A UV narrow spectrum low distortion double telecentric projection lithography lens

Abstract

The invention discloses an ultraviolet narrow spectrum low distortion double telecentric projection lithography lens, comprising a front lens group, a beam splitter prism, an aperture, a rear lens group and a focusing system; the front lens group comprises a first lens (1) to a tenth lens (10); the first lens (1), the second lens (2), the seventh lens (7) and the eighth lens (8) have negative focal powers, and the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the ninth lens (9) and the tenth lens (10) have positive focal powers; the rear lens group comprises an eleventh lens (12) to an eighteenth lens (19); the eleventh lens (12), the thirteenth lens (14), the fourteenth lens (15), the fifteenth lens (16), the sixteenth lens (17) and the eighteenth lens (19) have positive focal powers, and the twelfth lens (13) and the seventeenth lens (18) have negative focal powers; and the focusing system comprises two wedge prisms. This lens not only has the characteristics of ultraviolet narrow spectrum, double telecentricity, large effective field of view, small distortion and large numerical aperture, but also has the characteristics of high focusing accuracy and good focusing flexibility.

Description

Technical Field

[0001] The invention relates to the technical field of photolithography lenses, and in particular to an ultraviolet narrow spectrum low distortion double telecentric projection photolithography lens. Background Art

[0002] With the rapid development of the semiconductor industry, especially the urgent need for domestic self-sufficiency in the semiconductor industry, photolithography technology, as a key link in semiconductor manufacturing, has become increasingly important. As the core equipment for the preparation of micro-nano patterns, the performance of photolithography machines directly affects the quality and output of semiconductor products. In this context, the demand for high-resolution photolithography machines at home and abroad continues to increase.

[0003] Photolithography is used to print a characteristic pattern on the surface of a substrate. UV exposure machines and photolithography machines have very important applications in micro-processing fields such as microelectronics, optics, and circuit boards. The working principle of a photolithography machine is that a plasma light source emits ultraviolet light, which is collected by a collection system and then irradiated onto a mask plate by a transmission system. The ultraviolet spectrum pattern on the mask plate is accurately reduced to a certain proportion by a UV lens onto a silicon wafer coated with photoresist. After being processed by related subsequent processes, the required micro-pattern or circuit structure is left. The precision of the circuit structure mainly depends on the UV lens, which naturally becomes a key component of a photolithography machine.

[0004] Telecentric lenses have superior characteristics that are different from ordinary lenses: low distortion, constant magnification, etc. Therefore, they are widely used in the field of non-contact measurement of machine vision. Specially designed telecentric lenses are often used to avoid the perspective distortion of traditional lenses. Bi-telecentric lenses refer to imaging systems that meet the characteristics of both the object-side telecentric optical path and the image-side telecentric optical path. It contains the common advantages of the two telecentric optical paths, so the design is more difficult. Such lenses are often fixed magnification lenses, and the telecentricity of the object and image sides cannot meet high standards at the same time. The current bi-telecentric lenses cannot have good telecentricity and low distortion while ensuring long working distance and high magnification.

[0005] The development of the field of ultraviolet narrow-band projection lithography lens in China is still in its early stages. The ultraviolet lens currently used in the market is composed of a lens group consisting of multiple lenses assembled through a lens barrel according to a certain spacing size. Although it can basically realize the lithography function, the manufacturing technology is not yet fully mature, and glued lenses are mostly used. There are problems such as low system transmittance, a large number of aspherical lenses, and high design and manufacturing costs. In order to solve the above problems, the prior art, such as the Chinese invention patent with publication number CN111505912A, discloses an ultraviolet wide-spectrum lithography lens, including: an ultraviolet light source, a first lens group, a second lens group, and a plurality of lens groups arranged in sequence from the ultraviolet light source to the target. The third mirror group and the fourth mirror group, the ultraviolet light source includes a digital micro-reflector and a first lens, the first lens is a double convex lens; the first mirror group includes: a first number of positive lenses and a second number of negative lenses arranged in sequence from the ultraviolet light source to the target, and the combined focal length of the first mirror group is positive; the second mirror group includes: a third number of positive lenses and a fourth number of negative lenses arranged in sequence from the ultraviolet light source to the target, and the combined focal length of the second mirror group is positive, and the lens closest to the first mirror group in the second mirror group can move along the optical axis; the third mirror group includes: a fifth number of positive lenses arranged in sequence from the ultraviolet light source to the target, and the combined focal length of the third mirror group is positive. Although the above-mentioned prior art can reduce the cost of lithography, there are still problems such as insufficient system focusing accuracy, insufficient focusing flexibility, and insufficient distortion, which makes it difficult to meet the needs of high-precision lithography. Summary of the invention

[0006] The object of the present invention is to provide an ultraviolet narrow spectrum low distortion double telecentric projection lithography lens, which not only has the characteristics of ultraviolet narrow spectrum, double telecentricity, large effective field of view, small distortion and large numerical aperture, but also has the characteristics of high focusing accuracy and good focusing flexibility.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] An ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens, the lens comprising a front lens group, a beam splitter prism, an aperture, a rear lens group and a focusing system arranged in sequence from the object side to the image side;

[0009] The front lens group includes, arranged in sequence from the object side to the image side, a first lens with negative optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, an eighth lens with negative optical power, a ninth lens with positive optical power, and a tenth lens with positive optical power;

[0010] The rear lens group includes, from the object side to the image side, an eleventh lens with positive power, a twelfth lens with negative power, a thirteenth lens with positive power, a fourteenth lens with positive power, a fifteenth lens with positive power, a sixteenth lens with positive power, a seventeenth lens with negative power, and an eighteenth lens with positive power;

[0011] The focusing system includes two wedge-shaped prisms.

[0012] Preferably, there is a parallel optical path between the front lens group and the rear lens group, and the parallelism of the light rays in the parallel optical path of the lens is less than 0.1°.

[0013] Preferably, the thickness of the two wedge prisms is 5 mm, the included angle of the wedge prisms is 4.58 degrees, and the wedge prisms are arranged between the eighteenth lens and the image plane.

[0014] Preferably, the optical path structure of the lens is a double telecentric structure.

[0015] Preferably, the wavelength range value of the lens is 370nm≤λ≤380nm, and the main wavelength telecentricity of the object side and the image side of the lens is less than 0.1°.

[0016] Preferably, the object side of the first lens is concave, and the image side is concave;

[0017] The object side of the second lens is concave, and the image side is convex;

[0018] The object side of the third lens is concave, and the image side is convex;

[0019] The object side of the fourth lens is concave, and the image side is convex;

[0020] The object side of the fifth lens is convex, and the image side is convex;

[0021] The object side of the sixth lens is convex, and the image side is convex;

[0022] The object side of the seventh lens is concave, and the image side is concave;

[0023] The object side of the eighth lens is concave, and the image side is concave;

[0024] The object side of the ninth lens is concave, and the image side is convex;

[0025] The object side of the tenth lens is convex, and the image side is convex;

[0026] The object side of the eleventh lens is convex, and the image side is concave;

[0027] The object side of the twelfth lens is concave, and the image side is concave;

[0028] The object side of the thirteenth lens is convex, and the image side is convex;

[0029] The object side of the fourteenth lens is convex, and the image side is convex;

[0030] The object side of the fifteenth lens is convex, and the image side is convex;

[0031] The object side of the sixteenth lens is convex, and the image side is concave;

[0032] The object side of the seventeenth lens is concave, and the image side is concave;

[0033] The object side of the eighteenth lens is convex, and the image side is concave.

[0034] Preferably, the refractive index Nd1, the dispersion coefficient Vd1 and the focal length f1 of the first lens satisfy the following conditions: 1.4 <Nd1<1.5,90<Vd1<96,-175mm<f1<-173mm;

[0035] The refractive index Nd2, the dispersion coefficient Vd2 and the focal length f2 of the second lens satisfy the following conditions: 1.5 <Nd2<1.6,65<Vd2<70,-260mm<f2<-250mm;

[0036] The refractive index Nd3, the dispersion coefficient Vd3 and the focal length f3 of the third lens satisfy the following conditions: 1.8 <Nd3<1.9,35<Vd3<40,215mm<f3<225mm;

[0037] The refractive index Nd4, the dispersion coefficient Vd4 and the focal length f4 of the fourth lens satisfy the following conditions: 1.8 <Nd4<1.9,40<Vd4<50,210mm<f4<220mm;

[0038] The refractive index Nd5, the dispersion coefficient Vd5 and the focal length f5 of the fifth lens satisfy the following conditions: 1.4 <Nd5<1.5,80<Vd5<85,250mm<f5<260mm;

[0039] The refractive index Nd6, the dispersion coefficient Vd6 and the focal length f6 of the sixth lens satisfy the following conditions: 1.4 <Nd6<1.5,90<Vd6<96,200mm<f6<210mm;

[0040] The refractive index Nd7, the dispersion coefficient Vd7 and the focal length f7 of the seventh lens satisfy the following conditions: 1.6 <Nd7<1.7,30<Vd7<35,-85mm<f7<-75mm;

[0041] The refractive index Nd8, the dispersion coefficient Vd8 and the focal length f8 of the eighth lens satisfy the following conditions: 1.6 <Nd8<1.7,40<Vd8<50,-145mm<f8<-135mm;

[0042] The refractive index Nd9, the dispersion coefficient Vd9 and the focal length f9 of the ninth lens satisfy the following conditions: 1.7 <Nd9<1.8,40<Vd9<50,330mm<f9<335mm;

[0043] The refractive index Nd10, the dispersion coefficient Vd10 and the focal length f10 of the tenth lens satisfy the following conditions: 1.5 <Nd10<1.6,65<Vd10<70,200mm<f10<210mm;

[0044] The refractive index Nd11, the dispersion coefficient Vd11 and the focal length f11 of the eleventh lens satisfy the following conditions: 1.7 <Nd11<1.8,45<Vd11<50,405mm<f11<415mm;

[0045] The refractive index Nd12, the dispersion coefficient Vd12 and the focal length f12 of the twelfth lens satisfy the following conditions: 1.7 <Nd12<1.8,35<Vd12<40,-125mm<f12<-115mm;

[0046] The refractive index Nd13, the dispersion coefficient Vd13 and the focal length f13 of the thirteenth lens satisfy the following conditions: 1.4 <Nd13<1.5,80<Vd13<85,225mm<f13<235mm;

[0047] The refractive index Nd14, the dispersion coefficient Vd14 and the focal length f14 of the fourteenth lens satisfy the following conditions: 1.4 <Nd14<1.5,80<Vd14<85,245mm<f14<255mm;

[0048] The refractive index Nd15, the dispersion coefficient Vd15 and the focal length f15 of the fifteenth lens satisfy the following conditions: 1.4 <Nd15<1.5,80<Vd15<85,230mm<f15<240mm;

[0049] The refractive index Nd16, the dispersion coefficient Vd16 and the focal length f16 of the sixteenth lens satisfy the following conditions: 1.8 <Nd16<1.9,40<Vd16<45,190mm<f16<200mm;

[0050] The refractive index Nd17, the dispersion coefficient Vd17 and the focal length f17 of the seventeenth lens satisfy the following conditions: 1.5 <Nd17<1.6,50<Vd17<60,-110mm<f17<-100mm;

[0051] The refractive index Nd18, the dispersion coefficient Vd18 and the focal length f18 of the eighteenth lens satisfy the following conditions: 1.8 <Nd18<1.9,40<Vd18<45,340mm<f18<350mm。

[0052] Preferably, the effective field of view of the lens on the object side is φ72 mm, and the numerical aperture of the object side is 0.15; the effective field of view of the lens on the image side is φ36 mm, and the numerical aperture of the image side is 0.30.

[0053] Preferably, all eighteen lenses from the first lens to the eighteenth lens are glass spherical lenses.

[0054] The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens provided by the present invention has the following beneficial effects:

[0055] The lens provided by the present invention uses a small number of lenses, has a simple structure, does not use cemented lenses, has low cost, is easy to assemble and adjust, and has a high system transmittance; and has the structural characteristics of image and object telecentricity, and the object and image telecentricity are both less than 0.1°; there is a parallel optical path between the front lens group and the rear lens group, and light beams of different wavelengths can be efficiently monitored in combination with a beam splitter prism, and the parallelism of the parallel optical path is less than 0.1°; the spectral range is 370nm-380nm, and has small distortion, which does not exceed 0.05%; a dual prism focusing mechanism is adopted, which further enhances the flexibility and accuracy of focusing and meets the requirements of high-precision photolithography; based on the above advantages, the lens provided by the present invention has a very large application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0057] Figure 1 is a schematic diagram of the optical path of the lens provided in Embodiment 1 of the present invention;

[0058] Figure 2 is an MTF curve diagram of the lens provided in Example 1 of the present invention;

[0059] Figure 3is a distortion curve diagram of the lens provided in Example 1 of the present invention;

[0060] Figure 4 is a schematic diagram of the optical path of a lens provided in Embodiment 2 of the present invention;

[0061] Figure 5 is an MTF curve diagram of the lens provided in Example 2 of the present invention;

[0062] Figure 6 is a distortion curve diagram of the lens provided by Embodiment 2 of the present invention;

[0063] Description of Figure Numbers:

[0064]

[0065] DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for description purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features.

[0067] For ease of understanding, the technical terms involved in the present invention are explained and described below.

[0068] Lens: A component that uses the refraction principle of the lens to allow the light beam of the scene to pass through the lens and form a clear image on the focusing plane.

[0069] Object side and image side: With the lens as the boundary, the side where the object is located is the object side, and the surface of the lens close to the object side can be called the object side; with the lens as the boundary, the side where the image of the object is located is the image side, and the surface of the lens close to the image side can be called the image side.

[0070] Focal length: Also known as focal length, it is a measure of the convergence or divergence of light in an optical system. It refers to the distance from the optical center of a lens or lens group to the focus when an infinitely distant scene forms a clear image on the focal plane through a lens or lens group. It can also be understood as the vertical distance from the optical center of a lens or lens group to the focal plane. From a practical point of view, it can be understood as the distance from the center of the lens to the imaging plane. For a fixed-focus lens, the position of its optical center is fixed; for a lens module, the change of the optical center of the lens brings about a change in the focal length of the lens.

[0071] Focal power: It is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam. It characterizes the ability of the optical system to deflect the beam. A lens or lens group with positive focal power has a positive focal length and has the effect of converging the beam. A lens or lens group with negative focal power has a negative focal length and has the effect of diverging the beam.

[0072] Diaphragm: refers to the edge, frame or specially designed barrier with holes in the optical component of the optical assembly used to limit the size of the imaging beam or the imaging spatial unit.

[0073] Distortion, also known as distortion, is the degree of distortion of the image formed by the optical system on an object relative to the object itself. Distortion is due to the influence of aperture spherical aberration. The height of the intersection of the main light beam of different fields of view with the Gaussian image plane after passing through the optical system is not equal to the ideal image height. The difference between the two is the distortion. Therefore, distortion only changes the imaging position of the off-axis object point on the ideal plane, causing the shape of the image to be distorted, but does not affect the clarity of the image.

[0074] Example 1

[0075] like Figure 1 As shown, the ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens provided in Example 1 includes a front lens group, a beam splitter prism 11, an aperture, a rear lens group and a focusing system arranged in sequence from the object side to the image side;

[0076] The front lens group includes, from the object side to the image side, a first lens 1 with negative power, a second lens 2 with negative power, a third lens 3 with positive power, a fourth lens 4 with positive power, a fifth lens 5 with positive power, a sixth lens 6 with positive power, a seventh lens 7 with negative power, an eighth lens 8 with negative power, a ninth lens 9 with positive power, and a tenth lens 10 with positive power;

[0077] The rear lens group includes, from the object side to the image side, an eleventh lens 12 with positive refractive power, a twelfth lens 13 with negative refractive power, a thirteenth lens 14 with positive refractive power, a fourteenth lens 15 with positive refractive power, a fifteenth lens 16 with positive refractive power, a sixteenth lens 17 with positive refractive power, a seventeenth lens 18 with negative refractive power, and an eighteenth lens 19 with positive refractive power;

[0078] The aperture is arranged between the tenth lens 10 and the eleventh lens 12, and the beam splitter prism 11 is arranged between the tenth lens 10 and the aperture;

[0079] The focusing system includes two wedge prisms 20 .

[0080] In one implementation, the thickness of the two wedge prisms 20 is 5 mm, the included angle of the wedge prisms 20 is 4.58 degrees, and the wedge prisms 20 are disposed between the eighteenth lens 19 and the image plane.

[0081] In one implementation, there is a parallel optical path between the front lens group and the rear lens group, and the parallelism of the light in the parallel optical path of the lens is less than 0.1°. The optical path structure of the lens is a double telecentric structure.

[0082] In one implementation, the wavelength range of the lens is 370nm≤λ≤380nm, and the main wavelength telecentricity of the lens on the object side and the image side is less than 0.1°.

[0083] In one implementation, the effective field of view of the lens on the object side is φ72 mm, and the numerical aperture of the object side is 0.15; the effective field of view of the lens on the image side is φ36 mm, and the numerical aperture of the image side is 0.30.

[0084] All eighteen lenses of the first lens 1 to the eighteenth lens 19 are glass spherical lenses.

[0085] The object side of the first lens 1 is concave, and the image side is concave;

[0086] The object side of the second lens 2 is concave, and the image side is convex;

[0087] The object side of the third lens 3 is concave, and the image side is convex;

[0088] The fourth lens 4 has a concave surface on the object side and a convex surface on the image side;

[0089] The fifth lens 5 has a convex surface on the object side and a convex surface on the image side;

[0090] The sixth lens 6 has a convex surface on the object side and a convex surface on the image side;

[0091] The seventh lens 7 has a concave surface on its object side and a concave surface on its image side;

[0092] The object side of the eighth lens 8 is concave, and the image side is concave;

[0093] The ninth lens 9 has a concave surface on the object side and a convex surface on the image side;

[0094] The object side of the tenth lens 10 is convex, and the image side is convex;

[0095] The object side of the eleventh lens 12 is convex, and the image side is concave;

[0096] The object side of the twelfth lens 13 is concave, and the image side is concave;

[0097] The thirteenth lens 14 has a convex surface on the object side and a convex surface on the image side;

[0098] The object side of the fourteenth lens 15 is convex, and the image side is convex;

[0099] The fifteenth lens 16 has a convex surface on the object side and a convex surface on the image side;

[0100] The object side of the sixteenth lens 17 is convex, and the image side is concave;

[0101] The object side of the seventeenth lens 18 is concave, and the image side is concave;

[0102] The object side of the eighteenth lens 19 is convex, and the image side is concave.

[0103] In addition, the refractive index Nd1, the dispersion coefficient Vd1 and the focal length f1 of the first lens 1 satisfy the following conditions: 1.4 <Nd1<1.5,90<Vd1<96,-175mm<f1<-173mm;

[0104] The refractive index Nd2, the dispersion coefficient Vd2 and the focal length f2 of the second lens 2 satisfy the following conditions: 1.5 <Nd2<1.6,65<Vd2<70,-260mm<f2<-250mm;

[0105] The refractive index Nd3, the dispersion coefficient Vd3 and the focal length f3 of the third lens 3 satisfy the following conditions: 1.8 <Nd3<1.9,35<Vd3<40,215mm<f3<225mm;

[0106] The refractive index Nd4, the dispersion coefficient Vd4 and the focal length f4 of the fourth lens 4 satisfy the following conditions: 1.8 <Nd4<1.9,40<Vd4<50,210mm<f4<220mm;

[0107] The refractive index Nd5, the dispersion coefficient Vd5 and the focal length f5 of the fifth lens 5 satisfy the following conditions: 1.4 <Nd5<1.5,80<Vd5<85,250mm<f5<260mm;

[0108] The refractive index Nd6, the dispersion coefficient Vd6 and the focal length f6 of the sixth lens 6 satisfy the following conditions: 1.4 <Nd6<1.5,90<Vd6<96,200mm<f6<210mm;

[0109] The refractive index Nd7, the dispersion coefficient Vd7 and the focal length f7 of the seventh lens element 7 satisfy the following conditions: 1.6 <Nd7<1.7,30<Vd7<35,-85mm<f7<-75mm;

[0110] The refractive index Nd8, the dispersion coefficient Vd8 and the focal length f8 of the eighth lens 8 satisfy the following conditions: 1.6 <Nd8<1.7,40<Vd8<50,-145mm<f8<-135mm;

[0111] The refractive index Nd9, the dispersion coefficient Vd9 and the focal length f9 of the ninth lens 9 satisfy the following conditions: 1.7 <Nd9<1.8,40<Vd9<50,330mm<f9<335mm;

[0112] The refractive index Nd10, the dispersion coefficient Vd10 and the focal length f10 of the tenth lens 10 satisfy the following conditions: 1.5 <Nd10<1.6,65<Vd10<70,200mm<f10<210mm;

[0113] The refractive index Nd11, the dispersion coefficient Vd11 and the focal length f11 of the eleventh lens 12 satisfy the following conditions: 1.7 <Nd11<1.8,45<Vd11<50,405mm<f11<415mm;

[0114] The refractive index Nd12, the dispersion coefficient Vd12 and the focal length f12 of the twelfth lens 13 satisfy the following conditions: 1.7 <Nd12<1.8,35<Vd12<40,-125mm<f12<-115mm;

[0115] The refractive index Nd13, the dispersion coefficient Vd13 and the focal length f13 of the thirteenth lens 14 satisfy the following conditions: 1.4 <Nd13<1.5,80<Vd13<85,225mm<f13<235mm;

[0116] The refractive index Nd14, the dispersion coefficient Vd14 and the focal length f14 of the fourteenth lens 15 satisfy the following conditions: 1.4 <Nd14<1.5,80<Vd14<85,245mm<f14<255mm;

[0117] The refractive index Nd15, the dispersion coefficient Vd15 and the focal length f15 of the fifteenth lens 16 satisfy the following conditions: 1.4 <Nd15<1.5,80<Vd15<85,230mm<f15<240mm;

[0118] The refractive index Nd16, the dispersion coefficient Vd16 and the focal length f16 of the sixteenth lens 17 satisfy the following conditions: 1.8 <Nd16<1.9,40<Vd16<45,190mm<f16<200mm;

[0119] The refractive index Nd17, the dispersion coefficient Vd17 and the focal length f17 of the seventeenth lens 18 satisfy the following conditions: 1.5 <Nd17<1.6,50<Vd17<60,-110mm<f17<-100mm;

[0120] The refractive index Nd18, the dispersion coefficient Vd18 and the focal length f18 of the eighteenth lens 19 satisfy the following conditions: 1.8 <Nd18<1.9,40<Vd18<45,340mm<f18<350mm。

[0121] It should be noted that the specific parameters of the ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens in Example 1 are shown in Table 1, where the units of the radius of curvature and thickness are both millimeters (mm).

[0122] Table 1 Specific parameters of the ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens in Example 1

[0123]

[0124]

[0125] It should be noted that the serial numbers of each surface are Figure 1 The first lens 1 ... the eighteenth lens 19 in the image lens have serial numbers for each side surface arranged in the order from the object side surface to the image side surface: for example, S1 is the serial number for the object side surface of the first lens 1; S2 is the serial number for the image side surface of the first lens 1; S3 is the serial number for the object side surface of the second lens 2; and S4 is the serial number for the image side surface of the second lens 2.

[0126] like Figure 2 As shown in FIG. 1 , the theoretical MTF curve of the lens provided in Example 1 can ensure a contrast ratio of 800lp / mm greater than 0.3, and a good imaging effect. Figure 3 As shown, it is a lens distortion curve diagram provided in Example 1, and the distortion is between -0.02% and 0.02%, which is very small.

[0127] The lens provided in this embodiment uses a small number of lenses, has a simple structure, does not use cemented lenses, has low cost, is easy to assemble and adjust, and has a high system transmittance; and has the structural characteristics of image and object space telecentricity, and the object and image space telecentricity are both less than 0.1°; there is a parallel optical path between the front lens group and the rear lens group, and combined with a beam splitter prism, light beams of different wavelengths can be efficiently monitored, and the parallelism of the parallel optical path is less than 0.1°; the spectral range is 370nm-380nm, with small distortion, and the distortion is less than 0.02%; the dual prism focusing mechanism is adopted to further enhance the flexibility and accuracy of focusing to meet the needs of high-precision lithography.

[0128] Example 2

[0129] like Figure 4 , Figure 5 and Figure 6 As shown, compared with Example 1, Example 2 has substantially the same number and type of lenses, but differs in that specific lens parameters are different.

[0130] It should be noted that the specific parameters of the lens in Example 2 are shown in Table 2, where the units of the curvature radius and thickness are both millimeters (mm).

[0131] Table 2 Specific parameters of the lens in Example 2

[0132]

[0133]

[0134] Figure 5 The theoretical MTF curve of the lens provided in Example 2 can ensure a contrast ratio of 800lp / mm greater than 0.3, and a good imaging effect. Figure 6 As shown, it is a mirror distortion curve diagram provided in Example 2, the distortion is between -0.05% and 0.05%, and the distortion is very small.

[0135] The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens provided in this embodiment uses a small number of lenses and has a simple structure. No cemented lenses are used in the design, so the cost is low, the assembly and adjustment are easy, the system has high transmittance, and has the structural characteristics of image and object side telecentricity, and the object side and image side telecentricity are both less than 0.1°; there is a parallel optical path between the front lens group and the rear lens group, and light beams of different wavelengths can be efficiently monitored in combination with a splitter prism, and the parallelism of the parallel optical path is less than 0.1°; the spectral range is 370nm-380nm, with small distortion, the distortion is less than 0.05%, and a dual prism focusing mechanism is adopted to further enhance the flexibility and accuracy of focusing, meet the needs of high-precision lithography, and based on the above characteristics, the present invention has a very large application prospect.

[0136] The above description is only a preferred example of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens, characterized in that: The lens comprises a front lens group, a beam splitter prism (11), an aperture, a rear lens group and a focusing system which are arranged in sequence from the object side to the image side; The front lens group comprises, arranged in sequence from the object side to the image side, a first lens (1) with negative optical power, a second lens (2) with negative optical power, a third lens (3) with positive optical power, a fourth lens (4) with positive optical power, a fifth lens (5) with positive optical power, a sixth lens (6) with positive optical power, a seventh lens (7) with negative optical power, an eighth lens (8) with negative optical power, a ninth lens (9) with positive optical power and a tenth lens (10) with positive optical power; The rear lens group comprises, arranged in sequence from the object side to the image side, an eleventh lens (12) with positive focal power, a twelfth lens (13) with negative focal power, a thirteenth lens (14) with positive focal power, a fourteenth lens (15) with positive focal power, a fifteenth lens (16) with positive focal power, a sixteenth lens (17) with positive focal power, a seventeenth lens (18) with negative focal power, and an eighteenth lens (19) with positive focal power; The focusing system comprises two wedge-shaped prisms (20).

2. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to claim 1, characterized in that: There is a parallel optical path between the front lens group and the rear lens group, and the parallelism of the light rays in the parallel optical path of the lens is less than 0.1°.

3. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to any one of claims 1-2, characterized in that: The thickness of the two wedge-shaped prisms (20) is 5 mm, the included angle of the wedge-shaped prisms (20) is 4.58 degrees, and the wedge-shaped prisms (20) are arranged between the eighteenth lens (19) and the image plane.

4. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to any one of claims 1-2, characterized in that: The optical path structure of the lens is a double telecentric structure.

5. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to claim 4, characterized in that: The wavelength range value of the lens is 370nm≤λ≤380nm.

6. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to claim 5, characterized in that: The telecentricity of the main wavelength on the object side and the image side of the lens is less than 0.1°.

7. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to claim 1, characterized in that: The object side of the first lens (1) is concave, and the image side is concave; The object side of the second lens (2) is concave, and the image side is convex; The object side of the third lens (3) is concave, and the image side is convex; The fourth lens (4) has a concave object surface and a convex image surface; The fifth lens (5) has a convex surface on the object side and a convex surface on the image side; The sixth lens (6) has a convex surface on the object side and a convex surface on the image side; The seventh lens (7) has a concave surface on the object side and a concave surface on the image side; The object side of the eighth lens (8) is concave, and the image side is concave; The object side of the ninth lens (9) is concave, and the image side is convex; The object side of the tenth lens (10) is convex, and the image side is convex; The object side of the eleventh lens (12) is convex, and the image side is convex; The object side of the twelfth lens (13) is a concave surface, and the image side is a concave surface; The object side of the thirteenth lens (14) is convex, and the image side is convex; The object side of the fourteenth lens (15) is convex, and the image side is convex; The fifteenth lens (16) has a convex surface on the object side and a convex surface on the image side; The object side of the sixteenth lens (17) is convex, and the image side is concave; The object side of the seventeenth lens (18) is concave, and the image side is concave; The object side of the eighteenth lens (19) is convex, and the image side is concave.

8. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to claim 7, characterized in that: The refractive index Nd1, the dispersion coefficient Vd1 and the focal length f1 of the first lens (1) satisfy the following conditions: 1.4 <Nd1<1.5,90<Vd1<96,-175mm<f1<-173mm; The refractive index Nd2, the dispersion coefficient Vd2 and the focal length f2 of the second lens (2) satisfy the following conditions: 1.5 <Nd2<1.6,65<Vd2<70,-260mm<f2<-250mm; The refractive index Nd3, the dispersion coefficient Vd3 and the focal length f3 of the third lens (3) satisfy the following conditions: 1.8 <Nd3<1.9,35<Vd3<40,215mm<f3<225mm; The refractive index Nd4, the dispersion coefficient Vd4 and the focal length f4 of the fourth lens (4) satisfy the following conditions: 1.8 <Nd4<1.9,40<Vd4<50,210mm<f4<220mm; The refractive index Nd5, the dispersion coefficient Vd5 and the focal length f5 of the fifth lens (5) satisfy the following conditions: 1.4 <Nd5<1.5,80<Vd5<85,250mm<f5<260mm; The refractive index Nd6, the dispersion coefficient Vd6 and the focal length f6 of the sixth lens (6) satisfy the following conditions: 1.4 <Nd6<1.5,90<Vd6<96,200mm<f6<210mm; The refractive index Nd7, the dispersion coefficient Vd7 and the focal length f7 of the seventh lens (7) satisfy the following conditions: <Nd7<1.7,30<Vd7<35,-85mm<f7<-75mm; The refractive index Nd8, the dispersion coefficient Vd8 and the focal length f8 of the eighth lens (8) satisfy the following conditions: 1.6 <Nd8<1.7,40<Vd8<50,-145mm<f8<-135mm; The refractive index Nd9, the dispersion coefficient Vd9 and the focal length f9 of the ninth lens (9) satisfy the following conditions: 1.7 <Nd9<1.8,40<Vd9<50,330mm<f9<335mm; The refractive index Nd10, the dispersion coefficient Vd10 and the focal length f10 of the tenth lens (10) satisfy the following conditions: 1.5 <Nd10<1.6,65<Vd10<70,200mm<f10<210mm; The refractive index Nd11, the dispersion coefficient Vd11 and the focal length f11 of the eleventh lens (12) satisfy the following conditions: 1.7 <Nd11<1.8,45<Vd11<50,405mm<f11<415mm; The refractive index Nd12, the dispersion coefficient Vd12 and the focal length f12 of the twelfth lens (13) satisfy the following conditions: 1.7 <Nd12<1.8,35<Vd12<40,-125mm<f12<-115mm; The refractive index Nd13, the dispersion coefficient Vd13 and the focal length f13 of the thirteenth lens (14) satisfy the following conditions: 1.4 <Nd13<1.5,80<Vd13<85,225mm<f13<235mm; The refractive index Nd14, the dispersion coefficient Vd14 and the focal length f14 of the fourteenth lens (15) satisfy the following conditions: 1.4 <Nd14<1.5,80<Vd14<85,245mm<f14<255mm; The refractive index Nd15, the dispersion coefficient Vd15 and the focal length f15 of the fifteenth lens (16) satisfy the following conditions: 1.4 <Nd15<1.5,80<Vd15<85,230mm<f15<240mm; The refractive index Nd16, the dispersion coefficient Vd16 and the focal length f16 of the sixteenth lens (17) satisfy the following conditions: 1.8 <Nd16<1.9,40<Vd16<45,190mm<f16<200mm; The refractive index Nd17, the dispersion coefficient Vd17 and the focal length f17 of the seventeenth lens (18) satisfy the following conditions: 1.5 <Nd17<1.6,50<Vd17<60,-110mm<f17<-100mm; The refractive index Nd18, the dispersion coefficient Vd18 and the focal length f18 of the eighteenth lens (19) satisfy the following conditions: 1.8 <Nd18<1.9,40<Vd18<45,340mm<f18<350mm。 9. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to any one of claims 1-2 and 5-8, characterized in that: The effective field of view of the lens on the object side is φ72 mm, and the numerical aperture of the object side is 0.15; the effective field of view of the lens on the image side is φ36 mm, and the numerical aperture of the image side is 0.

30.

10. The ultraviolet narrow spectrum low distortion dual telecentric projection lithography lens according to any one of claims 1-2 and 5-8, characterized in that: All eighteen lenses from the first lens (1) to the eighteenth lens (19) are glass spherical lenses.

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