Substrate fixing device and method for manufacturing the same
The electrostatic chuck with recesses and protrusions stabilizes the adhesive layer thickness, addressing temperature variations and improving etching consistency in semiconductor manufacturing.
Patent Information
- Application Number
- JP2022133942
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-08-25
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2042-08-25
AI Technical Summary
Variations in heat density on the substrate mounting surface of the electrostatic chuck cause temperature variations on the substrate, leading to inconsistent etching rates in plasma etching devices, which reduces the yield of semiconductor devices.
An electrostatic chuck with a base plate and adhesive layer, featuring recesses on the adhesive surface with electronic components and a resin layer that includes a protruding portion to ensure uniform adhesive thickness and temperature control, using protrusions to stabilize the base plate and enhance temperature uniformity.
The configuration improves temperature uniformity on the substrate mounting surface, stabilizing the adhesive layer thickness and reducing temperature variations, thereby enhancing the consistency of etching processes.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a substrate holding device and a method for manufacturing the substrate holding device. [Background technology]
[0002] Conventionally, film deposition apparatuses and plasma etching apparatuses used in manufacturing semiconductor devices have stages for precisely holding substrates such as silicon wafers in vacuum processing chambers. As such a stage, for example, a substrate fixing device has been proposed that attracts and holds the substrate using an electrostatic chuck mounted on a base plate (see, for example, Patent Document 1).
[0003] The substrate fixing device includes a metal base plate, an electrostatic chuck mounted on the base plate, and an adhesive layer that bonds the base plate and the electrostatic chuck. The electrostatic chuck incorporates an electrode for attracting the substrate and a heating element for controlling the temperature of the substrate. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Japanese Patent Publication No. 2020-88304 Summary of the Invention [Problem to be solved by the invention]
[0005] However, in the above-described substrate fixing device, variations in heat density may occur on the substrate mounting surface of the electrostatic chuck that attracts the substrate. Such variations in heat density cause variations in temperature on the substrate. For example, in a plasma etching device, variations in substrate temperature cause variations in the etching rate, which can reduce the yield of semiconductor devices. Therefore, there is a need to improve the temperature uniformity on the substrate mounting surface of the electrostatic chuck. [Means for solving the problem]
[0006] According to one aspect of the present invention, there is provided an electrostatic chuck having a base plate with a first adhesive surface, a substrate mounting surface on which a substrate is mounted, and a second adhesive surface provided on the opposite side of the substrate mounting surface, the electrostatic chuck attracting and holding the substrate, and an adhesive layer bonding the first adhesive surface of the base plate and the second adhesive surface of the electrostatic chuck, wherein the electrostatic chuck has a recess provided on the second adhesive surface, an electronic component accommodated in the recess, a filling portion that fills the recess, and a resin layer having a protruding portion that protrudes from the recess and whose tip contacts the first adhesive surface, and the protruding portion is formed integrally and continuously with the filling portion. [Effects of the Invention]
[0007] According to one aspect of the present invention, it is possible to achieve an effect of improving the temperature uniformity on the substrate mounting surface. [Brief explanation of the drawings]
[0008] [Figure 1] 1 is a schematic cross-sectional view showing a substrate fixing device according to an embodiment of the present invention; [Figure 2] 1 is a schematic cross-sectional view showing a part of a substrate fixing device according to an embodiment. [Figure 3] FIG. 2 is a schematic plan view showing a part of the substrate fixing device of the embodiment. [Figure 4] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 5] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 6] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 7] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 8] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 9] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 10] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 11] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 12] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. [Figure 13] 5A to 5C are schematic cross-sectional views showing a method for manufacturing a substrate fixing device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0009] An embodiment will be described below with reference to the accompanying drawings. For convenience, the accompanying drawings may show characteristic portions enlarged to make the features easier to understand, and the dimensional ratios of each component may differ from one drawing to another. Also, in the cross-sectional views, the hatching of some components is shown with a matte finish, and the hatching of some components is omitted, in order to make the cross-sectional structure of each component easier to understand.
[0010] (Overall configuration of the substrate fixing device 10) As shown in Fig. 1, the substrate fixing device 10 has a base plate 20, an electrostatic chuck 30, and an adhesive layer 50. The base plate 20 is a base member for mounting the electrostatic chuck 30. The electrostatic chuck 30 is a part that attracts and holds a substrate W, which is an object to be attracted. The electrostatic chuck 30 is, for example, a temperature adjustment device that adjusts the temperature of the substrate W. The substrate W is, for example, a silicon wafer.
[0011] (Configuration of base plate 20) The base plate 20 is formed, for example, in the shape of a circular plate. The planar shape of the base plate 20 may be, for example, circular. The diameter of the base plate 20 may be, for example, about 200 mm to 300 mm. The thickness of the base plate 20 may be, for example, about 20 mm to 50 mm.
[0012] The base plate 20 can be made of, for example, a metal material such as aluminum or cemented carbide, or a composite material of such a metal material and a ceramic material. The base plate 20 can also be used, for example, as an electrode for controlling plasma. For example, by supplying a predetermined high-frequency power to the base plate 20, the energy for causing ions in the generated plasma state to collide with the substrate W attracted to the electrostatic chuck 30 can be controlled, thereby enabling an effective etching process.
[0013] The base plate 20 has a first adhesive surface 20A (here, the upper surface). The first adhesive surface 20A is the surface that is bonded to the adhesive layer 50. The first adhesive surface 20A faces the electrostatic chuck 30. Here, in this specification, "facing" includes both a case where a member separate from the two parts is interposed between the two parts and a case where nothing is interposed between the two parts.
[0014] A cooling path 21, for example, is provided inside the base plate 20. The cooling path 21 has an inlet 22 provided at one end and an outlet 23 provided at the other end. The cooling path 21 is connected to, for example, a cooling medium control device (not shown) provided outside the substrate fixing device 10. The cooling medium control device introduces a cooling medium from the inlet 22 into the cooling path 21 and discharges the cooling medium from the outlet 23. The cooling medium is circulated through the cooling path 21 to cool the base plate 20, thereby cooling the substrate W attracted to the electrostatic chuck 30. Note that, for example, water or Galden can be used as the cooling medium. In addition to the cooling path 21, the base plate 20 may be provided with a gas path or the like for introducing an inert gas to cool the substrate W attracted to the electrostatic chuck 30.
[0015] (Configuration of electrostatic chuck 30) The electrostatic chuck 30 is formed, for example, in the shape of a circular plate. The planar shape of the electrostatic chuck 30 may be, for example, circular. The diameter of the electrostatic chuck 30 may be, for example, equal to the diameter of the base plate 20, or may be larger than the diameter of the base plate 20. The diameter of the electrostatic chuck 30 in this embodiment is equal to the diameter of the base plate 20. The diameter of the electrostatic chuck 30 may be, for example, approximately 200 mm to 300 mm. The thickness of the electrostatic chuck 30 may be, for example, approximately 1 mm to 10 mm.
[0016] The electrostatic chuck 30 includes, for example, a substrate body (base) 31, an electrostatic electrode 32 and a heating element 33 built into the substrate body 31, an electronic component 34 built into the substrate body 31, and a resin layer 40. The electrostatic chuck 30 is, for example, a Johnsen-Rahbek type electrostatic chuck. However, the electrostatic chuck 30 may also be a Coulomb force type electrostatic chuck.
[0017] The substrate body 31 has a substrate mounting surface 31A (here, the upper surface) on which the substrate W is placed, and a second adhesive surface 31B (here, the lower surface) provided on the opposite side to the substrate mounting surface 31A. The substrate mounting surface 31A and the second adhesive surface 31B are provided on opposite sides to each other in the thickness direction (the up-down direction in the figure) of the substrate body 31. For example, the substrate mounting surface 31A and the second adhesive surface 31B are formed parallel to each other.
[0018] The substrate body 31 may be made of, for example, an insulating material. For example, the substrate body 31 may be made of ceramics such as alumina, aluminum nitride, or silicon nitride, or organic materials such as silicone resin or polyimide resin. In this embodiment, ceramics such as alumina or aluminum nitride are used as the material for the substrate body 31 because of their ease of availability, ease of processing, and relatively high resistance to plasma and the like. Aluminum nitride is particularly preferred for the substrate body 31 because it has a high thermal conductivity of approximately 15 W / mK to 250 W / mK, thereby reducing the temperature difference within the surface of the substrate W attracted to the electrostatic chuck 30.
[0019] A plurality of recesses 35 are provided on the second adhesive surface 31B of the substrate body 31. Each recess 35 is formed so as to recess from the second adhesive surface 31B toward the substrate mounting surface 31A. The depth of each recess 35 may be, for example, approximately 800 μm to 1000 μm. The planar shape of each recess 35 may be any shape and any size. The planar shape of each recess 35 may be, for example, a circular shape or an elliptical shape.
[0020] The electrostatic electrode 32 is an electrode for attracting the substrate W. The electrostatic electrode 32 is an electrode formed in a thin film. The electrostatic electrode 32 is built into the substrate body 31. For example, the electrostatic electrode 32 is built into a portion of the substrate body 31 located near the substrate mounting surface 31A in the thickness direction. The electrostatic electrode 32 is disposed, for example, on a plane parallel to the substrate mounting surface 31A. The electrostatic electrode 32 is electrically connected to an attraction power supply (not shown) provided outside the substrate fixing device 10. When a predetermined voltage is applied from the attraction power supply, the electrostatic electrode 32 generates an electrostatic attraction force between the electrostatic electrode 32 and the substrate W placed on the substrate mounting surface 31A. This allows the substrate W to be attracted and held on the substrate mounting surface 31A. The attraction and holding force of the electrostatic chuck 30 becomes stronger as the voltage applied to the electrostatic electrode 32 increases. The electrostatic electrode 32 may be monopolar or bipolar. For example, tungsten (W) or molybdenum (Mo) can be used as the material of the electrostatic electrode 32. Although each drawing shows one electrostatic electrode 32, in reality it includes multiple electrodes arranged on the same plane.
[0021] The plurality of heating elements 33 are for heating the substrate W. The plurality of heating elements 33 are built into the substrate main body 31. For example, the plurality of heating elements 33 are built into the substrate main body 31 between the electrostatic electrode 32 and the second adhesive surface 31B in the thickness direction of the substrate main body 31. The plurality of heating elements 33 are arranged, for example, on a plane parallel to the substrate mounting surface 31A. Each heating element 33 is electrically insulated from the electrostatic electrode 32. For example, copper (Cu), tungsten, nickel (Ni), constantan (an alloy of Cu / Ni / Mn / Fe), etc. can be used as the material of the heating elements 33. The thickness of the heating elements 33 can be, for example, about 20 μm to 100 μm. The plurality of heating elements 33 can be arranged, for example, in a concentric circular pattern.
[0022] The plurality of heating elements 33 are electrically connected to a heating power supply (not shown) provided outside the substrate fixing device 10. The plurality of heating elements 33 generate heat in response to a voltage applied from the heating power supply. The plurality of heating elements 33 heat the substrate mounting surface 31A of the substrate body 31 to a predetermined temperature. The heating elements 33 can heat the temperature of the substrate mounting surface 31A to, for example, about 250°C to 300°C.
[0023] The electronic component 34 is accommodated in the recess 35. The electronic component 34 is provided on the bottom surface of the recess 35. The electronic component 34 is electrically connected to, for example, the electrostatic electrode 32 or the heating element 33. The electronic component 34 is used, for example, for temperature control of the substrate mounting surface 31A. The electronic component 34 may be, for example, a diode, a capacitor, a thermistor, or the like.
[0024] (Configuration of resin layer 40) The resin layer 40 is formed, for example, so as to seal the electronic components 34 housed in each recess 35. The resin layer 40 can be made of a material such as silicone resin or epoxy resin. The resin layer 40 can also be made of a ceramic material such as alumina or aluminum nitride.
[0025] 2, each resin layer 40 has a filling portion 41 that fills the recess 35, and a protruding portion 42 that protrudes from the recess 35 and has a tip that contacts the first adhesive surface 20A of the base plate 20. In each resin layer 40, the filling portion 41 and the protruding portion 42 are formed continuously and integrally. Each resin layer 40 is formed, for example, from a single layer.
[0026] The filling portion 41 is formed to cover the entire electronic component 34. The filling portion 41 has, for example, a function to protect the electronic component 34 housed in the recess 35 and a function to fix the electronic component 34 in the recess 35. The filling portion 41 is formed, for example, to cover the entire side surface of the electronic component 34. The filling portion 41 is formed to cover the entire bottom surface of the electronic component 34. The filling portion 41 is formed, for example, to cover the entire surface of the recess 35 exposed from the electronic component 34. The filling portion 41 is formed, for example, to cover the entire bottom surface of the recess 35 exposed from the electronic component 34. The filling portion 41 is formed, for example, to cover the entire inner surface of the recess 35. Although not shown in the figure, the electronic component 34 has an electrode provided on, for example, the top surface.
[0027] The protrusion 42 protrudes further from the second adhesive surface 31B toward the first adhesive surface 20A of the base plate 20. The protrusion 42 is formed in a columnar shape protruding downward from the second adhesive surface 31B. The protrusion 42 extends from the second adhesive surface 31B to the first adhesive surface 20A of the base plate 20. The tip of the protrusion 42 contacts the first adhesive surface 20A of the base plate 20. The protrusion 42 is formed, for example, larger than the planar shape of the filling portion 41. The planar shape of the protrusion 42 is formed, for example, slightly larger than the planar shape of the filling portion 41. The protrusion 42 is formed, for example, so as to extend outward from the filling portion 41. The protrusion 42 is formed so as to cover the second adhesive surface 31B located on the periphery of the recess 35. The planar shape of the protrusion 42 can be any shape and any size. The planar shape of the protrusion 42 can be formed, for example, to be the same shape as the planar shape of the recess 35. The planar shape of the protrusion 42 can be formed, for example, in a circular or elliptical shape.
[0028] The protrusion 42 has, for example, a side surface 42A and a tip surface 42B provided at the tip of the protrusion 42. The protrusion 42 is formed, for example, in a hemispherical or semi-elliptical shape as a whole. The side surface 42A of the protrusion 42 is formed, for example, in a curved surface that curves in an arc shape. The side surface 42A of the protrusion 42 is formed, for example, in a convex curved surface. The side surface 42A of the protrusion 42 is formed, for example, so as to curve closer to the planar center of the protrusion 42 as it moves from the second adhesive surface 31B toward the first adhesive surface 20A.
[0029] The tip surface 42B of the protrusion 42 is formed, for example, as a flat surface. The tip surface 42B of the protrusion 42 is formed, for example, so as to extend parallel to the second adhesive surface 31B. The tip surface 42B of the protrusion 42 is formed, for example, so as to extend parallel to the first adhesive surface 20A. The protrusion 42 is provided so that the entire tip surface 42B is in contact with the first adhesive surface 20A.
[0030] The tip surface 42B of the protrusion 42 is, for example, a smooth surface with few irregularities. The tip surface 42B of the protrusion 42 is, for example, a polished surface. The tip surface 42B of the protrusion 42 has, for example, a smaller surface roughness than the side surface 42A of the protrusion 42. The planar shape of the tip surface 42B can be formed, for example, in the same shape as the planar shape of the recess 35. The planar shape of the tip surface 42B can be formed, for example, in a circular or elliptical shape.
[0031] The thickness of the protrusion 42, i.e., the thickness from the second adhesive surface 31B to the tip surface 42B, is set according to the design value (target value) of the thickness of the adhesive layer 50. The thickness of the protrusion 42 is set to be equal to the design value of the thickness of the adhesive layer 50. The protrusion 42 functions as a convex structure for controlling the thickness of the adhesive layer 50 to a desired thickness. The protrusion 42 functions, for example, as a support for supporting the base plate 20 on the electrostatic chuck 30. The protrusion 42 functions, for example, as a spacer for maintaining the distance between the second adhesive surface 31B and the first adhesive surface 20A at a desired thickness. The thickness of the protrusion 42 can be, for example, approximately 50 μm to 2000 μm.
[0032] 1, the plurality of protrusions 42 are formed to have the same thickness. Therefore, each of the plurality of protrusions 42 is formed so that the tip surface 42B comes into contact with the first adhesive surface 20A of the base plate 20.
[0033] As shown in Fig. 3, the multiple protrusions 42 are provided spaced apart from one another in a plan view, for example. The multiple protrusions 42 are provided, for example, dispersed on the second adhesive surface 31B. The multiple protrusions 42 are provided, for example, at least at three points that are not on the same line in a plane perpendicular to the thickness direction of the substrate fixing device 10. The multiple protrusions 42 are provided, for example, dispersed in all directions on the second adhesive surface 31B. Note that Fig. 3 is a plan view of the substrate fixing device 10 seen from below, and the base plate 20 and adhesive layer 50 are drawn perspectively.
[0034] 1, the plurality of protrusions 42 are provided to support the base plate 20 on the electrostatic chuck 30, for example, so that the second adhesive surface 31B of the electrostatic chuck 30 is not inclined relative to the first adhesive surface 20A of the base plate 20. By providing such protrusions 42, the in-plane uniformity of the thickness of the adhesive layer 50 can be improved.
[0035] (Configuration of adhesive layer 50) The adhesive layer 50 bonds the electrostatic chuck 30 to the base plate 20. The adhesive layer 50, for example, conducts heat from the electrostatic chuck 30 to the base plate 20. That is, the adhesive layer 50 functions as an adhesive that bonds the base plate 20 and the electrostatic chuck 30 together, and also functions as a heat-conducting member. For example, a material with high thermal conductivity can be used as the material for the adhesive layer 50. For example, a silicone adhesive can be used as the material for the adhesive layer 50. The adhesive layer 50 may be formed of a single layer, or may have a laminated structure in which multiple adhesive layers are stacked. For example, by forming the adhesive layer 50 into a two-layer structure combining an adhesive with high thermal conductivity and an adhesive with low elasticity, stress caused by the difference in thermal expansion between the adhesive layer 50 and the aluminum base plate 20 can be reduced.
[0036] The thickness of the adhesive layer 50 is equal to the thickness of the protrusion 42. The thickness of the adhesive layer 50 can be, for example, about 50 μm to 2000 μm. The adhesive layer 50 is formed, for example, so as to fill the gap between the electrostatic chuck 30 and the base plate 20 defined by the protrusion 42. The adhesive layer 50 is formed, for example, so as to cover the entire side surface 42A of the protrusion 42.
[0037] (Method of manufacturing the substrate fixing device 10) Next, a method for manufacturing the substrate fixing device 10 will be described. 4, green sheets 61, 62, 63, and 64 made of a ceramic material and an organic material are prepared. Each of the green sheets 61, 62, 63, and 64 is, for example, a sheet-like material made by mixing alumina with a binder, a solvent, etc. The planar size of each of the green sheets 61, 62, 63, and 64 corresponds to the planar size of the electrostatic chuck 30 shown in FIG.
[0038] The green sheet 61 will be fired in a process described later to become the substrate main body 31 in the portion on which the substrate W shown in FIG. 1 is mounted. The green sheet 62 will be fired in a process described later to form the electrostatic electrode 32 shown in FIG. 1 and to become the substrate main body 31 in the portion between the electrostatic electrode 32 and the heating element 33. The green sheet 63 will be fired in a process described later to form the heating element 33 shown in FIG. 1 and to become the substrate main body 31 in the portion between the heating element 33 and the recess 35. The green sheet 64 will be fired in a process described later to become the substrate main body 31 in the portion to be bonded to the adhesive layer 50. The green sheet 64 has a through hole 64X penetrating the green sheet 64 in the thickness direction. The through hole 64X is provided at a position corresponding to the recess 35 shown in FIG. 1. The planar size of the through hole 64X is set according to the planar size of the recess 35 shown in FIG. 1. The through hole 64X is formed, for example, by laser processing or mechanical processing.
[0039] 5, a wiring pattern 71 is formed on the upper surface of the green sheet 62 using a conductive paste (e.g., tungsten paste) by, for example, a printing method (screen printing). This wiring pattern 71 will become the electrostatic electrode 32 shown in FIG. 1 when fired in a step described later. The conductive paste may contain metal particles such as molybdenum or conductive ceramic particles, a binder, and a solvent. The wiring pattern 71 may also be formed on the lower surface of the green sheet 61.
[0040] 5, a conductive pattern 72 is formed on the upper surface of the green sheet 63 using a conductive paste (e.g., tungsten paste) by, for example, a printing method (screen printing). This conductive pattern 72 will become the heating element 33 shown in FIG. 1 when fired in a step described later. The conductive paste may contain metal particles such as molybdenum or conductive ceramic particles, a binder, and a solvent. The conductive pattern 72 may also be formed on the lower surface of the green sheet 62.
[0041] 6, the green sheet 63 with the side on which the conductor pattern 72 is formed facing up, the green sheet 62 with the side on which the wiring pattern 71 is formed facing up, and the green sheet 61 are laminated in this order on the green sheet 64. The green sheets 61, 62, 63, and 64 are bonded to one another, for example, by applying heat and pressure. By this process, the upper opening of the through-hole 64X of the green sheet 64 is blocked by the green sheet 63.
[0042] Next, in the step shown in Fig. 7, the structure shown in Fig. 6 is fired. As a result, the green sheets 61, 62, 63, and 64 shown in Fig. 6 are sintered to obtain the substrate main body 31. The firing temperature is, for example, 1500°C to 1600°C. This substrate main body 31 incorporates the electrostatic electrode 32 obtained by sintering the wiring pattern 71 shown in Fig. 6, and also incorporates the heating element 33 obtained by sintering the conductor pattern 72 shown in Fig. 6.
[0043] Next, both the top and bottom surfaces of the substrate body 31 are polished. As a result, the top surface of the substrate body 31 is formed as the substrate mounting surface 31A, and the bottom surface of the substrate body 31 is formed as the second adhesive surface 31B. After polishing, the substrate body 31 has a plurality of recesses 35 on the second adhesive surface 31B.
[0044] Next, the electronic component 34 is mounted on the bottom surface of the recess 35. For example, the electrodes of the electronic component 34 are joined to electrode pads (not shown) exposed on the bottom surface of the recess 35. The electrode pads exposed on the bottom surface of the recess 35 are electrically connected to the electrostatic electrode 32 or the heating element 33, for example.
[0045] Next, in the step shown in FIG. 8, a resin layer 40 is formed to fill the recess 35. The resin layer 40 is formed to have a filling portion 41 that fills the recess 35 and a protruding portion 42 that protrudes from the recess 35. At this time, the protruding portion 42 is formed, for example, in a hemispherical or semi-elliptical shape. In this step, the tip of the protruding portion 42 is formed into a curved surface that is curved in an arc. The resin layer 40 can be formed, for example, by applying a liquid insulating resin into the recess 35 by potting and then curing the insulating resin by heating. Note that the structure shown in FIG. 8 is depicted upside down compared to FIG. 7.
[0046] Next, in the step shown in FIG. 9, the tip (upper end in the drawing) of the protrusion 42 is polished until the thickness of the protrusion 42 reaches a desired thickness. For example, the tip of the protrusion 42 is polished until the thickness of the protrusion 42 reaches the design value of the thickness of the adhesive layer 50 shown in FIG. 1. This allows the thicknesses of the multiple protrusions 42 to be equal to each other. For example, even if the thicknesses of the multiple protrusions 42 vary in the step shown in FIG. 8, the polishing in this step can make the thicknesses of the multiple protrusions 42 uniform. Furthermore, the polishing in this step forms a planar tip surface 42B at the tip of the protrusion 42, which will serve as the polished surface. Note that the polishing of the protrusion 42 can be performed by, for example, mechanical polishing or chemical mechanical polishing (CMP), etc.
[0047] 10, the electrostatic chuck 30 can be manufactured by the above manufacturing steps. Note that in FIG. 10, the electrostatic chuck 30 is depicted upside down compared to FIG. In the step shown in FIG. 10, a base plate 20 in which the cooling passages 21 and the like are formed in advance is prepared separately from the electrostatic chuck 30.
[0048] 11 , an adhesive layer 50 is formed in a semi-cured state (B-stage) on the first adhesive surface 20A of the base plate 20. Next, the electrostatic chuck 30 is placed on the adhesive layer 50 so that the second adhesive surface 31B of the electrostatic chuck 30 faces the adhesive layer 50. This step causes the protrusions 42 of the resin layer 40 to bite into the semi-cured adhesive layer 50. For example, in this step, the thickness of the adhesive layer 50 is set to be thicker than the thickness of the protrusions 42, so that the tip surfaces 42B of the protrusions 42 do not contact the first adhesive surface 20A of the base plate 20.
[0049] Next, in the step shown in FIG. 12 , the structure shown in FIG. 11 is placed on a surface plate 80. At this time, the structure shown in FIG. 11 is turned upside down, and the structure shown in FIG. 11 is placed on the surface plate 80 so that the substrate mounting surface 31A of the electrostatic chuck 30 faces the upper surface of the surface plate 80. Next, while applying a load to the base plate 20 (see the arrow in the figure), the adhesive layer 50 is heated to a curing temperature or higher using an oven or the like to be cured. That is, the electrostatic chuck 30 and the base plate 20 are pressed while being heated to cure the adhesive layer 50. When the tip surface 42B of the protrusion 42 contacts the first adhesive surface 20A of the base plate 20 due to the pressure applied in this step, the protrusion 42 functions as a spacer between the electrostatic chuck 30 and the base plate 20. This allows the distance between the first adhesive surface 20A of the base plate 20 and the second adhesive surface 31B of the electrostatic chuck 30 to be uniform in a plane perpendicular to the stacking direction of the electrostatic chuck 30 and the base plate 20. This makes it possible to obtain excellent in-plane uniformity in the thickness of the adhesive layer 50. That is, the adhesive layer 50 can be formed with a uniform thickness in a plane perpendicular to the stacking direction of the electrostatic chuck 30 and the base plate 20. This makes it possible to suppress temperature variations on the substrate mounting surface 31A of the electrostatic chuck 30, thereby obtaining excellent temperature uniformity.
[0050] By the above manufacturing process, the substrate fixing device 10 can be manufactured on the surface plate 80. 13, the substrate holding device 10 is removed from the surface plate 80 shown in Fig. 12 and turned upside down. In this way, the substrate holding device 10 of this embodiment can be manufactured.
[0051] Next, the effects of this embodiment will be described. (1) The substrate fixing device 10 includes a base plate 20 having a first adhesive surface 20A, a substrate mounting surface 31A on which a substrate W is mounted, and an electrostatic chuck 30 having a second adhesive surface 31B provided on the opposite side of the substrate mounting surface 31A, and configured to attract and hold the substrate W. The substrate fixing device 10 includes an adhesive layer 50 that bonds the first adhesive surface 20A of the base plate 20 to the second adhesive surface 31B of the electrostatic chuck 30. The electrostatic chuck 30 includes a recess 35 provided in the second adhesive surface 31B and an electronic component 34 accommodated in the recess 35. The electrostatic chuck 30 includes a resin layer 40 having a filling portion 41 that fills the recess 35 and a protruding portion 42 that protrudes from the recess 35 and has a tip that contacts the first adhesive surface 20A. The protruding portion 42 is formed integrally and continuously with the filling portion 41.
[0052] According to this configuration, the protrusions 42 of the resin layer 40 function as spacers between the electrostatic chuck 30 and the base plate 20. This allows excellent in-plane uniformity in the thickness of the adhesive layer 50 to be obtained. That is, the adhesive layer 50 can be formed with a uniform thickness in a plane perpendicular to the stacking direction of the electrostatic chuck 30 and the base plate 20. Therefore, it is possible to suppress temperature variations on the substrate mounting surface 31A of the electrostatic chuck 30, and improve the temperature uniformity on the substrate mounting surface 31A.
[0053] (2) After forming the resin layer 40 having the filling portion 41 that fills the recess 35 in which the electronic component 34 is housed and the protruding portion 42 that protrudes from the recess 35, the protruding portion 42 is polished so that the protruding portion 42 has a desired thickness. In a conventional substrate-fixing device, the tip surface of the protruding portion 42 is polished so that it is flush with the second adhesive surface 31B of the electrostatic chuck 30. In contrast, in the substrate-fixing device 10 of the present embodiment, by changing only the amount by which the protruding portion 42 is polished, the protruding portion 42 is intentionally left unpolished, and the protruding portion 42 functions as a convex structure that controls the thickness of the adhesive layer 50. Therefore, the manufacturing method for the substrate-fixing device 10 of the present embodiment can suitably prevent an increase in the number of manufacturing steps compared to the manufacturing method for the conventional substrate-fixing device.
[0054] (3) The tip of the protrusion 42 has a tip surface 42B formed into a flat surface. This configuration increases the contact area between the tip surface 42B of the protrusion 42 and the first adhesive surface 20A of the base plate 20. This allows the protrusion 42 to stably support the base plate 20.
[0055] (4) The protruding portion 42 is formed to have a larger planar shape than the filling portion 41. With this configuration, the protruding portion 42 can stably support the base plate 20 compared to when the planar shape of the protruding portion 42 is formed to be the same size as the planar shape of the filling portion 41.
[0056] (5) The side surface 42A of the protrusion 42 is formed into a curved surface that curves toward the center of the plane of the protrusion 42 as it moves from the second adhesive surface 31B toward the first adhesive surface 20A. This configuration allows the base end portion of the protrusion 42 on the second adhesive surface 31B side, that is, the portion that serves as a base when supporting the base plate 20, to have a large planar shape. This allows the protrusion 42 to stably support the base plate 20.
[0057] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.
[0058] In the above embodiment, one electronic component 34 is accommodated in one recess 35, but this is not limiting. For example, one recess 35 may accommodate multiple electronic components 34. In this case, the multiple electronic components 34 accommodated in one recess 35 may be electronic components of different types.
[0059] In the above embodiment, there is no particular limitation on the number of recesses 35. For example, the number of recesses 35 may be three, or may be five or more. The number of protrusions 42 in the above embodiment is not particularly limited. For example, the number of protrusions 42 may be three, or may be five or more. For example, it is not necessary to provide a protrusion 42 for each of the plurality of recesses 35. In other words, the plurality of resin layers 40 may include a resin layer 40 composed only of a filling portion 41.
[0060] The tip surface 42B of the protrusion 42 in the above embodiment is not limited to a flat surface, but may be, for example, a convex curved surface. The side surface 42A of the protrusion 42 in the above embodiment is not limited to a curved surface, but may be, for example, a flat surface.
[0061] In the resin layer 40 of the above embodiment, the planar shape of the protruding portion 42 is formed to be larger than the planar shape of the filling portion 41, but this is not limited to this. For example, the planar shape of the protruding portion 42 may be formed to be the same size as the planar shape of the filling portion 41. For example, the planar shape of the protruding portion 42 may be formed to be smaller than the planar shape of the filling portion 41. [Explanation of symbols]
[0062] W substrate 10 Board fixing device 20 base plate 20A 1st adhesive surface 21 Cooling path 30 Electrostatic Chuck 31 Board body 31A PCB mounting surface 31B 2nd adhesive surface 32 Electrostatic Electrode (Electrode) 33 Heating element 34 Electronic Components 35 recess 40 resin layer 41 Filling section 42 Protrusion 42A side 42B tip surface 50 Adhesive layer
Claims
1. a base plate having a first adhesive surface; an electrostatic chuck having a substrate mounting surface on which a substrate is mounted and a second adhesive surface provided on the opposite side to the substrate mounting surface, and adapted to attract and hold the substrate; an adhesive layer that bonds the first adhesive surface of the base plate and the second adhesive surface of the electrostatic chuck, The electrostatic chuck comprises: a recess provided on the second adhesive surface; an electronic component accommodated in the recess; a resin layer having a filling portion that fills the recess and a protruding portion that protrudes from the recess and has a tip that contacts the first adhesive surface, The protruding portion is formed integrally with the filling portion.
2. The substrate fixing device according to claim 1 , wherein the tip of the protrusion has a tip surface formed in a flat surface.
3. 3. The substrate holding device according to claim 2, wherein the tip surface is a polished surface.
4. The protruding portion is formed to have a larger planar shape than the filling portion, The substrate fixing device according to claim 1 , wherein the protrusion is formed so as to cover the second adhesive surface located on the periphery of the recess.
5. a side surface of the protrusion is formed into a curved surface that curves toward a plane center of the protrusion as it moves from the second adhesive surface toward the first adhesive surface, The substrate fixing device according to claim 1 , wherein the adhesive layer covers the entire side surface of the protrusion.
6. the electrostatic chuck includes an electrode for attracting the substrate and a heating element for heating the substrate; The substrate fixing device according to claim 1 , wherein the electronic component is electrically connected to the electrode or the heating element.
7. The substrate fixing device according to claim 1 , wherein the base plate has a cooling passage through which a cooling medium flows.
8. providing a base plate having a first adhesive surface; a step of preparing a substrate body having a substrate mounting surface on which a substrate is mounted and a second adhesive surface provided on the opposite side to the substrate mounting surface, the second adhesive surface having a recess formed therein; accommodating an electronic component in the recess; forming a resin layer having a filling portion that fills the recessed portion and a protruding portion that is formed integrally with the filling portion and protrudes from the recessed portion; disposing a semi-cured adhesive layer and the protrusion between the second adhesive surface of the electrostatic chuck having the substrate body, the electronic component, and the resin layer and the first adhesive surface of the base plate; pressing the electrostatic chuck and the base plate together while heating them to harden the adhesive layer in a state where the tip of the protrusion is in contact with the first adhesive surface; A method for manufacturing a substrate fixing device having the same.
9. After the step of forming the resin layer, 9. The method for manufacturing a substrate fixing device according to claim 8, further comprising the step of polishing the tip of the protrusion to form a flat tip surface at the tip of the protrusion.
Citation Information
Patent Citations
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