A fiber lithography objective lens for laser direct writing

Abstract

This specification discloses a fiber optic lithography objective lens for laser direct writing. The objective lens includes: a first lens group with negative optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first lens group contains four lenses with optical powers sequentially arranged as positive, negative, negative, and positive; the second lens group contains three lenses with optical powers sequentially arranged as negative, positive, and negative; and the third lens group contains four lenses with optical powers sequentially arranged as positive, negative, positive, and positive. The first lens group receives the light source and refracts it to the second lens group. The second lens group collects the light emitted from the first lens group and refracts the collected light to the third lens group. The third lens group focuses the light onto the substrate. All lenses in the objective lens are aligned on the same optical axis. The objective lens in this specification can correct various aberrations, particularly distortion, field curvature, astigmatism, axial chromatic aberration, and magnification chromatic aberration.

Description

Technical Field

[0001] The present specification relates to the field of optical system design in micro-nano device processing and production equipment, and in particular to a fiber lithography objective lens for laser direct writing. Background Art

[0002] Laser direct writing is a technology for processing micro-nano components. It uses a laser beam to perform variable dose exposure on the resist material on the surface of the substrate. After development, the required relief profile is formed on the surface of the resist layer.

[0003] The fiber array laser direct writing system has the advantages of simple structure, high resolution, high direct writing efficiency, and the ability to directly write any graphics.

[0004] Currently, in the fiber array laser direct writing system, there may be large aberrations, such as distortion, field curvature, etc., so how to correct the aberrations is an urgent problem to be solved. Summary of the invention

[0005] This specification provides a fiber lithography objective lens for laser direct writing to partially solve the above-mentioned problems existing in the prior art.

[0006] This manual adopts the following technical solutions:

[0007] The present specification provides an objective lens for optical fiber lithography for laser direct writing, the objective lens comprising: a first lens group, a second lens group and a third lens group, the first lens group comprising a first lens, a second lens, a third lens and a fourth lens arranged in the order of incident light, the focal powers of the lenses in the first lens group are: the focal power of the first lens is positive, the focal power of the second lens is negative, the focal power of the third lens is negative, the focal power of the fourth lens is positive, the focal power of the first lens group as a whole is negative, a positive focal power indicates a convergence effect on the incident light, and a negative focal power indicates a divergence effect on the incident light:

[0008] The second lens group includes a fifth lens, a sixth lens and a seventh lens arranged in the order of incident light, the optical power of each lens in the second lens group is as follows: the optical power of the fifth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative, and the optical power of the second lens group as a whole is negative;

[0009] The third lens group includes an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in the order of incident light, the focal powers of the lenses in the third lens group are as follows: the focal power of the eighth lens is positive, the focal power of the ninth lens is negative, the focal power of the tenth lens is positive, and the focal power of the eleventh lens is positive, the aperture is located on the rear surface of the sixth lens, and the focal power of the third lens group as a whole is positive;

[0010] The first lens group receives a light source and refracts the light source to the second lens group. The second lens group collects light emitted from the first lens group and refracts the collected light to the third lens group. The third lens group focuses the light on the substrate. The lenses in the objective lens are on the same optical axis.

[0011] Optionally, the magnification of the objective lens is β=-0.125x.

[0012] Optionally, the light source is sent to the first lens group through a tube lens with a focal length of 200 mm.

[0013] Optionally, the bandwidth of the objective lens is 405nm±2nm, the object numerical aperture NA=0.9, the object field of view Φ=0.8mm, the theoretical resolution is σ=0.275μm, and each lens included in the objective lens is coated with an anti-reflection film of the bandwidth.

[0014] Optionally, the first lens is a biconvex lens, the second lens is a biconcave lens, the third lens is a biconcave lens, the fourth lens is a biconvex lens, the first lens and the second lens form a glued lens group, and the third lens and the fourth lens form a glued lens group.

[0015] Optionally, the fifth lens is a meniscus lens with its concave surface facing the substrate, the sixth lens is a biconvex lens, the seventh lens is a meniscus lens with its concave surface facing the light-emitting surface of the optical fiber, and the fifth lens, the sixth lens and the seventh lens form a cemented lens group.

[0016] Optionally, the eighth lens is a biconvex lens, the ninth lens is a meniscus lens with its concave surface facing the optical fiber light-emitting surface, the tenth lens is a meniscus lens with its concave surface facing the optical fiber light-emitting surface, the eleventh lens is a meniscus lens with its concave surface facing the base, and the eighth lens and the ninth lens form a cemented lens group.

[0017] Optionally, the refractive index range of the first lens is: (1.59, 1.63), the refractive index range of the second lens is: (1.74, 1.78), the refractive index range of the third lens is: (1.73, 1.77), and the refractive index range of the fourth lens is: (1.50, 1.54).

[0018] Optionally, the refractive index of the fifth lens is in the range of (1.79, 1.83), the refractive index of the sixth lens is in the range of (1.45, 1.49), and the refractive index of the seventh lens is in the range of (1.78, 1.82).

[0019] Optionally, the refractive index of the eighth lens is in the range of (1.70, 1.74), the refractive index of the ninth lens is in the range of (1.78, 1.82), the refractive index of the tenth lens is in the range of (1.63, 1.67), and the refractive index of the eleventh lens is in the range of (1.60, 1.64).

[0020] Optionally, the Abbe number of the first lens is in the range of (31.8, 34.8), the Abbe number of the second lens is in the range of (50.2, 54.2), the Abbe number of the third lens is in the range of (64.9, 68.9), and the Abbe number of the fourth lens is in the range of (92.6, 94.6).

[0021] Optionally, the Abbe number of the fifth lens is in the range of (33.9, 37.9), the Abbe number of the sixth lens is in the range of (46.9, 50.9), and the Abbe number of the seventh lens is in the range of (58.8, 62.8).

[0022] Optionally, the Abbe number of the eighth lens is in the range of (88.5, 92.5), the Abbe number of the ninth lens is in the range of (88.5, 92.5), the Abbe number of the tenth lens is in the range of (92.6, 96.6), and the Abbe number of the eleventh lens is in the range of (63.5, 67.5).

[0023] Optionally, the lens in the objective lens satisfies the following relationship:

[0024] 0.5 <f / epd<0.6,

[0025] 0.05 <bfl / f<0.08,

[0026] 0.52 <fno<0.58,

[0027] ttl<200mm,

[0028] 0.85° <fov<1.15°,

[0029] Among them, f is the focal length of the objective lens, epd is the entrance pupil diameter, bfl is the distance between the vertex of the back surface of the last lens and the base, fno is the aperture number of the objective lens, ttl is the distance from the object side of the first lens in the first lens group to the image plane of the objective lens, and fov is the maximum half field of view angle range of the objective lens.

[0030] The present specification provides a photolithography machine, which is used for performing laser direct writing on a photoresist by means of a laser, and the above-mentioned objective lens is provided on the photolithography machine.

[0031] At least one of the above technical solutions adopted in this specification can achieve the following beneficial effects:

[0032] It can be seen from the above-mentioned fiber lithography objective lens for laser direct writing that the objective lens may include: a first lens group with negative optical focal length, a second lens group with negative optical focal length, and a third lens group with positive optical focal length, the first lens group includes four lenses with optical focal lengths of positive, negative, negative, and positive, respectively; the second lens group includes three lenses with optical focal lengths of negative, positive, and negative, respectively; the third lens group includes four lenses with optical focal lengths of positive, negative, positive, and positive, respectively; the first lens group is responsible for receiving the light source and refracting the light source to the second lens group, the second lens group collects the light emitted from the first lens group and refracts the collected light to the third lens group, the third lens group focuses the light on the substrate, and the lenses in the objective lens are all on the same optical axis.

[0033] It can be seen from the above content that the objective lens provided in this specification is composed of three lens groups, and the optical focal powers of these three lens groups are negative, negative, and positive respectively. Each lens group is composed of multiple lenses. The objective lens provided in this specification can correct various aberrations, especially distortion, field curvature, astigmatism, axial chromatic aberration, and magnification chromatic aberration. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of a fiber lithography objective lens for laser direct writing provided in this specification;

[0036] Figure 2 A theoretical composite light diffraction MTF curve of the central field of view of a fiber lithography objective lens for laser direct writing provided in this specification;

[0037] Figure 3 This is an MTF curve diagram of a fiber lithography objective lens for laser direct writing provided in this specification;

[0038] Figure 4 This is an aberration curve diagram of a fiber lithography objective lens for laser direct writing provided in this specification. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this specification more clear, the technical solutions of this specification will be clearly and completely described below in combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0040] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings.

[0041] The optical fiber lithography objective lens for laser direct writing in this specification can be applied to a photolithography machine for laser direct writing, wherein in the photolithography machine, a fiber laser with a wavelength of 405 can be used as a light source (wavelength λ), and the output light source of the fiber laser can be output by dozens or even hundreds of single-mode optical fibers after being split by an optical fiber beam splitter. The optical fibers are closely arranged to form an optical fiber array, and the dot matrix formed by the optical fiber array port is collimated by a collimator (tube lens) to form a dot matrix image on the focal plane of the direct writing objective lens, thereby entering the objective lens system, and passing through the objective lens in this specification, a -0.125 times reduced image is formed on the image plane (silicon wafer with uniform photoresist) for laser direct writing.

[0042] Figure 1 A schematic structural diagram of a fiber lithography objective lens for laser direct writing provided in this specification includes: a first lens group G1 with negative focal power, a second lens group G2 with negative focal power, and a third lens group G3 with positive focal power, which are arranged from the incident direction of light, wherein, according to the incident direction of light, the first lens group includes four lenses (first lens, second lens, second lens, and fourth lens) with focal powers of positive, negative, negative, and positive in sequence; the second lens group includes three lenses (fifth lens, sixth lens, and seventh lens) with focal powers of negative, positive, and negative in sequence; the third lens group includes four lenses (eighth lens, ninth lens, tenth lens, and eleventh lens) with focal powers of positive, negative, positive, and positive in sequence;

[0043] The first lens group can receive a light source and refract the light source to the second lens group. The second lens group collects light emitted from the first lens group and refracts the collected light to the third lens group. The third lens group focuses the light on the substrate. The lenses in the objective lens are all on the same optical axis, and the aperture is located on the rear surface of the sixth lens.

[0044] Furthermore, the magnification of the objective lens in this specification is β=-0.125x, that is, it is reduced by 8 times, and is matched with a tube lens with a focal length of 200mm.

[0045] Furthermore, the bandwidth of the objective lens in this specification can be 405nm±1nm, the material can be glass material produced by Chengdu Guangming, and all lenses are coated with anti-reflection film under this band, the object side numerical aperture is NA=0.9, the object side field of view is Φ0.8mm, and the theoretical resolution is σ=0.275μm.

[0046] Furthermore, the first lens L1 in the first lens group G1 is a biconvex lens, the second lens L2 is a biconcave lens, the third lens L3 is a biconcave lens, and the fourth lens L4 is a biconvex lens. The first lens L1 and the second lens L2 form a cemented lens group, and the third lens L3 and the fourth lens L4 form a cemented lens group.

[0047] Furthermore, the fifth lens L5 in the second lens group G2 is a meniscus lens with its concave surface facing the substrate, the sixth lens L6 is a biconvex lens, and the seventh lens L7 is a meniscus lens with its concave surface facing the light emitting surface of the optical fiber (i.e., the concave surface faces the light source). The fifth lens L5, the sixth lens L6 and the seventh lens L7 form a cemented lens group.

[0048] Further, the eighth lens L8 in the third lens group G3 is a biconvex lens, the ninth lens L9 is a meniscus lens with its concave surface facing the light emitting surface of the optical fiber (i.e., the concave surface facing the light source), the tenth lens L10 is a meniscus lens with its concave surface facing the light emitting surface of the optical fiber (i.e., the concave surface facing the light source), the eleventh lens L11 is a meniscus lens with its concave surface facing the base, and the eighth lens L8 and the ninth lens L9 form a cemented lens group.

[0049] In the above objective lens: the refractive index range of the first lens L1 is: (1.59, 1.63), the refractive index range of the second lens L2 is: (1.74, 1.78), the refractive index range of the third lens L3 is: (1.73, 1.77), and the refractive index range of the fourth lens L4 is: (1.50, 1.54).

[0050] The refractive index of the fifth lens L5 is in the range of (1.79, 1.83), the refractive index of the sixth lens L6 is in the range of (1.45, 1.49), and the refractive index of the seventh lens L7 is in the range of (1.78, 1.82).

[0051] The refractive index of the eighth lens L8 is in the range of (1.70, 1.74), the refractive index of the ninth lens L9 is in the range of (1.78, 1.82), the refractive index of the tenth lens L10 is in the range of (1.63, 1.67), and the refractive index of the eleventh lens L11 is in the range of (1.60, 1.64).

[0052] That is, each lens in this specification satisfies the following relationship:

[0053] 1.59 <n11<1.63,

[0054] 1.74 <n12<1.78,

[0055] 1.73 <n13<1.77,

[0056] 1.50 <n14<1.54,

[0057] 1.79 <n21<1.83,

[0058] 1.45 <n22<1.49,

[0059] 1.78 <n23<1.82,

[0060] 1.70 <n31<1.74,

[0061] 1.78 <n32<1.82,

[0062] 1.63 <n33<1.67,

[0063] 1.60 <n34<1.64,

[0064] Wherein, n11 is the refractive index of the first lens L1 of the first lens group G1, n12 is the refractive index of the second lens L2 of the first lens group G1, n13 is the refractive index of the third lens L3 of the first lens group G1, n14 is the refractive index of the fourth lens L4 of the first lens group G1, n21 is the refractive index of the first lens L5 of the second lens group G2, n22 is the refractive index of the second lens L6 of the second lens group G2, n23 is the refractive index of the third lens L7 of the second lens group G2, n31 is the refractive index of the first lens L8 of the third lens group G3, n32 is the refractive index of the second lens L9 of the third lens group G3, n33 is the refractive index of the third lens L10 of the third lens group G3, and n34 is the refractive index of the fourth lens L11 of the third lens group G3.

[0065] Further, the Abbe number of the first lens L1 may be in the range of (31.8, 34.8), the Abbe number of the second lens L2 may be in the range of (50.2, 54.2), the Abbe number of the third lens L3 may be in the range of (64.9, 68.9), and the Abbe number of the fourth lens L4 may be in the range of (92.6, 94.6).

[0066] The Abbe number of the fifth lens L5 may be in the range of (33.9, 37.9), the Abbe number of the sixth lens L6 may be in the range of (46.9, 50.9), and the Abbe number of the seventh lens L7 may be in the range of (58.8, 62.8).

[0067] The Abbe number of the eighth lens L8 may be in the range of (88.5, 92.5), the Abbe number of the ninth lens L9 may be in the range of (88.5, 92.5), the Abbe number of the tenth lens L10 may be in the range of (92.6, 96.6), and the Abbe number of the eleventh lens L11 may be in the range of (63.5, 67.5).

[0068] That is, the above objective lens also satisfies the following relationship:

[0069] 31.8 <v11<34.8,

[0070] 50.2 <v12<54.2,

[0071] 64.9 <v13<68.9,

[0072] 92.6 <v14<94.6,

[0073] 33.9 <v21<37.9,

[0074] 46.9 <v22<50.9,

[0075] 58.8 <v23<62.8,

[0076] 88.5 <v31<92.5,

[0077] 88.5 <v32<92.5,

[0078] 92.6 <v33<96.6,

[0079] 63.5 <v34<67.5,

[0080] Wherein, v11 is the Abbe number of the first lens L1 in the first lens group G1, v12 is the Abbe number of the second lens L2 in the first lens group G1, v13 is the Abbe number of the third lens L3 in the first lens group G1, v14 is the Abbe number of the fourth lens L4 in the first lens group G1, v21 is the Abbe number of the first lens L5 in the second lens group G2, v22 is the Abbe number of the second lens L6 in the second lens group G2, v23 is the Abbe number of the third lens L7 in the second lens group G2, v31 is the Abbe number of the first lens L8 in the third lens group G3, v32 is the Abbe number of the second lens L9 in the third lens group G3, v33 is the Abbe number of the third lens L10 in the third lens group G3, and v34 is the Abbe number of the fourth lens L11 in the third lens group G3.

[0081] Furthermore, the objective lens in this specification also satisfies the following relationship:

[0082] 0.5 <f / epd<0.6,

[0083] 0.05 <bfl / f<0.08,

[0084] 0.52 <fno<0.58,

[0085] ttl<200mm,

[0086] 0.85° <fov<1.15°,

[0087] Among them, f is the focal length of the objective lens, epd is the entrance pupil diameter; bfl is the distance between the back surface vertex (close to the substrate direction) of the last lens L11 and the substrate; fno is the aperture number of the objective lens; ttl is the distance from the object side surface (DMD direction) of the first lens L1 of the first lens group G1 to the image plane (substrate direction) of the objective lens; FOV is the maximum half field of view angle range of the objective lens.

[0088] In the present invention, the image side numerical aperture NA of the lens is 0.9. According to the formula σ=(Kλ) / NA, K is 0.61, and the theoretical resolution σ of the lens can reach 0.275 um (K is a process coefficient factor).

[0089] During assembly, the air gap between lenses and the thickness of the lenses need to be fine-tuned to adjust the image quality deviation caused by surface processing and ensure that the imaging quality of the objective lens is optimal.

[0090] The parameters of the objective lens of the present invention can be shown in Table 1.

[0091]

[0092] Table 1: Parameters of the photolithography objective lens of the present invention

[0093] In practice, the objective lens can be simulated by simulation software according to the composition and parameters of the objective lens set above. It can be determined that after implementing this embodiment according to the above scheme, the image quality of the objective lens is relatively close to the theoretical calculation result.

[0094] like Figure 2 As shown, the theoretical diffraction-limited MTF curve of the objective lens is obtained through simulation analysis using the software ZEMAX.

[0095] like Figure 3 As shown in the figure, the theoretical composite light diffraction MTF curve of the central field of view of the objective lens is obtained by simulation analysis using the software ZEMAX. Figure 2 The diffraction limit is close, with the maximum MTF difference from the diffraction limit being less than 1%.

[0096] like Figure 4As shown, the theoretical field curvature (left) and F-tan (Theta) distortion curve (right) of the objective lens are obtained through simulation analysis using the software ZEMAX, wherein the meridian field curvature of the objective lens is 1um, the sagittal field curvature is 3um, and the maximum distortion is about 0.0850%.

[0097] The above specific implementation methods and results are not the best embodiment of the performance of the present invention, but all evaluation indicators have reached the design expectations.

[0098] This specification also provides a photolithography machine, which is used to perform laser direct writing on photoresist using a laser. The above-mentioned objective lens can be set on the photolithography machine. Since the process of performing laser direct writing using the objective lens has been explained in the above content, it will not be repeated here.

[0099] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0100] The above description is only an embodiment of the present specification and is not intended to limit the present specification. For those skilled in the art, the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present specification shall be included in the scope of the claims of the present specification.

Claims

1. A fiber lithography objective lens for laser direct writing, characterized in that: The objective lens comprises: a first lens group, a second lens group and a third lens group, the first lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in the order of incident light, the focal powers of the lenses in the first lens group are: the focal power of the first lens is positive, the focal power of the second lens is negative, the focal power of the third lens is negative, and the focal power of the fourth lens is positive, the focal power of the first lens group as a whole is negative, a positive focal power indicates a convergence effect on the incident light, and a negative focal power indicates a divergence effect on the incident light; The second lens group includes a fifth lens, a sixth lens and a seventh lens arranged in the order of incident light, the optical power of each lens in the second lens group is as follows: the optical power of the fifth lens is negative, the optical power of the sixth lens is positive, and the optical power of the seventh lens is negative, and the optical power of the second lens group as a whole is negative; The third lens group includes an eighth lens, a ninth lens, a tenth lens and an eleventh lens arranged in the order of incident light, and the focal powers of the lenses in the third lens group are as follows: the focal power of the eighth lens is positive, the focal power of the ninth lens is negative, the focal power of the tenth lens is positive, and the focal power of the eleventh lens is positive, and the focal power of the third lens group as a whole is positive; The first lens group receives a light source and refracts the light source to the second lens group, the second lens group collects light emitted from the first lens group and refracts the collected light to the third lens group, and the third lens group focuses the light on the substrate. The lenses in the objective lens are on the same optical axis, and the aperture is located on the rear surface of the sixth lens.

2. The optical fiber lithography objective lens according to claim 1, characterized in that: The magnification of the objective lens β=-0.125x.

3. The optical fiber lithography objective lens according to claim 1, characterized in that: The light source is sent to the first lens group through a tube lens with a focal length of 200 mm.

4. The optical fiber lithography objective lens according to claim 1, characterized in that: The bandwidth of the objective lens is 405nm±2nm, the object numerical aperture NA=0.9, the object field of view Φ=0.8mm, the theoretical resolution σ=0.275μm, and each lens included in the objective lens is coated with an anti-reflection film of the bandwidth.

5. The optical fiber lithography objective lens according to claim 1, characterized in that: The first lens is a biconvex lens, the second lens is a biconcave lens, the third lens is a biconcave lens, the fourth lens is a biconvex lens, the first lens and the second lens form a glued lens group, and the third lens and the fourth lens form a glued lens group.

6. The optical fiber lithography objective lens according to claim 1, characterized in that: The fifth lens is a meniscus lens with its concave surface facing the substrate, the sixth lens is a biconvex lens, the seventh lens is a meniscus lens with its concave surface facing the optical fiber light-emitting surface, and the fifth lens, the sixth lens and the seventh lens form a cemented lens group.

7. The optical fiber lithography objective lens according to claim 1, characterized in that: The eighth lens is a biconvex lens, the ninth lens is a meniscus lens with its concave surface facing the optical fiber light-emitting surface, the tenth lens is a meniscus lens with its concave surface facing the optical fiber light-emitting surface, the eleventh lens is a meniscus lens with its concave surface facing the base, and the eighth lens and the ninth lens form a cemented lens group.

8. The optical fiber lithography objective lens according to claim 1, characterized in that: The refractive index n11 of the first lens ranges from 1.59 < n11 < 1.63, the refractive index n12 of the second lens ranges from 1.74 < n12 < 1.78, the refractive index n13 of the third lens ranges from 1.73 < n13 < 1.77, and the refractive index n14 of the fourth lens ranges from 1.50 < n14 < 1.

54.

9. The optical fiber lithography objective lens according to claim 1, characterized in that: The refractive index n21 of the fifth lens ranges from 1.79 < n21 < 1.83, the refractive index n22 of the sixth lens ranges from 1.45 < n22 < 1.49, and the refractive index n23 of the seventh lens ranges from 1.78 < n23 < 1.

82.

10. The optical fiber lithography objective lens according to claim 1, characterized in that: The refractive index n31 of the eighth lens ranges from 1.70 < n31 < 1.74, the refractive index n32 of the ninth lens ranges from 1.78 < n32 < 1.82, the refractive index n33 of the tenth lens ranges from 1.63 < n33 < 1.67, and the refractive index n34 of the eleventh lens ranges from 1.60 < n34 < 1.

64.

11. The optical fiber lithography objective lens according to claim 1, characterized in that: The Abbe number v11 of the first lens ranges from 31.8 < v11 < 34.8, the Abbe number v12 of the second lens ranges from 50.2 < v12 < 54.2, the Abbe number v13 of the third lens ranges from 64.9 < v13 < 68.9, and the Abbe number v14 of the fourth lens ranges from 92.6 < v14 < 94.

6.

12. The optical fiber lithography objective lens according to claim 1, characterized in that: The Abbe number v21 of the fifth lens ranges from 33.9 < v21 < 37.9, the Abbe number v22 of the sixth lens ranges from 46.9 < v22 < 50.9, and the Abbe number v23 of the seventh lens ranges from 58.8 < v23 < 62.

8.

13. The optical fiber lithography objective lens according to claim 1, characterized in that: The Abbe number v31 of the eighth lens ranges from 88.5 < v31 < 92.5, the Abbe number v32 of the ninth lens ranges from 88.5 < v32 < 92.5, the Abbe number v33 of the tenth lens ranges from 92.6 < v33 < 96.6, and the Abbe number v34 of the eleventh lens ranges from 63.5 < v34 < 67.

5.

14. The optical fiber lithography objective lens according to claim 1, characterized in that: The lenses in the objective lens satisfy the following relational expressions: 0.5 < f / epd < 0.6, 0.05 < bfl / f < 0.08, 0.52 < fno < 0.58, ttl < 200 mm, 0.85° < fov < 1.15°, where f is the focal length of the objective lens, epd is the entrance pupil diameter, bfl is the distance from the vertex of the rear surface of the last lens to the substrate, fno is the f-number of the objective lens, ttl is the distance from the object side of the first lens in the first lens group to the image plane of the objective lens, and fov is the maximum half field of view angle range of the objective lens.

15. A photolithography machine, which is used for performing laser direct writing on a photoresist by means of a laser, characterized in that: The lithography machine is provided with the objective lens as described in any one of claims 1 to 14.

Images