A high-efficiency water-cooled EUV lithography mirror

Abstract

The present invention relates to the field of semiconductor lithography technology, and in particular to a high-efficiency water-cooled EUV lithography mirror, comprising a mirror body, a sealing plunger, and a blocking plunger. The mirror body is provided with a plurality of transverse channels and a plurality of longitudinal channels, the transverse channels and the longitudinal channels being interconnected and extending to the outside of the mirror body, the transverse channels and the longitudinal channels respectively forming openings at the edges of the mirror body; a plurality of sealing plungers are embedded in the openings, wherein at least two openings are retained as water inlets and water outlets; a plurality of blocking plungers are respectively embedded in the transverse channels and the longitudinal channels, so that a continuous water-cooling channel is formed between the water inlets and the water outlets. Thus, the mirror has high-efficiency and high-reliability cooling performance, can reduce the high-temperature influence of a high-power EUV light source on the lithography mirror, avoid thermal deformation, and improve the working performance and long-term stability of the lithography mirror.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lithography, and in particular provides a high-efficiency water-cooled EUV lithography machine reflecting mirror. Background Art

[0002] In EUV lithography machines, the reflectors need to achieve high reflectivity (>90%) near a wavelength of 13.5nm. The surface of the reflectors is usually a Mo / Si multilayer film structure. Due to the extremely high power of the EUV light source, the reflectors absorb the residual heat of the EUV light source, leading to the following problems:

[0003] 1. Thermal deformation: Temperature gradients cause nanoscale deformation of the mirror surface, reducing lithography resolution.

[0004] 2. Thermal stress: Uneven temperature distribution will generate thermal stress inside the reflector, which may cause damage to the reflector surface and shorten its service life.

[0005] 3. Increased maintenance costs: Thermal deformation and thermal stress will accelerate the aging of the reflector and increase the replacement frequency. Higher maintenance requirements and shorter replacement cycles will push up operating costs. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a high-efficiency water-cooled EUV lithography machine reflector, which has high-efficiency and high-reliability cooling performance, can reduce the high-temperature impact of high-power EUV light source on the lithography machine reflector, avoid thermal deformation, and improve the working performance and long-term stability of the lithography machine reflector.

[0007] The present invention provides a high-efficiency water-cooled EUV lithography machine reflective mirror, which specifically includes a mirror body, a sealing plunger and a blocking plunger. The interior of the mirror body is provided with a plurality of transverse channels and a plurality of longitudinal channels, which are interconnected and extend to the outside of the mirror body, and the transverse channels and the longitudinal channels respectively form openings at the edges of the mirror body; a plurality of sealing plungers are embedded in the openings, wherein at least two openings are retained as water inlets and water outlets; a plurality of blocking plungers are respectively embedded in the transverse channels and the longitudinal channels, so that a continuous water-cooling channel is formed between the water inlets and the water outlets.

[0008] Preferably, the main body of the sealing plunger is a cylinder; one end of the sealing plunger is provided with a first flow stabilizing surface and a first inclined surface intersecting with each other.

[0009] Preferably, the main body of the blocking plunger is a cylinder; second flow stabilizing surfaces are provided at both ends of the blocking plunger, and second inclined surfaces are also provided at both ends of the blocking plunger, wherein the second flow stabilizing surface and the second inclined surface located at the same end intersect.

[0010] Preferably, the first inclined surfaces of adjacent sealing plungers are suitable for fitting together so that the two first flow stabilization surfaces of adjacent sealing plungers are connected to form a continuous flow stabilization surface; the second inclined surface of the blocking plunger is suitable for fitting together with the first inclined surface of the sealing plunger so that the second flow stabilization surface of the blocking plunger is connected to the first flow stabilization surface of the sealing plunger to form a continuous flow stabilization surface.

[0011] Preferably, at least two supporting ears are provided on the mirror body; the water inlet and the water outlet are respectively opened on the supporting ears.

[0012] Preferably, the cross-sections of the transverse channel and the longitudinal channel along the radial direction are circular; and the centers of the transverse channel and the longitudinal channel along the axial direction are located in the neutral plane of the mirror body.

[0013] Preferably, the transverse channels and the longitudinal channels are formed by drilling.

[0014] Preferably, the sealing plunger is glued to the transverse channel and the longitudinal channel; and the blocking plunger is glued to the transverse channel and the longitudinal channel.

[0015] Preferably, the mirror body is made of glass-ceramics; the linear expansion coefficient of the mirror body is ≤1×10 -6 / K.

[0016] Preferably, the sealing plunger and the blocking plunger are made of the same material.

[0017] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0018] (1) The present invention provides a high-efficiency water-cooled EUV lithography mirror with high-efficiency and high-reliability cooling performance, which can reduce the high-temperature impact of high-power EUV light sources on the lithography mirror, avoid thermal deformation, and improve the working performance and long-term stability of the lithography mirror.

[0019] (2) The present invention provides a high-efficiency water-cooled EUV lithography machine reflector, which can optimize and adjust the path of the water-cooling channel as needed by setting transverse channels, longitudinal channels, sealing plungers and blocking plungers with adjustable positions and numbers, thereby improving the water-cooling heat dissipation efficiency of the high-efficiency water-cooled EUV lithography machine reflector.

[0020] (3) The present invention provides a high-efficiency water-cooled EUV lithography mirror, which can effectively prevent the cooling water from forming fluid turbulence inside the water-cooling channel by setting a first steady flow surface and a second steady flow surface to form a continuous steady flow surface, thereby avoiding disturbance of the mirror surface.

[0021] (4) The present invention provides a high-efficiency water-cooled EUV lithography mirror, which can reduce the influence of the mirror temperature difference on the mirror surface shape by optimizing the shape and material of the transverse channel, longitudinal channel sealing plunger and blocking plunger. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of a partial cross-sectional structure of a high-efficiency water-cooled EUV lithography machine reflector provided by an embodiment of the present invention;

[0024] Figure 2 This is a side view structural diagram of a high-efficiency water-cooled EUV lithography machine reflector provided by an embodiment of the present invention;

[0025] Figure 3 yes Figure 2 AA cross-sectional structural diagram of a high-efficiency water-cooled EUV lithography mirror according to the embodiment shown;

[0026] Figure 4 This is a schematic diagram of the working principle of a high-efficiency water-cooled EUV lithography mirror provided by an embodiment of the present invention;

[0027] Figure 5 1 is a schematic side view of the structure of a mirror body provided by an embodiment of the present invention;

[0028] Figure 6 yes Figure 5 A schematic diagram of the BB cross-sectional structure of the mirror body of the illustrated embodiment;

[0029] Figure 7 1 is a schematic structural diagram of a sealing plunger provided by an embodiment of the present invention;

[0030] Figure 8 1 is a schematic structural diagram of a blocking plunger provided in an embodiment of the present invention;

[0031] Figure 9 yes Figure 8 A schematic CC cross-sectional structural diagram of the blocking plunger of the illustrated embodiment.

[0032] Reference numerals include:

[0033] 1 mirror body, 11 transverse channel, 12 longitudinal channel, 13 opening, 14 lug, 2 sealing plunger, 21 first flow stabilizing surface, 22 first inclined surface, 3 blocking plunger, 31 second flow stabilizing surface, 32 second inclined surface, 41 water inlet, 42 water outlet, 43 water cooling channel. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention. Similar elements in different embodiments are labeled with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present invention to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present invention are not shown or described in the specification. This is to avoid the core part of the present invention being overwhelmed by too much description. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0035] It should be noted that, unless there is a conflict, the embodiments and features of the embodiments of the present invention can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence unless otherwise specified.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. 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, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0037] 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 in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; 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.

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] like Figures 1 to 6 As shown, an embodiment of the present invention provides a high-efficiency water-cooled EUV lithography mirror, which is particularly suitable for use in a high-power laser plasma light source environment, and specifically includes a mirror body 1, a sealing plunger 2, and a blocking plunger 3. A plurality of transverse channels 11 and a plurality of longitudinal channels 12 are provided inside the mirror body 1. The transverse channels 11 and the longitudinal channels 12 are interconnected and extend to the outside of the mirror body 1. The transverse channels 11 and the longitudinal channels 12 respectively form openings 13 at the edges of the mirror body 1. A plurality of sealing plungers 2 are embedded in the openings 13, wherein at least two openings 13 are retained as water inlets 41 and water outlets 42 for the inflow and outflow of cooling water. A plurality of blocking plungers 3 are respectively embedded in the transverse channels 11 and the longitudinal channels 12, so that a continuous water-cooling channel 43 is formed between the water inlet 41 and the water outlet 42. Therefore, the high-efficiency water-cooled EUV lithography mirror has high-efficiency and high-reliability cooling performance, which can reduce the high-temperature impact of high-power EUV light source on the lithography mirror, avoid thermal deformation, and improve the working performance and long-term stability of the lithography mirror.

[0040] Specifically, the cooling water is driven by a cooling pump outside the mirror body 1 and flows into the interior of the mirror body 1 from the water inlet 41; then it passes through the water cooling channel 43 formed by a plurality of sealing plungers 2 and blocking plungers 3, and turns to flow to the water outlet 42; finally, it flows out from the water outlet 42 to the outside of the mirror body 1; thereby, the heat of the reflector is absorbed and taken away by the circulating cooling water.

[0041] Among them, the interior of the mirror body 1 is provided with multiple transverse channels 11 and multiple longitudinal channels 12, and the positions and quantities of multiple sealing plungers 2 and multiple blocking plungers 3 can be set and adjusted arbitrarily, so as to optimize and adjust the path of the water-cooling channel 43 as needed, thereby improving the water cooling and heat dissipation efficiency of the high-efficiency water-cooled EUV lithography machine reflector.

[0042] Among them, the specific setting positions and numbers of the transverse channel 11, the longitudinal channel 12, the sealing plunger 2 and the blocking plunger 3 are not limited here, and they can be arranged and combined arbitrarily according to needs. It is only necessary to form a one-way continuous water-cooling channel 43 between the water inlet 41 and the water outlet 42 for water cooling the mirror body 1.

[0043] like Figure 7 As shown, the main body of the sealing plunger 2 is cylindrical and can be matched with the transverse channel 11 and the longitudinal channel 12. After the sealing plunger 2 is installed in the mirror body 1, the end near the water cooling channel 43 is provided with a first flow stabilization surface 21 and a first inclined surface 22 that intersect each other; the first flow stabilization surface 21 is used to form a continuous flow stabilization surface in the water cooling channel 43.

[0044] like Figure 8 and Figure 9 As shown, the main body of the blocking plunger 3 is cylindrical and can match the transverse channel 11 and the longitudinal channel 12. The blocking plunger 3 is provided with a second flow stabilizing surface 31 at both ends, and a second inclined surface 32 at both ends. The second flow stabilizing surface 31 and the second inclined surface 32 at the same end intersect; the second flow stabilizing surface 31 is used to form a continuous flow stabilizing surface in the water-cooling channel 43.

[0045] like Figure 3 and Figure 4 As shown, when the sealing plunger 2 and the blocking plunger 3 are embedded in the interior of the mirror body 1 to form the water-cooling channel 43, the sealing plunger 2 and the blocking plunger 3 may be assembled in the following manner: when the two sealing plungers 2 are assembled adjacent to each other, the first inclined surfaces 22 of the adjacent sealing plungers 2 are adapted to fit together, so that the two first flow stabilization surfaces 21 of the adjacent sealing plungers are connected to form a continuous flow stabilization surface. When the sealing plunger 2 and the blocking plunger 3 are assembled adjacent to each other, the second inclined surface 32 of the blocking plunger 3 is adapted to fit together with the first inclined surface 22 of the sealing plunger 2, so that the second flow stabilization surface 31 of the blocking plunger is connected to the first flow stabilization surface 21 of the sealing plunger to form a continuous flow stabilization surface.

[0046] Specifically, by setting the first flow stabilizing surface 21 and the second flow stabilizing surface 31 to connect at the turning point of the water-cooling channel 43 to form a continuous flow stabilizing surface, the cooling water can effectively avoid the formation of fluid turbulence when passing through the first flow stabilizing surface 21 and the second flow stabilizing surface 31, thereby avoiding the flow of cooling water inside the water-cooling channel 43 from disturbing the mirror surface shape.

[0047] Preferably, the first flow stabilizing surface 21 and the second flow stabilizing surface 31 adopt equal-diameter right-angle elbow surfaces, and the flow velocity distribution is controlled by curvature optimization, thereby suppressing fluid turbulence and avoiding disturbance to the mirror surface shape.

[0048] like Figures 1 to 4As shown, the mirror body 1 is also provided with at least two lugs 14. The lugs 14 are used to mount the mirror body 1 to a reflector mounting frame, and therefore the lugs 14 typically form protrusions on the mirror body 1. A water inlet 41 and a water outlet 42 are respectively provided on the lugs 14, so that when cooling water passes through the water cooling channel 43, it flows from the water inlet 41 at the first lug 14 into the water cooling channel 43 and then flows out from the water outlet 42 at the second lug 14 through the water cooling channel 43. In other words, the cooling water also participates in heat exchange at the lugs 14, thereby removing some heat and reducing the impact of temperature differences on the mirror surface on the mirror shape.

[0049] like Figure 1 、 Figure 2 and Figure 5 As shown, the cross-sections of the transverse channel 11 and the longitudinal channel 12 along the radial direction are circular, so that the transverse channel 11 can match the sealing plunger 2 and the blocking plunger 3, and the longitudinal channel 12 can also match the sealing plunger 2 and the blocking plunger 3. The centers of the transverse channel 11 and the longitudinal channel 12 along the axial direction are located in the neutral plane of the mirror body 1, avoiding deformation of the mirror surface due to inconsistent pressure on the front and back sides of the reflector.

[0050] In some possible embodiments, the transverse channel 11 and the longitudinal channel 12 are formed by drilling.

[0051] In some possible embodiments, the sealing plunger 2 is glued to the transverse channel 11 and the longitudinal channel 12, and the blocking plunger 3 is glued to the transverse channel 11 and the longitudinal channel 12, thereby ensuring the sealing and blocking effects and preventing cooling water leakage.

[0052] In some possible embodiments, the mirror body 1 is made of glass-ceramics, and the linear expansion coefficient of the mirror body 1 is ≤1×10 -6 / K, so that the mirror body 1 has high surface accuracy, specifically, the surface accuracy (RMS) of the reflector is maintained at ≤0.1nm.

[0053] In some possible embodiments, the sealing plunger 2 and the blocking plunger 3 are made of the same material, and the linear expansion coefficients of the sealing plunger 2 and the blocking plunger 3 match the linear expansion coefficient of the mirror body 1, thereby reducing the influence of the mirror temperature difference on the mirror surface shape.

[0054] Specifically, in actual applications, since the linear expansion coefficients of the sealing plunger 2, the blocking plunger 3 and the mirror body 1 cannot be exactly the same, when the difference between the linear expansion coefficients of the sealing plunger 2 and the blocking plunger 3 and the linear expansion coefficient of the mirror body 1 is within the allowable range, it is considered that the linear expansion coefficients of the sealing plunger 2 and the blocking plunger 3 match the linear expansion coefficient of the mirror body 1.

[0055] Preferably, the difference between the linear expansion coefficient of the sealing plunger 2 and the blocking plunger 3 and the linear expansion coefficient of the mirror body 1 is less than 1×10E-7 / K, it is considered that the linear expansion coefficients of the sealing plunger 2 and the blocking plunger 3 match the linear expansion coefficient of the mirror body 1.

[0056] Example:

[0057] like Figures 1 to 6 As shown, the embodiment of the present invention provides a high-efficiency water-cooled EUV lithography machine reflector, which specifically includes a mirror body 1, 10 sealing plungers 2 and 3 blocking plungers 3. The material of the mirror body 1 adopts a linear expansion coefficient of ≤1×10 -6 The mirror body 1 is constructed of micro-ceramic glass with a surface accuracy of ≤0.1nm. Two horizontal transverse channels 11 and four vertical longitudinal channels 12 are drilled into the interior of the mirror body 1. These channels 11 and 12 are interconnected and extend to the exterior of the mirror body 1, forming a total of 12 openings 13. The mirror body 1 is also equipped with three protruding lugs 14. The transverse channel 11 at the bottom extends through two of these lugs 14.

[0058] like Figures 3 and 4 As shown, the openings 13 of the two ears 14 at the bottom are retained as the water inlet 41 and the water outlet 42 respectively. Ten sealing plugs 2 are sequentially embedded in the remaining openings 13 and connected by gluing; three blocking plugs 3 are placed in accordance with the Figure 3 The positions shown are sequentially embedded in two transverse channels 11 , so that a continuous water cooling channel 43 is formed between the water inlet 41 and the water outlet 42 .

[0059] like Figures 1 to 6 As shown, the transverse channel 11 and the longitudinal channel 12 have circular cross-sections in the radial direction, and their axial centers are located within the neutral plane of the mirror body 1. The main bodies of the sealing plunger 2 and the blocking plunger 3 are cylindrical. One end of the sealing plunger 2 is provided with an intersecting first flow stabilizing surface 21 and a first inclined surface 22, and both ends of the blocking plunger 3 are provided with an intersecting second flow stabilizing surface 31 and a second inclined surface 32.

[0060] Among them, the first inclined surfaces 22 of adjacent sealing plungers 2 fit together, so that the two first flow stabilization surfaces 21 are connected to form a continuous flow stabilization surface; the second inclined surface 32 of the blocking plunger 3 fits into the first inclined surface 22 of the adjacent sealing plunger 2, so that the second flow stabilization surface 31 is connected to the first flow stabilization surface 21 to form a continuous flow stabilization surface.

[0061] In addition, the sealing plunger 2 and the blocking plunger 3 are made of the same material, and the linear expansion coefficients of the sealing plunger 2 and the blocking plunger 3 match the linear expansion coefficient of the mirror body 1 .

[0062] Experimental verification shows that the mirror temperature gradient of the high-efficiency water-cooled EUV lithography mirror of the present invention can be maintained at ≤0.01°C / cm, thereby meeting the high requirements of the EUV lithography machine for optical stability.

[0063] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0064] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A high-efficiency water-cooled EUV lithography mirror, characterized in that: include: A mirror body (1), wherein a plurality of transverse channels (11) and a plurality of longitudinal channels (12) are provided inside the mirror body (1), wherein the transverse channels (11) and the longitudinal channels (12) are interconnected and extend to the outside of the mirror body (1), and the transverse channels (11) and the longitudinal channels (12) respectively form openings (13) at the edges of the mirror body (1); A sealing plunger (2), wherein a plurality of the sealing plungers (2) are embedded in the openings (13), wherein at least two of the openings (13) are retained as water inlets (41) and water outlets (42); A blocking plunger (3), wherein a plurality of the blocking plungers (3) are respectively embedded in the transverse channel (11) and the longitudinal channel (12), so as to form a continuous water-cooling channel (43) between the water inlet (41) and the water outlet (42).

2. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The main body of the sealing plunger (2) is a cylinder; One end of the sealing plunger (2) is provided with a first flow stabilization surface (21) and a first inclined surface (22) intersecting with each other.

3. The high-efficiency water-cooled EUV lithography mirror according to claim 2, characterized in that: The main body of the blocking plunger (3) is a cylinder; The blocking plunger (3) is provided with a second flow stabilizing surface (31) at both ends, and a second inclined surface (32) is also provided at both ends of the blocking plunger (3), wherein the second flow stabilizing surface (31) and the second inclined surface (32) located at the same end intersect.

4. The high-efficiency water-cooled EUV lithography mirror according to claim 3, characterized in that: The first inclined surfaces (22) of adjacent sealing plungers (2) are adapted to fit together, so that the two first flow stabilization surfaces (21) of adjacent sealing plungers (2) are connected to form a continuous flow stabilization surface; The second inclined surface (32) of the blocking plunger (3) is adapted to fit the first inclined surface (22) of the sealing plunger (2), so that the second flow stabilizing surface (31) of the blocking plunger (3) and the first flow stabilizing surface (21) of the sealing plunger (2) are connected to form a continuous flow stabilizing surface.

5. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The mirror body (1) is also provided with at least two supporting ears (14); The water inlet (41) and the water outlet (42) are respectively opened on the support lug (14).

6. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The cross-sections of the transverse channel (11) and the longitudinal channel (12) along the radial direction are circular; The centers of the transverse hole (11) and the longitudinal hole (12) along the axial direction are located in the neutral plane of the mirror body (1).

7. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The transverse channel (11) and the longitudinal channel (12) are formed by drilling.

8. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The sealing plunger (2) is glued to the transverse channel (11) and the longitudinal channel (12); The blocking plunger (3) is glued to the transverse channel (11) and the longitudinal channel (12).

9. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The mirror body (1) is made of glass-ceramics; The linear expansion coefficient of the mirror body (1) is ≤1×10 -6 / K.

10. The high-efficiency water-cooled EUV lithography mirror according to claim 1, characterized in that: The sealing plunger (2) and the blocking plunger (3) are made of the same material.

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