Projection objective lens system

Abstract

The present application relates to the field of integrated circuit manufacturing technology, and in particular, to a projection objective lens system. The projection objective lens system includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group sequentially arranged in the direction from the object side to the image side of the projection objective lens system. The optical powers of the first lens group to the sixth lens group exhibit positive, negative, positive, negative, positive, and positive. According to the projection objective lens system of the present invention, better aberration control can be achieved, and thus more perfect pattern exposure can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuit manufacturing, and in particular to a projection objective system. Background Art

[0002] With the development of the integrated circuit industry, more and more requirements are put forward for chips in all walks of life. In the projection exposure process of chip manufacturing, the imaging quality of the projection objective largely restricts the quality of the exposed lines. Therefore, in recent years, the projection objective has been continuously developed and explored how to achieve more perfect graphic exposure through better aberration control.

[0003] The above information disclosed in this background art section is only used to enhance the understanding of the background of the present disclosure. Therefore, the above information may include any part that does not form the prior art and also information of the prior art that may not be taught to those of ordinary skill in the art. Summary of the Invention

[0004] The summary of the invention is provided to introduce, in a simplified form, selected concepts that will be further described in the detailed description below. The summary of the invention is neither intended to identify the key features or essential features of the claimed subject matter, nor intended to be used to help determine the scope of the claimed subject matter.

[0005] In order to achieve a better projection exposure imaging effect, the present invention provides a projection objective system, which can achieve more perfect graphic exposure through better aberration control.

[0006] The present invention provides a projection objective system, including a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group sequentially arranged along the object side to the image side direction of the projection objective system; the first lens group, the third lens group, the fifth lens group, and the sixth lens group have positive optical powers; the second lens group and the fourth lens group have negative optical powers.

[0007] Further, the first lens group satisfies: f1 / L < 0.5; where f1 is the focal length of the first lens group, and L is the object-image distance of the projection objective system.

[0008] Further, the first lens group includes at least one biconcave lens, at least one meniscus lens, and at least one biconvex lens.

[0009] Further, the first lens group includes a second lens to a sixth lens; the second lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the third lens is a meniscus lens with the object-side surface being concave and the image-side surface being convex; the fourth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the fifth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the sixth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave.

[0010] Further, the third lens, the fourth lens, and the fifth lens form a nearly symmetric positive lens group, and the optical powers of the third lens, the fourth lens, and the fifth lens are close to each other.

[0011] Further, the second lens group satisfies: f2 / L < -0.05; where f2 is the focal length of the second lens group, and L is the object-image distance of the projection objective system.

[0012] Further, the second lens group includes at least one biconcave lens.

[0013] Further, the second lens group includes a seventh lens and an eighth lens; the seventh lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the eighth lens is a biconcave lens with both the object-side surface and the image-side surface being concave.

[0014] Further, the third lens group satisfies: 0.01 < f3 / L < 0.5; where f3 is the focal length of the third lens group, and L is the object-image distance of the projection objective system.

[0015] Further, the third lens group includes at least one meniscus lens and at least one biconvex lens.

[0016] Further, the third lens group includes a ninth lens to a twelfth lens; the ninth lens is a meniscus lens with the object-side surface being concave and the image-side surface being convex; the tenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the eleventh lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the twelfth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave.

[0017] Further, the fourth lens group satisfies: f4 / L < -0.05; where f4 is the focal length of the fourth lens group, and L is the object-image distance of the projection objective system.

[0018] Further, the fourth lens group includes at least one biconcave lens.

[0019] Further, the fourth lens group includes a thirteenth lens and a fourteenth lens; the thirteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the fourteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave.

[0020] Further, the fifth lens group satisfies: 0.01 < f5 / L < 0.8; where f5 is the focal length of the fifth lens group, and L is the object-image distance of the projection objective system.

[0021] Further, the fifth lens group includes at least one biconvex lens.

[0022] Further, the fifth lens group includes a fifteenth lens and a sixteenth lens; the fifteenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the sixteenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex.

[0023] Further, the sixth lens group satisfies: 0.1 < f6 / L < 1.5; where f6 is the focal length of the sixth lens group, and L is the object-image distance of the projection objective system.

[0024] Further, the sixth lens group includes at least one biconcave lens, at least one meniscus lens, and at least one biconvex lens.

[0025] Further, the sixth lens group includes a seventeenth lens to a twenty-fourth lens; the seventeenth lens, the nineteenth lens, and the twentieth lens are biconvex lenses with both the object-side surface and the image-side surface being convex; the eighteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the twenty-first lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the twenty-second to the twenty-fourth lenses are meniscus lenses with the object-side surface being convex and the image-side surface being concave.

[0026] Further, the sixth lens of the first lens group and the ninth lens of the third lens group satisfy: 0.05 < ∣(R6A - R6B) / (R6A + R6B)∣ < 5; 0.05 < ∣(R9A - R9B) / (R9A + R9B)∣ < 5; where R6A is the curvature radius of the object-side surface of the sixth lens, R6B is the curvature radius of the image-side surface of the sixth lens; R9A is the curvature radius of the object-side surface of the ninth lens, and R9B is the curvature radius of the image-side surface of the ninth lens.

[0027] Further, the eleventh lens of the third lens group and the fourteenth lens of the fourth lens group satisfy: 0.05 < ∣(R11A - R11B) / (R11A + R11B)∣ < 5; 0.05 < ∣(R14A - R14B) / (R14A + R149B)∣ < 5; where: R11A is the radius of curvature of the object-side surface of the eleventh lens, R11B is the radius of curvature of the image-side surface of the eleventh lens; R14A is the radius of curvature of the object-side surface of the fourteenth lens, and R14B is the radius of curvature of the image-side surface of the fourteenth lens.

[0028] Further, the projection objective system further includes an aperture stop; the aperture stop is disposed between the image-side surface of the fifth lens group and the object-side surface of the sixth lens group.

[0029] Further, the projection objective system further includes a first lens and a twenty-fifth lens; the first lens is disposed on the image-side of the first lens group, and the twenty-fifth lens is disposed on the object-side of the sixth lens group; the first lens and the twenty-fifth lens are flat lenses.

[0030] Further, the object-side surface and the image-side surface of the lenses in the first lens group to the sixth lens group include four aspherical surfaces, and the maximum aspherical aberration sag height is less than 0.5 mm.

[0031] Further, the first lens group includes the second lens to the sixth lens, the second lens group includes the seventh lens and the eighth lens, the third lens group includes the ninth lens to the twelfth lens, the fourth lens group includes the thirteenth lens and the fourteenth lens, the fifth lens group includes the fifteenth lens and the sixteenth lens, and the sixth lens group includes the seventeenth lens to the twenty-fourth lens; the object-side surface of the second lens, the object-side surface of the eighth lens, the image-side surface of the thirteenth lens, and the image-side surface of the eighteenth lens are aspherical surfaces, and the maximum aspherical aberration sag height is 0.11 mm.

[0032] Further, the image-side numerical aperture of the projection objective system under I-line illumination with a wavelength of 365 nm and a spectral line width of 5 nm is 0.62; the object-image distance L of the projection objective system is 1000 mm; the magnification of the projection objective system is 1 / 5, and the exposure field is 22 * 22 mm.

[0033] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. Description of the Drawings

[0034] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic structural diagram of the projection objective lens system of Embodiment 1;

[0036] Figure 2 It presents the diffraction MTF imaging effect diagram of the projection objective lens system of Embodiment 1;

[0037] Figure 3 It presents the aberration curve diagram of the projection objective lens system of Embodiment 1;

[0038] Figure 4 It presents the field curvature and distortion diagram of the projection objective lens system of Embodiment 1;

[0039] Figure 5 It presents the RMS wavefront error diagram of the projection objective lens system of Embodiment 1;

[0040] Figure 6 It presents the telecentricity diagram of the projection objective lens system of Embodiment 1;

[0041] Figure 7 It is a schematic structural diagram of the projection objective lens system of Embodiment 2;

[0042] Figure 8 It presents the diffraction MTF imaging effect diagram of the projection objective lens system of Embodiment 2;

[0043] Figure 9 It presents the aberration curve diagram of the projection objective lens system of Embodiment 2;

[0044] Figure 10 It presents the field curvature and distortion diagram of the projection objective lens system of Embodiment 2;

[0045] Figure 11 It presents the RMS wavefront error diagram of the projection objective lens system of Embodiment 2;

[0046] Figure 12 It presents the telecentricity diagram of the projection objective lens system of Embodiment 2. Detailed implementation manners

[0047] The following specific embodiments are provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of the present application, various transformations, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent. For example, the order of operations described herein is merely exemplary and is not limited to the order set forth herein, but rather, changes that will be apparent after understanding the disclosure of the present application may be made, except for operations that must occur in a specific order. Additionally, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0048] The features described herein may be implemented in different forms and are not to be construed as limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0049] The present disclosure provides a projection objective lens system having good aberration control to achieve a projection exposure imaging effect.

[0050] Embodiment 1

[0051] Referring to Figure 1 Describe the projection objective lens system of Embodiment 1. The projection objective lens system is a projection objective lens system based on I-line illumination, that is, the wavelength of the incident light is 365 nm, the spectral line width is 5 nm, the total optical path length of the projection objective lens system, i.e., the object-image distance, is 1000 mm, the image-side numerical aperture is 0.62, the magnification is 1 / 5, the exposure field of view is 22 mm * 22 mm, the projection objective lens system is a double telecentric lens, and is in an environment surrounded by nitrogen.

[0052] The projection objective lens system includes a plurality of lens groups. For example, the projection objective lens system includes a first lens group L1, a second lens group L2, a third lens group L3, a fourth lens group L4, a fifth lens group L5, and a sixth lens group L6 arranged in sequence from the object side to the image side of the projection objective lens system, and as a whole presents an optical structure with two waists and three bellies.

[0053] The six lens groups have optical powers. For example, the first lens group L1, the third lens group L3, the fifth lens group L5, and the sixth lens group L6 have positive optical powers, and the second lens group L2 and the fourth lens group L4 have negative optical powers, such that the optical powers of the first lens group L1 to the sixth lens group L6 present positive, negative, positive, negative, positive, positive.

[0054] The first lens group L1 to the sixth lens group L6 each include a plurality of lenses. For example, the six lens groups together include 23 lenses, which are successively the second lens 2, the third lens 3, the fourth lens 4... the twenty-fourth lens 24 arranged in the direction from the object side to the image side of the projection hardware system. Among them, the first lens group L1 includes the second lens 2 to the sixth lens 6, the second lens group L2 includes the seventh lens 7 and the eighth lens 8, the third lens group L3 includes the ninth lens 9 to the twelfth lens 12, the fourth lens group L4 includes the thirteenth lens 13 and the fourteenth lens 14, the fifth lens group L5 includes the fifteenth lens 15 and the sixteenth lens 16, and the sixth lens group L6 includes the seventeenth lens 17 to the twenty-fourth lens 24.

[0055] The projection objective system further includes a first lens 1 and a twenty-fifth lens 25. The first lens 1 is located on the object side of the first lens group L1, that is, the first lens 1 is the lens closest to the object (or mask) in the projection objective system; the twenty-fifth lens 25 is located on the image side of the sixth lens group L6, that is, the twenty-fifth lens 25 is the lens closest to the imaging surface (or semiconductor substrate material layer 26, silicon wafer) in the projection objective system. Both the first lens 1 and the twenty-fifth lens 25 are flat lenses, which can play the role of a protection window and at the same time can achieve the effect of enclosing the nitrogen environment inside the projection objective system.

[0056] Regarding the first lens group L1 with positive optical power, among the second lens 2 to the sixth lens 6 in the first lens group L1, there are at least one double concave lens, at least one meniscus lens, and at least one double convex lens.

[0057] For example, the second lens 2 is a double concave lens, that is, both the object surface and the image surface of the second lens 2 are concave along the optical axis of the projection objective system; it can play a good role in expanding the light angle and at the same time can play a good role in correcting the field curvature of the system.

[0058] The fourth lens 4 is a double convex lens, that is, both the object surface and the image surface of the fourth lens 4 are convex along the optical axis; the third lens 3 and the fifth lens 5 are meniscus lenses bent towards the fourth lens 4, that is, the object surface of the third lens 3 is concave along the optical axis, the image surface of the third lens 3 is convex along the optical axis, the object surface of the fifth lens 5 is convex along the optical axis, and the image surface of the fifth lens 5 is concave along the optical axis. The third lens 3, the fourth lens 4, and the fifth lens 5 form a nearly symmetric positive lens group, and the optical powers of the third lens 3, the fourth lens 4, and the fifth lens 5 are close; as described above, the first lens group L1 has positive optical power, and through the third lens 3, the fourth lens 4, and the fifth lens 5, the required positive optical power of the first lens group L1 can be evenly divided well, and at the same time, it can play a good role in reducing the coma and astigmatism of the projection objective system.

[0059] The sixth lens group L6 is a meniscus lens bent towards the second lens group L2, that is, the object surface of the sixth lens 6 is convex along the optical axis, and the image surface of the sixth lens 6 is concave along the optical axis; as described above, the projection objective lens system of the present application presents an optical structure with two waists and three bellies, and the sixth lens 6 of the first lens group L1 is a meniscus lens bent towards the first waist; through the sixth lens 6, a positive lens group formed by the third lens 3, the fourth lens 4, and the fifth lens group L5 can achieve a good effect of eliminating chromatic aberration and spherical aberration.

[0060] The first lens group L1 satisfies: f1 / L < 0.5; where f1 is the focal length of the first lens group L1, and L is the object-image distance of the projection objective lens system, that is, a mask plate is arranged on the object side of the projection objective lens system, and a semiconductor substrate material layer 26 (such as a silicon wafer) is arranged on the image side of the projection objective lens system, and the object-image distance L is the distance between the image surface of the mask plate and the object surface of the silicon wafer on the optical axis. By making the first lens group L1 satisfy f1 / L < 0.5, the high-order spherical aberration of the first lens group L1 can be eliminated to a certain extent.

[0061] Regarding the second lens group L2 with negative optical power, at least one of the seventh lens 7 and the second lens 2 in the second lens group L2 is a negative lens with negative optical power. For example, at least one of the seventh lens 7 and the eighth lens 8 is a double concave lens.

[0062] For example, the object surface of the seventh lens 7 is convex along the optical axis, and the image surface of the seventh lens 7 is concave along the optical axis; the eighth lens 8 is a double concave lens, that is, both the object surface and the image surface of the eighth lens 8 are concave along the optical axis. By setting the eighth lens 8 as a double concave lens, the field curvature generated by the first lens group L1 can be eliminated to a certain extent.

[0063] The second lens group L2 satisfies: f2 / L < -0.05 to reduce the sum of the Petzval field curvatures of the first lens group L1 and the second lens group L2; where f2 is the focal length of the second lens group L2, and L is the object-image distance of the projection objective lens system.

[0064] Regarding the third lens group L3 with positive optical power, at least one meniscus lens and at least one double convex lens are included among the ninth lens 9 to the twelfth lens 12 in the third lens group L3.

[0065] For example, in the third lens group L3, the ninth lens 9 is a meniscus lens bent towards the second lens group L2, and the ninth lens 9 is also a meniscus lens bent towards the first waist of the projection objective lens system, that is, the object surface of the ninth lens 9 is concave along the optical axis, and the image surface of the ninth lens 9 is convex along the optical axis; by setting the ninth lens 9 as a meniscus lens, a good effect of smoothing the light path can be achieved.

[0066] Meanwhile, the sixth lens 6 and the ninth lens 9 located on both sides of the first waist satisfy: 0.05 < ∣(R6A - R6B) / (R6A + R6B)∣ < 5, 0.05 < ∣(R9A - R9B) / (R9A + R9B)∣ < 5; so as to achieve the purpose of eliminating high-order spherical aberration and coma while maintaining the smoothness of the waist light.

[0067] Among them, R6A is the curvature radius of the object-side surface of the sixth lens 6, and R6B is the curvature radius of the image-side surface of the sixth lens 6; R9A is the curvature radius of the object-side surface of the ninth lens 9, and R9B is the curvature radius of the image-side surface of the ninth lens 9.

[0068] The tenth lens 10 is a biconvex lens, that is, both the object-side surface and the image-side surface of the tenth lens 10 are convex along the optical axis; the object-side surface of the eleventh lens 11 is convex along the optical axis, and the image-side surface of the eleventh lens 11 is concave along the optical axis.

[0069] The twelfth lens 12 is a meniscus lens bent towards the fourth lens group L4, and the twelfth lens 12 is also a lens bent towards the second waist of the projection lens system, that is, the object-side surface of the twelfth lens 12 is convex along the optical axis, and the image-side surface of the twelfth lens 12 is concave along the optical axis.

[0070] By setting the first lens and the last lens of the third lens group L3, that is, the ninth lens 9 and the twelfth lens 12, as meniscus lenses bent towards the two waists respectively, it can play a very good role in smoothing the light trend, reducing the lens sensitivity, and balancing the spherical aberration and distortion generated by the tenth lens 10 and the eleventh lens 11.

[0071] The third lens group L3 satisfies 0.01 < f3 / L < 0.5 to achieve the purpose of correcting the high-order spherical aberration of the third lens group L3. Among them, f3 is the focal length of the third lens group L3, and L is the object-image distance of the projection objective system.

[0072] Regarding the fourth lens group L4 with negative optical power, at least one of the thirteenth lens 13 and the fourteenth lens 14 in the fourth lens group L4 is a biconcave lens.

[0073] For example, both the thirteenth lens 13 and the fourteenth lens 14 are biconcave lenses, that is, both the object-side surface and the image-side surface of the thirteenth lens 13 and the fourteenth lens 14 are concave along the optical axis.

[0074] Setting the fourth lens group L4 with negative optical power can converge and diverge the light passing through the third lens group L3. At the same time, the fourth lens group L4 is used to balance the large amount of field curvature generated by the third lens group L3, the fifth lens group L5, and the sixth lens group L6, and to stretch the light path as much as possible to match the large image-side numerical aperture of the projection objective system.

[0075] The fourth lens group L4 satisfies: f4 / L < -0.05, which is used to correct the sum of the partial Petzval field curvature generated by the first lens group L1 to the fourth lens group L4. Here, f4 is the focal length of the fourth lens group L4, and L is the object-image distance of the projection objective system.

[0076] The eleventh lens 11 of the third lens group L3 and the fourteenth lens 14 of the fourth lens group L4 are located on both sides of the second waist of the projection lens system. The radius of curvature of the eleventh lens 11 and the radius of curvature of the fourteenth lens 14 satisfy: 0.05 < ∣(R11A - R11B) / (R11A + R11B)∣ < 5, 0.05 < ∣(R14A - R14B) / (R14A + R149B)∣ < 5; to achieve the purpose of eliminating high-order spherical aberration and coma. Where: R11A is the radius of curvature of the object-side surface of the eleventh lens 11, R11B is the radius of curvature of the image-side surface of the eleventh lens 11; R14A is the radius of curvature of the object-side surface of the fourteenth lens 14, and R14B is the radius of curvature of the image-side surface of the fourteenth lens 14.

[0077] Regarding the fifth lens group L5 with positive optical power, at least one of the fifteenth lens 15 and the sixteenth lens 16 in the fifth lens group L5 is a biconvex lens. For example, both the fifteenth lens 15 and the sixteenth lens 16 are biconvex lenses, that is, the object-side surface and the image-side surface of the fifteenth lens 15 and the sixteenth lens 16 are convex along the optical axis.

[0078] An aperture stop is arranged between the fifth lens group L5 and the sixth lens group L6, and the fifth lens group L5 transmits the light to the aperture stop. The fifth lens group L5 satisfies: 0.01 < f5 / L < 0.8, to achieve the purpose of eliminating high-order spherical aberration. Here, f5 is the focal length of the fifth lens group L5.

[0079] Regarding the sixth lens group L6 with positive optical power, the sixth lens group L6 with positive optical power can converge the light after the aperture stop. Among the seventeenth lens 17 to the twenty-fourth lens 24 in the sixth lens group L6, there are at least one biconcave lens, at least one meniscus lens, and at least one biconvex lens.

[0080] For example, the seventeenth lens 17, the nineteenth lens 19, the twentieth lens 20, and the twenty-first lens 21 are biconvex lenses, that is, the object-side surface and the image-side surface of these lenses are convex along the optical axis; the seventeenth lens 17, the nineteenth lens 19, the twentieth lens 20, and the twenty-first lens 21 all have positive optical power, which can evenly distribute the positive optical power required by the sixth lens group L6 well. At the same time, it can converge light rays and reduce spherical aberration and coma, so as to match the large image-side numerical aperture of the projection objective system.

[0081] The eighteenth lens 18 is a biconcave lens, that is, the object-side surface and the image-side surface of the eighteenth lens 18 are concave along the optical axis; the eighteenth lens 18 is located between the seventeenth lens 17 and the nineteenth lens 19, both of which are biconvex lenses, to eliminate the field curvature of the sixth lens group L6 and complete the constraint on the field curvature of the image plane.

[0082] The object-side surfaces of the twenty-second lens 22 to the twenty-fourth lens 24 are convex along the optical axis, and the image-side surfaces are concave along the optical axis.

[0083] The sixth lens group L6 satisfies: 0.1 < f6 / L < 1.5 to reduce the influence of high-order spherical aberration on the projection objective system. Wherein, f6 is the focal length of the sixth lens group L6, and L is the object-image distance of the projection objective system.

[0084] All the lenses in the first lens group L1 to the sixth lens group L6, that is, the object-side surfaces and the image-side surfaces of the second lens 2 to the twenty-fourth lens 24 include four aspherical surfaces, and the highest aspherical surface degree sag height difference is less than 0.5 mm, which is convenient for processing.

[0085] For example, the object-side surface of the second lens 2, the object-side surface of the eighth lens 8, the image-side surface of the thirteenth lens 13, and the image-side surface of the eighteenth lens 18 are aspherical surfaces, and the maximum aspherical surface degree sag height difference is 0.11 mm, so as to have better adaptability to the processing technology.

[0086] Table 1

[0087]

[0088]

[0089]

[0090]

[0091] Among them, O represents the object side or the reticle, 1A and 1B respectively represent the object-side surface and the image-side surface of the first lens, 2A and 2B respectively represent the object-side surface and the image-side surface of the second lens, and so on, 25A and 25B respectively represent the object-side surface and the image-side surface of the twenty-fifth lens; I represents the image side or the semiconductor substrate material layer or the silicon wafer.

[0092] Table 2

[0093] 2A 8A 13B 18B Y radius -158.167 -151.499 615.2397 145.646 Quadric constant (K) 0 0 0 0 4th order coefficient (A) -9.27E-09 -5.07E-08 5.38E-08 2.34E-08 6th order coefficient (B) 3.90E-13 -3.35E-12 -1.61E-12 -9.01E-13 8th order coefficient (C) -9.03E-18 8.81E-16 3.76E-16 -1.12E-16 10th order coefficient (D) 8.50E-21 -1.70E-19 -5.51E-19 1.68E-20 12th order coefficient (E) -1.16E-24 7.04E-23 2.19E-22 -4.81E-24 14th order coefficient (F) 1.07E-28 -1.39E-26 -4.67E-26 5.69E-28 16th order coefficient (G) 0 0 0 0 18th order coefficient (H) 0 0 0 0 20th order coefficient (J) 0 0 0 0

[0094] Among them, 2A represents the object-side surface of the second lens, 8A represents the object-side surface of the eighth lens, 13B represents the image-side surface of the thirteenth lens, and 18B represents the image-side surface of the eighteenth lens.

[0095] Table 1 presents the lens characteristics of the projection objective system according to the first embodiment; Table 2 presents the aspherical characteristics of the lenses of the projection objective system according to the first embodiment.

[0096] Figure 2 The diffraction MTF imaging effect diagram of the projection objective system of the first embodiment is presented, Figure 3 The aberration curve diagram of the projection objective system of the first embodiment is presented, Figure 4 The field curvature distortion diagram of the projection objective system of the first embodiment is presented, Figure 5 The RMS wavefront error diagram of the projection objective system of the first embodiment is presented, Figure 6 The telecentricity diagram of the projection objective system of the first embodiment is presented.

[0097] Embodiment 2

[0098] Refer to Figure 7 Describe the projection objective system of Embodiment 2. What is the same between the projection objective system of Embodiment 2 and the projection objective system of Embodiment 1 is that it also includes 25 lenses. Except for the first lens and the twenty-fifth lens which are flat lenses, the remaining 23 lenses are also divided into six lens groups, and any lens group in Embodiment 2 contains the same number of lenses as the corresponding lens group in Embodiment 1, and the concave-convex shapes of the surfaces of each lens are also the same.

[0099] The difference between the projection objective system of Embodiment 2 and the projection objective system of Embodiment 1 is only that the projection objective system of Embodiment 1 is in an environment surrounded by nitrogen, while the projection objective system of Embodiment 2 is in an environment surrounded by air, resulting in some differences in the characteristics of the multiple lenses in Embodiment 2 and the multiple lenses in Embodiment 1.

[0100] Table 3 presents the lens characteristics of the projection objective system according to Embodiment 2; Table 4 presents the aspherical characteristics of the lenses of the projection objective system according to Embodiment 2.

[0101] Table 3

[0102]

[0103]

[0104]

[0105] Table 4

[0106]

[0107]

[0108] In Table 1 and Table 2, O represents the object side or the reticle, 1A and 1B respectively represent the object-side surface and the image-side surface of the first lens, 2A and 2B respectively represent the object-side surface and the image-side surface of the second lens, and so on. 25A and 25B respectively represent the object-side surface and the image-side surface of the twenty-fifth lens; I represents the image side or the semiconductor substrate material layer or the silicon wafer.

[0109] Figure 8 The diffraction MTF imaging effect diagram of the projection objective system of the second embodiment is presented. Figure 9 The aberration curve diagram of the projection objective system of the second embodiment is presented. Figure 10 The field curvature and distortion diagram of the projection objective system of the second embodiment is presented. Figure 11 The RMS wavefront error diagram of the projection objective system of the second embodiment is presented. Figure 12 The telecentricity diagram of the projection objective system of the second embodiment is presented.

[0110] According to the above embodiments, the projection objective system of the present application is a double telecentric objective system, and the maximum telecentricity on both the object and image sides is 0.28°, reducing the sensitivity interference between the reticle surface and the exposure surface. The projection objective system has a small number of lenses, which can ensure uniform imaging while having high brightness. The projection objective system of the present application divides multiple lenses into six lens groups, reducing the higher-order spherical aberration and coma of each lens group. The number of aspherical surfaces in the multiple lenses of the projection objective system of the present application is small, and the asphericity is low. The maximum sagitta height is only 0.11 mm, with low processing difficulty and a relatively mature processing technology. Through the reasonable configuration of multiple lenses, the projection objective system of the present application solves the problems of high resolution and low distortion, and has a compact and lightweight structure and shape. When the optical total length, i.e., the object-image distance L, is only 1000 mm, the maximum field curvature is 49 nm, the maximum astigmatism is 40 nm, the maximum distortion is 7 nm, and the maximum wave aberration is 7.6 nm, enabling a good projection exposure imaging effect.

[0111] Although the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail can be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein will be considered only in a descriptive sense and not for purposes of limitation. The description of a feature or aspect in each example will be considered applicable to a similar feature or aspect in other examples. Appropriate results can be obtained if the described techniques are performed in a different order and / or if the components in the described system, architecture, device, or circuit are combined in a different manner and / or replaced or supplemented with other components or their equivalents. Accordingly, the scope of the present disclosure is not limited by the specific embodiments, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents will be construed as being included in the present disclosure.

Claims

1. A projection objective lens system, characterized in that, it includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group sequentially arranged in the direction from the object side to the image side of the projection objective lens system; the first lens group, the third lens group, the fifth lens group, and the sixth lens group have positive optical powers; the second lens group and the fourth lens group have negative optical powers; the first lens group includes at least one biconcave lens, at least one meniscus lens, and at least one biconvex lens; the first lens group includes the second lens to the sixth lens; the second lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the third lens is a meniscus lens with the object-side surface being concave and the image-side surface being convex; the fourth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the fifth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the sixth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the third lens, the fourth lens, and the fifth lens form a group of approximately symmetric positive lens groups, and the optical powers of the third lens, the fourth lens, and the fifth lens are close.

2. The projection objective lens system according to claim 1, characterized in that, the first lens group satisfies: f1 / L < 0.5; wherein, f1 is the focal length of the first lens group, and L is the object-image distance of the projection objective lens system.

3. The projection objective lens system according to claim 1, characterized in that, the second lens group satisfies: f2 / L < -0.05; wherein, f2 is the focal length of the second lens group, and L is the object-image distance of the projection objective lens system.

4. The projection objective lens system according to claim 1, characterized in that, the second lens group includes at least one biconcave lens.

5. The projection objective lens system according to claim 4, characterized in that, the second lens group includes a seventh lens and an eighth lens; the seventh lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the eighth lens is a biconcave lens with both the object-side surface and the image-side surface being concave.

6. The projection objective lens system according to claim 1, characterized in that, the third lens group satisfies: 0.01 < f3 / L < 0.5; wherein, f3 is the focal length of the third lens group, and L is the object-image distance of the projection objective lens system.

7. The projection objective lens system according to claim 1, characterized in that, the third lens group includes at least one meniscus lens and at least one biconvex lens.

8. The projection objective lens system according to claim 7, characterized in that, the third lens group includes a ninth lens to a twelfth lens; the ninth lens is a meniscus lens with the object-side surface being concave and the image-side surface being convex; the tenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the eleventh lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the twelfth lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave.

9. The projection objective lens system according to claim 1, characterized in that the fourth lens group satisfies: f4 / L < -0.05; wherein, f4 is the focal length of the fourth lens group, and L is the object-image distance of the projection objective lens system.

10. The projection objective lens system according to claim 1, characterized in that the fourth lens group includes at least one biconcave lens.

11. The projection objective lens system according to claim 10, characterized in that the fourth lens group includes a thirteenth lens and a fourteenth lens; the thirteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the fourteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave.

12. The projection objective lens system according to claim 1, characterized in that the fifth lens group satisfies: 0.01 < f5 / L < 0.8; wherein, f5 is the focal length of the fifth lens group, and L is the object-image distance of the projection objective lens system.

13. The projection objective lens system according to claim 1, characterized in that the fifth lens group includes at least one biconvex lens.

14. The projection objective lens system according to claim 13, characterized in that the fifth lens group includes a fifteenth lens and a sixteenth lens; the fifteenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex; the sixteenth lens is a biconvex lens with both the object-side surface and the image-side surface being convex.

15. The projection objective lens system according to claim 1, characterized in that the sixth lens group satisfies: 0.1 < f6 / L < 1.5; wherein, f6 is the focal length of the sixth lens group, and L is the object-image distance of the projection objective lens system.

16. The projection objective lens system according to claim 1, characterized in that the sixth lens group includes at least one biconcave lens, at least one meniscus lens, and at least one biconvex lens.

17. The projection objective lens system according to claim 1, characterized in that the sixth lens group includes a seventeenth lens to a twenty-fourth lens; the seventeenth lens, the nineteenth lens, and the twentieth lens are biconvex lenses with both the object-side surface and the image-side surface being convex; the eighteenth lens is a biconcave lens with both the object-side surface and the image-side surface being concave; the twenty-first lens is a meniscus lens with the object-side surface being convex and the image-side surface being concave; the twenty-second lens to the twenty-fourth lens are meniscus lenses with the object-side surface being convex and the image-side surface being concave.

18. The projection objective lens system according to claim 1, characterized in that the sixth lens of the first lens group and the ninth lens of the third lens group satisfy: 0.05 < ∣(R6A - R6B) / (R6A + R6B)∣ < 5; 0.05 < ∣(R9A - R9B) / (R9A + R9B)∣ < 5; wherein, R6A is the curvature radius of the object-side surface of the sixth lens, and R6B is the curvature radius of the image-side surface of the sixth lens; R9A is the curvature radius of the object-side surface of the ninth lens, and R9B is the curvature radius of the image-side surface of the ninth lens.

19. The projection objective lens system according to claim 1, characterized in that, the eleventh lens of the third lens group and the fourteenth lens of the fourth lens group satisfy: 0.05 < ∣(R11A - R11B) / (R11A + R11B)∣ < 5; 0.05 < ∣(R14A - R14B) / (R14A + R149B)∣ < 5; wherein: R11A is the curvature radius of the object side surface of the eleventh lens, and R11B is the curvature radius of the image side surface of the eleventh lens; R14A is the curvature radius of the object side surface of the fourteenth lens, and R14B is the curvature radius of the image side surface of the fourteenth lens.

20. The projection objective lens system according to claim 1, characterized in that, the projection objective lens system further includes an aperture stop; the aperture stop is disposed between the image side surface of the fifth lens group and the object side surface of the sixth lens group.

21. The projection objective lens system according to claim 1, characterized in that, the projection objective lens system further includes a first lens and a twenty-fifth lens; the first lens is disposed on the image side of the first lens group, and the twenty-fifth lens is disposed on the object side of the sixth lens group; the first lens and the twenty-fifth lens are flat lenses.

22. The projection objective lens system according to claim 1, characterized in that, the object side surface and the image side surface of the lenses in the first lens group to the sixth lens group include four aspherical surfaces, and the maximum aspherical aberration sag height is less than 0.5 mm.

23. The projection objective lens system according to claim 22, characterized in that, the first lens group includes the second lens to the sixth lens, the second lens group includes the seventh lens and the eighth lens, the third lens group includes the ninth lens to the twelfth lens, the fourth lens group includes the thirteenth lens and the fourteenth lens, the fifth lens group includes the fifteenth lens and the sixteenth lens, and the sixth lens group includes the seventeenth lens to the twenty-fourth lens; the object side surface of the second lens, the object side surface of the eighth lens, the image side surface of the thirteenth lens, and the image side surface of the eighteenth lens are aspherical surfaces, and the maximum aspherical aberration sag height is 0.11 mm.

24. The projection objective lens system according to claim 1, characterized in that, the image side numerical aperture of the projection objective lens system under I-line illumination with a wavelength of 365 nm and a spectral line width of 5 nm is 0.62; the object-image distance L of the projection objective lens system is 1000 mm; the magnification of the projection objective lens system is 1 / 5, and the exposure field is 22 * 22 mm.

Images