A photolithography system, a photolithography method and a positive projection system based on 1:1 positive image projection imaging

Abstract

The application discloses a photoetching system, a photoetching method and a positive projection system based on 1:1 positive projection imaging. The photoetching system comprises a scanning workbench, a plane driving mechanism, a mask workbench for placing a mask, a substrate workbench for placing a substrate, and an optical system. The relative positions of the mask workbench and the substrate workbench remain unchanged. The plane driving mechanism is configured to drive a frame assembly to move on the scanning workbench in a plane motion. The optical system comprises an illumination assembly and a projection assembly. The projection assembly comprises two groups of first catadioptric mirror groups and second catadioptric mirror groups which are connected in series and have the same lens arrangement structure. The light rays emitted by the illumination assembly pass through the mask workbench, the first catadioptric mirror groups and the second catadioptric mirror groups in sequence and then reach the substrate workbench, and 1:1 positive projection is formed on the substrate workbench. The application is suitable for spectrum i line / h line / g line and has good complex achromatism effect.

Description

Technical Field

[0001] This invention relates to the field of photolithography, and more particularly to a photolithography system, photolithography method, and orthographic projection system based on 1:1 orthographic projection imaging. Background Technology

[0002] Currently, projection lithography technology is widely used in the manufacturing of integrated circuits (ICs) with nanometer-level resolution. Simultaneously, in semiconductor back-end processes, such as silicon wafer-level chip-scale packaging and bump packaging, projection lithography has become a mainstream technology. Furthermore, the introduction of larger silicon wafers in the future will further highlight the advantages of projection lithography. For projection lithography used in packaging processes, the optical system needs to have micrometer-level lithographic resolution capabilities, and it must also possess high yield and low cost characteristics.

[0003] Current photolithography systems typically employ a dual-stage structure where the mask and substrate move in opposite directions to scan. Projection lenses that meet the above conditions generally have complex structures, narrow applicable spectral ranges, poor thermal stability, and cannot control or adjust the shape of the photosensitive emulsion after curing, making it difficult to meet the high exposure dose requirements in photolithography processes.

[0004] The above background information is provided only to aid in understanding the concept and technical solution of this application. It does not necessarily belong to the prior art of this application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above information was disclosed before the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The purpose of this invention is to provide a photolithography system that requires only one scanning stage, keeps the relative positions of the mask and substrate unchanged, improves the projection components to achieve 1:1 orthographic projection, and is applicable to spectral i-line / h-line / g-line.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A photolithography system based on 1:1 orthographic projection imaging includes a scanning stage, a planar driving mechanism, a frame assembly, and an optical system. The frame assembly includes a frame body, a mask stage disposed on the upper part of the frame body, and a substrate stage disposed on the lower part of the frame body. The mask stage is configured to hold a mask having an exposure pattern and a first alignment mark, and the substrate stage is configured to hold a substrate having a photosensitive material and a second alignment mark. The relative positions of the mask stage and the substrate stage remain unchanged.

[0008] The planar drive mechanism is configured to drive the frame assembly to perform planar motion on the scanning stage;

[0009] The optical system includes an illumination component and a projection component. The projection component includes two sets of first catadioptric mirrors and second catadioptric mirrors connected in series. The first catadioptric mirrors and the second catadioptric mirrors have the same lens arrangement structure.

[0010] The light emitted from the illumination component passes sequentially through the mask stage, the first catadioptric mirror group, and the second catadioptric mirror group before reaching the substrate stage, where it forms a 1:1 orthographic projection on the substrate stage. The first alignment mark and the second alignment mark are used to characterize the alignment of the mask and the substrate.

[0011] Furthermore, following any one or a combination of the aforementioned technical solutions, both the first catadioptric lens group and the second catadioptric lens group have the following lens arrangement structure, including:

[0012] The system comprises a first reflecting surface, a first mirror group, a second mirror group, a third mirror group, a reflecting mirror, and a second reflecting surface, wherein the first and second mirror groups both have positive optical power, and the third mirror group includes at least one negative lens with negative optical power.

[0013] Light from the object surface is reflected by the first reflecting surface and then passes through the first mirror group, the second mirror group, and the third mirror group in sequence before reaching the reflecting mirror. The light rays reflected by the reflecting mirror then pass in the opposite direction through the third mirror group, the second mirror group, and the first mirror group in sequence before reaching the second reflecting surface. After being reflected by the second reflecting surface, the light rays reach the image surface.

[0014] Furthermore, following any one or a combination of the aforementioned technical solutions, the object plane of the first catadioptric mirror group is located at the position of the mask on the mask worktable, and the image plane of the first catadioptric mirror group coincides with the object plane of the second catadioptric mirror group.

[0015] The image plane of the second catadioptric mirror group is located at the position of the substrate on the substrate worktable;

[0016] The first catadioptric mirror group and the second catadioptric mirror group constitute a projection assembly for 1:1 orthographic projection.

[0017] Further, for any one of the above-described technical solutions or a combination of multiple technical solutions, both the first catadioptric lens group and the second catadioptric lens group satisfy: 0.45 < F1 / L < 1.5. If this ratio exceeds the upper limit, excessive primary spherical aberration and high-order spherical aberration will be caused. If this ratio is lower than the lower limit, excessive astigmatism aberration will be caused, affecting the optical performance of the lens; 0.45 < F2 / L < 1.05. If this ratio exceeds the upper limit, excessive spherical aberration and axial chromatic aberration will be caused. If this ratio is lower than the lower limit, excessive astigmatism aberration will be caused, affecting the optical performance of the lens. Here, F1 is the combined focal length of the first lens group, F2 is the combined focal length of the second lens group, and L is the optical distance from the object plane to the reflecting surface of the reflecting mirror;

[0018] And / or, the reflecting mirrors of the first catadioptric lens group and the second catadioptric lens group both have concave reflecting surfaces, and the radius of curvature R of the concave reflecting surface and the optical distance L from the object plane to the concave reflecting surface satisfy the following expression: 0.7 < -R / L < 1.5;

[0019] And / or, the third lens group successively includes a positive focal length lens, a biconcave lens, and a positive focal length lens with a convex object side surface. The focal length f3 of the biconcave lens and the optical distance L from the object plane to the reflecting surface of the reflecting mirror satisfy the following expression: 0.15 < ∣f3∣ / L < 0.7; If this ratio exceeds the upper limit, excessive spherical aberration and high-order axial chromatic aberration will be caused. If this ratio is lower than the lower limit, insufficient compensation for high-order axial chromatic aberration will be caused. In both cases, a good apochromatic effect cannot be achieved, affecting the optical performance of the lens;

[0020] And / or, the lens closest to the first lens group in the second lens group is a positive focal length lens, and the radius of curvature r21 of the object side surface of the positive focal length lens and the radius of curvature r22 of its image side surface satisfy the following expression: 0 < ∣r21 / r22∣ < 0.5; Satisfying this relationship can simultaneously achieve good compensation for spherical aberration and astigmatism aberration, improving the optical performance of the lens group;

[0021] And / or, the lens closest to the object plane in the first lens group is a biconvex lens, and the dispersion coefficient of the biconvex lens is defined as Vd1; the lens closest to the first lens group in the second lens group is a positive focal length lens, and the dispersion coefficient of the positive focal length lens is defined as Vd2; the third lens group includes multiple lenses, and the minimum dispersion coefficient of the negative lenses is defined as Vd3, and the following relationships are satisfied: 20 < Vd1−Vd2 < 55, 18 < Vd1−Vd3 < 53; Satisfying these two relationships can achieve balanced compensation for spherical aberration and axial chromatic aberration, achieving an apochromatic effect, and improving the optical performance of the lens in a wide spectral range;

[0022] And / or, both the first catadioptric lens group and the second catadioptric lens group satisfy: 0.05 < Hy / F1 < 0.35, where Hy is the image height corresponding to the maximum field angle of the catadioptric lens group, and F1 is the combined focal length of the first lens group. If this ratio exceeds the upper limit, the astigmatism aberration is too large. If this ratio is lower than the lower limit, the lens length becomes longer, resulting in a bulky device and affecting the overall performance of the device.

[0023] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the first lens group, the second lens group, the third lens group, and the reflector are arranged along the optical axis. The first reflecting surface and the second reflecting surface are two surfaces on the same reflector, and the first reflecting surface and the second reflecting surface are symmetrically distributed about the optical axis; both the first reflecting surface and the second reflecting surface are planes, and / or both the first reflecting surface and the second reflecting surface form an angle of 135° with the optical axis;

[0024] The first lens group includes a first lens, whose image-side optical axis position is convex and has a positive optical power;

[0025] The second lens group includes a second lens, whose object-side optical axis position is convex and whose image-side optical axis position is convex or concave;

[0026] The third lens group includes a third lens, a fourth lens, and a fifth lens. The third lens is a biconvex lens, the fourth lens is a biconcave lens, and the fifth lens is a positive optical power lens with a convex structure at the object-side optical axis position.

[0027] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the illumination component includes a light source, a homogenizing lens, and a condenser. The homogenizing lens uses a fly-eye integrator or a square bar integrator to homogenize the light beam emitted by the light source. The condenser focuses and transmits the homogenized light beam onto the mask located at the mask table. The exit pupil position of the light beam emitted by the condenser coincides with the entrance pupil position of the projection component.

[0028] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the light source is a high-pressure mercury lamp or an LED lamp with one or more wavelengths, and the light beam emitted by it includes characteristic spectral lines of 365 nm, 405 nm, and 436 nm;

[0029] The illumination component and the projection component remain stationary relative to the scanning table;

[0030] The exposure area output by the illumination component has a sharp corner structure in the vertical scanning direction.

[0031] Furthermore, in accordance with any or a combination of the aforementioned technical solutions, the optical system further includes an alignment position fine-tuning mechanism, which is installed between the mask stage and the first catadioptric mirror group, or between the first catadioptric mirror group and the second catadioptric mirror group, or between the second catadioptric mirror group and the substrate stage.

[0032] The alignment position fine-tuning mechanism includes an optically transparent plate and an adjustment device. The adjustment device is configured to adjust the angle of the optically transparent plate relative to the scanning stage so that the projection of the first alignment mark on the substrate coincides with the second alignment mark.

[0033] According to another aspect of the present invention, the present invention provides a photolithography method based on the photolithography system described above, comprising the following steps:

[0034] The substrate to be photolithographically etched is placed on the substrate worktable, and the corresponding mask is placed on the mask worktable;

[0035] The angle of the optically transparent plate relative to the scanning stage of the photolithography system is adjusted using the adjustment device of the alignment position fine-tuning mechanism until the projection of the first alignment mark on the mask onto the substrate coincides with the second alignment mark on the substrate.

[0036] The light source of the lithography system emits i-line, h-line, and / or g-line spectra, and drives the frame assembly of the lithography system to move along the scanning path on the scanning stage via a planar drive mechanism. The scanning path is related to the exposure pattern on the mask.

[0037] According to another aspect of the present invention, a 1:1 orthographic projection system is provided, comprising two sets of first and second catadioptric mirror groups connected in series, wherein the first and second catadioptric mirror groups have the same lens arrangement structure, including:

[0038] The system comprises a first reflecting surface, a first mirror group, a second mirror group, a third mirror group, a reflecting mirror, and a second reflecting surface, wherein the first and second mirror groups both have positive optical power, and the third mirror group includes at least one negative lens.

[0039] Light from the object surface is reflected by the first reflecting surface and then passes through the first mirror group, the second mirror group, and the third mirror group in sequence before reaching the reflecting mirror. The light rays reflected by the reflecting mirror then pass in the opposite direction through the third mirror group, the second mirror group, and the first mirror group in sequence before reaching the second reflecting surface. After being reflected by the second reflecting surface, the light rays reach the image surface.

[0040] In this system, the object plane of the first catadioptric mirror group is located at the position of the optical mask in the photolithography system, and the image plane of the first catadioptric mirror group coincides with the object plane of the second catadioptric mirror group; the image plane of the second catadioptric mirror group is located at the position of the substrate to be projected in the photolithography system; the first catadioptric mirror group and the second catadioptric mirror group constitute a 1:1 orthographic projection.

[0041] The beneficial effects of the technical solution provided by this invention are as follows:

[0042] a. Only one scanning stage is needed. Scanning exposure is performed while keeping the relative positions of the mask and substrate unchanged. The magnification is strictly controlled to 1. The requirements for the uniformity of the scanning stage's movement and the error of the serpentine oscillation are not high, which greatly simplifies the structure and reduces costs.

[0043] b. Two catadioptric mirror groups with specific structures are connected in series to achieve 1:1 orthographic projection, and are suitable for the i-line / h-line / g-line of the spectrum, with good apochromatic effect;

[0044] c. No aberration compensation mechanism or magnification adjustment mechanism is required, and it is easy to align the mask and substrate, making operation convenient. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram of a photolithography system provided as an exemplary embodiment of the present invention;

[0047] Figure 2 A lens arrangement structure diagram of a catadioptric mirror assembly provided in the first embodiment of the present invention;

[0048] Figure 3 for Figure 2 Axial chromatic aberration result curve of the catadioptric mirror group;

[0049] Figure 4 A lens arrangement structure diagram of a catadioptric mirror group provided in the second embodiment of the present invention;

[0050] Figure 5 for Figure 4 Axial chromatic aberration result curve of the catadioptric mirror group;

[0051] Figure 6 A schematic diagram of the shape of a first exposure area provided for an embodiment of the present invention;

[0052] Figure 7 A schematic diagram of the shape of the second exposure area provided for an embodiment of the present invention;

[0053] Figure 8 A schematic diagram illustrating the state of the alignment position fine-tuning mechanism for fine-tuning the exposure light area according to an embodiment of the present invention;

[0054] Figure 9 A schematic diagram showing the state in which the alignment position fine-tuning mechanism provided in an embodiment of the present invention does not fine-tune the exposed light area;

[0055] Figure 10 A schematic diagram of a downwardly contracting opening section formed by adjusting the photosensitive adhesive coated on the substrate surface through the selection of exposure wavelength, provided for an embodiment of the present invention;

[0056] Figure 11 A schematic diagram of a vertically equal-width opening cross-section formed by adjusting the photosensitive adhesive coated on the substrate surface through the selection of exposure wavelength, provided for an embodiment of the present invention;

[0057] Figure 12 This is a schematic diagram of a downwardly expanding opening cross-section formed by adjusting the photosensitive adhesive coated on the substrate surface through the selection of exposure wavelength, as provided in an embodiment of the present invention. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0060] In one embodiment of the present invention, a photolithography system based on 1:1 orthographic projection imaging is provided, such as... Figure 1 As shown, the photolithography system includes a scanning stage 100, a planar driving mechanism, a frame assembly, and an optical system. The frame assembly includes a frame body 210, a mask stage 220 disposed on the upper part of the frame body 210, and a substrate stage 230 disposed on the lower part of the frame body 210. The mask stage 220 is configured to place a mask 222 having an exposure pattern and a first alignment mark. The substrate stage 230 is configured to place a substrate 232 having a photosensitive material and a second alignment mark. The relative positions of the mask stage 220 and the substrate stage 230 remain unchanged.

[0061] The planar drive mechanism is configured to drive the frame assembly to perform planar motion on the scanning stage 100;

[0062] The optical system includes an illumination component and a projection component. The projection component includes two sets of first catadioptric mirror groups 310 and second catadioptric mirror groups 320 connected in series. The first catadioptric mirror group 310 and the second catadioptric mirror group 320 have the same lens arrangement structure.

[0063] The light emitted from the illumination component passes sequentially through the mask stage 220, the first catadioptric mirror group 310, and the second catadioptric mirror group 320 before reaching the substrate stage 230, and forms a 1:1 orthographic projection on the substrate stage 230. The first alignment mark and the second alignment mark are used to characterize the alignment of the mask 222 and the substrate 232.

[0064] The illumination assembly includes a light source 410, a homogenizing mirror 420, and a condenser mirror 430. The homogenizing mirror 420 uses a compound eye integrator or a square rod integrator to homogenize the light beam emitted by the light source 410. The condenser mirror 430 focuses and transmits the homogenized light beam onto the mask 222 located at the mask stage 220. The exit pupil position of the light beam emitted by the condenser mirror 430 coincides with the entrance pupil position of the projection assembly.

[0065] Specifically, the light source 410 is a high-pressure mercury lamp or LED lamp with one or more wavelengths, and the emitted light beam includes characteristic spectral lines of 365nm, 405nm, and 436nm; particularly, the exposure area output by the illumination component has, in the vertical scanning direction, a characteristic spectral line of 365nm, 405nm, and 436nm. Figure 6 and Figure 7 The sharp-angled structures 502 and 504 are shown. The illumination and projection components remain stationary relative to the scanning stage 100, as shown... Figure 1 As shown, for example, both the lighting components and the projection components can be fixed on the floor frame 300.

[0066] In an ideal situation, such as Figure 9 As shown, the exposure light eventually reaches the substrate 232 after passing through the mask 222, which can directly make the projection of the first alignment mark on the substrate 232 coincide with the second alignment mark 231.

[0067] In one embodiment of the present invention, the optical system further includes an alignment position fine-tuning mechanism 600, which is installed between the mask stage 220 and the first catadioptric mirror group 310, or between the first catadioptric mirror group 310 and the second catadioptric mirror group 320, or between the second catadioptric mirror group 320 and the substrate stage 230.

[0068] The alignment fine-tuning mechanism 600 includes an optically transparent plate and an adjustment device. The adjustment device is configured to adjust the angle of the optically transparent plate relative to the scanning stage 100 so that the projection of the first alignment mark on the substrate coincides with the second alignment mark 231. Figure 9 As shown, if light rays are incident perpendicularly on the optically transparent plate, the direction of the light rays will not change. This situation, in which no adjustment of the optically transparent plate is required, applies to the above ideal situation.

[0069] If there is a deviation between the first alignment mark and the second alignment mark 231 when the optical light-transmitting plate is not adjusted, then the tilt angle between the optical light-transmitting plate and the horizontal plane needs to be adjusted. Figure 8 As shown, when the incident light is not perpendicular to the optical light-transmitting plate, the direction of the light rays incident into the optical light-transmitting plate will change, and the light rays emitted from it will return to the vertical direction. Furthermore, the incident light rays and the emitted light rays will undergo horizontal translation, so as to make the projection of the first alignment mark on the substrate 232 coincide with the second alignment mark 231.

[0070] It should be noted that, Figure 8 and Figure 9 This is for illustrative purposes only and ignores the process of light passing through the first catadioptric mirror group 310 and the second catadioptric mirror group 320. Alternatively, it shows the optical path in an embodiment where the alignment fine-tuning mechanism 600 is disposed between the second catadioptric mirror group 320 and the substrate stage 230.

[0071] The first catadioptric mirror group 310 and the second catadioptric mirror group 320 both have the same lens arrangement structure, such as Figure 2 and Figure 4 As shown, the catadioptric lens assembly includes:

[0072] The system comprises a first reflecting surface R1, a first mirror group G1, a second mirror group G2, a third mirror group G3, a reflecting mirror M1, and a second reflecting surface R2, wherein the first mirror group G1 and the second mirror group G2 both have positive optical power, and the third mirror group G3 includes at least one negative lens with negative optical power.

[0073] Light from object plane P1 is reflected by the first reflecting surface R1 and then passes through the first mirror group G1, the second mirror group G2, and the third mirror group G3 in sequence before reaching the reflecting mirror M1. The light rays reflected by the reflecting mirror M1 then pass in the opposite direction through the third mirror group G3, the second mirror group G2, and the first mirror group G1 in sequence before reaching the second reflecting surface R2. After being reflected by the second reflecting surface R2, the light rays reach the image plane P2.

[0074] The first catadioptric mirror group 310 and the second catadioptric mirror group 320 are connected in series to form a 1:1 orthogonal projection, which is manifested in that: the object plane P1 of the first catadioptric mirror group 310 is located at the position of the mask 222 on the mask stage 220; the image plane P2 of the first catadioptric mirror group 310 coincides with the object plane P1 of the second catadioptric mirror group 320; the image plane P2 of the second catadioptric mirror group 320 is located at the position of the substrate 232 on the substrate stage 230; the first catadioptric mirror group 310 and the second catadioptric mirror group 320 constitute a projection component for a 1:1 orthogonal projection.

[0075] Specifically, such as Figure 2 and Figure 4 As shown, the first mirror group G1, the second mirror group G2, the third mirror group G3, and the reflecting mirror M1 are arranged along the optical axis. The first reflecting surface R1 and the second reflecting surface R2 are two surfaces on the same reflecting mirror, and the first reflecting surface R1 and the second reflecting surface R2 are symmetrically distributed with the optical axis as the central axis. The first reflecting surface R1 and the second reflecting surface R2 are both planes, and / or, the first reflecting surface R1 and the second reflecting surface R2 are both at an angle of 135° to the optical axis.

[0076] The first lens group G1 includes a first lens L1, which has a convex surface at the image-side optical axis position and positive optical power;

[0077] The second lens group G2 includes a second lens L2, which has a convex structure at its object-side optical axis position and a convex or concave structure at its image-side optical axis position.

[0078] The third lens group G3 includes a third lens L3, a fourth lens L4, and a fifth lens L5, wherein the third lens L3 is a biconvex lens, the fourth lens L4 is a biconcave lens, and the fifth lens L5 is a positive power lens with a convex structure at the object-side optical axis position.

[0079] Both the first catadioptric lens group 310 and the second catadioptric lens group 320 satisfy: 0.45 <F1 / L<1.5,0.45<F2 / L<1.05,0.7<-R / L<1.5,0.15<∣f3∣ / L<0.7,0<∣r21 / r22∣<0.5,20<Vd1-Vd2<55,18<Vd1-Vd3<53,0.05<Hy / F1<0.35;

[0080] Wherein, F1 is the combined focal length of the first lens group G1, F2 is the combined focal length of the second lens group G2, L is the optical distance from the object plane P1 to the reflecting surface of the reflecting mirror M1, R is the radius of curvature of the reflecting surface of the reflecting mirror M1 with a concave reflecting surface, f3 is the focal length of the fourth lens L4 in the third lens group G3, r21 is the radius of curvature of the object side of the second lens L2, r22 is the radius of curvature of the image side of the second lens L2, Vd1 is the dispersion coefficient of the first lens, Vd2 is the dispersion coefficient of the second lens, Vd3 is the dispersion coefficient of the negative lens, i.e., the fourth lens L4, in the third lens group G3, and Hy is the image height corresponding to the maximum field of view of the catadioptric lens group.

[0081] Especially satisfying: 0.75 <F1 / L<1.2,0.55<F2 / L<0.86,0.85<-R / L<1.2,0.20<∣f3∣ / L<0.45,0<∣r21 / r22∣<0.05,30<Vd1-Vd2<50,28<Vd1-Vd3<42,0.09<Hy / F1<0.18。

[0082] First Embodiment

[0083] In this embodiment, the lens arrangement of the catadioptric lens group is as follows: Figure 2 As shown, the optical parameters of the lenses and mirrors in each catadioptric mirror group are given in Table 1:

[0084] Table 1 Optical parameters of the catadioptric mirror assembly in the first embodiment

[0085]

[0086]

[0087] d0 is defined as the optical axis distance from the object plane to the object side of the first lens L1, and d1 is defined as the optical axis distance from the image side of the first lens L1 to the object side of the second lens L2. According to Table 1, d0 = 156.2343 mm and d1 = 381.9864 mm.

[0088] In this embodiment, the maximum field of view of the catadioptric mirror group corresponds to an image height Hy of 105 mm and an image-side numerical aperture of 0.1, which is a dimensionless parameter. Its calculation formula is NA = n × sin(θ), where n is the refractive index and θ is the angle between the light ray and the optical axis. The larger the value of NA, the wider the angle of light that the optical system can collect or transmit, thus providing higher resolution and clearer images.

[0089] In a specific numerical embodiment, the calculation results of the optical parameter relationships of the catadioptric mirror group are shown in Table 2:

[0090] Table 2. Calculation results of optical parameter relationships for the catadioptric mirror assembly in the first embodiment.

[0091] Serial Number expression numerical values (1) F1 / L = 0.896 (2) F2 / L = 0.728 (3) -R / L= 1.100 (4) ∣r21 / r22∣ 0.021 (5) |f3| / L= 0.362 (6) Vd1-Vd2 44.87 (7) Vd1-Vd3 38.28 (8) Hy / F1 = 0.147 (9) (d0+d1) / L= 0.673 (10) F1 / F2 = 1.230

[0092] In this embodiment, the calculated value is obtained by rounding.

[0093] Figure 3 The figure shows the axial chromatic aberration result curve of the catadioptric mirror group in this embodiment. The figure shows that the maximum defocus distance in the wavelength range of 0.36 to 0.44 micrometers is less than 4 micrometers, which is much smaller than the diffraction-limited focal depth range of 71 nm. This indicates that the catadioptric mirror group in this embodiment has good broadband spectral performance and is suitable for the three spectra of i / h / g lines. The three characteristic spectra compensate for first-order and high-order on-axis chromatic aberration and belong to apochromatic aberration. This application overcomes the existing technical difficulties in the industry.

[0094] Second Embodiment

[0095] In this embodiment, the lens arrangement of the catadioptric lens group is as follows: Figure 4 As shown, the optical parameters of the lenses and mirrors in each catadioptric mirror group are given in Table 3:

[0096] Table 3 Optical parameters of the catadioptric mirror assembly in the second embodiment

[0097]

[0098]

[0099] d0 is defined as the optical axis distance from the object plane to the object side of the first lens L1, and d1 is defined as the optical axis distance from the image side of the first lens L1 to the object side of the second lens L2. According to Table 1, d0 = 119.9995 mm and d1 = 406.2561 mm.

[0100] In this embodiment, the maximum field of view of the catadioptric mirror group corresponds to an image height Hy of 105 mm and an image-side numerical aperture of 0.75, which is a dimensionless parameter. Its calculation formula is NA = n × sin(θ), where n is the refractive index and θ is the angle between the light ray and the optical axis. The larger the value of NA, the wider the angle of light that the optical system can collect or transmit, thus providing higher resolution and clearer images.

[0101] In a specific numerical embodiment, the calculation results of the optical parameter relationships of the catadioptric mirror group are shown in Table 4:

[0102] Table 4. Calculation results of optical parameter relationships for the catadioptric mirror assembly in the second embodiment.

[0103] Serial Number expression numerical values (1) F1 / L = 0.970 (2) F2 / L = 0.673 (3) -R / L= 1.065 (4) ∣r21 / r22∣ 0.015 (5) |f3| / L= 0.266 (6) Vd1-Vd2 34.08 (7) Vd1-Vd3 31.58 (8) Hy / F1 = 0.135 (9) (d0+d1) / L= 0.658 (10) F1 / F2 = 1.441

[0104] In this embodiment, the calculated value is obtained by rounding.

[0105] Figure 5 The figure shows the axial chromatic aberration result curve of the catadioptric mirror group in this embodiment. The figure shows that the maximum defocus distance in the wavelength range of 0.36 to 0.44 micrometers is less than 13 micrometers, which is much smaller than the diffraction-limited focal depth range of 71 nm. This indicates that the catadioptric mirror group in this embodiment has good broadband spectral performance and is suitable for the three spectra of i / h / g lines. The three characteristic spectra compensate for first-order and high-order on-axis chromatic aberration and belong to apochromatic aberration. This application overcomes the existing technical difficulties in the industry.

[0106] When different wavelengths of the light source are selected for exposure, the photosensitive material on the substrate, after exposure and development, has different morphological characteristics in the cured residual photosensitive material. The optical lens includes a wavelength-selective filter. By selecting different wavelength filters, different characteristic spectral line regions are selected, suitable for photosensitive materials with different properties, or different curing cross sections, upper opening cross sections, vertical cross sections, and lower opening cross sections of the photosensitive adhesive can be constructed. Different exposure wavelengths have different effects on the photosensitive adhesive 234, and the vertical width of the opening can be controlled. That is, the opening shape can be adjusted by selecting the exposure wavelength, as shown below. Figures 10-12 As shown.

[0107] In one embodiment of the present invention, a photolithography method based on the photolithography system described above is provided, comprising the following steps:

[0108] The substrate to be photolithographically etched is placed on the substrate worktable, and the corresponding mask is placed on the mask worktable;

[0109] The angle of the optically transparent plate relative to the scanning stage of the photolithography system is adjusted using the adjustment device of the alignment position fine-tuning mechanism until the projection of the first alignment mark on the mask onto the substrate coincides with the second alignment mark on the substrate.

[0110] The light source of the lithography system emits i-line, h-line, and / or g-line spectra, and drives the frame assembly of the lithography system to move along the scanning path on the scanning stage via a planar drive mechanism. The scanning path is related to the exposure pattern on the mask.

[0111] In one embodiment of the present invention, a 1:1 orthographic projection system is provided, comprising two sets of first and second catadioptric mirror groups connected in series. The first and second catadioptric mirror groups have the same lens arrangement structure.

[0112] The system comprises a first reflecting surface, a first mirror group, a second mirror group, a third mirror group, a reflecting mirror, and a second reflecting surface, wherein the first and second mirror groups both have positive optical power, and the third mirror group includes at least one negative lens.

[0113] Light from the object surface is reflected by the first reflecting surface and then passes through the first mirror group, the second mirror group, and the third mirror group in sequence before reaching the reflecting mirror. The light rays reflected by the reflecting mirror then pass in the opposite direction through the third mirror group, the second mirror group, and the first mirror group in sequence before reaching the second reflecting surface. After being reflected by the second reflecting surface, the light rays reach the image surface.

[0114] In this system, the object plane of the first catadioptric mirror group is located at the position of the optical mask in the photolithography system, and the image plane of the first catadioptric mirror group coincides with the object plane of the second catadioptric mirror group; the image plane of the second catadioptric mirror group is located at the position of the substrate to be projected in the photolithography system; the first catadioptric mirror group and the second catadioptric mirror group constitute a 1:1 orthographic projection.

[0115] The 1:1 orthographic projection system provided in this embodiment belongs to the same inventive concept as the above-mentioned lithography system based on 1:1 orthographic projection imaging. Here, by referencing the entire text, all contents of the lithography system embodiment based on 1:1 orthographic projection imaging are incorporated into this orthographic projection system embodiment, and will not be repeated here.

[0116] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0117] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A photolithography system based on 1 : 1 orthographic projection imaging, characterized in that, It includes a scanning workbench, a planar driving mechanism, a frame component, and an optical system. Among them, the frame component includes a frame body, a mask workbench arranged on the upper part of the frame body, and a substrate workbench arranged on the lower part of the frame body. The mask workbench is configured to place a mask with an exposure pattern and a first alignment mark, the substrate workbench is configured to place a substrate with a photosensitive material and a second alignment mark, and the relative positions of the mask workbench and the substrate workbench remain unchanged; The planar driving mechanism is configured to drive the frame component to perform a planar motion on the scanning workbench; The optical system includes an illumination component and a projection component. The projection component includes two sets of serially connected first catadioptric lens groups and second catadioptric lens groups. The first catadioptric lens group and the second catadioptric lens group have the same lens arrangement structure, including: a first reflecting surface, a first lens group, a second lens group, a third lens group, a reflecting mirror, and a second reflecting surface. Among them, both the first lens group and the second lens group have positive optical power, and the third lens group includes at least one negative lens with negative optical power; light from the object surface is reflected by the first reflecting surface and then passes through the first lens group, the second lens group, and the third lens group in sequence to reach the reflecting mirror. The light after being reflected by the reflecting mirror passes through the third lens group, the second lens group, and the first lens group in reverse sequence to reach the second reflecting surface, and is reflected by the second reflecting surface to reach the image surface; The object surface of the first catadioptric lens group is located at the position of the mask on the mask workbench, and the image surface of the first catadioptric lens group coincides with the object surface of the second catadioptric lens group; the image surface of the second catadioptric lens group is located at the position of the substrate on the substrate workbench; the first catadioptric lens group and the second catadioptric lens group form a projection component for 1:1 positive image projection; The light emitted by the illumination component passes through the mask workbench, the first catadioptric lens group, and the second catadioptric lens group in sequence and then reaches the substrate workbench, and a 1:1 positive image projection is formed on the substrate workbench. The first alignment mark and the second alignment mark are used to represent the alignment of the mask and the substrate.

2. The photolithography system of claim 1, wherein, Both the first catadioptric lens group and the second catadioptric lens group satisfy: 0.45 < F1 / L < 1.5, 0.45 < F2 / L < 1.05, where F1 is the combined focal length of the first lens group, F2 is the combined focal length of the second lens group, and L is the optical distance from the object surface to the reflecting surface of the reflecting mirror; And / or, the reflecting mirrors of the first catadioptric lens group and the second catadioptric lens group both have concave reflecting surfaces, and the curvature radius R of the concave reflecting surface and the optical distance L from the object surface to the concave reflecting surface satisfy the following expression: 0.7 < -R / L < 1.5; And / or, the third lens group includes a positive optical power lens, a biconcave lens, and a positive optical power lens with a convex object side surface in sequence. The focal length f3 of the biconcave lens and the optical distance L from the object surface to the reflecting surface of the reflecting mirror satisfy the following expression: 0.15 < ∣f3∣ / L < 0.

7.

3. The photolithography system of claim 1, wherein, The lens in the second lens group closest to the first lens group is a positive focal length lens, and the curvature radius r21 of the object side surface and the curvature radius r22 of the image side surface of this positive focal length lens satisfy the following expression: 0 < ∣r21 / r22∣ < 0.5; And / or, the lens in the first lens group closest to the object surface is a biconvex lens, and the dispersion coefficient of this biconvex lens is defined as Vd1; the lens in the second lens group closest to the first lens group is a positive focal length lens, and the dispersion coefficient of this positive focal length lens is defined as Vd2; the third lens group includes multiple lenses, and the minimum dispersion coefficient of the negative lens therein is defined as Vd3, and the following relational expressions are satisfied: 20 < Vd1 - Vd2 < 55, 18 < Vd1 - Vd3 < 53; And / or, both the first catadioptric lens group and the second catadioptric lens group satisfy: 0.05 < Hy / F1 < 0.35, where Hy is the image height corresponding to the maximum field angle of the catadioptric lens group, and F1 is the combined focal length of the first lens group.

4. The photolithography system of claim 1, wherein, The first lens group, the second lens group, the third lens group, and the reflecting mirror are arranged along the optical axis. The first reflecting surface and the second reflecting surface are two surfaces on the same reflecting mirror, and the first reflecting surface and the second reflecting surface are symmetrically distributed about the optical axis; both the first reflecting surface and the second reflecting surface are flat surfaces, and / or both the first reflecting surface and the second reflecting surface form an angle of 135° with the optical axis.

5. The photolithography system of claim 1, wherein, The first lens group includes a first lens, the image-side optical axis position of which is convex and has a positive focal length; The second lens group includes a second lens, the object-side optical axis position of which is convex, and the image-side optical axis position of which is convex or concave; The third lens group includes a third lens, a fourth lens, and a fifth lens. Among them, the third lens is a biconvex lens, the fourth lens is a biconcave lens, and the fifth lens has a convex structure at the object-side optical axis position and a concave structure at the image-side optical axis position.

6. The photolithography system of claim 1, wherein, The illumination component includes a light source, a light homogenizing mirror, and a condenser. The light homogenizing mirror uses a fly-eye integrator or a square bar integrator to homogenize the light beam emitted by the light source. The condenser focuses and transmits the homogenized light beam onto the mask located at the mask stage. The exit pupil position of the light beam emitted by the condenser coincides with the entrance pupil position of the projection component.

7. The photolithography system of claim 6, wherein, The light source is a high-pressure mercury lamp or an LED lamp with one or more wavelengths, and the light beam emitted by it includes characteristic spectral lines of 365 nm, 405 nm, and 436 nm; The illumination component and the projection component remain stationary relative to the scanning stage; The exposure area output by the illumination component has a sharp corner structure in the vertical scanning direction.

8. The lithography system according to any one of claims 1 to 7, wherein, The optical system further includes an alignment position fine-tuning mechanism, which is installed between the mask stage and the first catadioptric lens group, or between the first catadioptric lens group and the second catadioptric lens group, or between the second catadioptric lens group and the substrate stage; The alignment position fine-tuning mechanism includes an optically transparent flat plate and an adjusting device. The adjusting device is configured to adjust the angle of the optically transparent flat plate relative to the scanning stage so that the projection of the first alignment mark on the substrate coincides with the second alignment mark.

9. A photolithography method based on the photolithography system of claim 8, characterized in that, Includes the following steps: The substrate to be photolithographically etched is placed on the substrate worktable, and the corresponding mask is placed on the mask worktable; The angle of the optically transparent plate relative to the scanning stage of the photolithography system is adjusted using the adjustment device of the alignment position fine-tuning mechanism until the projection of the first alignment mark on the mask onto the substrate coincides with the second alignment mark on the substrate. The light source of the lithography system emits i-line, h-line, and / or g-line spectra, and drives the frame assembly of the lithography system to move along the scanning path on the scanning stage via a planar drive mechanism. The scanning path is related to the exposure pattern on the mask.

10. A 1:1 orthographic projection system, characterized in that, A projection system applied to any one of claims 1 to 8, the projection system comprising two sets of tandem first catadioptric mirror groups and second catadioptric mirror groups, the first catadioptric mirror group and the second catadioptric mirror group having the same lens arrangement structure, comprising: The system comprises a first reflecting surface, a first mirror group, a second mirror group, a third mirror group, a reflecting mirror, and a second reflecting surface, wherein the first and second mirror groups both have positive optical power, and the third mirror group includes at least one negative lens. Light from the object surface is reflected by the first reflecting surface and then passes through the first mirror group, the second mirror group, and the third mirror group in sequence before reaching the reflecting mirror. The light rays reflected by the reflecting mirror then pass in the opposite direction through the third mirror group, the second mirror group, and the first mirror group in sequence before reaching the second reflecting surface. After being reflected by the second reflecting surface, the light rays reach the image surface. In this system, the object plane of the first catadioptric mirror group is located at the position of the optical mask in the photolithography system, and the image plane of the first catadioptric mirror group coincides with the object plane of the second catadioptric mirror group; the image plane of the second catadioptric mirror group is located at the position of the substrate to be projected in the photolithography system; the first catadioptric mirror group and the second catadioptric mirror group constitute a 1:1 orthographic projection.

Images