Air bath device

Abstract

The present invention belongs to the field of photolithography technology, and in particular relates to an air bath device. The air bath device of the present invention comprises: a rectifying injection unit, wherein a first annular injection port and a second annular injection port for injecting airflow are respectively provided on the first surface of the rectifying injection unit, the second annular injection port is provided around the outer circumference of the first annular injection port, and an installation area for accommodating a reading head is provided on the inner side of the first annular injection port, wherein the airflow injected by the first annular injection port and the second annular injection port have different flow rates. The air bath device of the present invention is a local air bath device, which is a secondary environmental control method for the area enclosed by the reading head and its optical path. Airflows of different flow rates are injected through the two injection ports, thereby forming two layers of airflow inside and outside, generating an area of relative static pressure around the reading head, which can effectively resist the influence of the disturbed airflow generated by the high-speed movement of the moving table, and ensure the measurement accuracy of the plane grating system.

Description

Technical Field

[0001] The invention belongs to the technical field of photolithography, and in particular relates to a gas bath device. Background Art

[0002] A photolithography machine is an ultra-precise, multidisciplinary industrial product and a core tool for semiconductor material processing and manufacturing. As a core component of a photolithography machine, the plane grating measurement subsystem is responsible for providing position measurement feedback for subsystems such as the dual worktable, leveling and focusing system, and wafer alignment system. The grating scale's readhead is mounted on and moves with the motion stage. During exposure, the stage scans along a predetermined trajectory, and the position of the readhead constantly changes as the stage's position changes. The readhead's piping must be constantly covered by an air bath to ensure a stable operating environment for the measurement system.

[0003] Complete air bath systems are a common option in the current environmental control field. They typically use multi-channel input and uniform gas input to provide a stable, uniform, and clean working environment. However, the high-speed movement of the motion stage disrupts this stable and uniform local environment. Even if the optical path between the readhead and the grating scale is only a few millimeters, the high-speed movement of the motion stage will still cause large temperature and pressure gradients to form in the readhead optical path, causing the readhead to be affected by airflow disturbances, affecting the measurement accuracy of the plane grating system.

[0004] Due to the compact internal space of the lithography equipment, unified gas supply cannot solve the problems of the impact of local disturbed airflow and the decline in measurement accuracy of core optical components. Therefore, it is necessary to invent a local gas bath device to control the environment of the core components to improve measurement accuracy. Summary of the Invention

[0005] The present invention provides an air bath device for solving the problem that a reading head is affected by airflow disturbance due to high-speed motion of a motion stage, and for avoiding systematic measurement errors caused by environmental changes such as temperature and pressure in a plane grating system.

[0006] The gas bath device of the present invention comprises: a rectifying spray unit,

[0007] The first surface of the rectifying injection unit is respectively provided with a first annular injection port and a second annular injection port for injecting airflow, the second annular injection port is arranged around the outer circumference of the first annular injection port, and the inner side of the first annular injection port is provided with a mounting area for accommodating a reading head.

[0008] The flow rates of the airflow ejected from the first annular injection port and the second annular injection port are different.

[0009] In one embodiment, the radial width of the first annular injection port is smaller than the radial width of the second annular injection port.

[0010] In one embodiment, the first annular injection port is filled with porous media.

[0011] In one embodiment, the radial width of the second annular injection port is smaller than the radial width of the first annular injection port.

[0012] In one embodiment, the second annular injection port is filled with a porous medium.

[0013] In one embodiment, the second annular injection port extends obliquely outward.

[0014] In one embodiment, the rectifying injection unit includes a buffer layer and an injection layer stacked together.

[0015] A buffer cavity is provided in the buffer layer, and a first annular buffer outlet and a second annular buffer outlet are respectively provided on the surface of the buffer layer adjacent to the ejection layer, which are communicated with the buffer cavity. The second annular buffer outlet is arranged around the outer circumference of the first annular buffer outlet.

[0016] The first annular injection port and the second annular injection port are provided on the injection layer, the first annular buffer outlet is connected to the first annular injection port, and the second annular buffer outlet is connected to the second annular injection port.

[0017] In one embodiment, the first annular buffer outlet and the second annular buffer outlet are both filled with porous media.

[0018] In one embodiment, it further comprises: a heat exchange unit,

[0019] The heat exchange unit is arranged on the water-cooling heat dissipation component of the sports platform so that the gas input into the heat exchange unit can exchange heat with the heat exchange liquid in the water-cooling heat dissipation component.

[0020] The heat exchange unit is connected to the rectifying injection unit so that the gas after heat exchange is input into the rectifying injection unit.

[0021] In one embodiment, the heat exchange unit comprises a heat exchange plate,

[0022] A heat exchange channel is provided inside the heat exchange plate, and the heat exchange plate is provided on the water-cooled heat dissipation component. The outlet end of the heat exchange channel is connected to the rectifying injection unit through a connecting pipe, and the connecting pipe is filled with porous medium.

[0023] Compared with the prior art, the advantages of the present invention are: the air bath device of the present invention is a local air bath device, which is a secondary environmental control method for the reading head and its optical path area. The first annular jet port on the inside and the second annular jet port on the outside respectively spray airflows of different flow rates, thereby forming two layers of airflow inside and outside, generating an area of relative static pressure around the reading head, which can effectively resist the influence of the disturbed airflow generated by the high-speed movement of the motion stage, and ensure the measurement accuracy of the plane grating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the accompanying drawings.

[0025] Figure 1 1 is a schematic structural diagram of an air bath device in one embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of a heat exchange unit and connecting pipes in one embodiment of the present invention;

[0027] Figure 3 1 is a schematic structural diagram of a buffer layer of a rectifying injection unit in one embodiment of the present invention;

[0028] Figure 4 1 is a schematic structural diagram of a spray layer of a rectifying spray unit in one embodiment of the present invention;

[0029] Figure 5 It is a schematic structural diagram of the injection layer of the rectifying injection unit in another embodiment of the present invention.

[0030] in, Figure 4 and Figure 5 In the figure, the curved line represents relatively high-speed "turbulent flow" and the straight line represents relatively low-speed "laminar flow".

[0031] Reference numerals:

[0032] 1. Rectification and injection unit; 2. Heat exchange unit; 3. Connecting pipes; 4. Reading head;

[0033] 5. Plane grating; 6. Porous medium; 7. Input air pipe;

[0034] 11. Spray layer; 12. Buffer layer;

[0035] 111, first annular injection port; 112, second annular injection port;

[0036] 121. Buffer chamber; 122. First annular buffer outlet;

[0037] 123. Second annular buffer outlet; 124. Buffer inlet;

[0038] 21. heat exchange plate; 211. heat exchange inlet;

[0039] 41. Optical path area. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings.

[0041] like Figure 1-5 As shown in FIG, the air bath device of the present invention includes: a rectifying injection unit 1. A first annular injection port 111 and a second annular injection port 112 for injecting airflow are respectively provided on the first surface of the rectifying injection unit 1. The second annular injection port 112 is provided around the outer periphery of the first annular injection port 111. The inner side of the first annular injection port 111 is provided with a mounting area for accommodating the reading head 4.

[0042] The airflow injected from the first annular injection port 111 and the airflow injected from the second annular injection port 112 have different flow rates.

[0043] The air bath device of the present invention is a local air bath device, which is a secondary environmental control method for the reading head 4 and its optical path area 41. The first annular injection port 111 on the inner side and the second annular injection port 112 on the outer side respectively inject airflows of different flow rates, thereby forming two layers of airflow inside and outside, generating an area of relative static pressure around the reading head 4, which can effectively resist the influence of the disturbed airflow generated by the high-speed movement of the motion stage, thereby ensuring the measurement accuracy of the plane grating measurement system.

[0044] Specifically, the air bath device's two annular jets surround the reading head 4, with the inner first annular jet 111 and the outer second annular jet 112 ejecting airflows at different velocities, forming two layers of airflow, one relatively slow-moving "laminar" flow and the other relatively fast-moving "turbulent" flow. The outer layer of airflow directly resists the turbulent airflow generated by the high-speed motion of the motion stage, while maintaining a certain degree of stability and uniformity in the inner layer of airflow. This, in turn, places the optical path 41 of the reading head 4, surrounded by the inner layer of airflow, in a relatively static pressure zone, effectively reducing the effects of temperature and pressure caused by the high-speed motion of the motion stage. Simultaneously, the inner layer of airflow fills the area it encloses, maintaining an internal pressure gradient.

[0045] In addition, the air bath device of the present invention fully considers the spatial dimensions between the reading head 4 and the plane grating 5, and has the characteristics of compact structure, easy disassembly and maintainability.

[0046] It should be noted that in the plane grating measurement system, the plane grating 5 is spaced apart from the reading head 4, and the reading head 4 is installed on the moving stage and moves with the moving stage. During exposure, the moving stage moves according to a predetermined trajectory, and the reading head 4 scans the plane grating 5 to perform measurement operations. The area between the reading head 4 and the plane grating 5 is the optical path area 41 of the reading head 4.

[0047] In one embodiment, the radial width of the first annular injection port 111 is smaller than the radial width of the second annular injection port 112 .

[0048] In this embodiment, Figure 4 As shown in the figure, the radial width of the inner first annular injection port 111 is smaller, specifically an annular injection gap, for injecting relatively high-speed "turbulent flow"; the radial width of the outer second annular injection port 112 is larger, for injecting relatively low-speed "laminar flow".

[0049] Preferably, the first annular injection port 111 is filled with a porous medium 6. The porous medium 6 has a specific porosity and pore size, which can regulate the internal pressure of the airflow, thereby playing a rectifying role. By filling the first annular injection port 111 with the porous medium 6, it can stably and evenly eject a relatively high-speed airflow.

[0050] More preferably, the second annular injection port 112 extends outwardly in an inclined manner. The second annular injection port 112 located on the outside is inclined outwardly to increase the effect of the air bath device in resisting external high-speed airflow.

[0051] In another embodiment, the radial width of the second annular injection port 112 is smaller than the radial width of the first annular injection port 111 .

[0052] In this embodiment, Figure 5 As shown in the figure, the radial width of the inner first annular injection port 111 is larger, and is used to inject relatively low-speed "laminar flow"; the radial width of the outer second annular injection port 112 is smaller, specifically an annular injection gap, and is used to inject relatively high-speed "turbulent flow".

[0053] Preferably, the second annular injection port 112 is filled with a porous medium 6. The porous medium 6 has a specific porosity and pore size, which can regulate the internal pressure of the airflow, thereby performing a rectifying function. By filling the second annular injection port 112 with the porous medium 6, it can stably and evenly eject a relatively high-speed airflow.

[0054] Further preferably, the second annular injection port 112 extends outwardly in an inclined manner. The second annular injection port 112 located on the outside is arranged to be inclined outwardly to increase the function and effect of the air bath device in resisting external high-speed airflow.

[0055] In one embodiment, the rectifying injection unit 1 includes a buffer layer 12 and an injection layer 11 arranged in a stacked manner. A buffer cavity 121 is provided within the buffer layer 12. A first annular buffer outlet 122 and a second annular buffer outlet 123 communicating with the buffer cavity 121 are provided on the surface of the buffer layer 12 adjacent to the injection layer 11. The second annular buffer outlet 123 is provided around the outer circumference of the first annular buffer outlet 122. A first annular injection port 111 and a second annular injection port 112 are provided on the injection layer 11. The first annular buffer outlet 122 is connected to the first annular injection port, and the second annular buffer outlet 123 is connected to the second annular injection port.

[0056] In this embodiment, the buffer layer 12 of the rectifying injection unit 1 plays a rectifying role, and the injection layer 11 controls the injection direction and flow rate of the airflow. The input gas first enters the buffer cavity 121 of the buffer layer 12, and then enters the corresponding first annular injection outlet and second annular injection outlet through the two outlets of the buffer layer 12 (the first annular buffer outlet 122 and the second annular buffer outlet 123) and is injected, forming two layers of airflow with different flow rates.

[0057] Preferably, the first annular buffer outlet 122 and the second annular buffer outlet 123 are both filled with porous media 6 to perform rectification and noise reduction.

[0058] Furthermore, the first annular buffer outlet 122 and the second annular buffer outlet 123 are filled with the same porous medium 6 having the same porosity.

[0059] like Figure 3 As shown in the figure, a buffer cavity 121 is provided inside the buffer layer 12, a first annular buffer outlet 122 and a second annular buffer outlet 123 are respectively provided on the top surface of the buffer layer 12, and a buffer inlet 124 connected to the buffer cavity 121 is provided in the center of the bottom surface of the buffer layer 12.

[0060] like Figure 4 and Figure 5 As shown in FIG, the ejection layer 11 is provided with a first annular ejection port 111 and a second annular ejection port 112. In addition, a mounting area for accommodating the reading head 4 is provided at the center of the ejection layer 11.

[0061] In one embodiment, the air bath device further includes a heat exchange unit 2. The heat exchange unit 2 is disposed on the water-cooled heat sink of the motion platform so that the gas input into the heat exchange unit 2 exchanges heat with the heat exchange liquid in the water-cooled heat sink. The heat exchange unit 2 is connected to the rectifying spray unit 1 so that the gas after heat exchange is input into the rectifying spray unit 1.

[0062] In this embodiment, the gas in the gas source device adopts passive temperature control. The input gas is heat exchanged through the heat exchange unit 2 and then ejected through the rectifier injection unit 1 to achieve temperature control of the injection gas, so that the environment around the reading head 4 can achieve ultra-high temperature stability and uniformity through the heat exchange unit 2.

[0063] Specifically, the heat exchange unit 2 includes a heat exchange plate 21, which is internally provided with a heat exchange channel. The heat exchange plate 21 is mounted on a water-cooled heat sink. The outlet of the heat exchange channel is connected to the rectifying spray unit 1 via a connecting pipe 3, which is filled with a porous medium 6. The porous medium 6 has a high flow resistance, which prolongs the time for the gas to flow through the heat exchange unit 2, allowing the gas to fully exchange heat. Furthermore, the porous medium 6 is a loose, porous, anisotropic material, which reduces the flow noise generated by the airflow in the narrow channel and increases the injection pressure at the rectifying spray unit 1.

[0064] Preferably, a thermally conductive gasket with high thermal conductivity is provided on the surface (bottom) of the heat exchange plate 21 in contact with the water-cooled heat sink component, and the heat exchange plate 21 is in contact with the water-cooled heat sink component through the thermally conductive gasket to perform temperature heat transfer and control.

[0065] like Figure 2 As shown in FIG, a heat exchange inlet 211 is provided on the upper surface of the heat exchange plate 21, and the input gas pipe 7 is connected to the heat exchange inlet 211. The input gas enters the heat exchange channel of the heat exchange plate 21 through the input gas pipe 7 for heat exchange.

[0066] More specifically, the connecting pipe 3 extends in a direction perpendicular to the plane where the heat exchange plate 21 is located, so as to be connected to the gas inlet of the rectifying injection unit 1 spaced apart above the heat exchange plate 21 .

[0067] It should be noted that the heat exchange plate 21 is provided with uniformly distributed heat exchange channels. Furthermore, the heat exchange channels are provided with multiple cut-off and merging intersections to further reduce the flow noise of the gas.

[0068] Example

[0069] In this embodiment, the air bath device includes a rectifying spray unit 1 and a heat exchange unit 2 , and the heat exchange unit 2 is connected to the rectifying spray unit 1 via a connecting pipe 3 .

[0070] The top surface of the rectifying injection unit 1 is provided with a first annular injection port 111 and a second annular injection port 112 for injecting air. The second annular injection port 112 is arranged around the outer periphery of the first annular injection port 111. The inner side of the first annular injection port 111 is provided with a mounting hole for accommodating the reading head 4. The airflow injected by the first annular injection port 111 and the second annular injection port 112 has different flow rates.

[0071] The heat exchange unit 2 is arranged on the water-cooling heat dissipation component of the motion platform so that the gas input into the heat exchange unit 2 can exchange heat with the heat exchange liquid in the water-cooling heat dissipation component.

[0072] After the input gas passes through the heat exchange unit 2 for heat exchange, it enters the rectifying injection unit 1 and is respectively ejected from the first annular injection port 111 and the second annular injection port 112. Since the flow rates of the airflow ejected from the two injection ports are different, two layers of "air curtains" are formed to envelop the pipeline area of the reading head 4, thereby controlling the environment around the reading head 4 and achieving ultra-high precision temperature stability, temperature uniformity, pressure gradient and other environmental control indicators.

[0073] To address the problem of current plane grating 5 measurement systems being affected by airflow disturbances, the present invention provides a localized air bath device suitable for use in dual-stage plane grating 5 measurement systems for photolithography machines. This air bath device provides a means of further localized environmental control for core optical components and the optical path envelope. This device reduces the impact of air disturbances on the optical path caused by the high-speed motion of the moving stage, improves the environmental stability and uniformity near the optical path, reduces system errors caused by environmental factors, and reduces the nanometer-resolution displacement measurement errors of the plane grating 5 test system, thereby improving the accuracy and stability of the photolithography machine.

[0074] Compared with other air bath devices, the present invention fully considers the spatial dimensions between the reading head 4 and the plane grating 5, has a compact structure, and is easy to disassemble and maintain. A relatively static pressure area is generated around the reading head 4, which can effectively reduce the impact of temperature and pressure caused by the high-speed movement of the motion table.

[0075] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical connections; direct connections or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0076] The descriptions such as "upper", "lower", "inside" and "outside" mentioned in the present invention are defined according to the usual meaning. For example, with reference to the direction of gravity, the direction of gravity is downward, and the opposite direction is upward. Similarly, the top end is upward, and the bottom end is downward. "Inside" and "outside" refer to the inside and outside relative to the outline of each component itself. They are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of the implementation of the present invention without substantial changes in the technical content. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0077] While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. An air bath device, characterized in that: include: a rectifying injection unit, the rectifying injection unit comprising a buffer layer having a buffer cavity formed therein, and an injection layer stacked with the buffer layer; A buffer inlet communicating with the buffer cavity is formed on a side wall of the buffer layer away from the ejection layer; The injection layer is formed with a first annular injection port and a second annular injection port respectively connected to the buffer cavity and used for injecting airflow, the second annular injection port is arranged around the outer circumference of the first annular injection port, and an installation area for accommodating a reading head is provided inside the first annular injection port. The radial widths of the first annular injection port and the second annular injection port are different, so that the flow velocities and flow paths of the injected airflow are different.

2. The air bath device according to claim 1, characterized in that The radial width of the first annular injection port is smaller than the radial width of the second annular injection port; and the first annular injection port is filled with porous medium.

3. The air bath device according to claim 1, characterized in that The radial width of the second annular injection port is smaller than the radial width of the first annular injection port; and the second annular injection port is filled with porous medium.

4. The air bath device according to any one of claims 1 to 3, characterized in that: The second annular injection port extends obliquely outward.

5. The air bath device according to any one of claims 1 to 3, characterized in that: A first annular buffer outlet and a second annular buffer outlet connected to the buffer cavity are respectively provided on the surfaces adjacent to the buffer layer. The second annular buffer outlet is arranged around the outer circumference of the first annular buffer outlet. The first annular buffer outlet is connected to the first annular injection port, and the second annular buffer outlet is connected to the second annular injection port.

6. The air bath device according to claim 5, characterized in that: The first annular buffer outlet and the second annular buffer outlet are both filled with porous media.

7. The air bath device according to any one of claims 1 to 3, characterized in that: Also includes: Heat exchange unit, The heat exchange unit is arranged on the water-cooling heat dissipation component of the sports platform so that the gas input into the heat exchange unit can exchange heat with the heat exchange liquid in the water-cooling heat dissipation component. The heat exchange unit is connected to the rectifying injection unit so that the gas after heat exchange is input into the rectifying injection unit.

8. The air bath device according to claim 7, characterized in that The heat exchange unit includes a heat exchange plate, A heat exchange channel is provided inside the heat exchange plate, and the heat exchange plate is provided on the water-cooled heat dissipation component. The outlet end of the heat exchange channel is connected to the rectifying injection unit through a connecting pipe, and the connecting pipe is filled with porous medium.

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