Lithographic illumination lens

Abstract

The application belongs to the field of optical devices, and particularly relates to a photolithography illumination lens. Embodiments of the application provide a photolithography illumination lens, which comprises, in sequence along the transmission direction of illumination light, a light source, a collimating lens group, a compound eye lens group and a focusing lens group; the light source is used for providing illumination light; the collimating lens group has positive focal power and is used for collimating the illumination light emitted by the light source; the compound eye lens group has positive focal power and is used for homogenizing the illumination light collimated by the collimating lens group; the focusing lens group has positive focal power and is used for focusing the illumination light homogenized by the compound eye lens group on an illumination plane; wherein the collimating lens group at least comprises, in sequence along the transmission direction of illumination light, a first lens, a second lens and a third lens, and the first lens, the second lens and the third lens are all spherical lenses. The photolithography illumination lens of the embodiments of the application can obtain a light spot with high uniformity and large illumination area, and also has the characteristics of low image-side numerical aperture and narrow transition zone.

Description

Technical Field

[0001] This application belongs to the field of optical devices, and specifically relates to a photolithography illumination lens. Background Technology

[0002] Surface plasmon lithography, as a super-diffractive electromagnetic mode, has a transmission wavelength much smaller than the vacuum wavelength at the same photon frequency. Lithography machines fabricated using surface plasmon lithography can achieve resolutions down to below a hundred nanometers. However, traditional illumination lenses have small illumination spot areas, which cannot meet the requirements of surface plasmon lithography. Summary of the Invention

[0003] This application provides a photolithography illumination lens that can solve the technical problem of small light spot area.

[0004] This application provides a photolithography illumination lens, including a light source, a collimating lens group, a compound eye lens group, and a focusing lens group arranged sequentially along the illumination light transmission direction;

[0005] A light source is used to provide illumination;

[0006] The collimating lens group has positive optical power and is used to collimate the illumination light emitted by the light source;

[0007] The compound lens group has positive optical power and is used to homogenize and shape the illumination light collimated by the collimating lens group;

[0008] The focusing lens group has positive optical power and is used to focus the illumination light that has been homogenized and shaped by the refractive lens group onto the illumination surface;

[0009] The collimating lens group includes at least a first lens, a second lens, and a third lens arranged sequentially along the direction of illumination light transmission, wherein the first lens, the second lens, and the third lens are all spherical mirrors.

[0010] According to the foregoing embodiments of this application, the focal length of the collimating lens group and the focal length of the compound lens group satisfy the following relationship:

[0011] 1.2 < F A / F B <1.3

[0012] Among them, F A F is the focal length of the collimating lens group. B The focal length of the compound eyeglasses group;

[0013] and / or

[0014] The focal lengths of the compound lens group and the focusing lens group satisfy the following relationship:

[0015] 0.1 < F A / F C <0.2

[0016] Among them, F C This is the focal length of the focusing lens group.

[0017] According to any of the foregoing embodiments of this application, the first lens, the second lens, and the third lens are all positive optical power.

[0018] According to any of the foregoing embodiments of this application, the focal length of the first lens and the focal length of the collimating lens group satisfy the following relationship:

[0019] 1.5 < F1 / F A <2.4

[0020] Where F1 is the focal length of the first lens;

[0021] and / or

[0022] The focal length of the second lens and the focal length of the collimating lens group satisfy the following relationship:

[0023] 2.1 < F2 / F A <3.2

[0024] Where F2 is the focal length of the second lens;

[0025] and / or

[0026] The focal length of the third lens and the focal length of the collimating lens group satisfy the following relationship:

[0027] 2.7 < F3 / F A <3.4

[0028] Where F3 is the focal length of the third lens.

[0029] According to any of the foregoing embodiments of this application, the light source side of the first lens is concave, the illumination side is convex, and the refractive index of the first lens satisfies the following relationship:

[0030] 1.4 < n A1 <1.5

[0031] Where, n A1 Let be the refractive index of the first lens;

[0032] and / or

[0033] The light source side of the second lens is concave, and the illumination side is convex. The refractive index of the second lens satisfies the following relationship:

[0034] 1.4 < n A2 <1.5

[0035] Where, n A2 Let be the refractive index of the second lens;

[0036] and / or

[0037] The light source side and the illumination side of the third lens are both convex. The refractive index of the third lens satisfies the following relationship:

[0038] 1.4 < n A3 <1.5

[0039] Where, n A3 is the refractive index of the third lens.

[0040] According to any of the foregoing embodiments of this application, the compound eyepiece assembly includes a first compound eye lens and a second compound eye lens arranged sequentially along the direction of illumination light transmission.

[0041] The light source side of the second compound eye lens coincides with the focal point of the first compound eye lens.

[0042] Both the first and second compound eye lenses are positive diopter.

[0043] According to any of the foregoing embodiments of this application, the focal length of the collimating lens group and the focal length of the microlens units in the first and second compound eye lenses satisfy the following relationship:

[0044] 0.3 < F0 / F A <0.8

[0045] Where F0 is the focal length of the microlens unit in the first and second compound eye lenses.

[0046] According to any of the foregoing embodiments of this application, the light source side of the first compound eye lens and the second compound eye lens are convex, and the illumination side is planar.

[0047] According to any of the foregoing embodiments of this application, the refractive indices of the first compound eye lens and the second compound eye lens satisfy the following relationship:

[0048] 1.4 < n B <1.5

[0049] Where, n B Let be the refractive index of the first compound eye lens and the second compound eye lens.

[0050] According to any of the foregoing embodiments of this application, the focusing lens group includes a fourth lens and a fifth lens.

[0051] Both the fourth and fifth lenses are positive power.

[0052] According to any of the foregoing embodiments of this application, the focal length of the fourth lens and the focal length of the collimating lens group satisfy the following relationship:

[0053] 7.8 < F4 / F A <8.7

[0054] Where F4 is the focal length of the fourth lens;

[0055] and / or

[0056] The focal length of the fifth lens and the focal length of the collimating lens group satisfy the following relationship:

[0057] 26 < F5 / F A <28.3

[0058] F5 is the focal length of the fifth lens.

[0059] According to any of the foregoing embodiments of this application, the light source side of the fourth lens is convex, the illumination side is convex, and the refractive index of the fourth lens satisfies the following relationship:

[0060] 1.4 < n C1 <1.5

[0061] Where, n C1 The refractive index of the fourth lens;

[0062] and / or

[0063] The light source side and the illumination side of the fifth lens are both convex. The refractive index of the fifth lens satisfies the following relationship:

[0064] 1.4 < n C2 <1.5

[0065] Where, n C2 is the refractive index of the fifth lens.

[0066] According to any of the foregoing embodiments of this application, the photolithography illumination lens further includes a first aperture stop;

[0067] The first aperture is positioned between the collimating lens group and the compound lens group to intercept edge rays in the illumination light collimated by the collimating lens group.

[0068] According to any of the foregoing embodiments of this application, the distance between the first aperture and the collimating lens group is 15mm to 17mm, the distance between the first aperture and the compound lens group is 22mm to 27mm, and the diameter of the first aperture is 87mm to 93mm.

[0069] According to any of the foregoing embodiments of this application, the photolithography illumination lens further includes a second aperture;

[0070] The second aperture is positioned between the compound lens group and the focusing lens group to intercept edge rays in the illumination light that has been uniformly shaped by the compound lens group.

[0071] According to any of the foregoing embodiments of this application, the distance between the second aperture and the compound lens group is 0.1mm to 0.5mm, the distance between the second aperture and the focusing lens group is 290mm to 300mm, and the diameter of the second aperture is 73mm to 80mm.

[0072] In the lithography illumination lens of this application embodiment, the compound eyepiece group plays a crucial role in uniform light distribution and beam shaping. A rectangular microlens structure can be used as needed to shape the light emitted from the light source into a highly uniform rectangular spot, ensuring smooth lithography illumination. By rationally setting the radius of curvature and size of the compound eyepiece group, a highly uniform spot with a large illumination area is obtained. All parts of this lithography illumination lens can use optical glass of the same material, effectively reducing costs. Simultaneously, this design also features a low image-side numerical aperture and a narrow transition region. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the structure of the photolithography illumination lens provided in the embodiments of this application;

[0074] Figure 2 This is a schematic diagram (grayscale image) of the illumination spot of the photolithography illumination lens provided in the embodiments of this application;

[0075] Figure 3 This is a schematic diagram (pseudo-color image) of the illumination spot of the photolithography illumination lens provided in the embodiments of this application. Detailed Implementation

[0076] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0077] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0078] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0079] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0080] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0081] It should be noted that, where there is no conflict, different features in the embodiments of this application can be combined with each other.

[0082] To facilitate understanding of the optical lenses provided in the embodiments of this application, the relevant terms used in this application are explained as follows:

[0083] Light source: A light-emitting component that provides illumination input;

[0084] Illuminated surface: The surface on the work surface where the light spot is projected after the light source is shaped by the illumination lens;

[0085] The optical axis is an axis that passes through the center of each optical lens.

[0086] With the lens as the boundary, the side where the light source is located is called the object side, and the surface of the lens closest to the light source is called the light source side surface.

[0087] With the lens as the boundary, the side where the image of the light source is located is called the illumination side, and the surface of the lens closest to the illumination side is called the illumination side surface.

[0088] Positive optical power, also known as positive refractive power, indicates that a lens has a positive focal length.

[0089] Negative optical power, also known as negative refractive power, indicates that a lens has a negative focal length.

[0090] Focal length is a measure of the convergence or divergence of light in an optical system. It refers to the distance from the optical center of the lens to the focal point where parallel light converges when incident.

[0091] Please see Figure 1 The lithography illumination lens 100 provided in this application embodiment includes a light source 01, a collimating lens group A, a compound eye lens group B, and a focusing lens group C arranged sequentially along the illumination light transmission direction.

[0092] Light source 01 is used to provide illumination. In some embodiments, light source 01 can be an LED light source 01 with a wavelength of 365nm and a certain divergence angle, providing illumination source 01 input for the entire lighting system. At the same time, it can avoid the environmental pollution caused by using high-pressure mercury lamps and reduce the risk of personal injury caused by inhaling mercury vapor.

[0093] Collimating lens group A has positive optical power and is used to collimate the illumination light emitted by light source 01 with a certain divergence angle. Collimating lens group A includes at least a first lens 1, a second lens 2, and a third lens 3 arranged sequentially along the illumination light transmission direction. The first lens 1, the second lens 2, and the third lens 3 are all spherical mirrors.

[0094] The compound lens group B has positive optical power and is used to homogenize and shape the illumination light collimated by the collimating lens group A to improve the uniformity of the light spot and obtain an illumination spot of a specific shape.

[0095] The focusing lens group C has positive optical power and is used to focus the illumination light shaped by the uniform light of the compressive lens group B onto the illumination surface O2; ultimately forming a large-area, highly uniform, low image-side numerical aperture, and narrow transition zone photolithographic illumination spot.

[0096] In this application, by employing a fully positive power lens group, the illumination light emitted by the light source 01 with a large divergence angle is effectively focused and shaped, ensuring that the light has a small incident angle on each lens surface, effectively reducing the tolerance sensitivity of the system and improving the assembly yield of the optical system; at the same time, all lenses of the collimating lens group A are spherical lenses, which effectively reduces costs while ensuring collimation effect; using this design scheme, fewer lenses can be used while ensuring the performance parameters of the optical system, effectively reducing costs.

[0097] In some embodiments, the focal length of the collimating lens group A and the focal length of the compound lens group B satisfy the following relationship:

[0098] 1.2 < F A / F B <1.3

[0099] Among them, F A F is the focal length of collimating lens group A. B This is the focal length of the compound eyepiece group B. This setting is beneficial for achieving a large area of ​​illumination spot.

[0100] In some embodiments, the focal length of the compound lens group B and the focal length of the focusing lens group C satisfy the following relationship:

[0101] 0.1 < F A / F C <0.2

[0102] Among them, F C This refers to the focal length of the focusing lens group C. This setting facilitates a longer image-side working distance, ensuring that the lithography illumination lens 100 can be properly assembled with the mechanical structure.

[0103] In some embodiments, the first lens 1, the second lens 2, and the third lens 3 are all positive optical power. This arrangement is beneficial for achieving high collimation of the diverging light from the light source. Through the converging effect of the positive optical power lenses, the three lenses converge step by step to obtain an output beam with high collimation in different fields of view.

[0104] In some embodiments, the focal length of the first lens 1 and the focal length of the collimating lens group A satisfy the following relationship:

[0105] 1.5 < F1 / F A <2.4

[0106] Here, F1 is the focal length of the first lens 1. This setting helps to achieve a preliminary converging effect on the illumination source and reduce the divergence angle of the edge light rays.

[0107] In some embodiments, the focal length of the second lens 2 and the focal length of the collimating lens group A satisfy the following relationship:

[0108] 2.1 < F2 / F A <3.2

[0109] Where F2 is the focal length of the second lens 2. This setting is beneficial for further converging and shaping the light from the light source, further reducing the divergence angle of the edge light. The optical power of this lens is relatively small, and its degree of convergence of the divergence angle of light is lower than that of the first lens, ensuring that the other field rays besides the edge rays have a small deflection angle.

[0110] In some embodiments, the focal length of the third lens 3 and the focal length of the collimating lens group A satisfy the following relationship:

[0111] 2.7 < F3 / F A <3.4

[0112] F3 is the focal length of the third lens 3. This setting is beneficial for achieving high collimation and shaping of light from the light source. The optical power of this lens is the smallest among the three lenses in the collimating lens group. It performs the final shaping of the light after it has been collimated and shaped by the first two lenses, so that the light rays in all fields of view, including the edge fields of view, have high collimation.

[0113] In some embodiments, the light source side of the first lens 1 is concave, and the illumination side is convex. The refractive index of the first lens 1 satisfies the following relationship:

[0114] 1.4 < n A1 <1.5

[0115] Where, n A1 Here is the refractive index of the first lens 1. This setting helps to ensure that the diverging rays from each field of view of the light source have a small incident angle on the sides of the first lens 01 and 02, which, while ensuring the convergence of the light from the light source, has low tolerance sensitivity and ensures a high assembly yield.

[0116] In some embodiments, the light source side of the second lens 2 is concave, and the illumination side is convex. The refractive index of the second lens 2 satisfies the following relationship:

[0117] 1.4 < n A2 <1.5

[0118] Where, n A2 Here is the refractive index of the second lens 2. This setting helps to ensure that the diverging rays from each field of view of the light source have a small incident angle on the sides of the second lens 01 and 02, which, while ensuring the convergence of the light from the light source, has low tolerance sensitivity and ensures a high assembly yield.

[0119] In some embodiments, the light source side of the third lens 3 is convex, the illumination side is convex, and the refractive index of the third lens 3 satisfies the following relationship:

[0120] 1.4 < n A3 <1.5

[0121] Where, n A3 The refractive index of the third lens 3 is given. This setting facilitates the achievement of smaller incident angles on the sides of the third lens 01 and 02 for diverging rays from each field of view of the light source. While ensuring the convergence of light from the light source, it also has lower tolerance sensitivity and guarantees a higher assembly yield.

[0122] The first lens 1, the second lens 2, and the third lens 3 are all made of optical quartz material with a refractive index of 1.4 to 1.5, which can ensure high transmittance of i-ray ultraviolet light and effectively reduce costs.

[0123] In this embodiment, the first lens 1, the second lens 2, and the third lens 3 are all spherical mirrors. Since the illumination source is an extended light source, the divergence angle of the light in different fields of view is different. It is necessary to fully collimate the diverging light in multiple fields of view. By reasonably designing the parameters of the three spherical mirrors, the light is collimated at least three times, so that the collimating lens group A can effectively reduce the cost while maintaining a high collimation effect.

[0124] In some embodiments, the compound eye lens group B includes a first compound eye lens 4 and a second compound eye lens 5 arranged sequentially along the direction of illumination light transmission. The light source side of the second compound eye lens 5 coincides with the focal point of the first compound eye lens 4. Both the first compound eye lens 4 and the second compound eye lens 5 are positive optical powers. The first compound eye lens 4 is used to differentiate the parallel light collimated by the collimating lens group A, and the second compound eye lens 5 is used to integrate the light emitted from the first compound eye lens 4, thereby achieving the purpose of homogenization and shaping of light.

[0125] In some embodiments, the first compound eye lens 4 and the second compound eye lens 5 are composed of identical microlens units spliced ​​together, and the focal length of the collimating lens group A and the focal length of the microlens units in the first compound eye lens 4 and the second compound eye lens 5 satisfy the following relationship:

[0126] 0.3 < F0 / F A <0.8

[0127] Where F0 is the focal length of the microlens unit in the first compound eye lens 4 and the second compound eye lens 5. This configuration is beneficial for achieving a large-area illumination spot.

[0128] In some embodiments, the size of the microlens unit is 3.6mm × 3.6mm, which can ensure a large illumination spot area, while ensuring the manufacturability of the microlens unit and the feasibility of bonding the microlens unit into a compound eye lens.

[0129] In some embodiments, the arrangement of the microlens units determines the final shape of the light spot. For example, if the microlens units are arranged in a rectangle, the resulting light spot shape is rectangular; if the microlens units are arranged in a circle, the resulting light spot shape is circular. In this embodiment, the first compound eye lens 4 and the second compound eye lens 5 have identical structures. The microlens units of both the first compound eye lens 4 and the second compound eye lens 5 are arranged in a rectangle, and the microlens units of the first compound eye lens 4 correspond one-to-one with the microlens units of the second compound eye lens 5.

[0130] In some embodiments, the light source side surfaces of the first compound eye lens 4 and the second compound eye lens 5 are convex, while the illumination side surfaces are planar. This arrangement facilitates the segmentation of the illumination source, allowing for differentiation followed by integration of the illumination source, thus achieving highly uniform illumination.

[0131] In some embodiments, the refractive indices of the first compound eye lens 4 and the second compound eye lens 5 satisfy the following relationship:

[0132] 1.4 < n B <1.5

[0133] Where, n BThe refractive index is the refractive index of the first compound eye lens 4 and the second compound eye lens 5. In the embodiments of this application, the first compound eye lens 4 and the second compound eye lens 5 are made of optical quartz material with a refractive index of 1.4 to 1.5, which can ensure high transmittance of i-ray ultraviolet light and effectively reduce costs.

[0134] In some embodiments, the focusing lens group C includes a fourth lens 6 and a fifth lens 7, both of which are positive optical powers. This arrangement facilitates the convergence and imaging of the illumination spot homogenized by the compound eye lens group, resulting in a highly uniform illumination spot.

[0135] In some embodiments, the focal length of the fourth lens 6 and the focal length of the collimating lens group A satisfy the following relationship:

[0136] 7.8 < F4 / F A <8.7

[0137] F4 is the focal length of the fourth lens 6. This setting facilitates imaging of illumination spots over long working distances and is also beneficial for lens mounting.

[0138] In some embodiments, the focal length of the fifth lens 7 and the focal length of the collimating lens group A satisfy the following relationship:

[0139] 26 < F5 / F A <28.3

[0140] F5 is the focal length of the fifth lens 7. This setting facilitates long-distance illumination spot imaging and is also beneficial for lens mounting.

[0141] In some embodiments, the light source side of the fourth lens 6 is convex, the illumination side is convex, and the refractive index of the fourth lens 6 satisfies the following relationship:

[0142] 1.4 < n C1 <1.5

[0143] Where, n C1 This is the refractive index of the fourth lens 6. This setting facilitates the convergence imaging of a highly uniform light spot after passing through the compound eye lens group.

[0144] In some embodiments, the light source side of the fifth lens 7 is convex, the illumination side is convex, and the refractive index of the fifth lens 7 satisfies the following relationship:

[0145] 1.4 < n C2 <1.5

[0146] Where, n C2 This is the refractive index of the fifth lens 7. This setting facilitates the convergence imaging of a highly uniform light spot after passing through the compound eye lens group.

[0147] In this embodiment, both the fourth lens 6 and the fifth lens 7 are made of optical quartz material with a refractive index of 1.4 to 1.5, which can ensure high transmittance for i-ray ultraviolet light and effectively reduce costs.

[0148] In some embodiments, the lithography illumination lens 100 further includes a first aperture stop S1; the first aperture stop S1 is disposed between the collimating lens group A and the compound lens group B, and is used to intercept edge rays in the illumination light collimated by the collimating lens group A. By setting the first aperture stop S1, stray light entering the compound lens group B can be reduced.

[0149] In some embodiments, the distance between the first aperture S1 and the collimating lens group A is 15mm to 17mm, the distance between the first aperture S1 and the compound lens group B is 22mm to 27mm, and the diameter of the first aperture S1 is 87mm to 93mm. This arrangement helps to reduce stray light generated in the compound lens group B while ensuring that sufficient illumination source O1 is transmitted to the compound lens group B.

[0150] In some embodiments, the lithography illumination lens 100 further includes a second aperture S2; the second aperture S2 is disposed between the compound lens group B and the focusing lens group C, and is used to intercept edge rays in the illumination light that has been homogenized and shaped by the compound lens group B.

[0151] In some embodiments, the distance between the second aperture S2 and the compound lens group B is 0.1mm to 0.5mm, the distance between the second aperture S2 and the focusing lens group C is 290mm to 300mm, and the diameter of the second aperture S2 is 73mm to 80mm. This arrangement is beneficial for controlling light rays with large edge divergence angles and stray light, while achieving large-area illumination.

[0152] In some instances, the key parameters of the lithography illumination lens 100 satisfy the following relationships: F / #=1 / (2NA), NA=nsin(u), (y / 2) / F2=(h / 2) / F3, tan(u)=Y / (2F2);

[0153] Where F / # represents the system aperture value, NA represents the system numerical aperture, u represents the image-side aperture angle, h represents the size of the illumination surface 02, and Y represents the size of the microlens unit; the working distance of the lithography illumination lens 100 is >365mm; the image-side numerical aperture of the lithography illumination lens 100 is <0.1.

[0154] like Figure 2 As shown, the illumination spot of the photolithography illumination lens 100 is a rectangle with an area > 80mm * 80mm; the non-uniformity of the illumination spot of the photolithography illumination lens 100 is < 3%; and the size of the transition zone of the photolithography illumination lens 100 is < 1mm. Figure 3As shown in the figure, the transition area is the yellow line area between the central red area and the outer blue area. It can be seen from the figure that the transition area of ​​the illumination spot formed by the photolithography illumination lens 100 in this embodiment is very narrow.

[0155] In summary, the lithography illumination lens 100 provided in this application embodiment is based on the design of the compound eyepiece group B, combined with the collimating lens group A using spherical lenses and the focusing lens group C. It has the advantages of high uniformity, low image-side numerical aperture, large illumination area, and narrow transition region. It can be used in the illumination system of i-line lithography machines, and in particular, it can be used in the illumination system of proximity / contact lithography machines and surface plasmon super-resolution lithography equipment. It can achieve large-area, high-uniformity illumination, while providing a large collimation of the illumination light, which fully ensures that the pattern is uniformly and effectively transferred onto the wafer.

[0156] The lithography illumination lens 100 provided in this embodiment consists of 5 lenses plus 2 compound eye lenses, achieving a good illumination effect with a relatively small number of lenses. Furthermore, all optical components are made of the same quartz material, effectively reducing costs. At the same time, the smaller number of lenses effectively reduces the cumulative tolerances in lens assembly, ensuring optimal illumination.

[0157] Example

[0158] In one specific embodiment of this application, a photolithography illumination lens 100 as shown in Table 1 is provided.

[0159]

[0160]

[0161] In one specific embodiment of this application, a photolithography illumination lens 100 is provided as shown in Table 1. The focal length of the first lens 1 is F1 = 130.99 mm, the focal length of the second lens 2 is F2 = 177.84 mm, the focal length of the third lens 3 is F3 = 207.4 mm, the focal length of the compound eye lens is F4 = 38.35 mm, the focal length of the double compound eye lens is F5 = 38.35 mm, the focal length of the fourth lens 6 is F6 = 548.65 mm, and the focal length of the fifth lens 7 is F7 = 1854.36 mm; all units are mm.

[0162] In this embodiment, the double compound eyeglass group B is made of microlenses with the same parameters bonded together;

[0163] In this embodiment, the size of the compound eye microlens unit of the double compound eye lens group B is 3.6mm×3.6mm, which ensures a large illumination spot area, while ensuring the manufacturability of the microlens unit and the feasibility of bonding the microlens unit into a compound eye lens.

[0164] In this embodiment, the image-side numerical aperture of the provided lithography illumination lens 100 is <0.1, which effectively ensures the image-side telecentricity and ensures that the lithography exposure pattern is transferred to the wafer surface with high quality.

[0165] Figure 2 The illumination spot pattern of the photolithography illumination lens 100 provided in this embodiment is shown in the figure. The illumination spot area is >80mm×80mm, the non-uniformity is <3%, and the transition area is <1mm, which effectively ensures the effect of large area, high uniformity, and narrow transition area.

[0166] In this embodiment, the lithography illumination lens 100 uses i-line 365nm ultraviolet light for imaging, which can be used for illumination of i-line lithography systems. In particular, it can be used in lithography systems such as i-line proximity / contact lithography machines and surface plasmon super-resolution lithography machines.

Claims

1. A photolithography illumination lens, characterized in that: It includes a light source, a collimating lens group, a compound eyepiece group, and a focusing lens group arranged sequentially along the direction of illumination light transmission. The lithography illumination lens has three lens groups with optical power. The light source is used to provide illumination light; The collimating lens group has positive optical power and is used to collimate the illumination light emitted by the light source; The collimating lens group consists of a first lens, a second lens, and a third lens arranged sequentially along the direction of illumination light transmission, wherein the first lens, the second lens, and the third lens are all spherical mirrors; The light source side of the first lens is concave, and the illumination side is convex. The light source side of the second lens is concave, and the illumination side is convex. The light source side and the illumination side of the third lens are both convex. The first lens, the second lens, and the third lens all have positive optical power; The compound eyeglass group has positive optical power and is used to homogenize and shape the illumination light collimated by the collimating lens group; The compound eyepiece assembly consists of a first compound eye lens and a second compound eye lens arranged sequentially along the direction of illumination light transmission; The first compound eye lens and the second compound eye lens have exactly the same parameters; Both the first and second compound eye lenses have convex light source sides and planar illumination sides; Both the first compound eye lens and the second compound eye lens have positive optical power; The microlens units of the first compound eye lens and the second compound eye lens are arranged in a rectangular shape, and the microlens units of the first compound eye lens correspond one-to-one with the microlens units of the second compound eye lens. The focusing lens group has positive optical power and is used to focus the illumination light, which has been uniformly shaped by the compound eye lens group, onto the illumination surface. The focusing lens group consists of a fourth lens and a fifth lens; The light source side of the fourth lens is convex, and the illumination side is convex. The light source side of the fifth lens is convex, and the illumination side is flat. Both the fourth lens and the fifth lens have positive optical power; The focal lengths of the collimating lens group and the compound lens group satisfy the following relationship: 1.2<F A / F B <1.3 Among them, F A F is the focal length of the collimating lens group. B The focal length of the compound eyeglasses group; and, The focal length of the compound eyeglass group and the focal length of the focusing lens group satisfy the following relationship: 0.1<F A / F C <0.2 Among them, F C is the focal length of the focusing lens group.

2. The photolithography illumination lens according to claim 1, characterized in that: The focal length of the first lens and the focal length of the collimating lens group satisfy the following relationship: 1.5<F1 / F A <2.4 Where F1 is the focal length of the first lens; and / or The focal length of the second lens and the focal length of the collimating lens group satisfy the following relationship: 2.1<F2 / F A <3.2 Where F2 is the focal length of the second lens; and / or The focal length of the third lens and the focal length of the collimating lens group satisfy the following relationship: 2.7 <F3 / F A <3.4 Wherein, F3 is the focal length of the third lens.

3. The photolithography illumination lens according to claim 1, characterized in that: The refractive index of the first lens satisfies the following relationship: 1.4＜n A1 ＜1.5 Where, n A1 Let be the refractive index of the first lens; and / or The refractive index of the second lens satisfies the following relationship 1.4＜n A2 ＜1.5 Where, n A2 The refractive index of the second lens is denoted as . and / or The refractive index of the third lens satisfies the following relationship: 1.4＜n A3 ＜1.5 Where, n A3 is the refractive index of the third lens.

4. The photolithography illumination lens according to claim 1, characterized in that: The light source side of the second compound eye lens coincides with the focal point of the first compound eye lens.

5. The photolithography illumination lens according to claim 4, characterized in that: The focal length of the collimating lens group and the focal length of the microlens units in the first and second compound eye lenses satisfy the following relationship: 0.3<F0 / F A <0.8 Wherein, F0 is the focal length of the microlens unit in the first and second compound eye lenses.

6. The photolithography illumination lens according to claim 5, characterized in that: The refractive indices of the first compound eye lens and the second compound eye lens satisfy the following relationship: 1.4＜n B ＜1.5 Where, n B The refractive indices of the first compound eye lens and the second compound eye lens are given.

7. The photolithography illumination lens according to claim 6, characterized in that: The focal length of the fourth lens and the focal length of the collimating lens group satisfy the following relationship: 7.8<F4 / F A <8.7 Wherein, F4 is the focal length of the fourth lens; and / or The focal length of the fifth lens and the focal length of the collimating lens group satisfy the following relationship: 26<F5 / F A <28.3 Wherein, F5 is the focal length of the fifth lens.

8. The photolithography illumination lens according to claim 7, characterized in that: The refractive index of the fourth lens satisfies the following relationship: 1.4＜n C1 ＜1.5 Where, n C1 The refractive index of the fourth lens; and / or The refractive index of the fifth lens satisfies the following relationship: 1.4＜n C2 ＜1.5 Where, n C2 The refractive index of the fifth lens is given.

9. The photolithography illumination lens according to claim 1, characterized in that: It also includes the first aperture; The first aperture is disposed between the collimating lens group and the compound lens group to intercept edge rays in the illumination light collimated by the collimating lens group.

10. The photolithography illumination lens according to claim 9, characterized in that: The distance between the first aperture and the collimating lens group is 15mm to 17mm, the distance between the first aperture and the compound lens group is 22mm to 27mm, and the diameter of the first aperture is 87mm to 93mm.

11. The photolithography illumination lens according to claim 10, characterized in that: It also includes the second aperture; The second aperture is positioned between the compound eyeglass group and the focusing lens group to intercept edge rays in the illumination light that has been uniformly shaped by the compound eyeglass group.

12. The photolithography illumination lens according to claim 11, characterized in that: The distance between the second aperture and the compound eyepiece group is 0.1mm to 0.5mm, the distance between the second aperture and the focusing lens group is 290mm to 300mm, and the diameter of the second aperture is 73mm to 80mm.

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