Lithographic equipment
The photolithography equipment, which combines an air-floating platform with a robotic arm, solves the problems of non-uniformity and damage in the mass production of volume gratings, achieving efficient and high-quality grating manufacturing and improving production efficiency and grating consistency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-31
- Publication Date
- 2026-04-03
AI Technical Summary
Existing technologies make it difficult to achieve efficient and low-cost mass production of volume gratings, and they also suffer from problems such as uneven grating period, reduced diffraction efficiency, and increased stray light.
The lithography equipment, which combines an air-floating platform with a robotic arm, achieves stable placement and exposure of gratings through a fully automated process. It utilizes a gantry for coarse positioning and a robotic arm for fine adjustment to avoid physical damage. Combined with a detection module, it optimizes parameters in real time to achieve high-precision and high-efficiency production.
This enables efficient and high-quality mass production of gratings, improves grating period consistency and diffraction efficiency, reduces the impact of environmental vibration and thermal drift, and enhances production efficiency and product quality.
Smart Images
Figure CN224081939U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photolithography technology, and more particularly to a photolithography apparatus. Background Technology
[0002] With breakthroughs in intelligent and integrated technologies, volume gratings are expected to be more widely used in cutting-edge fields such as AR display, quantum communication, and biomedicine.
[0003] The batch exposure technology for volume Bragg gratings (VBGs) is a core step in achieving efficient and low-cost manufacturing of VBGs. Currently, femtosecond laser direct writing technology is used for fabrication. This technology utilizes ultrafast lasers to induce nonlinear absorption inside a transparent medium, directly writing three-dimensional grating structures with sub-micron precision. It offers high degrees of freedom, supporting complex structures such as arbitrary tilt angles (0-90°), chirps, and gradient periods. Femtosecond laser direct writing technology is a non-contact processing method, requiring no mask, and is suitable for hard and brittle materials. However, this method has a slow writing speed (typically 1 mm / h), making it difficult to meet high-volume production needs, and it also suffers from heat accumulation leading to material damage.
[0004] Another method uses nanoimprint lithography (NIL), in which a pre-fabricated master VBG (volume Bragg grating) structure is transferred to photoresist or a flexible material via imprinting, and then cured to form a replicated grating. This process is characterized by high throughput and low cost, with a single imprint area >200 mm². 2 Hourly production capacity > 1000, and master template reuse count > 10 4 This method reduces the cost per unit by 90% and is applicable to polymers and sol-gel materials such as SU-8 and PDMS. However, master plate fabrication relies on electron beam lithography, which has a long cycle and high cost. Summary of the Invention
[0005] To overcome the above-mentioned shortcomings, this application proposes a photolithography device that can achieve stable and reliable mass production of bulk gratings.
[0006] To achieve the above objectives, this application adopts the following technical solution:
[0007] A photolithography apparatus includes:
[0008] Gantry cranes and air flotation platforms
[0009] The air flotation platform is equipped with a sample stage, which is used to place the grating to be exposed.
[0010] The gantry frame is mounted on the air-floating platform, and the top of the gantry frame has a crossbeam. An X / Y module is suspended on the crossbeam, and the X / Y module has a connecting end with a robotic arm for gripping samples. This method utilizes the air-floating platform to suspend the sample stage, isolating it from ground vibrations. Combined with the robotic arm, a fully automated photolithography process can be achieved, avoiding physical damage to the substrate or grating structure and enabling efficient and high-quality mass production of gratings.
[0011] Preferably, the lithography equipment includes a control module, which is electrically connected to drive the X / Y module to move and drive the robotic arm, and controls the X / Y module to move and drive the robotic arm to move based on instructions.
[0012] Preferably, the robotic arm is a 6-axis collaborative robotic arm.
[0013] Preferably, the photolithography equipment also includes a sealing cover, which is installed on the gantry and has a material handling port.
[0014] Preferably, the photolithography equipment is provided with a detection module disposed within a sealed enclosure. The detection module includes an integrated force sensor and / or a spectrometer, configured to dynamically optimize exposure parameters based on online monitoring data. The monitoring data includes diffraction efficiency and refractive index modulation depth, and the exposure parameters include at least one or a combination of power, time, or angle.
[0015] Preferably, the detection module includes a spot position sensor, and the robotic arm synchronously compensates for the effects of environmental vibration or thermal drift on the optical path based on the information fed back by the spot position sensor.
[0016] Preferably, the robotic arm is equipped with a vision module, which is used to assist in the positioning, clamping, and replacement of sample substrates.
[0017] Preferably, the lithography equipment includes multiple air-floating platforms arranged circumferentially along the gantry, and multiple air-floating platforms are operated in parallel by a robotic arm.
[0018] Beneficial effects
[0019] Compared with existing technologies, the photolithography equipment provided in this application uses a combination of a robotic arm and a gantry to achieve automatic pickup, alignment, and placement of gratings. The combination of coarse positioning by the gantry and fine adjustment by the robotic arm ensures alignment and placement accuracy (avoiding collisions between the grating substrate and the air-bearing platform, which could cause physical damage to the substrate or grating structure). This enables multi-element exposure production in a single operation, increases the number of materials that can be loaded, and achieves efficient and high-quality mass production of gratings. The photolithography equipment incorporates an air-bearing platform to reduce the impact of sample vibration and other factors, and introduces a robotic arm to automate the placement and exposure of holographic gratings, achieving efficient and high-quality mass production of gratings. Attached Figure Description
[0020] The accompanying drawings are provided to illustrate the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure. The shapes and sizes of the components in the drawings do not reflect actual proportions and are only intended to illustrate the content of this application.
[0021] Figure 1 The diagram shown is a structural schematic of an automated lithography equipment according to an embodiment of this application;
[0022] Figure 2 , Figure 3 This is a schematic diagram of the structure of the robotic arm according to an embodiment of this application;
[0023] Figure 4 This is a schematic diagram of the structure of the air flotation platform according to an embodiment of this application;
[0024] Figure 5 for Figure 4 Enlarged view of point a in the middle;
[0025] Figure 6 This is a three-dimensional structural diagram of the air flotation platform according to an embodiment of this application. Detailed Implementation
[0026] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.
[0027] In this application, the terms "upper," "lower," "inner," "middle," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0028] A volume grating is a three-dimensional periodic refractive index modulation structure formed within a transparent medium (such as glass, crystal, or photoresist), with its period typically ranging from submicron to nanometer scale. Unlike surface gratings, the optical properties of a volume grating are determined by the holographic structure within the material, offering advantages such as high diffraction efficiency, narrow bandwidth selectivity, and a high damage threshold. The fabrication of volume gratings relies on photolithography, the core of which involves forming a periodic structure within the medium through the interaction of light and material. As mentioned in the background section, current fabrication methods enable stable and reliable mass production. However, manual operation makes it difficult to guarantee absolute consistency in placement each time, potentially leading to non-uniform grating periods, reduced diffraction efficiency, or increased stray light.
[0029] Based on this, this application proposes a photolithography device that improves the feeding structure of existing photolithography technology to meet the requirements of consistency, high precision consistency, and mass production.
[0030] Next, combine Figures 1-6 This application describes a photolithography apparatus.
[0031] The lithography equipment includes a gantry 130 and an air-float platform 110. A sample stage 120 is mounted on the air-float platform for placing the grating to be exposed (not shown). The lithography equipment is equipped with a control module for driving the X / Y module movement and driving the robotic arm. This control module is prior art and will not be described in detail here.
[0032] The gantry 130 is ringed around the air-floating platform 110. An X / Y module 140 is suspended from the top crossbeam of the gantry. The X / Y module 140 has a connecting end 141, on which a robotic arm 150 is mounted. The X / Y module 140 drives the robotic arm 150 to move in the x and / or y directions to perform operations.
[0033] The robotic arm 150 is used to pick up the sample fixture from the feed table and place it on the sample stage of the air-floating platform. After determining the sample placement position, the sample fixture is removed, and the sample is left to be exposed. This cycle is repeated until all samples have been exposed. This photolithography equipment achieves fully automated integration of the entire process, enabling automatic sample clamping during exposure: the robotic arm, in conjunction with a vision system, completes substrate positioning, clamping, and replacement, reducing manual intervention time. This method can significantly improve the consistency of different batches of products (e.g., wavelength deviation of fiber optic sensing gratings <0.1nm). The air-floating platform 110 isolates the platform from ground vibrations, preventing damage to the platform's stability and avoiding minute displacement of the grating substrate, resulting in blurred or broken exposure lines. The air-floating platform 110 utilizes compressed air to form a micron-level air film between the platform and the support surface. Non-contact support is achieved through the hydrodynamic or hydrostatic effects of the air film, providing zero friction, high precision, and vibration resistance. High-strength aluminum alloy, granite, or ceramic are typically used to ensure rigidity and thermal stability. Surface treatment: precision grinding to nanometer-level flatness (≤0.1μm / m). 2 This ensures a uniform distribution of the air film. The air-floating surface has multiple air holes or air chambers to uniformly spray compressed air.
[0034] Figure 4 This is a schematic diagram of the structure of the air flotation platform according to an embodiment of this application; Figure 5 for Figure 4 Enlarged view of point a in the middle; Figure 6 This is a three-dimensional structural diagram of the air flotation platform according to an embodiment of this application.
[0035] The air flotation platform 110 has an air flotation surface with pressure equalization grooves 111 etched into the surface in a grid pattern (appearing as pores when viewed from above) to achieve uniform air pressure distribution. In one embodiment, a leveling mechanism is provided at the bottom of the air flotation platform 110 for real-time correction of the platform's levelness. A pressure sensor is installed inside the air flotation platform 110 for real-time monitoring of the air film pressure distribution. The air flotation platform 110 is matched with an air film generation system, which includes a high-pressure air compressor (pressure typically 0.4–0.8 MPa), preferably equipped with a multi-stage filter (to remove oil, water, and particles); an air chamber for storing and stabilizing air to reduce pressure fluctuations; and a throttle device including a microporous or capillary structure for controlling the gas flow rate to form a stable air film (air film thickness typically 5–20 μm).
[0036] In one embodiment, the robotic arm is a 6-axis collaborative robotic arm. The coarse positioning of the gantry 130 and the fine adjustment of the robotic arm 150 are combined to ensure alignment and placement accuracy (avoiding collisions between the grating substrate and the air-bearing platform, which could cause physical damage to the substrate or grating structure). Preferably, the robotic arm's precision servo system enables precise adjustment of the laser interference angle (e.g., ±0.001° error control) to ensure the periodic consistency of the interference fringes. For example, in the fabrication of tilted gratings (TFBG), the robotic arm can dynamically adjust the laser incident angle to optimize the uniformity of the grating tilt angle, eliminating human error. Avoiding the angle shifts or vibrations easily introduced by traditional manual adjustments, the robotic arm, through programmed path planning, avoids human interference, making it particularly suitable for the fabrication of large-size gratings (such as AR waveguide gratings). The end of the robotic arm has a mechanical gripper 151 for grasping samples. The gripper has a matching shape for different samples.
[0037] like Figure 2 and Figure 3 The diagram shown illustrates the structure of a robotic gripper according to another embodiment of this application. This gripper has a main body 251 capable of gripping a glass sheet (photo-thermo-refractive glass, PTR). The main body 251 is connected to a support 252, which is fixed to the main body of the robotic arm by a fastener 253 (see [link to documentation]). Figure 1 The main body 251 is connected to the extraction component (not shown) via a pipe. The bottom side of the main body 251 has a vent hole, and the extraction component draws air to grip the sample when it is being picked up. In other embodiments, the main body 251 may be a suction nozzle, through which the sample is drawn.
[0038] In one embodiment, during dynamic exposure, the robotic arm can simultaneously compensate for the effects of environmental vibration or thermal drift on the optical path (e.g., through a spot position sensor that provides real-time feedback), thereby improving process stability in complex environments.
[0039] In one embodiment, the gantry 130 is equipped with a frame, and a sealing plate is installed on the frame. The sealing plate provides a complete enclosure, ensuring operation within a cleanroom environment. This, combined with a local laminar flow hood, reduces particulate contamination. A constant temperature and humidity system and a vibration-damping foundation are also used to minimize environmental interference. At least one side of the sealing plate is made of transparent material, facilitating observation of the internal operation.
[0040] In one embodiment, see Figure 1 The lithography equipment is equipped with a detection module 160, which includes an integrated force sensor and / or spectrometer. Based on online monitoring data (such as diffraction efficiency and refractive index modulation depth), the detection module 160 dynamically optimizes exposure parameters (power, time, and angle) to achieve closed-loop control.
[0041] In one embodiment, a detection module (not shown) is provided on the sample stage. This detection module is used to detect the online diffraction efficiency and automatically compensate for parameter offsets using an algorithm (such as correcting optical path offsets to avoid cumulative errors). The detection module is electrically connected to the control module, and the algorithm automatically compensates for parameter offsets based on the information fed back from the detection module, improving exposure accuracy. It adjusts parameters in response to temperature drift, laser power fluctuations, etc., enabling real-time closed-loop control that cannot be achieved through manual intervention, thus improving exposure quality.
[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0043] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be used to limit the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit and essence of this application should be included within the scope of protection of this application.
Claims
1. A photolithography apparatus, characterized in that, include: Gantry cranes and air flotation platforms The air flotation platform is equipped with a sample stage, which is used to place the grating to be exposed. The gantry frame is mounted on the air flotation platform, and the top of the gantry frame has a crossbeam. An X / Y module is suspended on the crossbeam. The X / Y module has a connecting end, and a robotic arm is provided at the connecting end. The robotic arm is used to grip the sample.
2. The photolithography apparatus as described in claim 1, characterized in that, include: The control module is electrically connected to drive the X / Y module and drive the robotic arm, and controls the movement of the X / Y module and the movement of the robotic arm based on commands.
3. The photolithography apparatus as described in claim 1, characterized in that, The robotic arm is a 6-axis collaborative robotic arm.
4. The photolithography apparatus as described in claim 1, characterized in that, It also includes a sealing cover, which is installed on the gantry and has a material handling port.
5. The photolithography apparatus as described in claim 4, characterized in that, The photolithography equipment is equipped with a detection module located inside a sealed enclosure. The detection module includes an integrated force sensor and / or a spectrometer, and is configured to dynamically optimize exposure parameters based on online monitoring data. The monitoring data includes diffraction efficiency and refractive index modulation depth, and the exposure parameters include at least one or a combination of power, time, or angle.
6. The photolithography apparatus as described in claim 5, characterized in that, The detection module includes a spot position sensor, and the robotic arm synchronously compensates for the effects of environmental vibration or thermal drift on the optical path based on the information fed back by the spot position sensor.
7. The photolithography apparatus as described in claim 1, characterized in that, The robotic arm is equipped with a vision module, which is used to assist in the positioning, clamping, and replacement of sample substrates.
8. The photolithography apparatus as described in claim 1, characterized in that, The air flotation platform has an air flotation surface, and the air flotation surface has a pressure equalization groove, which is used to achieve uniform distribution of air pressure.
9. The photolithography apparatus as described in claim 8, characterized in that, The bottom of the air flotation platform is equipped with a leveling mechanism to correct the platform's levelness in real time.