the numerical aperture of the lens can be adjusted to suit different application scenarios. The maximum image-side numerical aperture of the ultraviolet lithography projection lens in this embodiment can reach 0.14. Because it has an aperture stop, the numerical aperture of the ultraviolet lithography projection lens can be continuously adjusted within the range of 0-0.14 by adjusting the diameter of the aperture stop.

[0086] Optical materials can generally be divided into two categories according to their refractive index and Abbe number: flint glass and crown glass.

[0087] Type A flint glass materials: high refractive index materials with low Abbe number, i.e., refractive index nd > 1.60 and Abbe number vd < 50; Type B crown glass materials: low refractive index materials with high Abbe number, i.e., refractive index nd < 1.60 and Abbe number > 55.

[0088] In the ultraviolet lithography projection lens of this embodiment, the first lens group G1 comprises at least two negative power lenses and two positive power lenses. The first lens group G1 contains at least one type A material and one type B material. The type B material in the first lens group G1 is wrapped around the biconvex positive power lens.

[0089] In the second lens group G2, the three lenses contain at least two Class B materials, and the lens containing the Class B materials is a lens with positive power.

[0090] In the third lens group G3, the four lenses contain at least one type A material and at least one type B material. In the third lens group G3, the lens containing type A material has a negative optical power, and the lens containing type B material has a positive optical power.

[0091] In the fourth lens group G4, there is only one lens, and the optical power of this lens is positive.

[0092] The ultraviolet lithography projection objective of this embodiment has a dual telecentric structure for the object and image sides. The principal rays of each field of view on the object side are incident on the front surface of the first parallel plate approximately parallel to the optical axis. On the object side, the principal rays of each field of view on the object surface are incident on the first optical element parallel to the optical axis, and the angle between the principal rays and the optical axis is <5mrad. On the image side, the principal rays of each field of view are emitted quasi-parallel to the optical axis and imaged on the image surface, with an angle between them and the optical axis of <4mrad. The principal rays of each field of view on the image side are emitted approximately parallel to the optical axis and converge on the image surface, which can improve the overlay accuracy.

[0093] In this embodiment, the object-side working distance is >65mm, and the image-side working distance is >205mm;

[0094] The ultraviolet lithography projection lens of this embodiment is mainly suitable for the ultraviolet spectral range, especially for lithography ultraviolet lithography projection lenses under mixed or monochromatic light sources in the 365~405nm band, and can be widely used in the field of ultraviolet lithography projection.

[0095] The system field curvature, astigmatism, and distortion of the ultraviolet lithography projection lens in this embodiment are as follows: Figure 2 As shown, its field curvature, astigmatism, and distortion have been corrected.

[0096] The MTF curve of the ultraviolet lithography projection lens in this embodiment Figure 3 As shown, the MTF curve is close to the diffraction limit.

[0097] In this embodiment, the telecentric angles of the ultraviolet lithography projection lens are as follows: Figure 4 As shown, the object-side telecentricity is less than 5 mrad, and the image-side telecentricity is less than 4 mrad.

[0098] The specific optical parameters of the ultraviolet lithography projection lens in this embodiment are shown in the table below.

[0099] Table 1. Specific optical parameters of the ultraviolet lithography projection lens in Example 1

[0100]

[0101] In the table, L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, and L12 represent:

[0102] Plano-concave positive lens L1, biconvex positive lens L2, meniscus negative lens L3, biconvex positive lens L4, biconvex positive lens L5, biconcave negative lens L6, biconvex positive lens L7, biconvex positive lens L8, biconcave negative lens L9, meniscus negative lens L10, meniscus negative lens L11, and biconvex positive lens L12.

[0103] Example 2

[0104] The specific structure of this embodiment is unrelated to that of Embodiment 1. Due to the conventional way of representing optical elements, the same reference numerals are used. Both can achieve the technical effect of this application: "a simple and high-performance ultraviolet lithography projection lens that can be used for ultraviolet SLM lithography. This lens can work in a mixed or monochromatic light source in the range of 365nm to 405nm. It has advantages such as simple structure, low lens processing cost, good aberrations, and no aspherical surfaces."

[0105] like Figure 5 As shown, the first lens group G1 in this embodiment includes a biconvex positive lens L1, a biconvex positive lens L2, a meniscus negative lens L3, a meniscus positive lens L4, a meniscus negative lens L5, and a biconcave negative lens L6;

[0106] The second lens group G2 includes a biconvex positive lens L7, a biconcave negative lens L8, a biconvex positive lens L9, and a biconvex positive lens L10;

[0107] The third lens group G3 includes a biconcave negative lens L11;

[0108] The fourth lens group G4 includes a meniscus positive lens L12, a meniscus negative lens L13, and a biconvex positive lens L14.

[0109] In this embodiment, the lens with positive optical power in the ultraviolet lithography projection lens is made of a low-dispersion material, and the lens with negative optical power is made of a high-dispersion material.

[0110] In this embodiment, the first lens group G1 contains at least two flint glass materials and two crown glass materials, with the crown glass materials on the biconvex positive lens L1 and the biconvex positive lens L2;

[0111] The second lens group G2 contains at least one flint glass material and two crown glass materials; the lens containing the crown glass material is a biconvex positive lens L7, a biconvex positive lens L9 and / or a biconvex positive lens L10; the lens containing the flint glass material is a biconcave negative lens L8.

[0112] The fourth lens group G4 contains at least one piece of flint glass material.

[0113] In this embodiment, the first lens group G1, the aperture stop, the second lens group G2, the third lens group G3, and the fourth lens group G4 satisfy the following relationship:

[0114] 2.41 < |f1 / f2| < 2.81

[0115] 0.86 < |f2 / f3| < 1.26

[0116] 0.05 < |f3 / f4| < 0.45

[0117] 0.03 < |f5 / fL| < 0.08

[0118] 1.67 <VL2 / VL4<2.65

[0119] 0.35 <VL6 / VL7<0.70

[0120] 0.25 <VL13 / VL14<1.00

[0121] in:

[0122] f1: Focal length of the first lens group G1; f2: Focal length of the second lens group G2; f3: Focal length of the third lens group G3; f4: Focal length of the fourth lens group G4; fL: Overall system focal length of the ultraviolet lithography projection lens; VL2: Abbe number of the material of the biconvex positive lens L2; ​​VL4: Abbe number of the material of the meniscus positive lens L4; VL6: Abbe number of the material of the biconcave negative lens L6; VL7: Abbe number of the material of the biconvex positive lens L7; VL13: Abbe number of the material of the meniscus negative lens L13; VL14: Abbe number of the material of the biconvex positive lens L14.

[0123] The ultraviolet lithography projection lens of this embodiment contains 14 optical elements, one object plane, one aperture stop, and one image plane. The designed ultraviolet lithography projection lens has eight parts arranged sequentially from the beam incident direction: object plane, first lens group G1, aperture stop, second lens group G2, third lens group G3, fourth lens group G4, and image plane.

[0124] The relationship between the lens groups further established the basis for object image quality optimization. The relationship corrected the aberrations of the system and defined the relationship between the aberrations of the system and the optical structure. Lenses with positive optical power used low dispersion materials, while lenses with negative optical power used high dispersion materials. The combination of high and low dispersion materials corrected the axial chromatic aberration.

[0125] In this embodiment, the aperture stop is located between the first lens group G1 and the second lens group G2. The effective aperture of the photolithography ultraviolet lithography projection lens can be adjusted by changing the diameter of the aperture stop; that is, the numerical aperture of the photolithography ultraviolet lithography projection lens can be adjusted to adapt to different application scenarios. The maximum image-side numerical aperture of the photolithography ultraviolet lithography projection lens provided in this embodiment can reach 0.14. Since this ultraviolet lithography projection lens also includes an aperture stop, the numerical aperture of the photolithography ultraviolet lithography projection lens can be continuously adjusted within the range of 0-0.14 by adjusting the diameter of the aperture stop.

[0126] In this embodiment, the first lens group G1 comprises at least two negative power lenses and two positive power lenses. The first lens group G1 contains at least two type A materials and two type B materials. In the first lens group G1, the type B material is wrapped around the biconvex positive power lens.

[0127] In the second lens group G2, the four lenses contain at least one type A material and at least two type B materials. In the second lens group G2, the lens containing type A material has a negative optical power, and the lens containing type B material has a positive optical power.

[0128] In the third lens group G3, there is only one lens, and the optical power of this lens is negative.

[0129] In the fourth lens group G4, the three lenses contain at least one type A material.

[0130] The ultraviolet lithography projection objective of this embodiment has a dual telecentric structure for the object and image sides. The principal rays of each field of view on the object side are incident on the front surface of the first parallel plate approximately parallel to the optical axis. On the object side, the principal rays of each field of view on the object surface are incident on the first optical element parallel to the optical axis, and the angle between the principal rays and the optical axis is <3.0 mrad. On the image side, the principal rays of each field of view are emitted quasi-parallel to the optical axis and imaged on the image surface, with an angle between them and the optical axis of <3.5 mrad. The principal rays of each field of view on the image side are emitted approximately parallel to the optical axis and converge on the image surface, which can improve the overlay accuracy.

[0131] The object-side working distance of the ultraviolet lithography projection objective lens in this embodiment is >94mm, and the image-side working distance is >209mm.

[0132] In this embodiment, the ultraviolet lithography projection lens exhibits field curvature, astigmatism, and distortion as follows: Figure 6 As shown, its field curvature, astigmatism, and distortion have been corrected.

[0133] The MTF curve of the ultraviolet lithography projection lens in this embodiment Figure 7 As shown, the MTF curve is close to the diffraction limit.

[0134] In this embodiment, the telecentric angle of the ultraviolet lithography projection lens is as follows: Figure 8 As shown, the object-side telecentricity is less than 3 mrad, and the image-side telecentricity is less than 3.5 mrad.

[0135] The specific optical parameters of the ultraviolet lithography projection lens in this embodiment are shown in the table below.

[0136] Table 2. Specific optical parameters of the ultraviolet lithography projection lens in Example 2

[0137]

[0138] In the table, L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12, L13, and L14 represent: biconvex positive lens L1, biconvex positive lens L2, meniscus negative lens L3, meniscus positive lens L4, meniscus negative lens L5, biconcave negative lens L6, biconvex positive lens L7, biconcave negative lens L8, biconvex positive lens L9, biconvex positive lens L10, biconcave negative lens L11, meniscus positive lens L12, meniscus negative lens L13, and biconvex positive lens L14, respectively.

[0139] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A UV lithography projection lens, characterized in that, The projection used for mixed or monochromatic ultraviolet lithography light sources consists of a first lens group G1, an aperture stop, a second lens group G2, a third lens group G3, and a fourth lens group G4, all with the optical axis aligned from the object plane to the image plane. The first lens group G1 has positive optical power; The second lens group G2 has positive optical power; The third lens group G3 has a negative optical power; The fourth lens group G4 has positive optical power; The ultraviolet lithography projection lens is a telecentric structure on both the object and image sides and does not include aspherical surfaces. The first lens group G1 includes: a plano-concave positive lens L1, a biconvex positive lens L2, a meniscus negative lens L3, and a biconvex positive lens L4; The second lens group G2 includes: a biconvex positive lens L5, a biconcave negative lens L6, and a biconvex positive lens L7; The third lens group G3 includes a biconvex positive lens L8, a biconcave negative lens L9, a meniscus negative lens L10, and a meniscus negative lens L11. The fourth lens group G4 includes a biconvex positive lens L12; The first lens group G1, the aperture stop, the second lens group G2, the third lens group G3, and the fourth lens group G4 satisfy the following relationship: 0.72 < |f1 / f2| < 1.12 0.83 < |f2 / f3| < 1.23 0.26 < |f3 / f4| < 0.66 0.23 < |f1 / f4| < 0.63 0.03 < |f1 / fL| < 0.09 1.67 <VL2 / VL4<2.61 1.93 <VL5 / VL6<2.23 1.93 <VL8 / VL9<1.93 Wherein: f1: focal length of the first lens group G1; f2: focal length of the second lens group G2; f3: focal length of the third lens group G3; f4: focal length of the fourth lens group G4; fL: overall system focal length of the ultraviolet lithography projection lens; VL2: Abbe number of the material of the biconvex positive lens L2; ​​VL4: Abbe number of the material of the biconvex positive lens L4; VL5: Abbe number of the material of the biconvex positive lens L5; VL6: Abbe number of the material of the biconcave negative lens L6; VL8: Abbe number of the biconvex positive lens L8; VL9: Abbe number of the material of the biconcave negative lens L9.

2. The ultraviolet lithography projection lens according to claim 1, characterized in that, The ultraviolet lithography projection lens uses a low-dispersion material for the lens with positive optical power and a high-dispersion material for the lens with negative optical power.

3. The ultraviolet lithography projection lens according to claim 1 or 2, characterized in that, The first lens group G1 contains at least one flint glass material and one crown glass material; wherein the crown glass material is on the biconvex positive lens L2 and / or the biconvex positive lens L4; In the second lens group G2, the three lenses contain at least two crown glass materials; wherein the lens containing the crown glass material is a biconvex positive lens L5 and / or a biconvex positive lens L7; The third lens group G3 contains at least one flint glass material and one crown glass material; wherein the lens containing the flint glass material is a biconcave negative lens L9, a meniscus negative lens L10 and / or a meniscus negative lens L11, and the lens containing the crown glass material is a biconvex positive lens L8.

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