In-situ detection and illumination system and micro-nano machining method

Abstract

The invention provides an in-situ detection and illumination system and a micro-nano processing method, which can be applied to the technical field of exposure illumination. The system comprises an objective lens, an ultraviolet illumination assembly, a visible light illumination assembly, an imaging observation assembly and an in-situ detection assembly, wherein multiple paths of light are coupled to the same objective lens through a first spectroscope, a second spectroscope and a third spectroscope. The ultraviolet illumination assembly is used for exposure, the visible light illumination assembly provides observation illumination, the imaging observation assembly is used for alignment observation, and the in-situ detection assembly collects interference spectrums through the receiving optical fiber set to achieve real-time leveling. The system further comprises a particle detection module which is used for detecting and screening pollution on the surface of the substrate before exposure. Through multi-light-path integration and intelligent control, the integration of exposure, in-situ detection, alignment and pollution detection functions is realized, and the integration level, the process reliability and the pattern transfer precision of the photoetching system are remarkably improved.

Description

Technical Field

[0001] This disclosure relates to the field of exposure lighting technology, and more specifically to an in-situ detection and lighting system and a micro / nano fabrication method. Background Technology

[0002] Micro-nano fabrication technology is a core technology in the field of micro-nano manufacturing, such as integrated circuits and microelectromechanical systems. It precisely replicates patterns from a mask onto a substrate using optical exposure. A complete micro-nano fabrication apparatus typically includes multiple functional modules, such as a workpiece stage module for transfer and positioning, a particle detection module for checking the cleanliness of the substrate surface, an in-situ detection module for measuring and leveling the gap between the mask and the substrate, an alignment module for identifying alignment marks, and an illumination module for pattern exposure.

[0003] Currently, to achieve the aforementioned multiple functions, conventional micro / nano fabrication devices typically employ a discrete, modular, serial operating architecture. That is, functions such as particle detection, in-situ leveling and alignment, and pattern exposure are performed by independent optical and mechanical modules, which are spatially distributed. This architecture leads to the following significant drawbacks:

[0004] (1) Low system integration and large size: The stacking and connection of multiple independent modules makes the whole machine structure complex and occupies a large space, which is not conducive to the compact and miniaturized design of the equipment.

[0005] (2) Poor compatibility and coordination: The optical references of each module are different, and the workflow needs to be frequently switched and calibrated, which not only reduces the process efficiency, but also introduces additional alignment error risks.

[0006] (3) High cost and complex maintenance: There are many discrete optical and mechanical components, resulting in high system manufacturing costs and complicated subsequent optical path calibration and maintenance.

[0007] Furthermore, while some existing integrated solutions attempt to merge certain functions, they face fundamental challenges in optical system design. These solutions often struggle to simultaneously meet the stringent requirements of high-precision in-situ detection for signal purity and signal-to-noise ratio, the demands of high-intensity pattern exposure for large-area illumination uniformity and energy density, and the compatibility of real-time process observation for rapid imaging and continuous monitoring within a single optical path. The root cause lies in the conflicting requirements of different functional modules regarding parameters such as the spectral characteristics, incident angle, energy distribution, and time modulation of the optical path. Simply reusing or switching optical paths often leads to crosstalk between the detection signal and the illumination light, or forces compromises on key performance aspects such as illumination uniformity, energy utilization, or detection resolution to accommodate multiple functions, thus limiting further improvements in overall system performance. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] To address the aforementioned issues, this disclosure provides an in-situ detection and illumination system and a micro / nano fabrication method. By using multiple beam splitters to coaxially couple four optical paths—ultraviolet illumination, visible light illumination, imaging observation, and spectral detection—to the same objective lens, a high degree of optical path integration and system miniaturization is achieved. Methodologically, the system can sequentially or simultaneously complete substrate dark-field particle detection, high-precision interferometric spectral gap measurement between the mask and substrate, real-time imaging alignment observation, and ultraviolet pattern exposure at the same station on the workpiece stage, forming an integrated in-situ parallel workflow of "detection-observation-exposure."

[0010] (II) Technical Solution

[0011] To address the aforementioned technical problems, embodiments of this disclosure propose an in-situ detection and illumination system and a micro / nano fabrication method.

[0012] According to a first aspect of this disclosure, an in-situ detection and illumination system is provided, characterized in that it comprises: an objective lens; an ultraviolet illumination assembly, which sequentially includes an ultraviolet light source, an ultraviolet illumination optical lens group, and a first beam splitter in the ultraviolet optical path direction; a visible light illumination assembly, which sequentially includes a broadband light source, a visible light illumination optical lens group, a third beam splitter, a second beam splitter, and a first beam splitter in the visible light illumination optical path direction; an imaging observation assembly, which includes a first beam splitter, a second beam splitter, an imaging optical lens group, and a second camera in the imaging optical path direction; and an in-situ detection assembly, which sequentially includes a first beam splitter, a second beam splitter, a third beam splitter, an in-situ detection optical lens group, a fourth beam splitter group, and a receiving fiber optic group in the in-situ detection optical path direction.

[0013] In some exemplary embodiments, the ultraviolet light source is connected to the ultraviolet illumination optical lens group via a water-cooled optical fiber, and the exit end face of the water-cooled optical fiber coincides with the focal plane of the ultraviolet illumination optical lens group.

[0014] In some exemplary embodiments, the illumination surface of the ultraviolet illumination optical lens group coincides with the imaging surface of the objective lens, and the primary imaging surface of the ultraviolet illumination optical lens group coincides with the aperture stop of the objective lens; the ultraviolet illumination optical lens group includes a motorized variable aperture stop, the diameter of which is adjustable.

[0015] In some exemplary embodiments, a filter is provided at the front end of the visible light illumination optical lens group to filter out short-wavelength light below a preset wavelength.

[0016] In some exemplary embodiments, the illumination surface of the visible light illumination optical lens group coincides with the image plane of the objective lens, and the primary imaging surface of the visible light illumination optical lens group coincides with the aperture stop of the objective lens; the optical path between the visible light illumination optical lens group and the aperture stop of the objective lens is greater than 200 mm.

[0017] In some exemplary embodiments, the objective lens and the imaging optical lens group in the imaging observation assembly together form a dual telecentric optical path; the target surface of the second camera coincides with the image plane of the imaging optical lens group.

[0018] In some exemplary embodiments, the receiving fiber group in the in-situ detection assembly includes multiple fixed fibers and at least one movable fiber; the end faces of the fixed fibers are uniformly distributed on the image plane of the in-situ detection optical mirror assembly, and are used to collect interference spectra at multiple fixed positions around the exposure area; the movable fiber is driven by a displacement mechanism, and its end face can move on the image plane of the in-situ detection optical mirror assembly, with the movement range covering the entire exposure field of view, and is used to collect interference spectra at any selected position within the exposure area.

[0019] In some exemplary embodiments, the system further includes a particle detection module, which includes an illumination source, an illumination lens group, a detection lens group, and a first camera; wherein the optical axis of the illumination lens group is arranged at an angle to the optical axis of the detection lens group, forming an obliquely incident dark field illumination optical path, which is used to generate scattered light from contaminant particles on the substrate surface and to be received by the detection lens group and the first camera.

[0020] In some exemplary embodiments, the system further includes: a support frame; a workpiece stage module disposed on the support frame for supporting and positioning the substrate; a mask suction cup module for fixing the mask; and a control system connected to the workpiece stage module, particle detection module, in-situ detection component, imaging observation component, and ultraviolet illumination component for coordinating the workflow of each module, processing detection data, and generating control commands.

[0021] According to a second aspect of this disclosure, a micro / nano fabrication method based on the above-mentioned in-situ detection and illumination system is provided, comprising the following steps: S1: mounting a mask and a substrate on a mask chuck module and a workpiece stage module, respectively; S2: moving the substrate to a particle detection position via the workpiece stage module, using the particle detection module to detect contamination in each preset exposure field, and selecting the fields that can be exposed; S3: moving the substrate to the exposure position, detecting the gap between the mask and the substrate via the in-situ detection component, and simultaneously performing alignment observation via the imaging observation component; the control system controls the workpiece stage module to complete leveling and alignment based on the detection results; S4: activating the ultraviolet illumination component to perform pattern exposure on the fields that have completed leveling and alignment; S5: stepping the substrate to the next selected exposeable field via the workpiece stage module, repeating steps S3 and S4 until the exposure of the entire substrate is completed.

[0022] (III) Beneficial Effects

[0023] As can be seen from the above technical solutions, the in-situ detection and illumination system and micro / nano fabrication method provided in this disclosure have at least the following beneficial effects:

[0024] (1) By using multiple spectroscopic elements to couple multiple functional optical paths such as ultraviolet exposure, visible light illumination and observation, and in-situ spectral detection to the same objective lens, the physical integration of multiple modules is realized. Compared with the scheme of multiple independent modules being distributed in the prior art, this disclosure significantly reduces the number of optical and mechanical components of the system, reduces the overall volume, reduces the system complexity and assembly difficulty, and facilitates the miniaturization and modular deployment of the equipment.

[0025] (2) Through the high integration of functional optical paths, this system enables a series of key process steps, such as particle contamination screening, mask-substrate gap detection, alignment observation, and pattern exposure, to be completed in situ at the same position (i.e., the exposure station) on the substrate carried by the workpiece stage. This completely changes the traditional "off-site" operation mode that requires moving the substrate between different functional stations and performing multiple alignments and calibrations. This "in-situ" working mode eliminates the accumulation of alignment errors introduced by workpiece stage movement and module switching, significantly shortens the preprocessing time of a single exposure, improves the overall production capacity, and significantly improves the overlay accuracy and linewidth uniformity of pattern transfer through real-time, in-situ feedback control of gap and alignment status.

[0026] (3) The system integrates two key detection capabilities: first, independent dark-field scattering particle detection, which can effectively identify and remove contaminated exposure fields before exposure, avoid defects, protect the mask, and improve yield; second, high-precision in-situ spectral interferometry gap detection, which, combined with fixed and movable fiber optic probes, can achieve high-precision gap control from rapid coarse leveling to full-field fine leveling. These two capabilities, combined with high-resolution imaging observation, form a multi-dimensional, full-process monitoring of the process status, providing a solid guarantee for obtaining high-quality exposure patterns.

[0027] (4) The ultraviolet illumination component adopts an integrated adjustable aperture design, which can flexibly adjust the illumination spot according to the size and shape of different exposure patterns. While ensuring illumination uniformity, it reduces the influence of invalid exposure and stray light, thereby improving energy utilization and pattern edge quality. The wide-spectrum design of the visible light illumination component and imaging observation component provides suitable illumination conditions for alignment mark recognition and spectral detection.

[0028] (5) By coordinating the work of the particle detection module, optical lens module and workpiece stage module through a unified controller, the entire process from contamination detection, exposure cycle planning, automatic leveling and alignment to exposure parameter control is fully automated and intelligent. The control system makes decisions based on real-time detection data, reducing manual intervention, which not only improves the consistency and reliability of the process, but also reduces the dependence on the skills of operators. Attached Figure Description

[0029] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 A schematic diagram of the structure of an in-situ detection and illumination system according to an embodiment of the present disclosure is shown.

[0031] Figure 2 A schematic diagram of the structure of a particle detection module according to an embodiment of the present disclosure is shown.

[0032] Figure 3 A schematic diagram illustrating the structure of an optical lens module according to an embodiment of the present disclosure is shown.

[0033] Figure 4 A schematic diagram of the structure of an ultraviolet illumination assembly according to an embodiment of the present disclosure is shown.

[0034] Figure 5 A schematic diagram of a visible light illumination assembly according to an embodiment of the present disclosure is shown.

[0035] Figure 6 A schematic diagram of the structure of an imaging observation assembly according to an embodiment of the present disclosure is shown.

[0036] Figure 7 A schematic diagram illustrating the structure of an in-situ detection component according to an embodiment of the present disclosure is shown; and

[0037] Figure 8 A flowchart illustrating a micro / nano fabrication method for an in-situ detection and illumination system based on an embodiment of the present disclosure is shown.

[0038] Figure label:

[0039] 1-Supporting framework;

[0040] 2-Workpiece stage module;

[0041] 3-Particle detection module;

[0042] 3-1-Lighting source;

[0043] 3-2-Illumination lens assembly;

[0044] 3-3-Detection mirror assembly;

[0045] 3-4-First camera;

[0046] 3-5-Active focusing module;

[0047] 4-Optical lens module;

[0048] 4-1-Objective lens;

[0049] 4-2-Ultraviolet light source;

[0050] 4-3-Ultraviolet Illumination Optical Mirror Group;

[0051] 4-3-1-Electric variable aperture;

[0052] 4-4-Broad spectrum light source;

[0053] 4-5-Visible light illumination optical lens group;

[0054] 4-5-1-Filter;

[0055] 4-6-imaging optical lens group;

[0056] 4-7-Second camera;

[0057] 4-8-In-situ detection optical lens group;

[0058] 4-8-1-Fourth beam splitter;

[0059] 4-8-2-Fixed optical fiber;

[0060] 4-8-3-Removable fiber optic cable;

[0061] 4-9- First beam splitter;

[0062] 4-10-Second beam splitter;

[0063] 4-11 Third beam splitter;

[0064] 5-Mask suction cup module;

[0065] 6-Control system. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0067] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0068] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0069] Figure 1A schematic diagram of the structure of an in-situ detection and illumination system according to an embodiment of the present disclosure is shown.

[0070] like Figure 1 As shown, the in-situ detection and illumination system according to an embodiment of this disclosure includes: a support frame 1; a workpiece stage module 2, disposed on the support frame 1, for supporting and positioning the substrate; an optical lens module 4, disposed above the workpiece stage module 2, for providing illumination to the mask and observing and detecting the mask and the substrate; a mask suction cup module 5, disposed between the optical lens module 4 and the workpiece stage module 2, for fixing the mask; a particle detection module 3, for non-contact dark-field detection of contaminant particles on the substrate surface before exposure; and a control system 6, connected to the workpiece stage module 2, the optical lens module 4, and the particle detection module 3, coordinating the sequential execution of particle detection, gap detection and leveling, alignment observation and compensation, and ultraviolet exposure processes by each module. Specifically, the optical lens module 4 integrates an objective lens, an ultraviolet illumination component, a visible light illumination component, an imaging observation component, and an in-situ detection component, which together constitute a multifunctional optical component for collaboratively realizing ultraviolet exposure illumination, in-situ gap detection between the mask and the substrate, leveling, and alignment observation.

[0071] Figure 2 A schematic diagram of the structure of particle detection module 3 according to an embodiment of the present disclosure is shown.

[0072] like Figure 2 As shown, the particle detection module 3 according to an embodiment of this disclosure includes: an illumination source 3-1, an illumination lens group 3-2, a detection lens group 3-3, and a first camera 3-4; wherein, the optical axis of the illumination lens group 3-2 is arranged at an angle to the optical axis of the detection lens group 3-3, forming an oblique incident dark field illumination light path. After the incident light uniformly illuminates the substrate surface, it is reflected to outside the field of view of the detection lens group 3-3. The contamination particles on the substrate surface generate scattered light, which is received by the detection lens group 3-3 and the first camera 3-4. The control system 6 analyzes the scattered light image acquired by the first camera 3-4, and identifies and marks the exposure area on the substrate surface where the contamination concentration exceeds a preset threshold.

[0073] For example, the system's single-field exposure range is 5mm × 5mm. The illumination source 3-1 is a high-power halogen lamp with a wavelength range covering 450nm-750nm. The illumination source 3-1 is guided into the illumination lens group 3-2 via optical fiber. The diameter of the fiber's exit end face is 6.4mm, and the numerical aperture (NA) is 0.57. The illumination lens group 3-2 is based on the Köhler illumination principle, with the primary imaging plane set as an aperture stop. The focal plane coincides with the fiber end face, ensuring the uniformity of illumination incident on the substrate, ultimately achieving a uniform illumination area greater than 5mm × 5mm.

[0074] The detection lens group 3-3 is a dual telecentric optical lens group with a field of view of 5×5mm, enabling the detection of single-field contamination. The numerical aperture NA of the lens group is 0.1, ensuring sufficient scattered light after uniform illumination of the contamination particles. This scattered light is received by the first camera 3-4, allowing for accurate analysis of particle contamination based on the intensity of the scattered light. The working distance of the detection lens group 3-3 is greater than 100mm to avoid structural interference between the illumination lens group 3-2 and the detection lens group 3-3. Furthermore, the detection lens group 3-3 is equipped with an active focusing module 3-5, which can actively focus on substrates of different thicknesses to improve the accuracy of contamination detection.

[0075] Figure 3 A schematic diagram of the structure of an optical lens module 4 according to an embodiment of the present disclosure is shown.

[0076] like Figure 3 As shown, the optical lens module 4 according to an embodiment of this disclosure includes: an objective lens 4-1, an ultraviolet light source 4-2, an ultraviolet illumination optical lens group 4-3, a broadband light source 4-4, a visible light illumination optical lens group 4-5, an imaging optical lens group 4-6, a camera 4-7, an in-situ detection optical lens group 4-8, a first beam splitter 4-9, a second beam splitter 4-10, and a third beam splitter 4-11. The object plane of the objective lens 4-1 coincides with the lower surface of the mask, providing support for illumination, imaging, and spectral acquisition of the lower surface of the mask. The illumination surface of the ultraviolet illumination optical lens group 4-3 coincides with the lower surface of the mask, providing uniform ultraviolet illumination for the lower surface of the mask; the illumination surface of the visible light illumination optical lens group 4-5 coincides with the lower surface of the mask, providing uniform visible light illumination for observation and spectral acquisition of the lower surface of the mask; the object plane of the imaging optical lens group 4-6 coincides with the lower surface of the mask, enabling real-time observation of the mask surface based on the camera 4-7; the object plane of the in-situ detection optical lens group 4-8 coincides with the lower surface of the mask, acquiring real-time interference spectra between the mask and the substrate based on optical fiber and spectrometer, and performing in-situ gap detection and leveling through the control system 6; the confocal surface of the optical lens module 4 enables parallel operation of multiple beams through the first beam splitter 4-9, the second beam splitter 4-10, and the third beam splitter 4-11. The splitting ratio of the multiple beam splitters can be modified according to the light intensity requirements of each beam path without affecting the final effect.

[0077] This design achieves high integration of the optical path and miniaturization of the system. By using a beam splitter, multiple optical paths, including ultraviolet illumination, visible light illumination, imaging observation, and in-situ spectral detection, are coupled to the same objective lens (4-1), sharing the optical axis and confocal surface. This significantly reduces the size of discrete modules and the number of optical components in traditional lithography systems, making the system structure more compact and easier to assemble. Secondly, the system supports in-situ detection and real-time control, allowing ultraviolet exposure, gap detection, and alignment observation to be completed at the same station without moving the workpiece stage to switch modules. This avoids alignment errors caused by position changes and enables precise leveling based on real-time interferometric spectral data, improving process accuracy and stability. Furthermore, multiple optical paths can operate in parallel or in a time-sharing manner without interference. Observation, alignment, and gap detection are performed synchronously before exposure, significantly shortening the time of traditional serial processes and greatly improving overall work efficiency. Simultaneously, the module integrates multiple functions such as illumination, imaging, and detection, offering strong compatibility and making it particularly suitable for micro-nano manufacturing and integrated circuit lithography fields with high precision and efficiency requirements. Finally, the design offers excellent scalability; the beam splitter parameters can be adjusted according to light intensity requirements and it can be adapted to different light sources and filtering schemes, facilitating functional optimization and application expansion. In summary, this optical lens module 4 not only achieves multifunctional integration but also comprehensively improves the precision, efficiency, and reliability of the lithography system through its in-situ parallel working mechanism.

[0078] The following combination Figures 4 to 7 right Figure 3 The structure will be described in detail.

[0079] Figure 4 A schematic diagram of the structure of an ultraviolet illumination assembly according to an embodiment of the present disclosure is shown.

[0080] like Figure 3 and Figure 4The ultraviolet illumination assembly according to an embodiment of this disclosure includes, in sequence, an ultraviolet light source 4-2, an ultraviolet illumination optical lens group 4-3, and a first beam splitter 4-9 in the ultraviolet light path direction. The illumination surface of the ultraviolet illumination optical lens group 4-3 coincides with the lower surface of the mask, providing uniform ultraviolet illumination to the lower surface of the mask. The center wavelength of the ultraviolet light source is 355nm to 375nm, and the maximum output power is 18W. The ultraviolet illumination assembly is coupled to the objective lens 4-1 via the first beam splitter 4-9. The ultraviolet light source 4-2 transmits the ultraviolet beam into the ultraviolet illumination optical lens group 4-3 via a water-cooled optical fiber. Optionally, the output end face diameter of the water-cooled optical fiber is 7mm to 8mm, and the numerical aperture is 0.5 to 0.6. The beam splitter separates the visible beam from the ultraviolet beam. An electrically adjustable aperture 4-3-1 is provided at the front end of the ultraviolet illumination optical lens group 4-3. The electrically adjustable aperture 4-3-1 is connected to the control system 6 and is used to adjust the size of the illumination spot. By combining the ultraviolet light source 4-2 with the ultraviolet illumination optical lens group 4-3 and using water-cooled optical fiber for beam transmission, not only is efficient ultraviolet illumination and thermal management achieved, ensuring stable output and lifespan of the light source, but the first beam splitter 4-9 also effectively separates the ultraviolet beam from the visible beam, ensuring the purity of the illumination spectrum and the accuracy of exposure. More importantly, by integrating a motorized variable aperture 4-3-1 at the front end of the ultraviolet illumination optical lens group 4-3 and connecting it to the control system 6, the size and shape of the illumination spot can be dynamically adjusted according to the size requirements of different exposure patterns. While ensuring exposure uniformity, this significantly improves the flexibility and adaptability of the illumination. Furthermore, the control system 6 controls the output of the ultraviolet light source 4-2 in the ultraviolet illumination assembly with a preset power and duration of exposure beam based on the leveling and alignment results.

[0081] For example, the center wavelength of the ultraviolet light source 4-2 is 365nm±10nm. The output time and intensity of the ultraviolet beam can be set by the control system 6 to achieve precise control of the exposure. The water-cooled fiber optic port is connected to the ultraviolet illumination optical lens group 4-3, with the fiber end face coinciding with the focal plane of the lens group, thus incident ultraviolet light into the ultraviolet illumination optical lens group 4-3. The illumination surface of the ultraviolet illumination optical lens group 4-3 coincides with the imaging surface of the objective lens 4-1, and the primary imaging surface coincides with the aperture stop of the objective lens 4-1. The field stop of the ultraviolet illumination optical lens group 4-3 and the imaging surface of the objective lens 4-1 form a primary conjugate surface. The field stop of the ultraviolet illumination optical lens group 4-3 is designed as a motorized variable aperture stop 4-3-1, and the diameter of the field stop can be changed by the control system 6 to achieve changes in the diameter of the illumination spot. The illumination uniformity of the illumination spot on the mask surface is not less than 97%, meeting the exposure requirements of different patterns. The illumination surface of the ultraviolet illumination optical lens group 4-3 coincides with the lower surface of the mask, providing uniform ultraviolet illumination to the lower surface of the mask.

[0082] Figure 5A schematic diagram of a visible light illumination assembly according to an embodiment of the present disclosure is shown.

[0083] like Figure 3 and Figure 5 As shown, the visible light illumination assembly according to an embodiment of this disclosure includes, in sequence, a broadband light source 4-4, a visible light illumination optical lens group 4-5, a third beam splitter 4-11, a second beam splitter 4-10, and a first beam splitter 4-9 in the visible light illumination optical path direction. The broadband light source 4-4 transmits a visible light beam to the visible light illumination optical lens group 4-5 via an optical fiber. The first beam splitter 4-9, the second beam splitter 4-10, and the third beam splitter 4-11 are positioned between the objective lens 4-1 and the visible light illumination optical lens group 4-5. The visible light beam is reflected by the third beam splitter 4-11, passes through the second beam splitter 4-10, and is then reflected by the first beam splitter 4-9 into the objective lens 4-1. A filter 4-5-1 is provided at the front end of the visible light illumination optical lens group 4-5 to filter out stray light not used for visible light illumination. The illumination surface of the visible light illumination optical lens group coincides with the image plane of objective lens 4-1, and the field stop of the visible light illumination optical lens group 4-5 is conjugate with the aperture stop of objective lens 4-1.

[0084] By employing a broadband light source 4-4 combined with a visible light illumination optical lens group 4-5, high-quality visible light illumination can be provided to the system beyond ultraviolet exposure, meeting the requirements for high-resolution imaging observation and spectral acquisition of the mask. The optical path design utilizes a multi-stage beam splitting structure consisting of a first beam splitter 4-9, a second beam splitter 4-10, and a third beam splitter 4-11 to achieve efficient separation and recombination of the visible light beam, ultraviolet beam, imaging beam, and interferometric detection beam. This allows multiple optical energy streams to operate coaxially without interference, ensuring the independence and synergy of each function within a compact spatial layout. Furthermore, the filter 4-5-1 positioned at the front end of the visible light illumination optical lens group 4-5 effectively filters out short-wavelength stray light, preventing it from adversely affecting the substrate processing, improving the contrast and signal-to-noise ratio of the observed image, and providing a cleaner background illumination for subsequent in-situ spectral detection. This design, while ensuring a large field of view and highly uniform illumination, achieves deep integration of the illumination, observation, and detection optical paths, providing a reliable optical foundation for real-time alignment, leveling, and quality monitoring in the photolithography process.

[0085] For example, the broadband light source 4-4 has a wavelength range of 370nm-1600nm, and the diameter of the fiber optic output end face is 4mm to 10mm. A filter 4-5-1 is placed at the front end of the visible light illumination optical lens group 4-5 to prevent short-wavelength light from affecting the substrate process. The illumination surface of the visible light illumination optical lens group 4-5 coincides with the imaging surface of the objective lens 4-1, and the primary imaging surface coincides with the aperture stop of the objective lens 4-1. The field stop of the visible light illumination optical lens group 4-5 and the imaging surface of the objective lens 4-1 form a primary conjugate surface. By adjusting the focal length of the two lens groups before and after the field stop, large-area uniform visible light illumination can be achieved on the mask surface. To accommodate the setup of multiple beam splitters, the spacing between the aperture stops of the visible light illumination optical lens group 4-5 and the objective lens 4-1 is greater than 200mm, with a uniformity greater than 95%.

[0086] Figure 6 A schematic diagram of the structure of an imaging observation assembly according to an embodiment of the present disclosure is shown.

[0087] like Figure 3 and Figure 6 As shown, the imaging observation assembly according to an embodiment of this disclosure includes, in sequence, a first beam splitter 4-9, a second beam splitter 4-10, an imaging optical mirror group 4-6, and a second camera 4-7 in the imaging optical path direction. The imaging optical path of the mask passes through the objective lens 4-1, is transmitted through the first beam splitter 4-9, and is reflected by the second beam splitter 4-10 before entering the imaging optical mirror group 4-6, and finally images onto the target surface of the second camera 4-7. The second camera 4-7 is fixed at the top of the imaging optical mirror group 4-6, and the target surface of the second camera 4-7 coincides with the image plane of the mirror group. The imaging optical mirror group 4-6 and the objective lens 4-1 together form a double telecentric optical path. Among them, a first beam splitter 4-9 and a second beam splitter 4-10 are designed between the objective lens 4-1 and the imaging optical lens group 4-6. The lower surface of the mask is imaged onto the target surface of the second camera 4-7 through the objective lens 4-1, the first beam splitter 4-9, the second beam splitter 4-10 and the imaging optical lens group 4-6. The mask surface is observed in real time based on the control system 6. Specifically, the control system 6 calculates the positional deviation between the mask and the substrate based on the alignment mark image collected by the second camera 4-7 in the imaging observation component, and generates an alignment compensation signal to drive the workpiece stage module 2 to perform lateral position correction.

[0088] The dual telecentric optical path, formed by objective lens 4-1 and imaging optical lens group 4-6, maintains constant imaging magnification under different object distances, effectively eliminating perspective errors and achieving high-precision, distortion-free imaging of mask surface patterns and alignment marks, providing reliable visual basis for alignment and leveling. The optical path utilizes a first beam splitter 4-9 and a second beam splitter 4-10 to efficiently separate the imaging beam from the composite optical path. While ensuring that the same objective lens 4-1 is shared with the ultraviolet illumination, visible illumination, and in-situ detection components, each optical path operates independently without interference, significantly improving the system's integration and structural compactness. This design supports in-situ real-time observation of the mask directly at the exposure station without moving the workpiece or switching modules. Combined with the control system 6, it can analyze the alignment status of the mask and substrate in real time, quickly complete position correction, significantly shorten process preparation time, and improve work efficiency and alignment accuracy. In addition, the imaging optical path has good compatibility and scalability, and can be adapted to second cameras 4-7 and lens groups with different resolutions and fields of view according to actual needs. Furthermore, by optimizing the coating of the beam splitter, the light energy utilization rate and image quality of the imaging band can be further improved, thereby providing stable, flexible and efficient visual observation and process monitoring support for photolithography.

[0089] Figure 7 A schematic diagram of the structure of an in-situ detection component according to an embodiment of the present disclosure is shown.

[0090] like Figure 3 and Figure 7As shown, the in-situ detection component according to an embodiment of this disclosure includes a first beam splitter 4-9, a second beam splitter 4-10, a third beam splitter 4-11, an in-situ detection optical mirror group 4-8, and a receiving fiber optic group; wherein the receiving fiber optic group includes at least one fixed fiber 4-8-2 and at least one movable fiber 4-8-3; the interference beam between the mask and the substrate is transmitted through the objective lens 4-1, the first beam splitter 4-9, and returned by the second beam splitter 4-10 and the third beam splitter 4-11, and then converged by the in-situ detection optical mirror group 4-8 to the receiving fiber optic group, and transmitted to the spectrometer for analysis. The aperture stop of the in-situ detection optical mirror group 4-8 is located at the aperture stop of the objective lens 4-1, forming a double telecentric optical path together with the objective lens 4-1. Between the objective lens 4-1 and the visible light illumination optical mirror group 4-5, a first beam splitter 4-9 transmits the light, while a second beam splitter 4-10 and a third beam splitter 4-11 are designed. The interference beam returning from the mask surface is reflected by the first beam splitter 4-9 and then passes through the second and third beam splitters 4-10 and 4-11 before entering the visible light illumination optical mirror group 4-5, where it is received by the receiving fiber optic group. The in-situ detection optical mirror group 4-8 is connected to the spectrometer in the control system 6 via the receiving fiber optic group. A fourth beam splitter 4-8-1 is located at the end of the in-situ detection optical mirror group 4-8, forming two image planes. The receiving fiber optic group includes multiple fixed fibers 4-8-2 and one movable fiber 4-8-3, with the fiber end faces coinciding with the two image planes of the mirror group. The spectrometer in the control system 6 acquires the interference spectrum between the mask and the substrate in real time. Based on the acquired interference spectrum data, it calculates the real-time gap between the mask and the substrate and feeds it back to control the workpiece stage module 22 to adjust its height and posture.

[0091] By constructing a dual telecentric optical path together with the in-situ detection optical lens group 4-8 and the objective lens 4-1, and using the first, second, and third beam splitters 4-11 to efficiently guide the interference beam from the gap between the mask and the substrate into the detection system, high-sensitivity and high-precision spectral interferometry measurement of the gap is achieved. The optical path design employs a receiving fiber group containing multiple fixed fibers and at least one movable fiber 4-8-3. The fixed fibers are distributed at key locations outside the exposure field, enabling rapid and stable multi-point coarse leveling, while the movable fiber 4-8-3 can flexibly scan within the exposure field to obtain the fine gap distribution across the entire field, thus supporting end-to-end leveling control from global tilt compensation to local flatness optimization. This detection optical path forms a dual-image plane structure through the fourth beam splitter 4-8-1, allowing the fixed and movable fibers 4-8-3 to work in parallel, achieving flexible switching of measurement modes without affecting the detection speed. Interference spectra are acquired in real time by a spectrometer and fed back to control system 6, forming a closed-loop leveling mechanism. This mechanism can dynamically respond to gap changes during the process, achieving in-situ gap control with nanometer-level precision. Furthermore, this optical path is deeply integrated with the illumination and imaging optical paths, allowing for simultaneous detection and adjustment at the exposure station without moving the workpiece or interrupting the process. This significantly improves leveling efficiency and process consistency, providing crucial flatness assurance for high-precision lithography pattern transfer.

[0092] For example, the overall magnification of the lens assembly is 2×. The fixed fiber 4-8-2 consists of three fibers evenly distributed outside the exposure field to achieve coarse leveling before exposure. The movable fiber 4-8-3 has a movement range greater than the exposure area, enabling gap detection at any position within the exposure field. This provides technical support for the exposure process.

[0093] Figure 8 A flowchart illustrating a micro / nano fabrication method for an in-situ detection and illumination system based on an embodiment of the present disclosure is shown.

[0094] like Figure 8 As shown, the micro / nano fabrication method for the in-situ detection and illumination system based on the embodiments of this disclosure includes steps S1 to S5.

[0095] In step S1, the mask and the substrate are respectively mounted on the mask suction cup module 5 and the workpiece stage module 2.

[0096] In step S2, the substrate is moved to the particle detection position by the workpiece stage module 2, and the particle detection module 3 is used to detect the contamination of each preset exposure field and select the fields that can be exposed.

[0097] In step S3, the substrate is moved to the exposure position, and the gap between the mask and the substrate is detected by the in-situ detection component. At the same time, the alignment is observed by the imaging observation component. The control system 6 controls the workpiece stage module 2 to complete the leveling and alignment according to the detection results.

[0098] In the embodiments of this disclosure, the in-situ detection component first performs multi-point coarse leveling using a fixed optical fiber, and then performs fine leveling by moving a movable optical fiber 4-8-3 within the exposure field.

[0099] In step S4, the ultraviolet illumination component is activated to perform graphic exposure on the scenes that have completed leveling and alignment.

[0100] In embodiments of this disclosure, the size of the illumination spot is matched by adjusting the electrically adjustable aperture 4-3-1 in the ultraviolet illumination assembly according to the size of the exposure pattern.

[0101] In step S5, the substrate is stepped to the next selected exposure field through the workpiece stage module 2, and steps S3 and S4 are repeated until the exposure of the entire substrate is completed.

[0102] Compared to traditional discrete module serial lithography processes, the method according to the embodiments of this disclosure has the following significant advantages: By integrating the four major functions of particle detection, gap measurement, alignment observation, and ultraviolet exposure in situ into the same workstation, the cumulative errors and time overhead caused by repeated workpiece stage movement and mechanical repositioning in traditional multi-module layouts are eliminated; Real-time closed-loop control of leveling-alignment-exposure is achieved by using synchronous spectral interference gap detection and imaging alignment observation, overcoming the problems of feedback lag and stepwise error amplification in traditional step-by-step execution; The intelligent strategy of "first dark field screening for contamination, then fixed-point exposure" avoids the ineffective execution of complex leveling and exposure processes in contaminated areas, improving mask lifespan and production yield; Full-field leveling from coarse to fine adjustment is achieved through a combination of fixed and movable optical fibers, and the exposure pattern size is dynamically adapted through an electrically adjustable aperture, significantly enhancing the system's adaptability, automation level, and overall production capacity while ensuring nanometer-level process accuracy.

[0103] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

Claims

1. An in-situ detection and illumination system, characterized in that, include: Objective lens; The ultraviolet illumination assembly includes, in sequence along the ultraviolet light path, an ultraviolet light source, an ultraviolet illumination optical lens group, and a first beam splitter; The visible light illumination assembly includes, in sequence along the visible light illumination optical path direction, a broadband light source, a visible light illumination optical lens group, a third beam splitter, a second beam splitter, and a first beam splitter; The imaging observation assembly, in the direction of the imaging optical path, includes, in sequence, a first beam splitter, a second beam splitter, an imaging optical lens group, and a second camera; and The in-situ detection component includes, in sequence along the in-situ detection optical path, a first beam splitter, a second beam splitter, a third beam splitter, an in-situ detection optical lens group, a fourth beam splitter group, and a receiving optical fiber group.

2. The in-situ detection and illumination system according to claim 1, characterized in that, The ultraviolet light source is connected to the ultraviolet illumination optical lens group via a water-cooled optical fiber, and the exit end face of the water-cooled optical fiber coincides with the focal plane of the ultraviolet illumination optical lens group.

3. The in-situ detection and illumination system according to claim 1, characterized in that, The illumination surface of the ultraviolet illumination optical lens group coincides with the imaging surface of the objective lens, and the primary imaging surface of the ultraviolet illumination optical lens group coincides with the aperture stop of the objective lens. The ultraviolet illumination optical lens assembly includes a motorized variable aperture, the diameter of which is adjustable.

4. The in-situ detection and illumination system according to claim 1, characterized in that, The front end of the visible light illumination optical lens group is provided with a filter to filter out short-wavelength light below a preset wavelength.

5. The in-situ detection and illumination system according to claim 1, characterized in that, The illumination surface of the visible light illumination optical lens group coincides with the image plane of the objective lens, and the primary imaging surface of the visible light illumination optical lens group coincides with the aperture stop of the objective lens; The optical path between the visible light illumination optical lens group and the aperture stop of the objective lens is greater than 200 mm.

6. The in-situ detection and illumination system according to claim 1, characterized in that, The objective lens and the imaging optical lens group in the imaging observation assembly together form a dual telecentric optical path; the target surface of the second camera coincides with the image plane of the imaging optical lens group.

7. The in-situ detection and illumination system according to claim 1, characterized in that, The receiving fiber optic group in the in-situ detection component includes multiple fixed optical fibers and at least one movable optical fiber. The end faces of the fixed optical fibers are evenly distributed on the image plane of the in-situ detection optical mirror group, and are used to collect interference spectra at multiple fixed positions around the exposure area. The movable optical fiber is driven by a displacement mechanism, and its end face can move on the image plane of the in-situ detection optical lens group. The movement range covers the entire exposure field of view and is used to collect interference spectra at any selected position within the exposure area.

8. The in-situ detection and illumination system according to claim 1, characterized in that, The system further includes a particle detection module, which comprises an illumination source, an illumination lens group, a detection lens group, and a first camera; wherein the optical axis of the illumination lens group is arranged at an angle to the optical axis of the detection lens group, forming an obliquely incident dark field illumination optical path, which is used to generate scattered light from contaminant particles on the substrate surface and to be received by the detection lens group and the first camera.

9. The in-situ detection and illumination system according to claim 8, characterized in that, The system also includes: Supporting framework; The workpiece stage module is mounted on the support frame and is used to support and position the substrate; Mask suction cup module, used to fix the mask; The control system is connected to the workpiece stage module, the particle detection module, the in-situ detection component, the imaging observation component, and the ultraviolet illumination component, and is used to coordinate the workflow of each module, process detection data, and generate control commands.

10. A micro / nano fabrication method based on the in-situ detection and illumination system according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Mount the mask and substrate onto the mask suction cup module and the workpiece stage module respectively; S2: The substrate is moved to the particle detection position by the workpiece stage module, and the contamination of each preset exposure field is detected by the particle detection module, and the exposure fields that can be exposed are selected. S3: Move the substrate to the exposure position, detect the gap between the mask and the substrate using the in-situ detection component, and simultaneously perform alignment observation using the imaging observation component; the control system controls the workpiece stage module to complete leveling and alignment based on the detection results; S4: Activate the ultraviolet illumination component to perform graphic exposure on the scenes that have completed leveling and alignment; S5: Step the substrate to the next selected exposure field using the workpiece stage module, and repeat steps S3 and S4 until the exposure of the entire substrate is completed.

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