Deep ultraviolet microscope objective and microscope

Abstract

The present application provides a kind of deep ultraviolet microscope objective and microscope.Therein deep ultraviolet microscope objective includes: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens and eighth lens are arranged in order from object side to image side with optical axis.The scheme of the present application is designed for 260 to 262nm wavelength range, the design value of resolution in the wavelength range is consistent with the theoretical value;And completely realize independent design, solve the problem that existing 50 times objective cannot meet many use requirements in optical detection;By setting the specific parameters and structure of each lens, so that the magnification of deep ultraviolet microscope objective is 50 times, object field is 0.6mm, can be used with 200mm focal length's tube lens, working distance is 13mm, numerical aperture is 0.528, improve the object field and working distance of deep ultraviolet microscope objective, and then improve the overall performance of microscope.

Description

Technical Field

[0001] The present invention relates to the field of microscopes, in particular to a deep ultraviolet microscope objective lens and a microscope. Background Art

[0002] With the advancement of semiconductor manufacturing processes, the transistor density of semiconductor chips is getting higher and higher, and the requirements for the resolution of detection systems are also getting higher and higher. According to the Rayleigh criterion of optical resolution limit: R = 0.61λ / NA, it can be known that to improve the resolution of the optical system, it is necessary to shorten the wavelength or increase the numerical aperture. However, in the field of semiconductor detection, increasing the numerical aperture has its limitations, and there is almost no available space for immersion objectives, so shortening the wavelength has become the best choice. At present, the application of deep ultraviolet band in optical detection systems is becoming more and more extensive, but there are few mature deep ultraviolet objective lenses on the domestic market, and the few optional objective lenses cannot meet all usage requirements. Summary of the Invention

[0003] An object of the present invention is to provide a deep ultraviolet microscope objective lens that improves the resolution within a specific ultraviolet wavelength range.

[0004] A further object of the present invention is to increase the object field of view and working distance of the deep ultraviolet microscope objective lens, thereby improving the overall performance of the microscope.

[0005] In particular, the present invention provides a deep ultraviolet microscope objective lens, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence from the object side to the image side on the same optical axis; the first lens has a concave surface facing the object side and a convex surface facing the image side; the second lens has a concave surface facing the object side and a convex surface facing the image side; the third lens has a concave surface facing the object side and a convex surface facing the image side; the fourth lens has a convex surface facing the object side and a convex surface facing the image side; the fifth lens has a convex surface facing the object side and a concave surface facing the image side; the sixth lens has a concave surface facing the object side and a convex surface facing the image side; the seventh lens has a concave surface facing the object side and a convex surface facing the image side; the eighth lens has a convex surface facing the object side and a concave surface facing the image side.

[0006] Optionally, the first lens, the second lens, the third lens, the fifth lens, and the seventh lens are all positive meniscus lenses; the fourth lens is a biconvex positive lens; and the sixth lens and the eighth lens are all negative meniscus lenses.

[0007] Optionally, the first lens, the third lens, the fifth lens, and the seventh lens are all made of calcium fluoride; and the second lens, the fourth lens, the sixth lens, and the eighth lens are all made of fused quartz.

[0008] Optionally, the surface of the first lens facing the object side is the first mirror surface, and the surface of the first lens facing the image side is the second mirror surface; the surface of the second lens facing the object side is the third mirror surface, and the surface of the second lens facing the image side is the fourth mirror surface; the surface of the third lens facing the object side is the fifth mirror surface, and the surface of the third lens facing the image side is the sixth mirror surface; the surface of the fourth lens facing the object side is the seventh mirror surface, and the surface of the fourth lens facing the image side is the eighth mirror surface; the surface of the fifth lens facing the object side is the ninth mirror surface, and the surface of the fifth lens facing the image side is the tenth mirror surface; the surface of the sixth lens facing the object side is the eleventh mirror surface, and the surface of the sixth lens facing the object side is the eleventh mirror surface. The surface facing the image side is the twelfth mirror surface; the surface of the seventh lens facing the object side is the thirteenth mirror surface, and the surface of the seventh lens facing the image side is the fourteenth mirror surface; the surface of the eighth lens facing the object side is the fifteenth mirror surface, and the surface of the eighth lens facing the image side is the sixteenth mirror surface. The curvature radii of the first mirror surface, the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the eighth mirror surface, the tenth mirror surface, the eleventh mirror surface, the twelfth mirror surface, the thirteenth mirror surface, and the fourteenth mirror surface are all negative numbers; the curvature radii of the seventh mirror surface, the ninth mirror surface, the fifteenth mirror surface, and the sixteenth mirror surface are all positive numbers.

[0009] Optionally, the radius of curvature of the first mirror surface is -14.6 to -14.58 mm; the radius of curvature of the second mirror surface is -9.96 to -9.94 mm; the radius of curvature of the third mirror surface is -28.89 to -28.87 mm; the radius of curvature of the fourth mirror surface is -15.49 to -15.47 mm; the radius of curvature of the fifth mirror surface is -117.24 to -117.22 mm; the radius of curvature of the sixth mirror surface is -24.99 to -24.97 mm; the radius of curvature of the seventh mirror surface is 79.12 to 79.14 mm; and the radius of curvature of the eighth mirror surface is -53.23 to -53.21 mm. ; The radius of curvature of the ninth mirror surface is 26.71 to 26.73 mm; the radius of curvature of the tenth mirror surface is -676.94 to -676.92 mm; the radius of curvature of the eleventh mirror surface is -10.72 to -10.7 mm; the radius of curvature of the twelfth mirror surface is -200.48 to -200.46 mm; the radius of curvature of the thirteenth mirror surface is -9.93 to -9.91 mm; the radius of curvature of the fourteenth mirror surface is -12.7 to -12.68 mm; the radius of curvature of the fifteenth mirror surface is 84.1 to 84.12 mm; and the radius of curvature of the sixteenth mirror surface is 13.94 to 13.96 mm.

[0010] Optionally, the clear aperture of the first mirror is 5.94 mm; the clear aperture of the second mirror is 6.39 mm; the clear aperture of the third mirror is 6.94 mm; the clear aperture of the fourth mirror is 7.41 mm; the clear aperture of the fifth mirror is 7.8 mm; the clear aperture of the sixth mirror is 8.05 mm; the clear aperture of the seventh mirror is 8.24 mm; the clear aperture of the eighth mirror is 8.26 mm; and the clear aperture of the eighth mirror is 8.26 mm. The clear aperture of the ninth mirror is 8.04mm; the clear aperture of the tenth mirror is 6.78mm; the clear aperture of the eleventh mirror is 3.25mm; the clear aperture of the twelfth mirror is 3.22mm; the clear aperture of the thirteenth mirror is 3.2mm; the clear aperture of the fourteenth mirror is 4.27mm; the clear aperture of the fifteenth mirror is 3.62mm; and the clear aperture of the sixteenth mirror is 3.45mm.

[0011] Optionally, the mirror distance between the first mirror surface and the second mirror surface is 1.99 to 2.01 mm; the mirror distance between the second mirror surface and the third mirror surface is 0.09 to 0.11 mm; the mirror distance between the third mirror surface and the fourth mirror surface is 2.49 to 2.51 mm; the mirror distance between the fourth mirror surface and the fifth mirror surface is 0.09 to 0.11 mm; the mirror distance between the fifth mirror surface and the sixth mirror surface is 2.49 to 2.51 mm; the mirror distance between the sixth mirror surface and the seventh mirror surface is 0.09 to 0.11 mm; the mirror distance between the seventh mirror surface and the eighth mirror surface is 1.98 to 2 mm; the mirror distance between the eighth mirror surface and the ninth mirror surface is 4.71 to 4.71 mm. .73mm; the mirror distance between the ninth mirror plane and the tenth mirror plane is 11.68 to 11.7mm; the mirror distance between the tenth mirror plane and the eleventh mirror plane is 19.65 to 19.67mm; the mirror distance between the eleventh mirror plane and the twelfth mirror plane is 1.99 to 2.01mm; the mirror distance between the twelfth mirror plane and the thirteenth mirror plane is 1.19 to 1.21mm; the mirror distance between the thirteenth mirror plane and the fourteenth mirror plane is 11.99 to 12.01mm; the mirror distance between the fourteenth mirror plane and the fifteenth mirror plane is 19.99 to 20.01mm; the mirror distance between the fifteenth mirror plane and the sixteenth mirror plane is 4.43 to 4.45mm.

[0012] Optionally, the deep ultraviolet microscope objective lens is applicable to a wavelength range of 260 to 262 nm, and the focal length of the tube lens that can be used is 200 mm.

[0013] Optionally, the edge or the outer frame of the first mirror serves as an aperture stop.

[0014] According to another aspect of the present invention, a microscope is provided, comprising any one of the above-mentioned deep ultraviolet microscope objective lenses.

[0015] The deep ultraviolet microscope objective lens of the present invention is designed for the wavelength range of 260 to 262 nm. The designed value of the resolution within this wavelength range is consistent with the theoretical value. It is also a completely independent design, solving the problem that the existing 50x objective lens cannot meet many usage requirements in optical detection.

[0016] Furthermore, the deep ultraviolet microscope objective lens of the present invention, by setting the specific parameters and structures of each lens, makes the magnification of the deep ultraviolet microscope objective lens be 50 times, and the object field of view be 0.6mm, which has a higher field of view than the conventional commercial 50x microscope objective lens. It can be used with a tube lens with a focal length of 200mm, and the working distance is 13mm, which is larger than the conventional objective lens. The corresponding numerical aperture is larger, which is 0.528, which can improve the object field of view and working distance of the deep ultraviolet microscope objective lens, thereby improving the overall performance of the microscope.

[0017] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0019] Figure 1 1 is a schematic structural diagram of a deep ultraviolet microscope objective lens according to an embodiment of the present invention;

[0020] Figure 2 is a point diagram of different fields of view of a deep ultraviolet microscope objective according to one embodiment of the present invention;

[0021] Figure 3 is a modulation transfer function curve diagram of a deep ultraviolet microscope objective lens according to one embodiment of the present invention; and

[0022] Figure 4 4 is a field curvature distortion diagram of a deep ultraviolet microscope objective lens according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] This embodiment provides a deep ultraviolet microscope objective lens that can improve the resolution within a specific ultraviolet wavelength range. Figure 1 FIG. 1 is a schematic structural diagram of a deep ultraviolet microscope objective lens according to an embodiment of the present invention. Figure 1As shown, the deep ultraviolet microscope objective lens of this embodiment includes: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an eighth lens L8, which are arranged on the same optical axis from the object side to the image side.

[0024] Among them, the first lens L1 has a concave surface facing the object side and a convex surface facing the image side; the second lens L2 has a concave surface facing the object side and a convex surface facing the image side; the third lens L3 has a concave surface facing the object side and a convex surface facing the image side; the fourth lens L4 has a convex surface facing the object side and a convex surface facing the image side; the fifth lens L5 has a convex surface facing the object side and a concave surface facing the image side; the sixth lens L6 has a concave surface facing the object side and a convex surface facing the image side; the seventh lens L7 has a concave surface facing the object side and a convex surface facing the image side; and the eighth lens L8 has a convex surface facing the object side and a concave surface facing the image side.

[0025] In a specific embodiment, the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, and the seventh lens L7 are all positive meniscus lenses. A positive meniscus lens is a lens composed of two curved surfaces with similar radii of curvature and has a positive focal length. A positive meniscus lens can typically be used to reduce the focal length of another lens and increase the numerical aperture. When expanding, contracting, or diverging collimated light, the light beam can be incident on the convex surface of the positive meniscus lens, thereby reducing spherical aberration. When used for converging light, the light beam can be incident on the concave surface of the positive meniscus lens.

[0026] The fourth lens element, L4, is a biconvex positive lens. Both the sixth and eighth lenses, L6 and L8, are negative meniscus lenses. A negative meniscus lens is a lens composed of two surfaces with similar radii of curvature, exhibiting a negative focal length. Negative meniscus lenses are typically used for applications such as beam expansion, increasing focal length, and reducing numerical aperture. When expanding or diverging collimated light, the beam can be incident on the convex surface of the negative meniscus lens, thereby reducing spherical aberration. When used for converging light, the beam can be incident on the concave surface.

[0027] In a preferred embodiment, the specific materials of first lens element L1 through eighth lens element L8 can be referenced in Table 1. As shown in Table 1, first lens element L1, third lens element L3, fifth lens element L5, and seventh lens element L7 can all be made of calcium fluoride. Calcium fluoride has a high refractive index and low dispersion. Lenses made of calcium fluoride are particularly well-suited for use in the ultraviolet (UV) spectrum, providing clear imaging.

[0028] The second lens element L2, the fourth lens element L4, the sixth lens element L6, and the eighth lens element L8 can all be made of fused silica. Lenses made of fused silica have extremely high light transmittance, being able to transmit ultraviolet and infrared rays; their thermal expansion coefficient is extremely small, with excellent thermal shock resistance; they are heat-resistant and acid-resistant, with good chemical stability; their ultra-low roughness and excellent surface shape deviation make them suitable for high-precision optical applications; their surface defects are few, and their aperture is large, making them suitable for a variety of optical applications; aspheric lenses can correct spherical aberration, reducing the total number of components in the optical system, making the structural design more compact and functionally complete.

[0029] In summary, all lenses used in the deep ultraviolet microscope objective lens of this embodiment are made of calcium fluoride or fused quartz, and all lens surfaces are spherical, which is very easy to process, can effectively reduce the processing difficulty, and improve the processing efficiency and processing quality.

[0030] Table 1

[0031] Lens name Material First lens L1 calcium fluoride Second lens L2 Fused Silica The third lens L3 calcium fluoride Fourth lens L4 Fused Silica Fifth lens L5 calcium fluoride Sixth lens L6 Fused Silica Seventh lens L7 calcium fluoride Eighth lens L8 Fused Silica

[0032] In a specific embodiment, the surface of the first lens L1 facing the object side is the first mirror surface S1, and the surface of the first lens L1 facing the image side is the second mirror surface S2; the surface of the second lens L2 facing the object side is the third mirror surface S3, and the surface of the second lens L2 facing the image side is the fourth mirror surface S4; the surface of the third lens L3 facing the object side is the fifth mirror surface S5, and the surface of the third lens L3 facing the image side is the sixth mirror surface S6; the surface of the fourth lens L4 facing the object side is the seventh mirror surface S7, and the surface of the fourth lens L4 facing the image side is the eighth mirror surface S8; The object-facing surface of the fifth lens L5 is the ninth mirror surface S9, and the image-facing surface of the fifth lens L5 is the tenth mirror surface S10; the object-facing surface of the sixth lens L6 is the eleventh mirror surface S11, and the image-facing surface of the sixth lens L6 is the twelfth mirror surface S12; the object-facing surface of the seventh lens L7 is the thirteenth mirror surface S13, and the image-facing surface of the seventh lens L7 is the fourteenth mirror surface S14; the object-facing surface of the eighth lens L8 is the fifteenth mirror surface S15, and the image-facing surface of the eighth lens L8 is the sixteenth mirror surface S16.

[0033] Moreover, the curvature radii of the first mirror S1, the second mirror S2, the third mirror S3, the fourth mirror S4, the fifth mirror S5, the sixth mirror S6, the eighth mirror S8, the tenth mirror S10, the eleventh mirror S11, the twelfth mirror S12, the thirteenth mirror S13, and the fourteenth mirror S14 are all negative numbers; the curvature radii of the seventh mirror S7, the ninth mirror S9, the fifteenth mirror S15, and the sixteenth mirror S16 are all positive numbers.

[0034] In a preferred embodiment, the specific values ​​of the curvature radius, the clear aperture, and the mirror distance between two adjacent mirrors of the first mirror surface S1 to the sixteenth mirror surface S16 can be referred to Table 2. As shown in Table 2, the curvature radius of the first mirror surface S1 is -14.6 to -14.58 mm, the clear aperture is 5.94 mm, and the mirror distance between the first mirror surface S1 and the second mirror surface S2 is 1.99 to 2.01 mm. The curvature radius of the second mirror surface S2 is -9.96 to -9.94 mm, the clear aperture is 6.39 mm, and the mirror distance between the second mirror surface S2 and the third mirror surface S3 is 0.09 to 0.11 mm. The curvature radius of the third mirror surface S3 is -28.89 to -28.87 mm, the clear aperture is 6.94 mm, and the mirror distance between the third mirror surface S3 and the fourth mirror surface S4 is 2.49 to 2.51 mm.

[0035] The radius of curvature of the fourth mirror surface S4 is -15.49 to -15.47 mm, the clear aperture is 7.41 mm, and the mirror distance between the fourth mirror surface S4 and the fifth mirror surface S5 is 0.09 to 0.11 mm. The radius of curvature of the fifth mirror surface S5 is -117.24 to -117.22 mm, the clear aperture is 7.8 mm, and the mirror distance between the fifth mirror surface S5 and the sixth mirror surface S6 is 2.49 to 2.51 mm. The radius of curvature of the sixth mirror surface S6 is -24.99 to -24.97 mm, the clear aperture is 8.05 mm, and the mirror distance between the sixth mirror surface S6 and the seventh mirror surface S7 is 0.09 to 0.11 mm.

[0036] The seventh mirror surface S7 has a radius of curvature of 79.12 to 79.14 mm, a clear aperture of 8.24 mm, and a mirror distance between the seventh mirror surface S7 and the eighth mirror surface S8 of 1.98 to 2 mm. The eighth mirror surface S8 has a radius of curvature of -53.23 to -53.21 mm, a clear aperture of 8.26 mm, and a mirror distance between the eighth mirror surface S8 and the ninth mirror surface S9 of 4.71 to 4.73 mm. The ninth mirror surface S9 has a radius of curvature of 26.71 to 26.73 mm, a clear aperture of 8.04 mm, and a mirror distance between the ninth mirror surface S9 and the tenth mirror surface S10 of 11.68 to 11.7 mm.

[0037] The tenth mirror surface S10 has a radius of curvature of -676.94 to -676.92 mm, a clear aperture of 6.783 mm, and a mirror distance between the tenth mirror surface S10 and the eleventh mirror surface S11 of 19.65 to 19.67 mm. The eleventh mirror surface S11 has a radius of curvature of -10.72 to -10.7 mm, a clear aperture of 3.25 mm, and a mirror distance between the eleventh mirror surface S11 and the twelfth mirror surface S12 of 1.99 to 2.01 mm. The twelfth mirror surface S12 has a radius of curvature of -200.48 to -200.46 mm, a clear aperture of 3.22 mm, and a mirror distance between the twelfth mirror surface S12 and the thirteenth mirror surface S13 of 1.19 to 1.21 mm.

[0038] The radius of curvature of the thirteenth mirror surface is -9.93 to -9.91 mm, the clear aperture is 3.2 mm, and the mirror distance between the thirteenth mirror surface S13 and the fourteenth mirror surface S14 is 11.99 to 12.01 mm. The radius of curvature of the fourteenth mirror surface is -12.7 to -12.68 mm, the clear aperture is 4.27 mm, and the mirror distance between the fourteenth mirror surface S14 and the fifteenth mirror surface S15 is 19.99 to 20.01 mm. The radius of curvature of the fifteenth mirror surface S15 is 84.1 to 84.12 mm, the clear aperture is 3.62 mm, and the mirror distance between the fifteenth mirror surface S15 and the sixteenth mirror surface S16 is 4.43 to 4.45 mm. The radius of curvature of the sixteenth mirror surface S16 is 13.94 to 13.96 mm, and the clear aperture is 3.45 mm.

[0039] Table 2

[0040] Mirror Name Curvature radius (mm) Clear aperture (mm) Mirror distance (mm) First mirror S1 -14.6 to -14.58 5.94 1.99 to 2.01 Second mirror S2 -9.96 to -9.94 6.39 0.09 to 0.11 The third mirror S3 -28.89 to -28.87 6.94 2.49 to 2.51 Fourth mirror S4 -15.49 to -15.47 7.41 0.09 to 0.11 Fifth mirror S5 -117.24 to -117.22 7.8 2.49 to 2.51 Sixth mirror S6 -24.99 to -24.97 8.05 0.09 to 0.11 Seventh Mirror S7 79.12 to 79.14 8.24 1.98 to 2 Eighth mirror S8 -53.23 to -53.21 8.26 4.71 to 4.73 Ninth Mirror S9 26.71 to 26.73 8.04 11.68 to 11.7 Tenth Mirror S10 -676.94 to -676.92 6.78 19.65 to 19.67 Mirror S11 -10.72 to -10.7 3.25 1.99 to 2.01 Mirror S12 -200.48 to -200.46 3.22 January 19 to January 21 Mirror S13 -9.93 to -9.91 3.2 11.99 to 12.01 Fourteenth mirror S14 -12.7 to -12.68 4.27 19.99 to 20.01 Fifteenth mirror S15 84.1 to 84.12 3.62 4.43 to 4.45 Mirror S16 13.94 to 13.96 3.45 unlimited

[0041] By referring to the specific parameters and structures of each lens in Tables 1 and 2 above, the magnification of the deep ultraviolet microscope objective lens can be set to 50 times, and the object field of view is 0.6mm, which has a higher field of view than conventional commercial 50x microscope objective lenses. It can be used with a 200mm focal length tube lens, and the working distance is 13mm, which is larger than that of conventional objective lenses. The corresponding numerical aperture is larger, 0.528, which can improve the object field of view and working distance of the deep ultraviolet microscope objective lens, thereby improving the overall performance of the microscope. In addition, it is designed for the wavelength range of 260 to 262nm, and the design value of the resolution within this wavelength range is consistent with the theoretical value; and it is fully independently designed, solving the problem that the existing 50x objective lens cannot meet many usage requirements in optical detection.

[0042] Specifically, according to the Rayleigh criterion, the resolution limit of the deep ultraviolet microscope objective lens of this embodiment is: 0.61λ / NA = 0.61×0.261 / 0.528 ≈ 0.302μm. According to the objective lens design MTF calculation, when the MTF value = 0.1, the frequency is approximately 3145lp / mm, and the resolution = 1 / 3145 ≈ 0.318μm. In other words, the theoretical value of the resolution of the deep ultraviolet microscope objective lens of this embodiment is 0.302μm, and the designed value is 0.318μm, which are basically consistent, and can effectively improve the resolution within a specific ultraviolet wavelength range.

[0043] In a preferred embodiment, the edge or outer frame of the first mirror surface S1 serves as an aperture stop. The aperture stop limits the aperture of the light beam. Furthermore, it should be noted that the mirror distance from the object plane to the first mirror surface S1 can be 13 mm. The mirror distance between the sixteenth mirror surface S16 and the image plane is infinite.

[0044] Figure 2 1 is a point diagram of different fields of view of a deep ultraviolet microscope objective according to one embodiment of the present invention. Figure 2 The focusing situation of light with a wavelength of 261nm at the focal point under different object plane fields of view is shown. The object plane field of view of field (1) is 0.600mm, the object plane field of view of field (2) is 0.300mm, and the object plane half field of view of field (3) is 0.000mm. The test data are as follows: the RMS radius (root mean square) when the field of view is (1) is 0.106μm, and the GEO radius (maximum) is 0.353μm; the RMS radius when the field of view is (2) is 0.027μm, and the GEO radius is 0.059μm; the RMS radius when the field of view is (3) is 0.013μm, and the GEO radius is 0.018μm.

[0045] Among them, RMS radius is also called root mean square spot radius, which is an indicator used to describe the size of the beam. It is the spot radius obtained by taking the square root of the quadratic average of the light intensity distribution. GEO radius (Geometric Optical Radius) represents the radius of the smallest center circle that contains all light rays. Specifically, GEO radius is the radius of the smallest center circle that can satisfy all light rays falling within its range. Figure 2 It can be seen that the focused spots of light with a wavelength of 261 nm in different fields of view are all within a small range, indicating that the deep ultraviolet microscope objective lens of this embodiment has an excellent focusing effect. It can be seen that the aberration of the deep ultraviolet microscope objective lens of this embodiment is well controlled.

[0046] Figure 3 4 is a modulation transfer function curve of a deep ultraviolet microscope objective lens according to an embodiment of the present invention. Figure 3The vertical axis is the modulus of the normalized transfer function, and the horizontal axis is the spatial frequency, in units of lp / mm. The outermost line is the transfer function curve of the system under the diffraction limit. Figure 3 As shown, for the deep ultraviolet microscope objective lens of this embodiment, when the object plane field of view is 0.600mm, 0.300mm and 0.000mm, the transfer function curves of light with a wavelength of 261nm in the meridian plane and the sagittal plane show that the on-axis field of view transfer function curve and the off-axis field of view transfer function curve are both close to the diffraction limit, indicating that the imaging contrast of the optical system's full field of view is very high and the imaging layering is clear.

[0047] Figure 4 4 is a field curvature distortion diagram of a deep ultraviolet microscope objective lens according to an embodiment of the present invention. Figure 4 The left side of the figure is the field curvature diagram, the vertical axis is the field of view in the direction of incident light of the objective lens, and the horizontal axis is the field curvature value, in μm. Figure 4 The figure on the right is the distortion diagram, the vertical axis is the field of view during imaging, and the horizontal axis is the distortion amount (%). When testing the field curvature diagram, the data obtained are as follows: the maximum field of view is 4.346 degrees, the sagittal field curvature is 0.0002mm, and the meridional field curvature is 0.0000mm. When testing the distortion diagram, the data obtained are as follows: the maximum field of view is 4.346 degrees, and the maximum distortion amount is 1.3017%. Figure 4 As shown, the field curvature of light with a wavelength of 261nm is less than 0.06mm in both the meridian and sagittal planes, ensuring clear imaging across the entire field of view without introducing additional field curvature. Distortion across the entire field of view is within 1.5%, demonstrating excellent distortion correction and wide-field imaging performance.

[0048] This embodiment also provides a microscope, which includes the deep ultraviolet microscope objective lens of any of the above embodiments. In a specific embodiment, by setting the specific parameters and structures of each lens, the magnification of the deep ultraviolet microscope objective lens can be made 50 times, the object field of view is 0.6mm, and it has a higher field of view than a conventional commercial 50x microscope objective lens. It can be used with a tube lens with a focal length of 200mm and a working distance of 13mm, which is larger than a conventional objective lens. The corresponding numerical aperture is larger, which is 0.528, and can improve the object field of view and working distance of the deep ultraviolet microscope objective lens, thereby improving the overall performance of the microscope. In addition, it is designed for the wavelength range of 260 to 262nm, and the design value of the resolution within this wavelength range is consistent with the theoretical value; and it fully realizes independent design, which solves the problem that the existing 50x objective lens cannot meet many usage requirements in optical detection.

[0049] Those skilled in the art should understand that, unless otherwise specified, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise", etc. in the embodiments of the present invention used to indicate orientation or positional relationships are merely for the convenience of describing and understanding the technical solutions of the present invention, and do not indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the definition of "first", "second", etc. can explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or more of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0051] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," and the like should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly limited. A person of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact via another feature between them. That is, in the description of this embodiment, the first feature being "above," "above," and "above" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below," "below," or "below" the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0053] In the description of the present embodiment, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples.

[0054] At this point, those skilled in the art will recognize that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A deep ultraviolet microscope objective lens, characterized in that: include: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, which are arranged in sequence from the object side to the image side on the same optical axis; The first lens has a concave surface facing the object side and a convex surface facing the image side; the second lens has a concave surface facing the object side and a convex surface facing the image side; the third lens has a concave surface facing the object side and a convex surface facing the image side; the fourth lens has a convex surface facing the object side and a convex surface facing the image side; the fifth lens has a convex surface facing the object side and a concave surface facing the image side; the sixth lens has a concave surface facing the object side and a convex surface facing the image side; the seventh lens has a concave surface facing the object side and a convex surface facing the image side; the eighth lens has a convex surface facing the object side and a concave surface facing the image side; Furthermore, there are 8 lenses with optical power; The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens are positive lenses; The sixth lens and the eighth lens are negative lenses; The deep ultraviolet microscope objective lens has a magnification of 50 times, an object field of view of 0.6 mm, and a numerical aperture of 0.

528.

2. The deep ultraviolet microscope objective lens according to claim 1, characterized in that The first lens, the second lens, the third lens, the fifth lens, and the seventh lens are all positive meniscus lenses; the fourth lens is a biconvex positive lens; and the sixth lens and the eighth lens are all negative meniscus lenses.

3. The deep ultraviolet microscope objective lens according to claim 2, characterized in that The first lens, the third lens, the fifth lens, and the seventh lens are all made of calcium fluoride; the second lens, the fourth lens, the sixth lens, and the eighth lens are all made of fused silica.

4. The deep ultraviolet microscope objective lens according to claim 3, characterized in that The surface of the first lens facing the object side is the first mirror surface, and the surface of the first lens facing the image side is the second mirror surface; the surface of the second lens facing the object side is the third mirror surface, and the surface of the second lens facing the image side is the fourth mirror surface; the surface of the third lens facing the object side is the fifth mirror surface, and the surface of the third lens facing the image side is the sixth mirror surface; The surface of the fourth lens facing the object side is the seventh mirror surface, and the surface of the fourth lens facing the image side is the eighth mirror surface; the surface of the fifth lens facing the object side is the ninth mirror surface, and the surface of the fifth lens facing the image side is the tenth mirror surface; The surface of the sixth lens facing the object side is the eleventh mirror surface, and the surface of the sixth lens facing the image side is the twelfth mirror surface; the surface of the seventh lens facing the object side is the thirteenth mirror surface, and the surface of the seventh lens facing the image side is the fourteenth mirror surface; the surface of the eighth lens facing the object side is the fifteenth mirror surface, and the surface of the eighth lens facing the image side is the sixteenth mirror surface, The curvature radii of the first mirror surface, the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the eighth mirror surface, the tenth mirror surface, the eleventh mirror surface, the twelfth mirror surface, the thirteenth mirror surface, and the fourteenth mirror surface are all negative numbers; the curvature radii of the seventh mirror surface, the ninth mirror surface, the fifteenth mirror surface, and the sixteenth mirror surface are all positive numbers.

5. The deep ultraviolet microscope objective lens according to claim 4, characterized in that: The curvature radius of the first mirror surface is -14.6 to -14.58 mm; The curvature radius of the second mirror surface is -9.96 to -9.94 mm; The curvature radius of the third mirror surface is -28.89 to -28.87 mm; The curvature radius of the fourth mirror surface is -15.49 to -15.47 mm; The curvature radius of the fifth mirror surface is -117.24 to -117.22 mm; The curvature radius of the sixth mirror surface is -24.99 to -24.97 mm; The curvature radius of the seventh mirror surface is 79.12 to 79.14 mm; The curvature radius of the eighth mirror surface is -53.23 to -53.21 mm; The curvature radius of the ninth mirror surface is 26.71 to 26.73 mm; The curvature radius of the tenth mirror surface is -676.94 to -676.92 mm; The curvature radius of the eleventh mirror surface is -10.72 to -10.7 mm; The curvature radius of the twelfth mirror surface is -200.48 to -200.46 mm; The curvature radius of the thirteenth mirror surface is -9.93 to -9.91 mm; The curvature radius of the fourteenth mirror surface is -12.7 to -12.68 mm; The curvature radius of the fifteenth mirror surface is 84.1 to 84.12 mm; The curvature radius of the sixteenth mirror surface is 13.94 to 13.96 mm.

6. The deep ultraviolet microscope objective lens according to claim 5, characterized in that: The clear aperture of the first mirror is 5.94 mm; The clear aperture of the second mirror is 6.39 mm; The clear aperture of the third mirror is 6.94 mm; The clear aperture of the fourth mirror is 7.41 mm; The clear aperture of the fifth mirror is 7.8 mm; The clear aperture of the sixth mirror is 8.05 mm; The clear aperture of the seventh mirror is 8.24 mm; The clear aperture of the eighth mirror is 8.26 mm; The clear aperture of the ninth mirror is 8.04 mm; The clear aperture of the tenth mirror is 6.78 mm; The clear aperture of the eleventh mirror surface is 3.25 mm; The clear aperture of the twelfth mirror is 3.22 mm; The clear aperture of the thirteenth mirror is 3.2 mm; The clear aperture of the fourteenth mirror is 4.27 mm; The clear aperture of the fifteenth mirror is 3.62 mm; The clear aperture of the sixteenth mirror surface is 3.45 mm.

7. The deep ultraviolet microscope objective lens according to claim 6, characterized in that The mirror distance between the first mirror surface and the second mirror surface is 1.99 to 2.01 mm; The mirror distance between the second mirror surface and the third mirror surface is 0.09 to 0.11 mm; The mirror distance between the third mirror surface and the fourth mirror surface is 2.49 to 2.51 mm; The mirror distance between the fourth mirror surface and the fifth mirror surface is 0.09 to 0.11 mm; The mirror distance between the fifth mirror surface and the sixth mirror surface is 2.49 to 2.51 mm; The mirror distance between the sixth mirror surface and the seventh mirror surface is 0.09 to 0.11 mm; The mirror distance between the seventh mirror surface and the eighth mirror surface is 1.98 to 2 mm; The mirror distance between the eighth mirror surface and the ninth mirror surface is 4.71 to 4.73 mm; The mirror distance between the ninth mirror surface and the tenth mirror surface is 11.68 to 11.7 mm; The mirror distance between the tenth mirror surface and the eleventh mirror surface is 19.65 to 19.67 mm; The mirror distance between the eleventh mirror surface and the twelfth mirror surface is 1.99 to 2.01 mm; The mirror distance between the twelfth mirror surface and the thirteenth mirror surface is 1.19 to 1.21 mm; The mirror distance between the thirteenth mirror surface and the fourteenth mirror surface is 11.99 to 12.01 mm; The mirror distance between the fourteenth mirror surface and the fifteenth mirror surface is 19.99 to 20.01 mm; The mirror distance between the fifteenth mirror surface and the sixteenth mirror surface is 4.43 to 4.45 mm.

8. The deep ultraviolet microscope objective lens according to claim 7, characterized in that: The deep ultraviolet microscope objective lens is applicable to a wavelength range of 260 to 262 nm, and the focal length of the tube lens that can be used with it is 200 mm.

9. The deep ultraviolet microscope objective lens according to claim 4, characterized in that: The edge or outer frame of the first mirror serves as an aperture stop.

10. A microscope comprising the deep ultraviolet microscope objective lens according to any one of claims 1 to 9.

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