A barometric pressure compensation device and apparatus

Abstract

The utility model provides a kind of air pressure compensation device, for the dynamic deformation problem caused by the fixed end of long strip reflector in super-precision motion platform equipment, air pressure compensation device is set rigid container, and the dynamic compensation is realized using the air film stiffness and air pressure difference in rigid container: when sliding table accelerates motion, the container internal air pressure is increased by the bending trend of long strip mirror, and reverse force is generated to inhibit deformation;When stationary or uniform speed, air pressure is reduced, and external atmospheric pressure provides support force.The air pressure compensation device does not need intermediate mechanical fixed point, avoids over-constraint problem, has high precision and easy installation, and is suitable for super-precision motion platform in the field of semiconductor manufacturing, precision detection and the like.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor manufacturing equipment, and in particular relates to a pressure compensation device and equipment. Background Technology

[0002] In the semiconductor manufacturing field, the wafer stage positioning accuracy of a lithography machine directly determines the limits of chip feature sizes. Laser interferometers and grating interferometers, as two core positioning technologies, have significantly different technical approaches that impact equipment performance. Laser interferometers, using a helium-neon laser wavelength (approximately 633 nm) as a reference, achieve nanometer-level positioning by measuring the phase difference between two-frequency lasers. This offers the advantage of being traceable to the International System of Units (SI) and is widely used in ultra-precision equipment such as extreme ultraviolet (EUV) and deep ultraviolet (DUV) lithography machines. However, the fixing method of the core component of this technology—the elongated reflector—still faces the dual challenges of dynamic stability and installation accuracy.

[0003] Currently, the elongated mirrors (typically over 300 mm in length) in dual-frequency laser interferometers generally employ a three-point support structure with rigid clamping at both ends and a suspended middle section. This design leads to the following problems during acceleration and deceleration of the motion stage (acceleration can reach over 5 m / s²): Uneven moment distribution: The fixed points at both ends of the elongated mirror bear the main load, while the suspended middle area experiences concentrated moment, causing micron-level deflection deformation of the mirror surface; Dynamic response hysteresis: Traditional fixing methods cannot compensate for deformation in real time, resulting in a phase difference between the displacement signal measured by the interferometer and the actual motion, ultimately translating into positioning errors.

[0004] Traditional solutions still have significant limitations: 1. Using epoxy resin or other adhesives to completely bond the bottom surface of the long mirror to the base results in approximately 1-3% volume shrinkage during the adhesive curing process, leading to residual stress on the mirror surface and affecting initial installation accuracy. Furthermore, the Young's modulus of the adhesive (E ≈ 2-4 GPa) is much lower than that of glass (E ≈ 70 GPa), making it prone to creep deformation under long-term thermal cycling. 2. Adding a mechanical support point (such as a ball-head plunger) in the middle of the long mirror can reduce flexural deformation, but it introduces over-constraint problems: Degree of freedom conflict: The length change of the long mirror due to thermal expansion is restricted by the mechanical support point, leading to thermal stress. 3. Nonlinear contact stiffness: The contact stiffness of the mechanical support point does not match the stiffness of the long mirror itself, easily causing high-frequency vibration amplification effects. Summary of the Invention

[0005] Therefore, it is necessary to provide a pressure compensation device and equipment to address the aforementioned technical problems.

[0006] In a first aspect, this application provides a pressure compensation device for deformation compensation of a long strip mirror in a laser interferometer. The device includes a rigid container, which is connected to the long strip mirror through multiple micropores. A pressure damping cavity is formed inside the rigid container. When the long strip mirror deforms, air pressure flows between the long strip mirror and the pressure damping cavity through the micropores to balance the deformation stress of the long strip mirror. The surface of the rigid container is distributed with interconnected micropores, and the internal pores are interconnected.

[0007] In one embodiment, the spacing between the pneumatic damping cavities is 6 micrometers.

[0008] In one embodiment, the rigid container includes a horizontal container and / or a vertical container, located in the horizontal and vertical suspended areas of the long mirror, respectively.

[0009] In one embodiment, the rigid container is made of ceramic, metal, or composite material.

[0010] In one embodiment, the ceramic is alumina, silicon nitride, or zirconium oxide, or silicon carbide; the metal is sintered stainless steel or aluminum alloy; and the composite material is carbon fiber reinforced silicon carbide.

[0011] In one embodiment, the rigid container has a micropore diameter of 50 micrometers and a porosity of 30%-60%.

[0012] In one embodiment, the air film stiffness of the pneumatic damping cavity is .

[0013] In one embodiment, a pressure regulating component is also included, which is connected to the pneumatic damping cavity and is used to adjust the air pressure in the pneumatic damping cavity in real time according to the deformation of the elongated mirror. The pressure regulating component includes a pressure sensor and a pressure regulating valve. The pressure sensor is used to detect the real-time air pressure in the pneumatic damping cavity, and the pressure regulating valve adjusts the gas flow rate entering the pneumatic damping cavity according to the detection result of the pressure sensor.

[0014] In one embodiment, a sealing gasket is provided at the connection between the rigid container and the elongated mirror. The sealing gasket is made of rubber to prevent gas leakage.

[0015] Secondly, this application also provides a fixing device for a long mirror, characterized in that it includes an XY motion slide, a long mirror, and the air pressure compensation device described in the above embodiments. The two ends of the long mirror are connected to the slide via flexible connectors, the middle part is suspended, and the air pressure compensation device is located below the middle part of the long mirror.

[0016] The aforementioned air pressure compensation device and equipment utilize a rigid container to form an elastic damper, achieving dynamic compensation through the air film stiffness and air pressure difference: when the slide accelerates, the bending tendency of the elongated mirror increases the air pressure inside the container, generating a counterforce to suppress deformation; when stationary or moving at a constant speed, the air pressure decreases, and the external atmospheric pressure provides support. Through a dual-container structure in both horizontal and vertical directions, bidirectional dynamic stability is achieved. This method eliminates the need for intermediate mechanical fixing points, avoiding over-constraint problems, and combines high precision with ease of installation, making it suitable for ultra-precision motion platforms in semiconductor manufacturing, precision testing, and other fields. The core innovation lies in the integrated design of the air pressure damping device and the elongated mirror, effectively resolving the contradiction between dynamic deformation and installation complexity in traditional methods. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the long strip mirror fixing device for a dual-frequency laser interferometer in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the long strip mirror fixing device for a dual-frequency laser interferometer in one embodiment of the present invention; Figure 3 This is a layout diagram of the air pressure damping cavity in the suspended area of ​​the fixed structure in one embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the principle of long strip mirror deformation and air pressure compensation during slide acceleration in one embodiment of the present invention; Figure 5 This is an enlarged schematic diagram of the microporous structure in one embodiment of the present invention.

[0019] exist Figures 1 to 5 middle, 1: Sliding table; 2: Long strip mirror; 3: Horizontal rigid container; 4: Vertical rigid container; 5: Mount 1; 6: Mount 2; 7: Laser Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This application provides a pressure compensation device for compensating the deformation of a long mirror in a laser interferometer. Figure 1-2 As shown, the device includes: a rigid container (3, 4), which is connected to the elongated mirror (2) through multiple micropores. A pressure damping cavity is formed inside the rigid container. When the elongated mirror (2) deforms, the pressure flows between the elongated mirror (2) and the pressure damping cavity through the micropores to balance the deformation stress of the elongated mirror. The surface of the rigid container is distributed with interconnected micropores, and the internal pores are interconnected.

[0021] The long mirror (2) is supported at both ends by a sliding table (1); At least one rigid container (3, 4) is fixed on the slide (1) and located on one or both sides of the suspended area in the middle of the long mirror (2); In one embodiment, the rigid container includes a horizontal container and a vertical container, located in the horizontal and vertical suspended areas of the long mirror, respectively.

[0022] A pressure damping cavity is formed between the elongated mirror (2) and the rigid container (3, 4), with a spacing of 5-10 micrometers; In one embodiment, the spacing between the pneumatic damping cavities is 6 micrometers.

[0023] The rigid containers (3, 4) have interconnected micropores on their surface, with a pore size of 20-100 micrometers, and the internal pores are interconnected.

[0024] In one embodiment, a sealing gasket is provided at the connection between the rigid container and the elongated mirror. The sealing gasket is made of rubber to prevent gas leakage.

[0025] refer to Figure 4 As shown, the dynamic compensation mechanism of the fixing device is as follows: Since there is no support in the middle, the force at both ends of the long mirror is greater than that in the middle, causing the middle part to bend as shown in the figure. When this tendency occurs, the long mirror is equivalent to pressurizing the alumina ceramic container. At the same time, the increased pressure inside the pressure container will give the long mirror a reaction force, suppressing this deformation tendency. Similarly, when the acceleration is opposite to the direction shown in the figure, the deformation tendency is also opposite to that shown in the figure. The long mirror tends to move away from the horizontal pressure container. The pressure inside the pressure container will be less than the atmospheric pressure. At this time, the external atmospheric pressure will give the long mirror a force, suppressing the tendency of the long mirror to move away from the pressure container. The principle of action in the height direction is similar. The two directions work together to ensure the stability of the middle part of the long mirror on the sliding table.

[0026] In another embodiment, the air pressure compensation device may further include a pressure regulating component, which is connected to the air pressure damping cavity and is used to adjust the air pressure in the air pressure damping cavity in real time according to the deformation of the elongated mirror; the pressure regulating component includes a pressure sensor and an air pressure regulating valve, the pressure sensor is used to detect the real-time air pressure in the air pressure damping cavity, and the air pressure regulating valve adjusts the gas flow rate entering the air pressure damping cavity according to the detection result of the pressure sensor.

[0027] The elongated mirror (2) can be made of glass, quartz or sapphire with a surface roughness Ra≤10nm to ensure high reflection accuracy and low scattering loss. The two ends of the elongated mirror are fixed to the XY slide (1) by ceramic bases (5, 6). This fixing method ensures the stability of the elongated mirror and avoids excessive constraint on the elongated mirror body, preventing stress from causing deterioration of optical performance.

[0028] In one embodiment, the rigid containers (3, 4) can be selected as alumina ceramic containers (Al2O3 purity 99.6%): one alumina ceramic container is set in the horizontal and one in the vertical directions, and the surface micropores have a pore size of 20-100 micrometers and a porosity of 30%-60%. These micropores are formed into an array interconnected structure through laser micromachining, so that the pores inside the container are interconnected, forming a pressure damping cavity, which can store some air, while also ensuring the sensitivity of the entire system to changes in air pressure, such as... Figure 5 As shown. This microporous design and manufacturing process enable the pneumatic damping cavity to dynamically suppress the deformation of the long mirror by real-time changes in air pressure difference during the acceleration and deceleration of the slide table.

[0029] The air pressure damping cavity has a distance of 5-10 μm between the elongated mirror and the container, forming a nearly sealed air film with a stiffness of [missing information]. The stiffness value is achieved through precise control of the spacing and micro-hole parameters, ensuring sufficient support while maintaining the flexibility of the elongated mirror's movement. When the sliding table is at a constant speed or with minimal acceleration / deceleration, the elongated mirror will not deform and affect the system's accuracy when suspended. Preferably, the spacing between the elongated mirror and the container is set to 6 μm.

[0030] Optionally, such as Figure 3 As shown, the rigid containers (3, 4) include a horizontal container (3) and a vertical container (4), which are located in the horizontal and vertical suspended areas of the long mirror (2) respectively, forming horizontal and vertical air pressure damping cavities.

[0031] Optionally, the rigid containers (3, 4) are made of ceramic, metal or composite materials.

[0032] Furthermore, the ceramic is alumina, silicon nitride, or zirconium oxide; The metal is sintered stainless steel or aluminum alloy; The composite material is carbon fiber reinforced silicon carbide.

[0033] Those skilled in the art will understand that the above examples are merely examples of materials or structures for conventional rigid containers. The core function of these rigid containers is to achieve dynamic compensation of pressure differences through a microporous structure, such as... Figure 5 As shown, those skilled in the art can balance performance, cost, and environmental adaptability by reasonably selecting replacement materials.

[0034] The rigid containers (3, 4) are fixed to the slide (1) by adhesive, welding or mechanical fastening.

[0035] Those skilled in the art will understand that the structure shown in the figure is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the device to which the present application is applied. The specific device may include more or fewer components than those shown in the figure, or may combine certain components, or may have different component arrangements.

[0036] In one embodiment, an ultra-precision motion platform device is also provided, comprising: XY motion slide; Dual-frequency laser interferometer system; In the above embodiment, the elongated mirror fixing device uses the elongated mirror to reflect laser light to determine the position of the sliding table.

[0037] In one embodiment, a method for fixing the long strip mirror of a dual-frequency laser interferometer is also provided, comprising the following steps: Fix both ends of the long mirror to the sliding table; A rigid container is set in the suspended area in the middle of the long mirror to form a pneumatic damping cavity with a spacing of 5-10 micrometers; The pressure difference in the pneumatic damping cavity is used to dynamically suppress the deformation of the long mirror during acceleration and deceleration on the slide.

[0038] 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.

[0039] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It is understood that this invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention.

Claims

1. A pressure compensation device, characterized in that, The device is used for deformation compensation of a long strip mirror in a laser interferometer. It includes a rigid container that is connected to the long strip mirror through multiple micropores. A pressure damping cavity is formed inside the rigid container. When the long strip mirror deforms, air pressure flows between the long strip mirror and the pressure damping cavity through the micropores to balance the deformation stress of the long strip mirror. The surface of the rigid container is distributed with interconnected micropores, and the internal pores are interconnected. It also includes a pressure regulating component, which is connected to the pneumatic damping cavity and is used to adjust the air pressure in the pneumatic damping cavity in real time according to the deformation of the long mirror. The pressure regulating component includes a pressure sensor and a pressure regulating valve. The pressure sensor is used to detect the real-time air pressure in the pneumatic damping cavity, and the pressure regulating valve adjusts the gas flow rate entering the pneumatic damping cavity according to the detection result of the pressure sensor.

2. The apparatus according to claim 1, characterized in that, The spacing between the pneumatic damping cavities is 6 micrometers.

3. The apparatus according to claim 1, characterized in that, The rigid container includes a horizontal container and / or a vertical container, located in the horizontal and vertical suspended areas of the long mirror, respectively.

4. The apparatus according to claim 1, characterized in that, The rigid container is made of ceramic, metal, or composite material.

5. The apparatus according to claim 4, characterized in that, The ceramic is alumina, silicon nitride, or zirconium oxide, or silicon carbide; the metal is sintered stainless steel or aluminum alloy; the composite material is carbon fiber reinforced silicon carbide.

6. The apparatus according to claim 1, characterized in that, The rigid container has a micropore diameter of 50 micrometers and a porosity of 30%-60%.

7. The apparatus according to claim 1, characterized in that, The air film stiffness of the pneumatic damping cavity is .

8. The air pressure compensation device according to claim 1, characterized in that, A sealing gasket made of rubber is provided at the connection between the rigid container and the long mirror to prevent gas leakage.

9. A device for fixing a long mirror, characterized in that, The device includes an XY motion slide, a long mirror, and a pressure compensation device as described in any one of claims 1-8. The two ends of the long mirror are connected to the slide via flexible connectors, and the middle part is suspended. The pressure compensation device is located in the middle of the long mirror.

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