Lens remanufacturing system and lens remanufacturing method

Abstract

The invention discloses a lens remanufacturing system and a lens remanufacturing method. The lens remanufacturing method comprises the following steps: removing a damaged lens from a lithography tool; generating an initial profile of a new lens based on the surface profile of the damaged lens; optimizing the initial profile of the new lens by simulating optical characteristics of the new lens in the lithography tool to produce an optimized profile; manufacturing the new lens based on the optimized profile; and installing the new lens in the lithography tool to replace the damaged lens.

Description

Technical Field

[0001] The present disclosure relates to a lens remanufacturing system and a lens remanufacturing method. Background Art

[0002] In semiconductor manufacturing, lithography tools are used to apply a pattern to a substrate by selectively exposing a photoresist layer on the substrate to a radiation beam. Optical lenses are used in lithography equipment to direct the radiation beam from the radiation source to the substrate being processed. The optical lenses in lithography tools are made of high-quality materials and require regular replacement due to contamination during operation. Summary of the Invention

[0003] In some embodiments of the present disclosure, a method for lens remanufacturing is characterized in that it includes the following steps: removing a damaged lens from a lithography tool; generating an initial profile of a new lens based on the surface profile of the damaged lens; optimizing the initial profile of the new lens by simulating the optical properties of the new lens in the lithography tool to generate an optimized profile; manufacturing a new lens based on the optimized profile; and installing the new lens in the lithography tool to replace the damaged lens.

[0004] In some embodiments of the present disclosure, a method for lens reconstruction is characterized in that it includes the following steps: removing a damaged lens from a lithography tool; generating a profile of a new lens based on the surface profile of the damaged lens; manufacturing a new lens based on the profile, wherein manufacturing the new lens includes the following steps: shaping a workpiece; performing rough polishing on the workpiece; performing fine polishing on the workpiece, wherein the fine polishing is a non-contact polishing method; and coating the workpiece; and installing the new lens in the lithography tool to replace the damaged lens.

[0005] In some embodiments of the present disclosure, a lens remanufacturing system includes a processor and a lens manufacturing tool. The processor is configured to generate a profile of a new lens based on a surface profile of a damaged lens. The lens manufacturing tool is configured to manufacture the new lens based on the profile. The lens manufacturing tool includes a rough polishing tool and a fine polishing tool. The rough polishing tool is configured to perform a first polish on the workpiece of the new lens using a rotary polisher. The fine polishing tool is configured to perform a second polish on the workpiece of the new lens using a focused ion beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The various aspects of the present disclosure are best understood from the following detailed description in conjunction with the accompanying drawings. Note that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of discussion.

[0007] Figure 1 is a schematic diagram of a lithography tool according to some embodiments;

[0008] Figure 2is a schematic diagram of a damaged lens according to some embodiments;

[0009] Figure 3 A lens repair method for a lithography tool according to some embodiments;

[0010] Figure 4 A method for remaking a lens based on a damaged lens according to some embodiments;

[0011] Figure 5A 、 Figure 5B and Figure 5C is a schematic diagram of a geometric matrix, a roughness matrix, and a defect matrix according to some embodiments;

[0012] Figure 6 A method for manufacturing a lens according to some embodiments;

[0013] Figure 7 is a schematic diagram of a focused ion beam (FIB) system according to some embodiments.

[0014] Figure 8 is a block diagram of a lens reconstruction system according to some embodiments.

[0015]

Explanation of symbols

[0016] 100: Micro-shading tools

[0017] 102: Light Source

[0018] 104: Beam Steering System

[0019] 106: Beam matching unit

[0020] 108:Variable attenuator

[0021] 120: Zoom-rotating prism optical system

[0022] 122: Zoom lens

[0023] 124: Rotating Prism

[0024] 126: Motor drive

[0025] 130: Integrator

[0026] 132, 134: Quartz rod

[0027] 136:Right-angle prism

[0028] 138:Energy Sensor

[0029] 140: Light shield mechanism

[0030] 142: Fixed shutter unit

[0031] 144: Movable shutter unit

[0032] 150: Mask imaging optical system / REMA imaging optical system

[0033] 150H: Shell

[0034] 152: Focusing lens

[0035] 154: Focusing lens

[0036] 156: Reflector

[0037] 160: Mask stage

[0038] 170: Projection optical system

[0039] 172: Projection lens

[0040] 180: Wafer table

[0041] 200: Focused ion beam system

[0042] 210: Focused Ion Beam Generator

[0043] 220: Gas injection system

[0044] 230: Electron beam scanning electron microscope

[0045] 240: Detector

[0046] 500:Lens Remaking System

[0047] 510: Microlithography Tools

[0048] 520: Geometric Desensitization Interference Tool

[0049] 530: Processor

[0050] 540:Lens manufacturing tools

[0051] 541: Coarse shaping tool

[0052] 542: Fine Shaping Tools

[0053] 543: Rough polishing tool

[0054] 544: Fine polishing tools

[0055] 545:Edging tools

[0056] 546:Coating Simulation Tool

[0057] 547:Coating tools

[0058] S101~S105 / S201~S205, S301~S307: Operation

[0059] DF: Defect

[0060] DL: Damaged lens

[0061] IL: Radiation beam

[0062] IB: Focused Ion Beam

[0063] M1, M2, M3: Methods

[0064] MA:Mask

[0065] W: Wafer

[0066] WP:Workpiece DETAILED DESCRIPTION

[0067] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the disclosure. Of course, these are merely examples and are not intended to be limiting. For example, in the description below, forming a first feature above or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features so that the first and second features may not be in direct contact. In addition, the disclosure may repeat element symbols or letters in various examples. This repetition is for simplicity and clarity and does not, in itself, specify the relationship between the various embodiments or configurations discussed.

[0068] Furthermore, for ease of description, spatially relative terms, such as "below," "beneath," "beneath," "above," and "above," may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0069] As used herein, "about," "approximately," "roughly," or "substantially" may generally mean within 20%, or within 10%, or within 5% of a given value or range. The values ​​given herein are approximate, meaning that if not explicitly stated, the terms "about," "approximately," "roughly," or "substantially" can be inferred. However, one of ordinary skill in the art will recognize that the values ​​or ranges cited throughout the description are examples only and may decrease or change as integrated circuits shrink.

[0070] The advanced lithography processes, methods, and materials described in this disclosure can be used in many applications, including fin-type field effect transistors (FinFETs). For example, fins can be patterned to create relatively tight spacing between features, for which the disclosure is well suited. Furthermore, spacers used to form the fins of FinFETs can be processed according to the disclosure.

[0071] Figure 1 FIG2 is a schematic diagram of a lithography tool according to some embodiments. A lithography tool 100 is shown. Lithography tool 100 may include alignment and exposure tools, also known as steppers and scanners, for transferring circuit design patterns to a photosensitive layer on a substrate. Lithography tool 100 may be an ultraviolet (UV) lithography tool, a deep ultraviolet (DUV) lithography tool, an immersion lithography tool, an extreme ultraviolet (EUV) lithography tool, an electron beam lithography tool, an X-ray lithography tool, an ion projection lithography tool, or any suitable exposure tool that uses a laser radiation source to generate a radiation beam for exposure.

[0072] The lithography tool 100 includes a light source 102. In some embodiments, the light source 102 may be an ArF excimer laser light source (oscillation wavelength 193 nm). As the exposure light source, a laser that emits laser light in the ultraviolet range during the oscillation step, such as a KrF excimer laser (wavelength 248 nm) or an F2 laser (wavelength 157 nm), or a device that emits high-harmonic laser light obtained by wavelength conversion of near-infrared laser light from a solid-state laser light source (YAG laser, semiconductor laser, or the like) substantially in the vacuum ultraviolet range, as well as a mercury discharge lamp or the like commonly used in such exposure equipment can be used.

[0073] exist Figure 1 , a radiation beam IL is generated by a light source 102. The radiation beam IL passes through a beam steering system 104. In some embodiments, the beam steering system 104 may include one or more steering mirrors to adjust the propagation direction of the radiation beam IL.

[0074] The beam steering system 104 directs the radiation beam IL to a beam-matching unit (BMU) 106, which includes a movable mirror or the like, to match the beam to the optical path position of the projection exposure apparatus. A variable attenuator 108 is disposed adjacent to the beam-matching unit 106. In some embodiments, the variable attenuator 108 is used to adjust the average energy of each pulse of the radiation beam IL. For example, multiple filters with different beam attenuation ratios may be used so that these filters can be switched sequentially to change the beam attenuation ratio.

[0075] The lithography tool 100 further includes a shutter system 110 located downstream of and optically coupled to the beam matching unit 106. In some embodiments, the shutter system 110 may include at least one shutter. For example, two shutters may be provided to control the output of the radiation beam IL. A safety shutter is held open by a coil and configured to automatically close when any panel of the lithography apparatus housing is opened. The rotary shutter is driven by a motor during each exposure.

[0076] The lithography tool 100 further includes a zoom-and-aromatic optical system 120 located downstream of the shutter system 110 and optically coupled to the shutter system 110. The zoom-and-aromatic optical system 120 includes a set of zoom lenses 122 and an aromatic prism 124, driven by a motor drive 126. Here, two convex lenses are illustrated as examples of the zoom lenses 122. However, it should be understood that this is merely illustrative, and the zoom lenses 122 may include a plurality of lenses, including a combination of convex and / or concave lenses. The zoom lenses 122 are configured to determine the size of the light beam or the outer radius of the annular illumination pattern. The zoom lenses 122 may be collectively referred to as a zoom lens system.

[0077] The axicon prism 124 comprises a concave conical lens and a complementary convex conical lens, the spacing of which can be adjusted by a motor drive 126. The distance between the two elements of the axicon prism 124 can be adjusted by moving one of the elements along the optical axis. This allows adjustment of the annularity of the radiation beam IL. When the axicon prism 124 is closed, that is, the gap between the conical surfaces is zero, the radiation beam IL can have a circular disk shape. When a gap exists between the conical surfaces of the axicon prism 124, an annular intensity distribution can be generated, with the inner radial extent of the annular shape determined by the distance between the two conical surfaces.

[0078] exist Figure 1 In the embodiment of the present invention, the zoom lens 122 is located between the axicon prism 124 and the light source 102 along the optical path of the radiation beam IL. However, the relative positions of the zoom lens 122 and the axicon prism 124 may be interchanged. For example, in other embodiments, the axicon prism 124 is located between the zoom lens 122 and the light source 102 along the optical path of the radiation beam IL.

[0079] The lithography tool 100 further includes an integrator 130 located downstream of and optically coupled to the zoom-and-arotic optical system 120. In some embodiments, the integrator 130 comprises two elongated quartz rods 132 and 134 connected to a right-angle prism 136. The hypotenuse surfaces of the right-angle prism 136 are partially silvered to allow a small, known fraction of the beam energy to pass through an energy sensor 138. The radiation beam IL undergoes multiple internal reflections within the quartz rods 132 and 134, resulting in multiple, spaced-apart virtual sources observed in retrospect, thereby balancing the intensity distribution of the radiation beam IL. The function of the integrator is to improve the uniformity of the spatial and / or angular intensity distribution of the radiation beam IL.

[0080] The lithography tool 100 further includes a mask shutter mechanism 140 located downstream of the integrator 130 and optically coupled to the integrator 130. In some embodiments, the mask shutter mechanism 140 may include a fixed shutter unit 142 and a movable shutter unit 144 disposed adjacent to the fixed shutter unit 142. The fixed shutter unit 142 may include blades forming a fixed aperture. The movable shutter unit 144 may include movable blades having an adjustable aperture. The arrangement surface of the movable blades constituting the movable shutter unit 144 is conjugate with the pattern surface of the mask (e.g., mask MA). By using the fixed shutter unit 142 and the movable shutter unit 144, the slit-shaped illumination area illuminating the mask (e.g., mask MA) can be set to a rectangular shape of a preferred size and form.

[0081] The lithography tool 100 further includes a reticle masking (REMA) imaging optical system 150 located downstream of the reticle shutter mechanism 140 and optically coupled to the reticle shutter mechanism 140. The REMA imaging optical system 150 includes a housing 150H. In some embodiments, the air (oxygen) concentration within the housing 150H does not exceed a few percent, and the housing 150H can be filled with clean, dry nitrogen (N2), helium (He), and / or other inert gases with an air (oxygen) concentration of less than about 1%. The REMA imaging optical system 150 includes a first set of condensing lenses 152 and a second set of condensing lenses 154, wherein the first set of condensing lenses 152 and the second set of condensing lenses 154 are optically coupled to each other via a reflector 156. In some embodiments, the first set of condensing lenses 152 may include one or more lenses, and the present disclosure is not limited thereto. Similarly, the second set of condensing lenses 154 may include one or more lenses.

[0082] Lithography tool 100 further includes a reticle MA located downstream of and optically coupled to REMA imaging optical system 150. Reticle MA is held by a reticle stage 160. Radiation beam IL passes through a first set of condenser lenses 152, a reflector 156 to bend the optical path, and a second set of condenser lenses 154 to illuminate an illumination region within the circuit pattern region of reticle MA. Reticle MA is secured to reticle stage 160, for example, via a vacuum chuck. The structure of reticle stage 160 enables precise two-dimensional actuation within a plane perpendicular to the optical axis of radiation beam IL to perform positioning of reticle MA.

[0083] As used herein, the term "reticle" should be broadly interpreted to refer to any device that can be used to impart a radiation beam to produce a pattern, such as in a target portion of a wafer. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example, if the pattern includes phase-shifting features or so-called assist features. Typically, the pattern imparted to the radiation beam will correspond to a specific functional layer in a device being created in the target portion, such as an integrated circuit. In some embodiments, the term "reticle" may also be referred to as a "mask" or "reticle."

[0084] The lithography tool 100 further includes a projection optical system 170 located downstream of the reticle MA and optically coupled to the reticle MA. The projection optical system 170 may include a plurality of projection lenses 172. The projection optical system 170 projects a radiation beam IL from the reticle MA onto a wafer W coated with a photosensitive material (e.g., photoresist). In some embodiments, the wafer W is mounted on a wafer stage 180 during the lithography process.

[0085] Along the optical path of the radiation beam IL, the radiation beam IL passes through the beam steering system 104, the beam matching unit 106 (and the variable attenuator 108), the shutter system 110, the zoom-rotary axicon optical system 120, the integrator 130, the mask shutter mechanism 140, the REMA imaging optical system 150, the mask MA, and the projection optical system 170, and is incident on the wafer W. In other words, the above units are optically coupled to each other.

[0086] During semiconductor manufacturing, lithography is one of the most critical processes. Projection lenses shrink an image from a mask (reticle) and project it onto the wafer to create high-density circuit patterns. However, the lenses closest to the optical inlet and outlet of the optical system may be exposed to ambient air. After long-term use (e.g., 3-5 years), they can suffer from crystallization and contamination, which can impair lens uniformity, transmittance, telecentricity, and other performance. Because the lithography process is highly sensitive to optical behavior, unhealthy lens conditions can lead to low product yield or even scrap.

[0087] exist Figure 1In FIG. 1 , the optical system of the lithography tool 100 includes a zoom-and-anixon optical system 120, a REMA imaging optical system 150, and a projection optical system 170. With respect to the zoom-and-anixon optical system 120, the lenses closest to the optical entrance and the optical exit of the zoom-and-anixon optical system 120 may be the outermost zoom lens 122 and / or the outermost lens of the anilox prism 124. For example, the entrance lens of the zoom-and-anixon optical system 120 may be one of the zoom lens 122 and the anilox prism 124 closest to the shutter system 110, while the exit lens of the zoom-and-anixon optical system 120 may be the other of the zoom lens 122 and the anilox prism 124 closest to the integrator 130. In other words, the incident lens of the zoom-aniline prism optical system 120 may be the bottommost lens of the zoom lens 122 and the anilox prism 124 , and the exit lens of the zoom-aniline prism optical system 120 may be the topmost lens of the zoom lens 122 and the anilox prism 124 .

[0088] For the REMA imaging optical system 150, the lenses closest to the optical entrance and optical exit of the REMA imaging optical system 150 may be the outermost condenser lens 152 and the outermost condenser lens 154. For example, the entrance lens of the REMA imaging optical system 150 may be one of the condenser lenses 152 closest to the mask shutter mechanism 140, and the exit lens of the REMA imaging optical system 150 may be one of the condenser lenses 154 closest to the mask MA.

[0089] For the projection optical system 170, the lens closest to the optical entrance and optical exit of the projection optical system 170 may be the outermost projection lenses 172. For example, the incident lens of the projection optical system 170 may be one of the projection lenses 172 closest to the mask MA, and the exit lens of the projection optical system 170 may be one of the projection lenses 172 closest to the wafer W. In other words, the incident lens of the projection optical system 170 may be the topmost lens of the projection lenses 172, and the exit lens of the projection optical system 170 may be the bottommost lens of the projection lenses 172.

[0090] To restore lens performance, one method is to clean the lens surface with deionized water or a solvent. This deionized water or solvent may dissolve contaminants, but this method may not remove insoluble or internal lens crystals. Furthermore, this method may leave mechanical scratches or damage to the lens surface due to improper operation. Currently, due to the complexity of the optical system, there is no wafer fab lens repair method for lithography tools. For lenses with unacceptable performance, one approach is to replace the entire lens assembly. However, most lenses in lithography tools are aspherical lenses, which are much more expensive and difficult to manufacture than spherical lenses. To make matters worse, the manufacturing of such lens assemblies is typically time-consuming, making it difficult to quickly replace damaged lenses. Another disadvantage of this method is the replacement process. Once the new lens assembly arrives at the fab, the lithography tool must be disassembled for the replacement process, which can take up to 50 days to complete hardware installation and machine calibration. The embodiments of the present disclosure provide a method that costs only 1 / 20 of the previous method and, more importantly, reduces the installation and waiting time for the new lens, which will significantly improve wafer fab productivity.

[0091] Figure 2 Schematic diagram of a damaged lens according to some embodiments. A damaged lens DL is shown. The damaged lens DL may be the entrance lens or exit lens of the zoom-axicon optical system 120, the REMA imaging optical system 150, or the projection optical system 170 described above. The damaged lens DL includes at least one defect DF. For example, the defect DF may be irreparable crystallization, contamination, and / or mechanical damage (e.g., scratches).

[0092] Embodiments of the present disclosure provide a lens remanufacturing method for preparing a lens suitable for use in an original optical system. Specifically, a lens is remanufactured based on the surface profile of a damaged lens (e.g., damaged lens DL), and the damaged lens of the optical system is replaced with the remanufactured lens. This lens remanufacturing method can save time and costs, as discussed in more detail below.

[0093] Figure 3 A method for repairing a lens of a lithography tool according to some embodiments is provided. Method M1 is provided. While method M1 is described as a series of actions, it should be understood that these actions are not limiting, as the order of the actions may be varied in other embodiments. In other embodiments, some illustrated and / or described actions may be omitted in whole or in part.

[0094] Method M1 begins with operation S101, where a lithography process is performed using a lithography tool. The lithography process can be performed using the lithography tool 100, such as Figure 1 discussed, so for the sake of brevity, the relevant details will not be repeated.

[0095] Method M1 proceeds to operation S102, where lenses are removed from the lithography tool. As described above, lithography processes may be performed multiple times during semiconductor manufacturing. After extended use, the entrance and exit lenses of the optical system in lithography tool 100 may become damaged. Such lenses may be removed from lithography tool 100. The entrance and exit lenses of the optical system in lithography tool 100 have been described above, and therefore, the relevant details will not be repeated.

[0096] Method M1 proceeds to operation S103 to determine whether the surface condition of the lens is acceptable. In some embodiments, the lens removed from lithography tool 100 may first be subjected to a surface cleaning process. The surface cleaning process involves using deionized water or a solvent to remove contaminants or particles from the lens surface. After the surface cleaning process is completed, the surface condition of the lens is determined.

[0097] In some embodiments, when the defects of the lens are within a threshold condition, the surface condition of the lens is determined to be acceptable. On the other hand, when the defects of the lens exceed the threshold condition, the surface condition of the lens is determined to be unacceptable. For example, if the lens includes irreparable surface crystallization, surface contamination, and / or surface damage (e.g., scratches), the surface condition of the lens may be determined to be unacceptable.

[0098] If the surface condition of the lens is acceptable, method M1 returns to operation S101 , for example, by installing the lens back into lithography tool 100 and performing a lithography process using the same lens.

[0099] If the surface condition of the lens is unacceptable, method M1 proceeds to operation S104, where a new lens is fabricated based on the damaged lens. In some embodiments, if the surface condition of the original lens is determined to be unacceptable, the original lens may be referred to as a damaged lens. In operation S104, surface information of the damaged lens is detected, and the detected surface information of the damaged lens is used to fabricate a new lens. Figure 4 The details of operation S104 will be discussed.

[0100] Method M1 proceeds to operation S105, where the damaged lens is replaced with a new lens. The new lens is installed back into the lithography tool 100 to replace the damaged lens. Method M1 then returns to operation S101. For example, the new lens can be used to perform a lithography process. The damaged lens can be discarded. It should be noted that only the damaged lens of the lithography tool 100 is replaced with the new lens, while the other lenses in the lithography tool 100 remain unchanged. That is, by using this method, the entire lens assembly of the lithography tool 100 does not need to be replaced. Therefore, using the lens remanufacturing method can save time and cost.

[0101] Figure 4 A method for remaking a lens based on a damaged lens according to some embodiments. In more detail, method M2 describes Figure 3 Operation S104 in .

[0102] Method M2 begins with operation S201, generating surface information of a damaged lens. To reconstruct the damaged lens, geometrically desensitized interferometry (GDI) is first used to accurately measure the surface profile of the damaged lens. The GDI system utilizes a combination of reflective and refractive optical elements to perform beam splitting and recombination operations to determine the surface profile. With nanometer-scale precision, all retrieved data is recorded in a matrix. The surface profile matrix includes all information about the damaged lens' surface profile, including geometry (e.g., shape), surface roughness, and defects.

[0103] Method M2 proceeds to operation S202, where the surface information is divided into a geometry matrix, a roughness matrix, and a defect matrix. In some embodiments, because the measured surface profile contains roughness and defects such as crystallization, contamination, and mechanical damage, data processing is required to restore a perfect profile. Therefore, a computational process is performed to divide the measured data (e.g., the original surface profile matrix) into three matrices: a geometry matrix, a roughness matrix, and a defect matrix.

[0104] Figure 5A 、 Figure 5B and Figure 5C Schematic diagram of a geometric matrix, a roughness matrix, and a defect matrix according to some embodiments. Figure 5A As shown, the geometry matrix records the "shape" of the damaged lens. For example, it can be seen that Figure 5A In , only the damaged shape is shown, and the geometric matrix can be considered as a perfect outline because it does not include surface roughness and defects. Figure 5B In the roughness matrix, the "surface roughness profile" of the damaged lens is recorded. For example, it can be seen that the surface morphology of the damaged lens is as follows Figure 5B As shown. Figure 5C In the defect matrix, the defect profile of the damaged lens is recorded. For example, it can be seen that the shape of the defect of the damaged lens is as follows Figure 5C shown.

[0105] Method M2 proceeds to operation S203, where an initial profile of the new lens is generated. In some embodiments, the geometry matrix and roughness matrix derived from the damaged lens are used as the initial profile of the new lens. That is, the defect matrix is ​​not used as part of the initial profile of the new lens. In other words, the surface profile of the damaged lens without defects is set as the initial profile of the new lens.

[0106] Method M2 proceeds to operation S204, where the initial profile of the new lens is optimized to produce an optimized profile of the new lens. In some embodiments, the geometry matrix and the roughness matrix derived from the damaged lens are used as inputs for simulating the optical properties of the new lens in a lithography tool (e.g., lithography tool 100). The profile matrix of the new lens (e.g., a combination of the geometry matrix and the roughness matrix) is simulated using finite element analysis to verify the theoretical performance of the new lens. The optimization process also includes an iterative process until the desired lens profile of the new lens is obtained. More specifically, the iterative process includes iteratively modifying the parameters of the new lens until the desired lens profile of the new lens is obtained. Here, the parameters of the new lens include the size, radius, surface finish, air space, and centering of the new lens.

[0107] Method M2 proceeds to operation S205, where a new lens is manufactured according to the optimized profile. Once the optimized profile of the new lens is generated, the new lens can be manufactured according to the optimized profile. That is, the manufactured new lens can include a profile that is substantially the same as the simulated optimized profile.

[0108] Figure 6 In more detail, method M3 describes a method for manufacturing a lens according to some embodiments. Figure 4 Operation S205 in .

[0109] Method M3 begins with operation S301 to perform coarse shaping. In the coarse shaping, a piece of lens material (eg, glass) is cut using a glass saw to obtain a workpiece.

[0110] Method M3 proceeds to operation S302 to perform fine shaping. After the rough shaping is completed, fine shaping is performed to shape the workpiece so that the workpiece has a desired size and a desired surface curvature.

[0111] Method M3 proceeds to operation S303 for coarse polishing. After fine shaping is completed, the workpiece is coarse polished. In some embodiments, coarse polishing can be a contact polishing method. For example, a rotary polisher presses an abrasive against the workpiece surface to polish the workpiece surface. That is, during coarse polishing, the polisher may come into contact with the workpiece surface.

[0112] Method M3 proceeds to operation S304 to perform fine polishing. After the rough polishing is completed, the workpiece is fine polished. In some embodiments, the fine polishing may be a non-contact polishing method. The fine polishing may include using a multi-stage focused ion beam (FIB) method. Figure 7, shows a schematic diagram of a focused ion beam (FIB) system according to some embodiments. A focused ion beam system 200 is shown. The focused ion beam system 200 includes a focused ion beam generator 210 for generating a focused ion beam IB on a workpiece WP (e.g., a new lens). In some embodiments, the focused ion beam generator 210 may include an ion source, at least one electromagnetic (e.g., electrostatic) lens, and at least one deflector, which together are used to generate the focused ion beam. The focused ion beam system 200 further includes a gas injection system 220 (GIS). The gas injection system 220 is used to provide gas on the workpiece WP to enhance the polishing operation performed on the workpiece WP. The focused ion beam system 200 further includes a scanning electron microscope 230 (SEM) for generating an electron beam toward the workpiece WP and a detector 240 for detecting secondary or backscattered particles generated by the ion beam or electron beam impacting the surface of the workpiece WP.

[0113] During the fine polishing of a workpiece, several polishing cycles may be performed on the workpiece surface to obtain the desired surface roughness. More specifically, the ion beam energy of the polishing cycle may be reduced from cycle to cycle. That is, the ion beam energy of each polishing cycle is lower than the ion beam energy of the previous polishing cycle. This is because the lower the energy, the better the polishing effect and the longer the polishing time. This focused ion beam process has high flexibility because different surface properties can be achieved by energy control. In addition, the method can remove subsurface contamination in the workpiece, thereby improving the coating quality in the next step. In some embodiments, the focused ion beam process can provide a better surface roughness for the new lens. For example, by using a focused ion beam process for the fine polishing step, the surface roughness of the new lens can be lower than the surface roughness of the original lens (e.g., a damaged lens). For example, the root mean square (RMS) roughness of the new lens is lower than the RMS roughness of the original lens (e.g., a damaged lens).

[0114] Method M3 proceeds to operation S305 to perform lens edging. The workpiece undergoes lens edging so that the final lens can be adapted for lithography tools. For example, lens edging includes grinding the edge of the workpiece using an edging tool (such as a grinding wheel) until the desired lens shape is achieved.

[0115] Method M3 proceeds to operation S306 to perform coating simulation. After the lens edge grinding is completed, the workpiece will be coated with several layers. However, the coating is usually composed of 20 to 40 layers, and this complexity makes it difficult to achieve the same performance as the original lens. Therefore, a coating simulation is performed to reverse engineer the coating layer by layer and simulate the final coating quality. In more detail, the coating simulation includes using a spectrometer to obtain the optical properties of the workpiece (without coating), and the optical properties can be used to simulate the optical properties of the new lens to produce simulation results. The simulation results may include information about the coating. Here, the optical properties may include diameter, radius of curvature, surface asphericity coefficient, surface accuracy, surface defects, roughness, coating thickness, transmittance, reflectivity, refractive index, etc.

[0116] Method M3 proceeds to operation S307 for surface coating. After the coating simulation is completed, the workpiece is coated with a coating according to the simulation results. In some embodiments, the coating may include lanthanides, fluorides, etc.

[0117] Figure 8 FIG. 5 is a block diagram of a lens re-fabrication system according to some embodiments. FIG. 5 shows a lens re-fabrication system 500 . The lens re-fabrication system 500 includes a lithography tool 510 , a geometrically-desensitized interferometry (GDI) tool 520 , a processor 530 , and a lens manufacturing tool 540 , which are interconnected.

[0118] The lithography tool 510 may be used to perform a lithography process. In some embodiments, the lithography tool 510 may be the lithography tool 100, such as Figure 1 shown.

[0119] The geometric desensitization interferometry tool 520 can be used to measure the surface profile of a lens, such as a damaged lens as described above. In some embodiments, the geometric desensitization interferometry tool 520 may include an interferometer. The interferometer detects the surface morphology by comparing the surface of a workpiece (e.g., the surface of a damaged lens) with a reference surface. The reference surface may be a flat surface or a surface with a known surface morphology. The interferometer further includes a wave source, a polarization beam splitter, an imaging module, and an analyzer. The wave source is used to provide a wave. In some embodiments, the wave may be ultraviolet light, visible light, or infrared light. The polarization beam splitter is used to split the wave into two polarized waves, which are directed to the workpiece surface and the reference surface, respectively. The imaging module is used to detect the interference wave generated by recombining the two reflected polarized waves from the workpiece surface and the reference surface, respectively. The analyzer is used to determine the height of the relevant area based on the interference wave.

[0120] The processor 530 may be a computer with suitable software to execute operations S202, S203, and S204 of method M2, such as Figure 4As shown. For example, the processor 530 may receive surface information of a damaged lens from the geometric desensitization interferometry tool 520. The processor 530 may be configured to separate the surface information into a geometry matrix, a roughness matrix, and a defect matrix (e.g., operation S202). The processor 530 may be configured to generate an initial profile of a new lens (e.g., operation S203). The processor 530 may be configured to use finite element analysis to check the theoretical performance of the new lens. The processor 530 may be configured to simulate the theoretical performance of the new lens using an iterative process until a desired lens profile of the new lens is obtained (e.g., operation S204).

[0121] The lens manufacturing tool 540 is used to perform operation S205 of method M2, such as Figure 4 The lens manufacturing tool 540 includes a rough shaping tool 541 , a fine shaping tool 542 , a rough polishing tool 543 , a fine polishing tool 544 , an edge grinding tool 545 , a coating simulation tool 546 and a coating tool 547 .

[0122] The coarse shaping tool 541 is used to perform Figure 6 Operation S301 of method M3. In some embodiments, the rough shaping tool 541 may include a glass saw for cutting a plate of lens material (eg, glass) to obtain a workpiece.

[0123] Fine shaping tool 542 is used to perform Figure 6 In some embodiments, the fine shaping tool 542 may include a mold and a heater. For example, the workpiece may be heated to a soft state using a heater, rolled into a round shape, and pressed into a desired size and approximately the desired surface curvature in a mold.

[0124] Rough polishing tool 543 is used to perform Figure 6 In some embodiments, the rough polishing tool 543 may include a support and a rotary polisher. For example, the workpiece is placed on the support, and the rotary polisher presses the abrasive against the workpiece surface to polish the workpiece surface.

[0125] Fine polishing tool 544 is used to perform Figure 6 In some embodiments, the fine polishing tool 544 may include a focused ion beam system 200, such as Figure 7 For example, the fine polishing tool 544 is used to polish the workpiece using a focused ion beam.

[0126] The edge grinding tool 545 is used to perform Figure 6 In some embodiments, the edge grinding tool 545 may include an edge grinding tool, such as a grinding wheel. For example, the edge grinding tool 545 is used to grind the edge of the workpiece.

[0127] Coating simulation tool 546 is used to perform Figure 6 In some embodiments, the coating simulation tool 546 may include a spectrometer and a computer. For example, the spectrometer is used to obtain the optical properties of the workpiece (without coating), and the computer is used to simulate the optical properties of the new lens.

[0128] Coating tool 547 is used to perform Figure 6 Operation S307 of method M3 of the present invention is described. In some embodiments, coating tool 547 may include a support and a nozzle. For example, a workpiece is placed on the support. The nozzle, connected to a coating material tank, is used to apply a coating material in liquid or gaseous form to the surface of the workpiece. The support can rotate the workpiece to form a thin film of the coating material on the surface of the workpiece.

[0129] Based on the aforementioned embodiments, it can be seen that the present disclosure offers advantages in manufacturing integrated circuits. However, it is understood that other embodiments may provide additional advantages, and not all advantages are necessarily disclosed herein, nor are the specific advantages of all embodiments required. Embodiments of the present disclosure provide a lens remanufacturing method for manufacturing a lens suitable for an original optical system. More specifically, a lens is remanufactured based on the surface profile of a damaged lens, and the damaged lens of the optical system is replaced with the remanufactured lens. Using this lens remanufacturing method can save time and cost.

[0130] In some embodiments of the present disclosure, a method includes the following steps: removing a damaged lens from a lithography tool; generating an initial profile of a new lens based on a surface profile of the damaged lens; optimizing the initial profile of the new lens by simulating optical properties of the new lens in the lithography tool to generate an optimized profile; manufacturing a new lens based on the optimized profile; and installing the new lens in the lithography tool to replace the damaged lens.

[0131] In some embodiments, a geometric desensitization interferometry method is used to generate the surface profile of the damaged lens.

[0132] In some embodiments, the surface profile of the damaged lens is in matrix form, and the method further includes the following steps: dividing the matrix into a geometric matrix, a roughness matrix, and a defect matrix, wherein the geometric matrix records the shape of the damaged lens, the roughness matrix records the surface roughness profile of the damaged lens, and the defect matrix records the defect profile of the damaged lens.

[0133] In some embodiments, an initial profile of a new lens is generated based on a geometry matrix and a roughness matrix without using a defect matrix.

[0134] In some embodiments, the initial profile of the new lens is optimized using finite element analysis to simulate the optical properties of the new lens, and an iterative process is used until the desired lens profile of the new lens is obtained.

[0135] In some embodiments, a lithography tool includes a light source, a zoom-and-axicon optical system optically coupled to the light source, a reticle shadow imaging system coupled to the zoom-and-axicon optical system, a reticle optically coupled to the reticle shadow imaging optical system, and a projection optical system optically coupled to the reticle. The damaged lens is a lens closest to an optical entrance or an optical exit of the zoom-and-axicon optical system, a lens closest to an optical entrance or an optical exit of the reticle shadow imaging optical system, or a lens closest to an optical entrance or an optical exit of the projection optical system.

[0136] In some embodiments, manufacturing a new lens based on the optimized profile includes the following steps: shaping a workpiece; performing rough polishing on the workpiece; performing fine polishing on the workpiece using a focused ion beam method; and coating the workpiece.

[0137] In some embodiments, the method further includes the steps of performing a coating simulation on the workpiece to generate a simulation result, and coating the workpiece based on the simulation result.

[0138] In some embodiments of the present disclosure, a method includes the following steps: removing a damaged lens from a lithography tool; generating a profile of a new lens based on a surface profile of the damaged lens; manufacturing a new lens based on the profile, wherein manufacturing the new lens includes the following steps: shaping a workpiece; performing rough polishing on the workpiece; performing fine polishing on the workpiece, wherein the fine polishing is a non-contact polishing method; and coating the workpiece; and installing the new lens in the lithography tool to replace the damaged lens.

[0139] In some embodiments, the fine polishing is performed using a focused ion beam method.

[0140] In some embodiments, the focused ion beam method includes multiple polishing cycles, and the ion beam energy of each polishing cycle is lower than the ion beam energy of the previous polishing cycle.

[0141] In some embodiments, the rough polishing is a contact polishing method.

[0142] In some embodiments, generating a profile of a new lens based on the surface profile of a damaged lens includes the following steps: using a geometric desensitization interference method to generate the surface profile of the damaged lens; generating an initial profile of the new lens based on the surface profile of the damaged lens; and optimizing the initial profile of the new lens by simulating the optical properties of the new lens in a lithography tool to generate an optimized profile as the profile of the new lens.

[0143] In some embodiments, the surface profile of the damaged lens is in the form of a matrix, and the method further includes the following steps: dividing the matrix into a geometric matrix, a roughness matrix, and a defect matrix, wherein the geometric matrix records the shape of the damaged lens, the roughness matrix records the surface roughness profile of the damaged lens, and the defect matrix records the defect profile of the damaged lens, and wherein an initial profile of a new lens is generated based on the geometric matrix and the roughness matrix without using the defect matrix.

[0144] In some embodiments, the damaged lens is the lens closest to an optical entrance of the optical system of the lithography tool or an optical exit of the optical system of the lithography tool.

[0145] In some embodiments of the present disclosure, a lens remanufacturing system includes a processor and a lens manufacturing tool. The processor is configured to generate a profile of a new lens based on a surface profile of a damaged lens. The lens manufacturing tool is configured to manufacture the new lens based on the profile. The lens manufacturing tool includes a rough polishing tool and a fine polishing tool. The rough polishing tool is configured to perform a first polish on the workpiece of the new lens using a rotary polisher. The fine polishing tool is configured to perform a second polish on the workpiece of the new lens using a focused ion beam.

[0146] In some embodiments, the first polishing is a contact polishing method, and the second polishing is a non-contact polishing method.

[0147] In some embodiments, the second polishing includes a plurality of polishing cycles, and the ion beam energy of each polishing cycle is lower than the ion beam energy of the previous polishing cycle.

[0148] In some embodiments, the lens reconstruction system further includes an interferometer to generate a surface profile of the damaged lens.

[0149] In some embodiments, the surface profile of the damaged lens is in matrix form, and the processor is used to separate the matrix into a geometric matrix, a roughness matrix, and a defect matrix, wherein the geometric matrix records the shape of the damaged lens, the roughness matrix records the surface roughness profile of the damaged lens, and the defect matrix records the defect profile of the damaged lens, and wherein the processor generates the profile of the new lens based on the geometric matrix and the roughness matrix without using the defect matrix.

[0150] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art will understand that they can easily use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also recognize that these equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and modifications may be made to these equivalent constructions without departing from the spirit and scope of the present disclosure.

Claims

1. A method for remaking a lens, characterized in that: The following steps are involved: removing a damaged lens from a lithography tool; generating an initial profile of a new lens based on a surface profile of the damaged lens; optimizing the initial profile of the new lens by simulating an optical property of the new lens in the lithography tool to generate an optimized profile; manufacturing the new lens based on the optimized profile; and The new lens is installed in the lithography tool to replace the damaged lens.

2. The method according to claim 1, wherein A geometric desensitization interferometry method is used to generate the surface profile of the damaged lens.

3. The method according to claim 2, wherein The surface profile of the damaged lens is in the form of a matrix, and the method further includes the following steps: dividing the matrix into a geometric matrix, a roughness matrix, and a defect matrix, wherein the geometric matrix records a shape of the damaged lens, the roughness matrix records a surface roughness profile of the damaged lens, and the defect matrix records a defect profile of the damaged lens.

4. The method according to claim 3, wherein The initial profile of a new lens is generated based on the geometric matrix and the roughness matrix without using the defect matrix.

5. A method for remaking a lens, characterized in that: The following steps are involved: removing a damaged lens from a lithography tool; generating a profile of a new lens based on a surface profile of the damaged lens; The new lens is manufactured based on the profile, wherein manufacturing the new lens comprises the following steps: shaping a workpiece; performing a rough polishing on the workpiece; Performing a finish polishing on the workpiece, wherein the finish polishing is a non-contact polishing method; and coating the workpiece; and The new lens is installed in the lithography tool to replace the damaged lens.

6. The method according to claim 5, wherein Generating the profile of the new lens based on the surface profile of the damaged lens comprises the following steps: Generating the surface profile of the damaged lens using a geometric desensitization interferometry method; generating an initial profile of the new lens based on the surface profile of the damaged lens; and The initial profile of the new lens is optimized by simulating an optical characteristic of the new lens in the lithography tool to generate an optimized profile as the profile of the new lens.

7. The method according to claim 6, wherein The surface profile of the damaged lens is in a matrix form, and the method further comprises the following steps: dividing the matrix into a geometric matrix, a roughness matrix and a defect matrix, wherein the geometry matrix records a shape of the damaged lens, the roughness matrix records a surface roughness profile of the damaged lens, and the defect matrix records a defect profile of the damaged lens, and The initial profile of the new lens is generated based on the geometric matrix and the roughness matrix without using the defect matrix.

8. A lens remaking system, characterized in that: Include: a processor for generating a profile of a new lens based on a surface profile of a damaged lens; and a lens manufacturing tool for manufacturing the new lens based on the profile, wherein the lens manufacturing tool comprises: a rough polishing tool for performing a first polishing of a workpiece of the new lens using a rotary polishing machine; and A fine polishing tool is used to perform a second polishing on the workpiece of the new lens using a focused ion beam.

9. The lens reproduction system according to claim 8, wherein: The first polishing is a contact polishing method, and the second polishing is a non-contact polishing method.

10. The lens reproduction system according to claim 8, wherein: The second polishing includes a plurality of polishing cycles, and an ion beam energy of each polishing cycle is lower than an ion beam energy of a previous polishing cycle.

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