Numerical aperture adjusting device and numerical aperture adjusting method for off-axis lighting system

Abstract

The invention provides an off-axis lighting system numerical aperture adjusting device which can be applied to the technical field of lighting mechanical structures. The device comprises an off-axis lens group which is fixedly installed at the Z-direction motion output end of a lens cone Z-direction driving system; the lens cone Z-direction driving system is configured to drive the m off-axis lens groups to move in the axial direction; the four-side displacement angle driving system comprises an annular plate and m reflector adjusting units; the reflector adjusting unit comprises a reflector group Z-direction driving module and a reflector group angle driving module; a reflector group is arranged at the output end of the reflector group angle driving module; the reflector set Z-direction driving module drives the reflector set to move in the axial direction, the reflector set angle driving module drives the reflector set to rotate around the circumference parallel to the annular plate, and adjustment of the numerical aperture is achieved by adjusting the spatial position and angle of the reflector set. M is an integer greater than or equal to 2.

Description

Technical Field

[0001] This disclosure relates to the field of lighting mechanical structure technology, and more specifically to a numerical aperture adjustment device and method for an off-axis lighting system. Background Technology

[0002] Off-axis illumination, a core technology of modern projection lithography systems, significantly improves imaging resolution and increases process depth of focus by directing the illumination beam at an angle deviating from the optical axis onto the photomask. It has become an indispensable technique in high-end lithography processes. In this technology, numerical aperture (NA) is the key parameter determining the system's resolution and optical field characteristics; its size directly determines the fineness of the lithographic lines and the image quality.

[0003] In practical applications of photolithography, the numerical aperture (NAP) of off-axis illumination systems often needs to be flexibly adjusted to adapt to diverse process requirements, given different feature sizes and process nodes. Currently, the industry-standard NAP adjustment solution is mechanically replaceable lens assemblies. Specifically, operators need to manually replace the entire off-axis illumination lens assembly with different optical properties according to the target NAP. While this method is feasible in principle, it reveals several inherent drawbacks in practice: First, frequent disassembly and installation operations are not only inefficient but also severely impact production continuity and process debugging agility; second, mechanical contact and repeated disassembly and installation processes can easily lead to contamination or scratches on precision optical lenses, resulting in irreversible performance damage and high maintenance costs; third, the reinstalled lens assembly requires complex and time-consuming optical path realignment and calibration, making it difficult to guarantee consistent optical performance after each replacement.

[0004] Numerical aperture is a dimensionless parameter used to measure the angular range of light collected or transmitted by an optical system. Its calculation formula is as follows:

[0005] NA=n*sinα

[0006] In the formula: NA is the numerical aperture; n is the refractive index of the medium; α is half of the maximum incident angle of the light.

[0007] There are two main methods to adjust the numerical aperture without changing the mirror assembly: one is to change the light transmission medium (generally various liquid media are used in engineering), and the other is to change the incident angle of the light. However, the method of adjusting the equivalent numerical aperture by changing the light transmission medium also faces the risks of medium residue, mixing leading to refractive index instability, and the introduction of contaminants such as bubbles, resulting in significant challenges to system complexity and reliability. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] To address the aforementioned issues, this disclosure provides a numerical aperture adjustment device and method for an off-axis illumination system. By driving a mirror assembly angle drive module to change the tilt angle of the mirrors, the incident angle of light is adjusted, achieving continuous adjustment of the numerical aperture. The Z-axis drive system of the lens barrel synchronously adjusts the position of the off-axis mirror assembly, compensating for changes in optical path caused by changes in the optical path, ensuring the imaging surface remains stable during numerical aperture adjustment, and guaranteeing the consistency of the optical system's imaging performance.

[0010] (II) Technical Solution

[0011] To address the aforementioned technical problems, embodiments of this disclosure propose a numerical aperture adjustment device and a numerical aperture adjustment method for an off-axis lighting system.

[0012] According to the first aspect of this disclosure, a numerical aperture adjustment device for an off-axis illumination system is provided, comprising: m off-axis mirror groups, a mirror barrel Z-axis drive system, a four-sided displacement angle drive system, and a structural support member. The m off-axis mirror groups are arranged in a circular array around the axis of the mirror barrel Z-axis drive system and are fixedly mounted on the Z-axis motion output end of the mirror barrel Z-axis drive system. The mirror barrel Z-axis drive system is mounted on the structural support member and is configured to drive the m off-axis mirror groups to move synchronously or independently along the axial direction. The four-sided displacement angle drive system is fixedly mounted on the structural support member and includes a horizontally arranged ring plate and m reflector adjustment units. Each of the mirror adjustment units corresponds one-to-one with m off-axis mirror groups, and m mirror adjustment units are fixedly installed on the surface of the ring plate. Each mirror adjustment unit includes a mirror group Z-axis drive module and a mirror group angle drive module. The mirror group angle drive module is installed at the Z-axis motion output end of the mirror group Z-axis drive module. The output end of the mirror group angle drive module is equipped with a mirror group. The mirror group Z-axis drive module is configured to drive the mirror group to move along the axial direction, and the mirror group angle drive module is configured to drive the mirror group to rotate around the ring plate. By adjusting the spatial position and angle of the mirror group, the numerical aperture of the off-axis lighting system can be continuously adjusted. m is an integer greater than or equal to 2.

[0013] In some exemplary embodiments, the structural support includes a Z-axis washer, a Z-axis support base, an off-axis illumination support plate, and a lens integrated barrel, which are fixedly connected from top to bottom; wherein, the lens barrel Z-axis drive system is fixedly installed on the top of the Z-axis washer; and the ring plate of the four-sided displacement angle drive system is fixedly installed above the lens integrated barrel.

[0014] In some exemplary embodiments, the lens barrel Z-axis drive system includes a horizontally arranged base and m Z-axis transmission modules. The m Z-axis transmission modules are vertically mounted on the base in a centrally symmetrical manner with the center of the base as the reference. Each Z-axis transmission module drives an off-axis lens group to move independently along the axial direction.

[0015] In some exemplary embodiments, each Z-axis transmission module includes: a first drive motor, fixedly mounted on the lower surface of the base via a first motor mount; a first lead screw, coaxially connected to the output shaft of the first drive motor via a first coupling, and the first lead screw is arranged in a vertical direction; two first ball screw support seats, respectively fixed on the upper and lower sides of the support plate, for supporting the two ends of the first lead screw; two vertically arranged first guide rails, fixedly mounted on the support plate in a direction parallel to the first lead screw; an off-axis lens holder, slidably connected to the two first guide rails via a linear bearing; and a lens barrel Z-axis drive block, one end of which is fixedly connected to the off-axis lens holder, and the other end of which engages with the first lead screw through an internal threaded hole; wherein, the first drive motor drives the first lead screw to rotate via the first coupling, and then drives the off-axis lens holder to move linearly in the Z-axis direction via threaded transmission.

[0016] In some exemplary embodiments, each Z-axis transmission module further includes a first position detection unit, which includes: two first photoelectric switches, fixedly mounted on the support plate and located beside the first lead screw, corresponding to the two extreme positions of the off-axis mirror support movement stroke; and a first photoelectric switch baffle, fixedly mounted on the mirror barrel Z-axis drive block and moving with the mirror barrel Z-axis drive block.

[0017] In some exemplary embodiments, the Z-axis drive module of the reflector assembly includes: a Z-axis base, fixedly mounted on the upper surface of the ring plate; a rotating base, slidably connected to the Z-axis base via at least two vertically arranged second guide rails; a second drive motor, fixedly mounted on the side of the Z-axis base via a second motor mount; a second lead screw, coaxially connected to the output shaft of the second drive motor via a second coupling; two second ball screw support seats, fixed on the upper and lower sides of the Z-axis base for supporting the two ends of the second lead screw; and a lead screw nut seat, engaging with the second lead screw through an internal threaded hole, and the lead screw nut seat is fixedly connected to the rotating base; wherein, the second drive motor drives the second lead screw to rotate, and the second lead screw drives the rotating base to move linearly along the Z-axis via the lead screw nut seat.

[0018] In some exemplary embodiments, the reflector group angle driving module includes: a reflector frame for mounting and fixing a reflector; a diamond-shaped adjustment mechanism, the bottom of which is hinged to a rotating base via a first hinge connector, and the top of which is hinged to the back of the reflector frame via a second hinge connector; and a reflector hinge, fixedly mounted on the rotating base, with the bottom of the reflector frame hinged to the reflector hinge to allow the reflector frame to rotate about the axis of the reflector hinge.

[0019] In some exemplary embodiments, the rhombic adjustment mechanism includes: a third drive motor, fixedly mounted via a rhombic adjustment motor end seat; a third lead screw, horizontally positioned and coaxially connected to the output shaft of the third drive motor; a rhombic nut seat, engaging with the third lead screw via a rhombic lead screw nut; and four rhombic adjustment rods connected end-to-end via connecting hinges at both ends, forming a rhombic linkage mechanism. In the rhombic linkage mechanism, the first bottom corner node is connected to the rhombic adjustment motor end seat via a hinge, and the second bottom corner node is connected to the rhombic nut seat via a hinge. The first top corner node is hinged to the rotating base via a first hinge connecting seat, and the second top corner node is hinged to the back of the reflector frame via a second hinge connecting seat. The third drive motor drives the third lead screw to rotate, causing the rhombic nut seat to move linearly along the axis of the third lead screw, thereby changing the shape of the rhombic linkage mechanism. This, in turn, pushes and pulls the reflector frame via the second hinge connecting seat, causing the reflector frame to rotate around the axis of the reflector hinge.

[0020] In some exemplary embodiments, the Z-axis drive module of the reflector group further includes a second position detection unit, which includes: two second photoelectric switches, fixedly installed on the Z-axis base and located beside the second lead screw respectively, corresponding to the two extreme positions of the rotation base's travel; and a second photoelectric switch baffle, fixedly installed on the lead screw nut seat and moving with the lead screw nut seat.

[0021] According to a second aspect of this disclosure, a numerical aperture adjustment method based on the above-described off-axis illumination system numerical aperture adjustment device is provided, comprising: receiving a target numerical aperture command; calculating the target tilt angle of each mirror group according to the target numerical aperture; driving the angle driving module of each mirror group to adjust the mirror group to the target tilt angle to change the incident angle of light; calculating the target Z-axis position of the off-axis mirror group according to the target tilt angle or the target numerical aperture; and driving the mirror barrel Z-axis driving system to move the off-axis mirror group to the target Z-axis position to compensate for the optical path difference caused by the change in the optical path, thereby realizing the adjustment of the numerical aperture.

[0022] (III) Beneficial Effects

[0023] As can be seen from the above technical solutions, the numerical aperture adjustment device and method for an off-axis lighting system provided in this disclosure have at least the following beneficial effects:

[0024] (1) By changing the tilt angle of the reflector by driving the reflector group angle driving module, the incident angle of light is adjusted, thereby realizing continuous adjustment of the numerical aperture. This method replaces the operation of replacing the mirror group, saving the time of disassembly, installation and recalibration of the optical path, and improving the efficiency of process debugging and production preparation. It fundamentally avoids the problems of scratches and contamination of optical lenses that may be caused by the assembly and disassembly process, and reduces the maintenance requirements and replacement costs of optical components.

[0025] (2) The position of the off-axis lens group is synchronously adjusted by the Z-axis drive system of the lens barrel to compensate for the change in optical path caused by the change in optical path, so that the imaging surface remains stable during the numerical aperture adjustment process and ensures the consistency of the imaging performance of the optical system.

[0026] (3) A photoelectric switch position detection unit combined with a ball screw transmission mechanism is used to realize closed-loop control of the reflector angle and mirror group position, thereby improving the repeatability of the adjustment process.

[0027] (4) The multi-degree-of-freedom adjustment function is integrated into a single device, and all adjustment functions are realized through electronic control, which provides a basis for integration into automated lithography equipment. Attached Figure Description

[0028] 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:

[0029] Figure 1 A schematic diagram of the structure of a numerical aperture adjustment device for an off-axis lighting system according to an embodiment of the present disclosure is shown.

[0030] Figure 2 A schematic diagram of the structure of a lens barrel Z-axis drive system according to an embodiment of the present disclosure is shown.

[0031] Figure 3 This schematic diagram illustrates the structure of a Z-axis transmission module in a lens barrel Z-axis drive system according to an embodiment of the present disclosure;

[0032] Figure 4 A schematic diagram of the structure of a quadrilateral displacement angle driving system according to an embodiment of the present disclosure is shown.

[0033] Figure 5 The schematic diagram illustrates the internal structure of the Z-axis drive module of the mirror group in a quadrilateral displacement angle drive system according to an embodiment of the present disclosure.

[0034] Figure 6 A schematic diagram illustrating the structure of the rhomboid adjustment mechanism in the mirror assembly angle driving module according to an embodiment of the present disclosure; and

[0035] Figure 7 A flowchart illustrating a numerical aperture adjustment method according to an embodiment of the present disclosure is shown schematically.

[0036] Figure label:

[0037] 1: Off-axis lens group;

[0038] 2: Lens barrel Z-axis drive system;

[0039] 2-1: Base;

[0040] 2-2: First drive motor;

[0041] 2-3: Z-axis drive gearbox for the mirror barrel;

[0042] 2-4: First motor mount;

[0043] 2-5: Off-axis lens holder;

[0044] 2-6: Z-axis drive block for the lens barrel;

[0045] 2-7: First guide rail;

[0046] 2-8: Pallet;

[0047] 2-9: First coupling;

[0048] 2-10: First ball screw support seat;

[0049] 2-11: First photoelectric switch;

[0050] 2-12: First photoelectric switch baffle;

[0051] 2-13: Z-axis drive block for the lens barrel;

[0052] 2-14: First lead screw;

[0053] 3: Z-axis washer;

[0054] 4: Z-axis support seat;

[0055] 5: Off-axis lighting support plate;

[0056] 6: Four-sided displacement angle drive system;

[0057] 6-1: Second drive motor;

[0058] 6-2: Z-axis drive gearbox for the reflector assembly;

[0059] 6-3: Second motor mount;

[0060] 6-4: Second coupling;

[0061] 6-5, 6-17: Second ball screw support seat;

[0062] 6-6: Second guide rail;

[0063] 6-7: Second lead screw;

[0064] 6-8: Z-axis base;

[0065] 6-9: Rotating base;

[0066] 6-10: Ring plate;

[0067] 6-11: Reflector frame;

[0068] 6-12: Mirror assembly;

[0069] 6-13: Reflector hinge;

[0070] 6-14: Second photoelectric switch baffle;

[0071] 6-15: Second photoelectric switch;

[0072] 6-16: Z-axis drive screw nut seat for the reflector assembly;

[0073] 6-18: Diamond-shaped nut seat;

[0074] 6-19: Diamond-shaped screw nut;

[0075] 6-20: First hinge connector;

[0076] 6-21, 6-27: Connecting hinges;

[0077] 6-22: Diamond-shaped adjusting rod;

[0078] 6-23: Third lead screw;

[0079] 6-24: Rhombus-shaped adjusting motor end mount;

[0080] 6-25: Reflector assembly angle drive gearbox;

[0081] 6-26: Third drive motor;

[0082] 6-28: Second hinge connector;

[0083] 7: Lens integrated with lens barrel;

[0084] 8: Workpiece stage. Detailed Implementation

[0085] 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.

[0086] 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.

[0087] 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.

[0088] Figure 1 A schematic diagram of the structure of an off-axis lighting system numerical aperture adjustment device according to an embodiment of the present disclosure is shown.

[0089] like Figure 1 As shown, a numerical aperture adjustment device for an off-axis illumination system according to an embodiment of this disclosure includes: m off-axis mirror groups 1, a mirror barrel Z-axis drive system 2, a four-sided displacement angle drive system 6, and a structural support. The m off-axis mirror groups 1 are arranged in a circular array around the axis of the mirror barrel Z-axis drive system 2 and are fixedly installed on the Z-axis motion output end of the mirror barrel Z-axis drive system 2. The mirror barrel Z-axis drive system 2 is mounted on the structural support and is configured to drive the m off-axis mirror groups 1 to move synchronously or independently along the axial direction. The four-sided displacement angle drive system 6 is fixedly installed on the structural support and includes horizontally arranged ring plates 6-10 and m mirror adjustment units. The m mirror adjustment units are connected to the m off-axis mirrors... Group 1 corresponds one-to-one with m reflector adjustment units fixedly installed on the surface of ring plate 6-10; each reflector adjustment unit includes a reflector group Z-axis drive module and a reflector group angle drive module, the reflector group angle drive module is installed at the Z-axis motion output end of the reflector group Z-axis drive module; the output end of the reflector group angle drive module is provided with reflector group 6-12; the reflector group Z-axis drive module is configured to drive reflector group 6-12 to move along the axis of the reflector group Z-axis drive module, and the reflector group angle drive module is configured to drive reflector group 6-12 to rotate around the ring plate 6-10. By adjusting the spatial position and angle of reflector group 6-12, the numerical aperture of the off-axis lighting system can be continuously adjusted; m is an integer greater than or equal to 2. Figure 1 In the disclosed embodiment, the quadrilateral displacement angle driving system 6 with m=4 includes one ring plate 6-10 and four reflector adjustment units. The four reflector adjustment units are evenly arranged on the ring plate 6-10 at 90° intervals along the circumference of the ring plate 6-10 (see...). Figure 4 It should be noted that the accompanying drawings in this application are for better understanding of the structure of this scheme and are not intended to limit the value of m.

[0090] By arranging m off-axis mirror groups 1 and m mirror adjustment units in a circular array, multiple independent off-axis illumination channels are established. This symmetrical layout not only ensures the uniformity of the illumination field but also enables flexible control of the off-axis illumination mode by controlling each channel individually. The coordinated operation of the mirror barrel Z-axis drive system 2 and the four-sided displacement angle drive system 6 allows the system to maintain optimized optical path parameters while adjusting the numerical aperture, providing a highly configurable solution for different process requirements.

[0091] In such Figure 1 In the illustrated embodiment, the structural support is composed of a Z-axis washer 3, a Z-axis support base 4, an off-axis illumination support plate 5, and a lens integrated barrel 7, which are fixedly connected from top to bottom to form a hierarchical rigid support system. The lens barrel Z-axis drive system 2 is fixedly installed on top of the Z-axis washer 3, and the ring plates 6-10 of the four-sided displacement angle drive system 6 are fixedly installed above the lens integrated barrel 7. Furthermore, this structural support is connected to the fixing components of other external devices through the lens integrated barrel 7, making the lens integrated barrel 7 the basic mechanical interface and main load-bearing structure of the entire device. This not only provides a unified installation benchmark for the internal optical and drive components but also achieves high-precision, standardized docking with external systems.

[0092] In the embodiments of this disclosure, light from the off-axis illumination source is refracted by the off-axis mirror group 1 and then incident on the reflecting mirror group 6-12. The light is then reflected by the reflecting mirror group 6-12 and converged onto the workpiece stage 8 of another device, forming an off-axis illumination light field. The Z-axis drive modules of the mirror group in the mirror barrel Z-axis drive system 2 and the quadrilateral displacement angle drive system 6 are respectively responsible for adjusting the relative height of the off-axis mirror barrel and the reflecting mirror group 6-12 in the Z-axis direction to ensure compliance with optical design requirements. The angle drive module of the reflecting mirror group in the quadrilateral displacement angle drive system 6 is responsible for adjusting the incident angle of the off-axis illumination light field and directly affects the size of the numerical aperture. This optical path design forms a stable off-axis illumination light field through the dual effects of refraction by the off-axis mirror group 1 and reflection by the reflecting mirror group 6-12. The coordinated use of the mirror barrel Z-axis drive system 2 and the reflecting mirror group Z-axis drive module enables precise control of the optical path and beam direction, ensuring that optical performance meeting design requirements can be obtained under different numerical aperture settings. This design allows the system to maintain optical path stability while achieving continuous adjustment of the numerical aperture.

[0093] Figure 2 A schematic diagram of the structure of the lens barrel Z-axis drive system 2 according to an embodiment of the present disclosure is shown.

[0094] like Figure 2As shown, the Z-axis drive system 2 of the lens barrel according to an embodiment of this disclosure includes a horizontally arranged base 2-1 and m Z-axis drive modules. The m Z-axis drive modules are vertically mounted on the base 2-1 in a centrally symmetrical manner with the center of the base 2-1 as the reference. Each Z-axis drive module drives an off-axis lens group 1 to move independently along the axial direction. The centrally symmetrical arrangement of the m Z-axis drive modules enables each off-axis lens group 1 to be independently and accurately positioned in the Z-axis. This modular design not only improves the reliability of the system but also allows for independent calibration of each optical channel, effectively compensating for optical performance deviations caused by manufacturing tolerances and installation errors, and ensuring the consistency of the performance of each optical channel.

[0095] Figure 3 The schematic diagram illustrates the structure of the Z-axis transmission module in the lens barrel Z-axis drive system 2 according to an embodiment of the present disclosure.

[0096] like Figure 3 As shown, each Z-axis transmission module in the Z-axis drive system 2 of the lens barrel according to an embodiment of this disclosure includes: a first drive motor 2-2, which is fixedly mounted on the lower surface of the base 2-1 via a motor mount 2-4; a first lead screw 2-14, which is coaxially connected to the output shaft of the first drive motor 2-2 via a first coupling 2-9, and the first lead screw 2-14 is arranged in a vertical direction; two first ball screw support seats 2-10, which are respectively fixed on the upper and lower sides of the support plate 2-8, for supporting the two ends of the first lead screw 2-14; and two vertically arranged first guide rails 2-7, which are parallel to the... The first lead screw 2-14 is fixedly mounted on the support plate 2-8. The off-axis mirror support 2-5 is slidably connected to the two first guide rails 2-7 via linear bearings. The Z-axis drive block 2-6 of the mirror barrel has one end fixedly connected to the off-axis mirror support 2-5, and the other end meshes with the first lead screw 2-14 through an internal threaded hole. The first drive motor 2-2 drives the first lead screw 2-14 to rotate through the first coupling 2-9, thereby driving the off-axis mirror support 2-5 to move linearly along the Z-axis via threaded transmission. This achieves spatial position adjustment of the off-axis mirror assembly 1 in the Z-axis. The Z-axis drive block 2-6 of the mirror barrel is installed inside the Z-axis drive sleeve 2-13 of the mirror barrel.

[0097] To achieve calibration and real-time monitoring of the off-axis mirror assembly 1's position in the Z-axis space, each Z-axis transmission module may further include a first position detection unit. The first position detection unit includes: two first photoelectric switches 2-11, fixedly mounted on the support plate 2-8, located beside the first lead screw 2-14 and corresponding to the two extreme positions of the off-axis mirror support 2-5's travel; and a first photoelectric switch baffle 2-12, fixedly mounted on the mirror barrel Z-axis drive block 2-6, and moving with the mirror barrel Z-axis drive block 2-6. At the two extreme positions of the travel, the first photoelectric switch baffle 2-12 transmits position information to the first photoelectric switch 2-11 for zero-position calibration. Based on the zero-position information and motor rotation information, the current position information of the off-axis mirror assembly 1 can be calculated in real time.

[0098] The Z-axis transmission module employs a servo motor drive combined with a ball screw transmission scheme, along with linear guide rail guidance, to achieve high-precision and high-rigidity Z-axis positioning. The inclusion of a first position detection unit enables closed-loop control of the system. Zero-position calibration is performed via a photoelectric switch, and combined with motor encoder signals, high-precision position feedback and real-time monitoring are achieved, ensuring repeatability and accuracy over long-term use.

[0099] Figure 5 The diagram schematically illustrates the internal structure of the Z-axis drive module of the mirror group in the quadrilateral displacement angle drive system 6 according to an embodiment of the present disclosure.

[0100] like Figure 5 As shown, the Z-axis driving module of the reflector group in the quadrilateral displacement angle driving system 6 according to an embodiment of this disclosure includes: a Z-axis base 6-8, fixedly installed on the upper surface of the ring plate 6-10; a rotating base 6-9, slidably connected to the Z-axis base 6-8 via at least two vertically arranged second guide rails 6-6; a second drive motor 6-1, fixedly installed on the side of the Z-axis base 6-8 via a second motor seat 6-3; a second lead screw 6-7, coaxially connected to the output shaft of the second drive motor 6-1 via a second coupling 6-4; two second ball screw support seats, fixed on the upper and lower sides of the Z-axis base 6-8, for supporting the two ends of the second lead screw 6-7; and a lead screw nut seat, meshing with the second lead screw 6-7 through an internal threaded hole, and the lead screw nut seat is fixedly connected to the rotating base 6-9; wherein, the second drive motor 6-1 drives the second lead screw 6-7 to rotate, and the second lead screw 6-7 drives the rotating base 6-9 to move linearly along the Z-axis via the lead screw nut seat.

[0101] In the embodiments of this disclosure, the power of the Z-axis drive module of the reflector assembly is provided by the second drive motor 6-1 and regulated by the Z-axis drive transmission 6-2 of the reflector assembly; the power of the Z-axis drive module of the reflector assembly is transmitted through the second coupling 6-4 and drives the second lead screw 6-7 to rotate; the second lead screw 6-7 drives the lead screw nut seat to move in the Z-axis and drives the rotating base 6-9 to move together; the rotating base 6-9 drives the reflector frame 6-11 mounted on it to move in the Z-axis, thereby realizing the spatial position adjustment of the reflector assembly 6-12 in the Z-axis.

[0102] The Z-axis drive module of the reflector assembly employs a precision linear motion mechanism. Through a combination of servo motors, ball screws, and linear guides, it achieves nanometer-level positioning accuracy of the reflector assembly 6-12 in the Z direction. This design ensures that the rotation center position of the reflector assembly 6-12 remains stable when adjusting its angle, avoiding additional optical path deviations caused by position changes and ensuring the accuracy of numerical aperture adjustment.

[0103] Figure 6 The schematic diagram illustrates the structure of the diamond-shaped adjustment mechanism in the reflector group angle driving module according to an embodiment of the present disclosure.

[0104] like Figure 6 As shown, the reflector group angle driving module according to an embodiment of this disclosure includes: a reflector frame 6-11 for mounting and fixing the reflector group 6-12; a rhombus adjustment mechanism, the bottom of which is hinged to the rotating base 6-9 via a first hinge connecting seat 6-20, and the top of which is hinged to the back of the reflector frame 6-11 via a second hinge connecting seat 6-28; and a reflector hinge 6-13, which is fixedly mounted on the rotating base 6-9, and the bottom of the reflector frame 6-11 is hinged to the reflector hinge 6-13 so that the reflector frame 6-11 rotates around the axis of the reflector hinge 6-13.

[0105] In the embodiments disclosed herein, the rhombic adjustment mechanism includes: a third drive motor 6-26, fixedly mounted via a rhombic adjustment motor end seat 6-24; a third lead screw 6-23, horizontally arranged and coaxially connected to the output shaft of the third drive motor 6-26; a rhombic nut seat 6-18, meshing with the third lead screw 6-23 via a rhombic lead screw nut 6-19; and four rhombic adjustment rods 6-22, connected end-to-end via connecting hinges at both ends to form a rhombic linkage mechanism; in the rhombic linkage mechanism, the first bottom corner node is connected to the rhombic adjustment motor end seat 6-24 via a hinge, and the second bottom corner node... The first apex node is hinged to the rotating base 6-9 via the first hinge connector 6-20, and the second apex node is hinged to the back of the reflector frame 6-11 via the second hinge connector 6-28. The third drive motor 6-26 drives the third lead screw 6-23 to rotate, causing the rhombus nut seat 6-18 to move linearly along the axis of the third lead screw 6-23, thereby changing the shape of the rhombus linkage mechanism. Then, the second hinge connector 6-28 pushes and pulls the reflector frame 6-11, causing the reflector frame 6-11 to rotate around the axis of the reflector hinge 6-13.

[0106] In the embodiments disclosed herein, the angle adjustment of the reflector assembly 6-12 is powered by a third drive motor 6-26, and the motor speed is adjusted by a reflector assembly angle drive transmission 6-25. When the third lead screw is subjected to torque and rotates, it causes the reflector assembly Z-direction drive diamond nut seat 6-18 and the diamond adjustment motor end seat 6-24 mounted thereon to move towards or away from each other. The relative movement of the reflector assembly Z-direction drive diamond nut seat 6-18 and the diamond adjustment motor end seat 6-24 will drive the components mounted on both... The four rhomboid adjusting rods 6-22 move, causing the hinge connecting seats mounted on the four rhomboid adjusting rods 6-22 to move apart or toward each other; the separation or movement of the two hinge connecting seats will drive the reflector frame 6-11 to rotate around the reflector hinge 6-13 and realize the adjustment of the axial angle between the surface of the reflector assembly 6-12 and the ring plate 6-10; the current angle information of the reflector assembly 6-12 can be calculated by the rotation of the rhomboid adjusting drive motor and the speed change information of the reflector assembly angle drive gearbox 6-25.

[0107] The diamond-shaped adjustment mechanism, through a unique four-bar linkage design, precisely converts the linear motion of the drive motor into angular changes in the 6-12 reflector assembly. This mechanism boasts advantages such as excellent motion symmetry, zero backlash, and high rigidity, enabling angle adjustment accuracy down to the micro-radius level. The hinged connection design eliminates the backlash problem of traditional rotary mechanisms, ensuring the repeatability and stability of angle adjustments.

[0108] To achieve calibration and real-time monitoring of the Z-axis spatial position of the reflector assembly 6-12, the Z-axis drive module of the reflector assembly according to this embodiment may further include a second position detection unit. The second position detection unit includes: two second photoelectric switches 6-15, fixedly mounted on the Z-axis base 6-8, located beside the second lead screw 6-7 and corresponding to the two extreme positions of the travel stroke of the rotating base 6-9; and a second photoelectric switch baffle 6-14, fixedly mounted on the lead screw nut seat and moving with the lead screw nut seat. The second photoelectric switch baffle 6-14, mounted on the rhomboid nut seat 6-18, also transmits position information to the second photoelectric switch 6-15 for zero-position calibration at the two extreme positions of the travel stroke. Based on this information and the motor rotation information, the current Z-axis position information of the reflector assembly 6-12 can be calculated in real time. The setting of the second position detection unit enables full closed-loop control of the Z-axis position of the reflector assembly 6-12. By using photoelectric switches for zero-position calibration and combining the encoder feedback of the servo motor, the system can monitor and correct position deviations in real time, ensuring stable performance during long-term use and improving the system's reliability and service life.

[0109] Figure 7 A flowchart illustrating the numerical aperture adjustment method of the numerical aperture adjustment device for an off-axis lighting system according to an embodiment of the present disclosure is shown.

[0110] like Figure 7 As shown, the illumination method of the off-axis illumination optomechanical device according to an embodiment of the present disclosure includes steps S110 to S150.

[0111] In step S110, the target numerical aperture command is received.

[0112] In step S120, the target tilt angle of each mirror group 6-12 is calculated based on the target numerical aperture.

[0113] In step S130, the angle driving module of each reflector group is driven to adjust the reflector group 6-12 to the target tilt angle to change the incident angle of light.

[0114] In step S140, the Z-axis position of the off-axis mirror group 1 is calculated based on the target tilt angle or the target numerical aperture.

[0115] In step S150, the Z-axis drive system 2 of the drive tube is used to move the off-axis mirror group 1 to the target Z-axis position to compensate for the optical path difference caused by the change in the optical path and realize the adjustment of the numerical aperture.

[0116] The adjustment method of this disclosure achieves automation and intelligence in numerical aperture adjustment through a systematic control process. It converts numerical aperture commands into specific mechanical motion parameters, and through coordinated control of angle adjustment and position compensation, ensures the stability of imaging quality while changing the numerical aperture. This method simplifies the operation process, improves process repeatability, and provides a reliable guarantee for the stable implementation of high-end lithography processes.

[0117] 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. A numerical aperture adjustment device for an off-axis lighting system, characterized in that, include: The system consists of m off-axis mirror groups, a Z-axis drive system for the mirror barrel, a four-sided displacement angle drive system, and structural support components. The m off-axis lens groups are arranged in a ring array with the axis of the lens barrel Z-axis drive system as the center, and are fixedly installed at the Z-axis motion output end of the lens barrel Z-axis drive system. The Z-axis drive system for the lens barrel is mounted on the structural support member, and the Z-axis drive system for the lens barrel is configured to drive the m off-axis lens groups to move synchronously or independently along the axial direction. The four-sided displacement angle driving system is fixedly installed on the structural support. The four-sided displacement angle driving system includes a horizontally arranged ring plate and m mirror adjustment units. The m mirror adjustment units correspond one-to-one with the m off-axis mirror groups, and the m mirror adjustment units are fixedly installed on the surface of the ring plate. Each of the aforementioned mirror adjustment units includes a mirror group Z-axis drive module and a mirror group angle drive module. The mirror group angle drive module is installed at the Z-axis motion output end of the mirror group Z-axis drive module. The output end of the mirror group angle drive module is provided with a mirror group. The Z-axis driving module of the reflector group is configured to drive the reflector group to move along the axial direction, and the angle driving module of the reflector group is configured to drive the reflector group to rotate around the ring plate. By adjusting the spatial position and angle of the reflector group, the numerical aperture of the off-axis lighting system can be continuously adjusted. m is an integer greater than or equal to 2.

2. The numerical aperture adjustment device for an off-axis lighting system according to claim 1, characterized in that, The structural support includes a Z-axis washer, a Z-axis support base, an off-axis lighting support plate, and a lens integrated barrel, which are fixedly connected from top to bottom. The Z-axis drive system of the lens barrel is fixedly installed on the top of the Z-axis washer; The ring plate of the four-sided displacement angle driving system is fixedly installed above the lens integrated barrel.

3. The numerical aperture adjustment device for an off-axis lighting system according to claim 1 or 2, characterized in that, The Z-axis drive system for the lens barrel includes a horizontally arranged base and m Z-axis transmission modules. The m Z-axis transmission modules are vertically mounted on the base in a centrally symmetrical manner with the center of the base as the reference. Each Z-axis transmission module drives one of the off-axis lens groups to move independently along the axial direction.

4. The numerical aperture adjustment device for an off-axis lighting system according to claim 3, characterized in that, Each of the Z-axis transmission modules includes: The first drive motor is fixedly mounted on the lower surface of the base via a first motor mount; The first lead screw is coaxially connected to the output shaft of the first drive motor via a first coupling, and the first lead screw is arranged in a vertical direction; Two first ball screw support seats are fixed on the upper and lower sides of the support plate respectively, and are used to support the two ends of the first screw. Two vertically arranged first guide rails are fixedly installed on the support plate in a direction parallel to the first lead screw; The off-axis mirror holder is slidably connected to the two first guide rails via linear bearings; A Z-axis drive block for the lens barrel, one end of which is fixedly connected to the off-axis lens holder, and the other end of which engages with the first lead screw through an internal threaded hole; The first drive motor drives the first lead screw to rotate through the first coupling, and then drives the off-axis mirror support to move linearly along the Z direction through thread transmission.

5. The numerical aperture adjustment device for an off-axis lighting system according to claim 4, characterized in that, Each of the Z-axis transmission modules further includes a first position detection unit, the first position detection unit comprising: Two first photoelectric switches are fixedly installed on the support plate and are located beside the first lead screw, corresponding to the two extreme positions of the off-axis mirror support's movement stroke. The first photoelectric switch baffle is fixedly installed on the Z-axis drive block of the lens barrel and moves with the Z-axis drive block of the lens barrel.

6. The numerical aperture adjustment device for an off-axis lighting system according to claim 1 or 2, characterized in that, The Z-axis driving module for the reflector assembly includes: The Z-axis base is fixedly installed on the upper surface of the ring plate; The rotating base is slidably connected to the Z-axis base via at least two vertically arranged second guide rails; The second drive motor is fixedly mounted on the side of the Z-axis base via a second motor mount; The second lead screw is coaxially connected to the output shaft of the second drive motor via a second coupling. Two second ball screw support seats are fixed on the upper and lower sides of the Z-axis base to support the two ends of the second screw. The lead screw nut seat engages with the second lead screw through an internal threaded hole, and the lead screw nut seat is fixedly connected to the rotating base; The second drive motor drives the second lead screw to rotate, and the second lead screw drives the rotating base to move linearly along the Z-axis through the lead screw nut seat.

7. The numerical aperture adjustment device for an off-axis lighting system according to claim 6, characterized in that, The reflector group angle driving module includes: A mirror frame is used to mount and fix the mirror assembly. A rhombus-shaped adjustment mechanism, wherein the bottom of the rhombus-shaped adjustment mechanism is hinged to the rotating base via a first hinge connecting seat, and the top of the rhombus-shaped adjustment mechanism is hinged to the back of the reflector frame via a second hinge connecting seat; A reflector hinge is fixedly mounted on the rotating base, and the bottom of the reflector frame is hinged to the reflector hinge so that the reflector frame can rotate around the axis of the reflector hinge.

8. The numerical aperture adjustment device for an off-axis lighting system according to claim 7, characterized in that, The rhomboid adjustment mechanism includes: The third drive motor is fixedly installed via a diamond-shaped adjustable motor end mount; The third lead screw is horizontally arranged and coaxially connected to the output shaft of the third drive motor; The diamond-shaped nut seat engages with the third lead screw via a diamond-shaped lead screw nut; Four rhomboid adjusting rods are connected end to end by hinges to form a rhomboid linkage mechanism. In the rhomboid linkage mechanism, the first bottom corner node is connected to the rhomboid adjusting motor end seat by a hinge, and the second bottom corner node is connected to the rhomboid nut seat by a hinge. The first top corner node is hinged to the rotating base by the first hinge connecting seat, and the second top corner node is hinged to the back of the reflector frame by the second hinge connecting seat. The third drive motor drives the third lead screw to rotate, causing the diamond-shaped nut seat to move linearly along the axis of the third lead screw, thereby changing the shape of the diamond-shaped linkage mechanism. Then, the second hinge connecting seat pushes and pulls the reflector frame, causing the reflector frame to rotate around the axis of the reflector hinge.

9. The numerical aperture adjustment device for an off-axis lighting system according to claim 6, characterized in that, The Z-axis driving module for the reflector assembly further includes a second position detection unit, which includes: Two second photoelectric switches are fixedly installed on the Z-axis base and are located beside the second lead screw, corresponding to the two extreme positions of the rotation base's travel. The second photoelectric switch baffle is fixedly installed on the lead screw nut seat and moves with the lead screw nut seat.

10. A numerical aperture adjustment method based on the numerical aperture adjustment device for an off-axis lighting system as described in any one of claims 1-9, characterized in that, include: Receive the target numerical aperture command; Calculate the target tilt angle of each mirror group based on the target numerical aperture; Drive the angle driving module of each reflector group to adjust the reflector group to the target tilt angle, so as to change the incident angle of light; Calculate the Z-axis position of the off-axis mirror group based on the target tilt angle or the target numerical aperture; The Z-axis drive system of the lens barrel is driven to move the off-axis lens group to the target Z-axis position to compensate for the optical path difference caused by the change of optical path and realize the adjustment of numerical aperture.

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