Fixed focus optical system, photolithography objective and photolithography apparatus

Abstract

The application discloses a kind of fixed focus optical system, photoetching objective and photoetching equipment, fixed focus optical system includes first convex-concave spherical lens, second biconvex spherical lens, third biconcave spherical lens, fourth convex-concave spherical lens, fifth concave-convex spherical lens, sixth concave-convex spherical lens, seventh biconvex spherical lens, eighth biconcave spherical lens, ninth biconvex spherical lens, tenth biconvex spherical lens, eleventh biconcave spherical lens, twelfth biconvex spherical lens, thirteenth convex-concave spherical lens, fourteenth biconcave spherical lens, fifteenth plano-convex spherical lens, sixteenth convex-concave spherical lens, seventeenth convex-concave spherical lens are sequentially arranged from object side to image side.Make the optical total length of fixed focus optical system can be controlled in 125mm range, make the whole fixed focus optical system compact structure, and the aperture number that can be realized is 0.76, and the dual-band imaging of 365±5nm / 590±30nm is realized, to provide a kind of compact, large aperture, ultraviolet / visible light dual-band fixed focus optical system.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and more particularly to fixed-focus optical systems, lithography objectives, and lithography equipment. Background Technology

[0002] In recent years, the further development of equipment in the field of lithography has led to increasingly higher demands on lithography lenses, which need to meet the requirements of ultraviolet lithography as well as the monitoring and alignment capabilities of visible light. Summary of the Invention

[0003] The main objective of this invention is to provide a fixed-focus optical system, a lithography objective lens, and a lithography apparatus, aiming to provide a compact, large-aperture, ultraviolet / visible dual-band fixed-focus optical system.

[0004] To achieve the above objectives, the present invention proposes a fixed-focus optical system, which has an object side and an image side arranged opposite to each other along the optical axis. The fixed-focus optical system includes a first convex-concave spherical lens, a second biconvex spherical lens, a third biconcave spherical lens, a fourth convex-concave spherical lens, a fifth concave-convex spherical lens, a sixth concave-convex spherical lens, a seventh biconvex spherical lens, an eighth biconcave spherical lens, a ninth biconvex spherical lens, a tenth biconvex spherical lens, an eleventh biconcave spherical lens, a twelfth biconvex-concave spherical lens, a thirteenth convex-concave spherical lens, a fourteenth biconcave spherical lens, a fifteenth plano-convex spherical lens, a sixteenth convex-concave spherical lens, and a seventeenth convex-concave spherical lens arranged sequentially from the object side to the image side.

[0005] In this system, the concave surfaces of the first, fourth, sixth, thirteenth, sixteenth, and seventeenth convex-concave spherical lenses face the image side; the concave surface of the fifth convex-concave spherical lens faces the object side; and the convex surface of the fifteenth plano-convex spherical lens faces the object side. The total optical length (TTL) of the fixed-focus optical system is ≤125mm, and the aperture number (F) of the fixed-focus optical system is 0.76.

[0006] Optionally, the optical power of the first convex-concave spherical lens is negative;

[0007] The optical power of the second biconvex spherical lens is positive;

[0008] The optical power of the third biconcave spherical lens is negative;

[0009] The optical power of the fourth convex-concave spherical lens is positive.

[0010] The optical power of the fifth concave-convex spherical lens is negative;

[0011] The optical power of the sixth concave-convex spherical lens is positive;

[0012] The optical power of the seventh biconvex spherical lens is positive.

[0013] The optical power of the eighth biconcave spherical lens is negative;

[0014] The optical power of the ninth biconvex spherical lens is positive.

[0015] The optical power of the tenth biconvex spherical lens is positive.

[0016] The optical power of the eleventh biconcave spherical lens is negative;

[0017] The optical power of the twelfth biconvex spherical lens is positive.

[0018] The optical power of the thirteenth convex-concave spherical lens is positive.

[0019] The optical power of the fourteenth biconcave spherical lens is negative;

[0020] The optical power of the fifteenth plano-convex spherical lens is positive.

[0021] The optical power of the sixteenth convex-concave spherical lens is positive.

[0022] The optical power of the seventeenth convex-concave spherical lens is positive.

[0023] Optionally, the optical power of the first convex-concave spherical lens is -38.861; the optical power of the second biconvex spherical lens is 24.088.

[0024] The optical power of the third biconcave spherical lens is -28.458;

[0025] The optical power of the fourth convex-concave spherical lens is 95.599.

[0026] The optical power of the fifth concave-convex spherical lens is -16.532;

[0027] The optical power of the sixth concave-convex spherical lens is 29.829;

[0028] The optical power of the seventh biconvex spherical lens is 45.607;

[0029] The optical power of the eighth biconcave spherical lens is -35.136;

[0030] The optical power of the ninth biconvex spherical lens is 47.465;

[0031] The optical power of the tenth biconvex spherical lens is 55.774;

[0032] The optical power of the eleventh biconcave spherical lens is -38.337;

[0033] The optical power of the twelfth biconvex spherical lens is 53.643;

[0034] The optical power of the thirteenth convex-concave spherical lens is 41.727;

[0035] The optical power of the fourteenth biconcave spherical lens is -25.821;

[0036] The optical power of the fifteenth plano-convex spherical lens is 31.7;

[0037] The optical power of the sixteenth convex-concave spherical lens is 26.65;

[0038] The optical power of the seventeenth convex-concave spherical lens is 122.566.

[0039] Optionally, the refractive index n1 of the first convex-concave spherical lens is 1.49;

[0040] The refractive index of the second biconvex spherical lens is n2 = 1.62;

[0041] The refractive index of the third biconcave spherical lens is n3 = 1.52;

[0042] The refractive index of the fourth convex-concave spherical lens is n4 = 1.62;

[0043] The refractive index of the fifth concave-convex spherical lens is n5 = 1.62;

[0044] The refractive index of the sixth concave-convex spherical lens is n6 = 1.46;

[0045] The refractive index of the seventh biconvex spherical lens is n7 = 1.46;

[0046] The refractive index of the eighth biconcave spherical lens is n8 = 1.62;

[0047] The refractive index of the ninth biconvex spherical lens is n9 = 1.46;

[0048] The refractive index of the tenth biconvex spherical lens is n10 = 1.52;

[0049] The refractive index of the eleventh biconcave spherical lens is n11 = 1.52;

[0050] The refractive index of the twelfth biconvex spherical lens is n12 = 1.46;

[0051] The refractive index of the thirteenth convex-concave spherical lens is n13 = 1.46;

[0052] The refractive index of the fourteenth biconcave spherical lens is n14 = 1.46;

[0053] The refractive index of the fifteenth plano-convex spherical lens is n15 = 1.46;

[0054] The refractive index of the sixteenth convex-concave spherical lens is n16 = 1.46;

[0055] The refractive index of the seventeenth convex-concave spherical lens is n17 = 1.46.

[0056] Optionally, the dispersion coefficient vd1 of the first convex-concave spherical lens is 70.4; and the dispersion coefficient vd2 of the second biconvex spherical lens is 36.4.

[0057] The dispersion coefficient of the third biconcave spherical lens is vd3 = 63.3;

[0058] The dispersion coefficient of the fourth convex-concave spherical lens is vd4 = 36.4;

[0059] The dispersion coefficient vd5 of the fifth concave-convex spherical lens is 90.3;

[0060] The dispersion coefficient vd6 of the sixth concave-convex spherical lens is 90.3.

[0061] The dispersion coefficient of the seventh biconvex spherical lens is vd7 = 36.4;

[0062] The dispersion coefficient vd8 of the eighth biconcave spherical lens is 90.3.

[0063] The dispersion coefficient vd9 of the ninth biconvex spherical lens is 90.3.

[0064] The dispersion coefficient vd10 of the tenth biconvex spherical lens is 63.3;

[0065] The dispersion coefficient vd11 of the eleventh biconcave spherical lens is 63.3;

[0066] The dispersion coefficient vd12 of the twelfth biconvex spherical lens is 90.3.

[0067] The dispersion coefficient vd13 of the thirteenth convex-concave spherical lens is 90.3.

[0068] The dispersion coefficient vd14 of the fourteenth biconcave spherical lens is 67.8;

[0069] The dispersion coefficient vd15 of the fifteenth plano-convex spherical lens is 90.3.

[0070] The dispersion coefficient vd16 of the sixteenth convex-concave spherical lens is 90.3;

[0071] The dispersion coefficient vd17 of the seventeenth convex-concave spherical lens is 90.3.

[0072] Optionally, the first convex-concave spherical lens, the second biconvex spherical lens, the third biconcave spherical lens, the fourth convex-concave spherical lens, the fifth concave-convex spherical lens, the sixth concave-convex spherical lens, the seventh biconvex spherical lens, the eighth biconcave spherical lens, the ninth biconvex spherical lens, the tenth biconvex spherical lens, the eleventh biconcave spherical lens, the twelfth biconvex spherical lens, the thirteenth convex-concave spherical lens, the fourteenth biconcave spherical lens, the fifteenth plano-convex spherical lens, the sixteenth convex-concave spherical lens, and the seventeenth convex-concave spherical lens are all made of glass.

[0073] Optionally, the total focal length of the fixed-focus optical system is f, and the total optical length of the fixed-focus optical system is TTL, wherein 0.05 < f / TTL < 0.06.

[0074] Optionally, the fixed-focus optical system further includes a filter and a photosensitive chip in sequence from the object side to the image side, with the filter and the photosensitive chip disposed on the side of the seventeenth convex-concave spherical lens closer to the image side.

[0075] The present invention also provides a photolithography objective lens, which includes the above-described fixed-focus optical system.

[0076] The present invention also provides a photolithography apparatus, the photolithography apparatus including the photolithography objective lens described above.

[0077] The technical solution provided by this invention comprises, from the object side to the image side, a first convex-concave spherical lens, a second biconvex spherical lens, a third biconcave spherical lens, a fourth convex-concave spherical lens, a fifth concave-convex spherical lens, a sixth concave-convex spherical lens, a seventh biconvex spherical lens, an eighth biconcave spherical lens, a ninth biconvex spherical lens, a tenth biconvex spherical lens, an eleventh biconcave spherical lens, a twelfth biconvex-concave spherical lens, a thirteenth convex-concave spherical lens, a fourteenth biconcave spherical lens, a fifteenth plano-convex spherical lens, a sixteenth convex-concave spherical lens, and a seventeenth convex-concave spherical lens. The first convex-concave spherical lens, with its large aperture, can collect more light information at the same focal length, achieving clear imaging in low light. Through the reasonable arrangement of seventeen lenses, the total optical length of the fixed-focus optical system can be controlled within 125mm, making the entire fixed-focus optical system compact and achieving an aperture number of 0.76. It also achieves dual-band imaging of 365±5nm / 590±30nm, providing a compact, large-aperture, ultraviolet / visible dual-band fixed-focus optical system. Attached Figure Description

[0078] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0079] Figure 1 This is a schematic diagram of the fixed-focus optical system provided by the present invention;

[0080] Figure 2 for Figure 1 MTF curve of the fixed-focus optical system in the 365±5nm band;

[0081] Figure 3 for Figure 1 MTF curve of the fixed-focus optical system in the 590±30nm band;

[0082] Figure 4 for Figure 1 A dot plot of the fixed-focus optical system in the 365±5nm band;

[0083] Figure 5 for Figure 1 A dot plot of the fixed-focus optical system in the 590±30nm band;

[0084] Figure 6 for Figure 1 The distortion / field curve of the fixed-focus optical system in the 365±5nm band;

[0085] Figure 7 for Figure 1 The distortion / field curve of the fixed-focus optical system in the 590±30nm band.

[0086] Explanation of icon numbers:

[0087] 101 First convex-concave spherical lens 110 Tenth biconvex spherical lens 102 Second biconvex spherical lens 111 Eleventh Biconcave Spherical Lens 103 Third biconcave spherical lens 112 Twelfth Biconvex Spherical Lens 104 Fourth convex-concave spherical lens 113 Thirteenth Convex-Concave Spherical Lens 105 Fifth concave-convex spherical lens 114 Fourteenth Biconcave Spherical Lens 106 Sixth concave-convex spherical lens 115 The fifteenth plano-convex spherical lens 107 Seventh biconvex spherical lens 116 Sixteenth Convex-Concave Spherical Lens 108 Eighth biconcave spherical lens 117 Seventeenth Convex-Concave Spherical Lens 109 Ninth Biconvex Spherical Lens

[0088] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0089] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0090] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0091] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0092] The further development of equipment in the field of photolithography has led to increasingly higher demands on photolithography lenses, which need to meet the requirements of ultraviolet lithography as well as have the ability to monitor and align visible light.

[0093] To address the aforementioned problems, this invention provides a fixed-focus optical system. Figures 1 to 7 This is a specific embodiment of the fixed-focus optical system provided by the present invention.

[0094] Please see Figure 1The fixed-focus optical system includes an object side and an image side arranged opposite each other along the optical axis. The fixed-focus optical system includes, from the object side to the image side, a first convex-concave spherical lens 101, a second biconvex spherical lens 102, a third biconcave spherical lens 103, a fourth convex-concave spherical lens 104, a fifth concave-convex spherical lens 105, a sixth concave-convex spherical lens 106, a seventh biconvex spherical lens 107, an eighth biconcave spherical lens 108, a ninth biconvex spherical lens 109, a tenth biconvex spherical lens 110, an eleventh biconcave spherical lens 111, a twelfth biconvex spherical lens 112, a thirteenth convex-concave spherical lens 113, and a fourteenth biconcave spherical lens 114. 4. A fifteenth plano-convex spherical lens 115, a sixteenth convex-concave spherical lens 116, and a seventeenth convex-concave spherical lens 117; wherein the concave surfaces of the first convex-concave spherical lens 101, the fourth convex-concave spherical lens 104, the sixth convex-concave spherical lens 106, the thirteenth convex-concave spherical lens 113, the sixteenth convex-concave spherical lens 116, and the seventeenth convex-concave spherical lens 117 are arranged facing the image side; the concave surface of the fifth convex-concave spherical lens 105 is arranged facing the object side; the convex surface of the fifteenth plano-convex spherical lens 115 is arranged facing the object side, the total optical length (TTL) of the fixed-focus optical system is ≤125mm, and the aperture number (F) of the fixed-focus optical system is 0.76.

[0095] In the technical solution provided by this invention, from the object side to the image side, a first convex-concave spherical lens 101, a second biconvex spherical lens 102, a third biconcave spherical lens 103, a fourth convex-concave spherical lens 104, a fifth concave-convex spherical lens 105, a sixth concave-convex spherical lens 106, a seventh biconvex spherical lens 107, an eighth biconcave spherical lens 108, a ninth biconvex spherical lens 109, a tenth biconvex spherical lens 110, an eleventh biconcave spherical lens 111, a twelfth biconvex spherical lens 112, a thirteenth convex-concave spherical lens 113, a fourteenth biconcave spherical lens 114, and a fifteenth plano-convex spherical lens 11 are sequentially arranged. 5. The sixteenth and seventeenth convex-concave spherical lenses 116 and 117, through the large aperture of the first convex-concave spherical lens 101, can collect more light information under the same focal length, achieving a clear imaging effect in low light. Through the reasonable arrangement of the seventeen lenses, the total optical length of the fixed-focus optical system can be controlled within 125mm, making the entire fixed-focus optical system compact in structure, and achieving an aperture size of 0.76, and realizing dual-band imaging of 365±5nm / 590±30nm, so as to provide a compact, large-aperture, ultraviolet / visible dual-band fixed-focus optical system.

[0096] It should be noted that the fixed-focus optical system is a dual-band objective lens. When photolithography is required, ultraviolet photolithography can be performed by connecting a tube with a diameter of 365±5nm to the fixed-focus optical system. When a tube with a diameter of 590±30nm and a camera are connected, it can be used as an imaging system to monitor the exposure surface and perform alignment functions. By adding a beam splitter between the objective lens and the tube, the above two functions can be achieved simultaneously.

[0097] Specifically, in this embodiment, the optical power of the first convex-concave spherical lens 101 is negative; the optical power of the second biconvex spherical lens 102 is positive; the optical power of the third biconcave spherical lens 103 is negative; the optical power of the fourth convex-concave spherical lens 104 is positive; the optical power of the fifth convex-concave spherical lens 105 is negative; the optical power of the sixth convex-concave spherical lens 106 is positive; the optical power of the seventh biconvex spherical lens 107 is positive; the optical power of the eighth biconcave spherical lens 108 is negative; and the optical power of the ninth biconvex spherical lens 104 is negative. The optical power of lens 109 is positive; the optical power of the tenth biconvex spherical lens 110 is positive; the optical power of the eleventh biconcave spherical lens 111 is negative; the optical power of the twelfth biconvex spherical lens 112 is positive; the optical power of the thirteenth convex-concave spherical lens 113 is positive; the optical power of the fourteenth biconcave spherical lens 114 is negative; the optical power of the fifteenth plano-convex spherical lens 115 is positive; the optical power of the sixteenth convex-concave spherical lens 116 is positive; and the optical power of the seventeenth convex-concave spherical lens 117 is positive.

[0098] More specifically, the optical power of the first convex-concave spherical lens is -38.861; the optical power of the second biconvex spherical lens is 24.088; the optical power of the third biconcave spherical lens is -28.458; the optical power of the fourth convex-concave spherical lens is 95.599; the optical power of the fifth convex-concave spherical lens is -16.532; the optical power of the sixth convex-concave spherical lens is 29.829; the optical power of the seventh biconvex spherical lens is 45.607; the optical power of the eighth biconcave spherical lens is -35.136; and the optical power of the ninth biconvex spherical lens is... The optical power of the lens is 47.465; the optical power of the tenth biconvex spherical lens is 55.774; the optical power of the eleventh biconcave spherical lens is -38.337; the optical power of the twelfth biconvex spherical lens is 53.643; the optical power of the thirteenth convex-concave spherical lens is 41.727; the optical power of the fourteenth biconcave spherical lens is -25.821; the optical power of the fifteenth plano-convex spherical lens is 31.7; the optical power of the sixteenth convex-concave spherical lens is 26.65; and the optical power of the seventeenth convex-concave spherical lens is 122.566. This allows the fixed-focus optical system to have a large aperture (F ≤ 0.76), resulting in greater light transmission compared to other products, and enabling clear imaging even in low light conditions.

[0099] Specifically, in this embodiment, the refractive index n1 of the first convex-concave spherical lens 101 is 1.49; the refractive index n2 of the second biconvex spherical lens 102 is 1.62; the refractive index n3 of the third biconcave spherical lens 103 is 1.52; the refractive index n4 of the fourth convex-concave spherical lens 104 is 1.62; the refractive index n5 of the fifth convex-concave spherical lens 105 is 1.62; the refractive index n6 of the sixth convex-concave spherical lens 106 is 1.46; the refractive index n7 of the seventh biconvex spherical lens 107 is 1.46; the refractive index n8 of the eighth biconcave spherical lens 108 is 1.62; and the refractive index n8 of the ninth biconvex spherical lens 109 is 1.49. The refractive index n9 = 1.46; the refractive index n10 of the tenth biconvex spherical lens 110 = 1.52; the refractive index n11 of the eleventh biconcave spherical lens 111 = 1.52; the refractive index n12 of the twelfth biconvex spherical lens 112 = 1.46; the refractive index n13 of the thirteenth convex-concave spherical lens 113 = 1.46; the refractive index n14 of the fourteenth biconcave spherical lens 114 = 1.46; the refractive index n15 of the fifteenth plano-convex spherical lens 115 = 1.46; the refractive index n16 of the sixteenth convex-concave spherical lens 116 = 1.46; and the refractive index n17 of the seventeenth convex-concave spherical lens 117 = 1.46.

[0100] Specifically, in optical lenses, the dispersion of light leads to undesirable chromatic aberration, resulting in blurring or a blurred effect or "color fringing" around the observed object. To ensure good image quality in the fixed-focus optical system, in this embodiment, the dispersion coefficients are as follows: the first convex-concave spherical lens 101 has a dispersion coefficient vd1 = 70.4; the second biconvex spherical lens 102 has a dispersion coefficient vd2 = 36.4; the third biconcave spherical lens 103 has a dispersion coefficient vd3 = 63.3; the fourth convex-concave spherical lens 104 has a dispersion coefficient vd4 = 36.4; the fifth convex-concave spherical lens 105 has a dispersion coefficient vd5 = 90.3; the sixth convex-concave spherical lens 106 has a dispersion coefficient vd6 = 90.3; the seventh biconvex spherical lens 107 has a dispersion coefficient vd7 = 36.4; and the eighth biconcave spherical lens 105 has a dispersion coefficient vd7 = 36.4. The dispersion coefficient vd8 of lens 108 is 90.3; the dispersion coefficient vd9 of the ninth biconvex spherical lens 109 is 90.3; the dispersion coefficient vd10 of the tenth biconvex spherical lens 110 is 63.3; the dispersion coefficient vd11 of the eleventh biconcave spherical lens 111 is 63.3; the dispersion coefficient vd12 of the twelfth biconvex spherical lens 112 is 90.3; the dispersion coefficient vd13 of the thirteenth convex-concave spherical lens 113 is 90.3; the dispersion coefficient vd14 of the fourteenth biconcave spherical lens 114 is 67.8; the dispersion coefficient vd15 of the fifteenth plano-convex spherical lens 115 is 90.3; the dispersion coefficient vd16 of the sixteenth convex-concave spherical lens 116 is 90.3; and the dispersion coefficient vd17 of the seventeenth convex-concave spherical lens 117 is 90.3. The dispersion coefficient is used to measure the degree of light dispersion in a transparent medium. The Abbe number is an index used to represent the dispersion ability of a transparent medium. The larger the dispersion coefficient (Abbe number), the less obvious the dispersion, and the better the image quality of the lens. In this embodiment, the dispersion coefficients of each lens are controlled at a high value, so that the dispersion of the fixed-focus optical system is not obvious and the image quality of the lens is good.

[0101] Specifically, in order to ensure good stability of the fixed-focus optical system, in this embodiment, the first convex-concave spherical lens 101, the second biconvex spherical lens 102, the third biconcave spherical lens 103, the fourth convex-concave spherical lens 104, the fifth concave-convex spherical lens 105, the sixth concave-convex spherical lens 106, the seventh biconvex spherical lens 107, the eighth biconcave spherical lens 108, the ninth biconvex spherical lens 109, the tenth biconvex spherical lens 110, the eleventh biconcave spherical lens 111, the twelfth biconvex spherical lens 112, the thirteenth convex-concave spherical lens 113, the fourteenth biconcave spherical lens 114, the fifteenth plano-convex spherical lens 115, the sixteenth convex-concave spherical lens 116, and the seventeenth convex-concave spherical lens 117 are all made of glass. In this way, by rationally allocating the lens power and considering the thermal expansion coefficient of the glass material, the lens can achieve clear imaging in an environment of 20±1℃, ensuring the high yield of processing and assembly, and further reducing costs.

[0102] Specifically, the total focal length of the fixed-focus optical system is f, and the total optical length of the fixed-focus optical system is TTL, where 0.05 < f / TTL < 0.06. This configuration satisfies the trend of lens miniaturization.

[0103] Specifically, the fixed-focus optical system further includes a filter and a photosensitive chip in sequence from the object side to the image side, and the filter and the photosensitive chip are disposed on the side of the seventeenth convex-concave spherical lens 117 near the image side.

[0104] It is understood that the surface of the photosensitive chip facing the object is the imaging surface.

[0105] The filter is located between the seventeenth convex-concave spherical lens 117 and the imaging surface. The filter can effectively filter out stray light in non-working wavelength bands to reduce optical noise, reduce difficulties for subsequent optoelectronic module processing, and thus improve imaging quality.

[0106] Specifically, the imaging surface can be understood as the surface of the photosensitive chip facing the object, that is, the surface of a camera element such as a CCD or CMOS. It is understood that the light carrying information about the object being photographed can sequentially pass through the first convex-concave spherical lens 101, the second biconvex spherical lens 102, the third biconcave spherical lens 103, the fourth convex-concave spherical lens 104, the fifth concave-convex spherical lens 105, the sixth concave-convex spherical lens 106, and the seventh biconvex spherical lens. The lens 107, the eighth biconcave spherical lens 108, the ninth biconvex spherical lens 109, the tenth biconvex spherical lens 110, the eleventh biconcave spherical lens 111, the twelfth biconvex spherical lens 112, the thirteenth convex-concave spherical lens 113, the fourteenth biconcave spherical lens 114, the fifteenth plano-convex spherical lens 115, the sixteenth convex-concave spherical lens 116, the seventeenth convex-concave spherical lens 117, and the filter are all used to finally image the light onto the imaging surface.

[0107] Specifically, in this embodiment, the surface shape, radius of curvature, and thickness interval of the lens are shown in the table below:

[0108]

[0109]

[0110] Furthermore, in this embodiment, the first convex-concave spherical lens 101, the second biconvex spherical lens 102, the third biconcave spherical lens 103, the fourth convex-concave spherical lens 104, the fifth concave-convex spherical lens 105, the sixth concave-convex spherical lens 106, the seventh biconvex spherical lens 107, the eighth biconcave spherical lens 108, the ninth biconvex spherical lens 109, the tenth biconvex spherical lens 110, the eleventh biconcave spherical lens 111, the twelfth biconvex spherical lens 112, the thirteenth convex-concave spherical lens 113, the fourteenth biconcave spherical lens 114, the fifteenth plano-convex spherical lens 115, the sixteenth convex-concave spherical lens 116, and the seventeenth convex-concave spherical lens 117 are all spherical lenses. Because the reflection of spherical lenses follows the law of reflection of light, they can converge or diverge light. Furthermore, by using spherical lenses, which are easy to process, costs can be greatly reduced and processing difficulty can be lowered. Under the premise of ensuring image quality and reliability, the assembly sensitivity is low, which improves the yield of finished products.

[0111] Figures 2 to 3 The MTF curves of the fixed-focus optical system in the 365±5nm and 590±30nm wavelength bands are displayed respectively. Figures 4 to 5 The dot plots of the fixed-focus optical system in the 365±5nm and 590±30nm wavelength bands are shown respectively. Figures 6 to 7The distortion and field curvature of the fixed-focus optical system are shown in the 365±5nm and 590±30nm bands, respectively.

[0112] As can be seen from the above figures, the spherical aberration, field curvature, and distortion of the fixed-focus optical system in this embodiment can all be well corrected.

[0113] In summary, the fixed-focus optical system can achieve the maximum effective optical diameter. The total optical length is no more than 125mm; entrance pupil diameter: 9.68mm; numerical aperture (NA): 0.7; exposure / observation area: 0.67mm × 0.67mm; achieving dual-band wavelengths: 365±5nm / 590±30nm. When photolithography is required, ultraviolet lithography can be performed by connecting a 365±5nm diameter tube to the fixed-focus optical system. When connected to a 590±30nm diameter tube and a camera, it can function as an imaging system for monitoring and aligning the exposure surface. Adding a beam splitter between the objective lens and the tube allows for the simultaneous implementation of both functions.

[0114] Furthermore, the present invention also provides a lithography objective lens, which includes the fixed-focus optical system described in the above technical solutions. Since the lithography objective lens includes the fixed-focus optical system, the specific structure of which is described in the above embodiments. As the fixed-focus optical system of the lithography objective lens adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0115] The present invention also provides a lithography apparatus, wherein the lithography objective lens includes the lithography objective lens described in the above technical solution. Since the lithography objective lens includes the lithography objective lens, the specific structure of the lithography objective lens is as described in the above embodiments. Since the lithography objective lens of this lithography objective lens adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0116] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A fixed-focus optical system, characterized in that, The fixed-focus optical system has an object side and an image side arranged opposite to each other along the optical axis. The fixed-focus optical system includes a first convex-concave spherical lens, a second biconvex spherical lens, a third biconcave spherical lens, a fourth convex-concave spherical lens, a fifth concave-convex spherical lens, a sixth concave-convex spherical lens, a seventh biconvex spherical lens, an eighth biconcave spherical lens, a ninth biconvex spherical lens, a tenth biconvex spherical lens, an eleventh biconcave spherical lens, a twelfth biconvex spherical lens, a thirteenth convex-concave spherical lens, a fourteenth biconcave spherical lens, a fifteenth plano-convex spherical lens, a sixteenth convex-concave spherical lens, and a seventeenth convex-concave spherical lens arranged sequentially from the object side to the image side. In this system, the concave surfaces of the first, fourth, sixth, thirteenth, sixteenth, and seventeenth convex-concave spherical lenses face the image side; the concave surface of the fifth convex-concave spherical lens faces the object side; and the convex surface of the fifteenth plano-convex spherical lens faces the object side. The total optical length (TTL) of the fixed-focus optical system is ≤125mm, and the aperture number (F) of the fixed-focus optical system is 0.

76.

2. The fixed-focus optical system as described in claim 1, characterized in that, The optical power of the first convex-concave spherical lens is negative; The optical power of the second biconvex spherical lens is positive; The optical power of the third biconcave spherical lens is negative; The optical power of the fourth convex-concave spherical lens is positive. The optical power of the fifth concave-convex spherical lens is negative; The optical power of the sixth concave-convex spherical lens is positive; The optical power of the seventh biconvex spherical lens is positive. The optical power of the eighth biconcave spherical lens is negative; The optical power of the ninth biconvex spherical lens is positive. The optical power of the tenth biconvex spherical lens is positive. The optical power of the eleventh biconcave spherical lens is negative; The optical power of the twelfth biconvex spherical lens is positive. The optical power of the thirteenth convex-concave spherical lens is positive. The optical power of the fourteenth biconcave spherical lens is negative; The optical power of the fifteenth plano-convex spherical lens is positive. The optical power of the sixteenth convex-concave spherical lens is positive. The optical power of the seventeenth convex-concave spherical lens is positive.

3. The fixed-focus optical system as described in claim 1, characterized in that, The optical power of the first convex-concave spherical lens is -38.861; The optical power of the second biconvex spherical lens is 24.088; The optical power of the third biconcave spherical lens is -28.458; The optical power of the fourth convex-concave spherical lens is 95.

599. The optical power of the fifth concave-convex spherical lens is -16.532; The optical power of the sixth concave-convex spherical lens is 29.829; The optical power of the seventh biconvex spherical lens is 45.607; The optical power of the eighth biconcave spherical lens is -35.136; The optical power of the ninth biconvex spherical lens is 47.465; The optical power of the tenth biconvex spherical lens is 55.774; The optical power of the eleventh biconcave spherical lens is -38.

337. The optical power of the twelfth biconvex spherical lens is 53.643; The optical power of the thirteenth convex-concave spherical lens is 41.727; The optical power of the fourteenth biconcave spherical lens is -25.821; The optical power of the fifteenth plano-convex spherical lens is 31.7; The optical power of the sixteenth convex-concave spherical lens is 26.65; The optical power of the seventeenth convex-concave spherical lens is 122.

566.

4. The fixed-focus optical system as described in claim 1, characterized in that, The refractive index of the first convex-concave spherical lens is n1 = 1.49; The refractive index of the second biconvex spherical lens is n2 = 1.62; The refractive index of the third biconcave spherical lens is n3 = 1.52; The refractive index of the fourth convex-concave spherical lens is n4 = 1.62; The refractive index of the fifth concave-convex spherical lens is n5 = 1.62; The refractive index of the sixth concave-convex spherical lens is n6 = 1.46; The refractive index of the seventh biconvex spherical lens is n7 = 1.46; The refractive index of the eighth biconcave spherical lens is n8 = 1.62; The refractive index of the ninth biconvex spherical lens is n9 = 1.46; The refractive index of the tenth biconvex spherical lens is n10 = 1.52; The refractive index of the eleventh biconcave spherical lens is n11 = 1.52; The refractive index of the twelfth biconvex spherical lens is n12 = 1.46; The refractive index of the thirteenth convex-concave spherical lens is n13 = 1.46; The refractive index of the fourteenth biconcave spherical lens is n14 = 1.46; The refractive index of the fifteenth plano-convex spherical lens is n15 = 1.46; The refractive index of the sixteenth convex-concave spherical lens is n16 = 1.46; The refractive index of the seventeenth convex-concave spherical lens is n17 = 1.

46.

5. The fixed-focus optical system as described in claim 1, characterized in that, The dispersion coefficient of the first convex-concave spherical lens is vd1 = 70.4; The dispersion coefficient of the second biconvex spherical lens is vd2 = 36.4; The dispersion coefficient of the third biconcave spherical lens is vd3 = 63.3; The dispersion coefficient of the fourth convex-concave spherical lens is vd4 = 36.4; The dispersion coefficient vd5 of the fifth concave-convex spherical lens is 90.3; The dispersion coefficient vd6 of the sixth concave-convex spherical lens is 90.3; The dispersion coefficient of the seventh biconvex spherical lens is vd7 = 36.4; The dispersion coefficient vd8 of the eighth biconcave spherical lens is 90.

3. The dispersion coefficient vd9 of the ninth biconvex spherical lens is 90.

3. The dispersion coefficient vd10 of the tenth biconvex spherical lens is 63.3; The dispersion coefficient vd11 of the eleventh biconcave spherical lens is 63.3; The dispersion coefficient vd12 of the twelfth biconvex spherical lens is 90.

3. The dispersion coefficient vd13 of the thirteenth convex-concave spherical lens is 90.

3. The dispersion coefficient vd14 of the fourteenth biconcave spherical lens is 67.8; The dispersion coefficient vd15 of the fifteenth plano-convex spherical lens is 90.

3. The dispersion coefficient vd16 of the sixteenth convex-concave spherical lens is 90.3; The dispersion coefficient vd17 of the seventeenth convex-concave spherical lens is 90.

3.

6. The fixed-focus optical system as described in claim 1, characterized in that, The first convex-concave spherical lens, the second biconvex spherical lens, the third biconcave spherical lens, the fourth convex-concave spherical lens, the fifth concave-convex spherical lens, the sixth concave-convex spherical lens, the seventh biconvex spherical lens, the eighth biconcave spherical lens, the ninth biconvex spherical lens, the tenth biconvex spherical lens, the eleventh biconcave spherical lens, the twelfth biconvex spherical lens, the thirteenth convex-concave spherical lens, the fourteenth biconcave spherical lens, the fifteenth plano-convex spherical lens, the sixteenth convex-concave spherical lens, and the seventeenth convex-concave spherical lens are all made of glass.

7. The fixed-focus optical system as described in claim 1, characterized in that, The total focal length of the fixed-focus optical system is f, and the total optical length of the fixed-focus optical system is TTL, where 0.05 < f / TTL < 0.

06.

8. The fixed-focus optical system as described in claim 1, characterized in that, The fixed-focus optical system further includes a filter and a photosensitive chip in sequence from the object side to the image side. The filter and the photosensitive chip are located on the side of the seventeenth convex-concave spherical lens closer to the image side.

9. A photolithography objective lens, characterized in that, Includes the fixed-focus optical system as described in any one of claims 1 to 8.

10. A photolithography apparatus, characterized in that, The photolithography objective lens as described in claim 9.

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