Wafer holder

Abstract

To provide a wafer holding table capable of cooling a wafer more efficiently.SOLUTION: A wafer holding table is a wafer holding table having a disk-shaped platform. The platform has a wafer mount surface and a refrigerant flow path provided inside the platform. The flow path includes a first flow path extending in a radial direction of the platform, an arc-shaped second flow path provided in an outer peripheral region of the platform, and a plurality of third flow paths which is arranged side by side so as to connect the first flow path and the second flow path. The first flow path has a first opening end provided on the outer surface of the platform, and a first closed end provided inside the platform. The second flow path has a second opening end provided on the outer surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a wafer holder. [Background technology]

[0002] Patent Document 1 discloses a substrate mounting table. The substrate mounting table corresponds to the wafer holding table in this disclosure. The substrate mounting table is used in an inspection device, such as a prober, that controls the temperature of a semiconductor wafer on which circuits are formed to a predetermined temperature and measures the electrical performance of each chip before cutting the wafer into individual chips. This measurement of electrical performance detects defective chips. During inspection, the wafer is heated by a heater to reproduce the chip mounting environment, or cooled by a heat exchanger. After heating, the wafer is quickly cooled by the heat exchanger.

[0003] The substrate mounting table disclosed in Patent Document 1 includes a chuck top supported by a cylindrical support on a disk-shaped base. An inlet and an outlet for a coolant are provided on the outer periphery of the chuck top. An outgoing coolant path connected to the inlet and a return coolant path connected to the outlet are provided inside the chuck top. The outgoing coolant path is a spiral flow path extending from the outer periphery to the inner periphery of the chuck top. The return coolant path is a spiral flow path extending from the inner periphery to the outer periphery of the chuck top. In such a substrate mounting table, a wafer mounted on the chuck top is cooled by circulating a coolant through the flow path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-212775 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for a wafer holder that can cool a wafer more efficiently.

[0006] In the substrate mounting table described in Patent Document 1, the contact area between the coolant and the chuck top is secured by circulating the coolant through a spiral flow path, and the wafer can be cooled. However, in consideration of shortening the inspection time, more efficient cooling of the wafer is desired. On the other hand, it is also desired that the substrate mounting table be easy to process and assemble.

[0007] An object of the present disclosure is to provide a wafer holder that can cool a wafer more efficiently. [Means for solving the problem]

[0008] A wafer holding stand of the present disclosure is a wafer holding stand including a disk-shaped mounting stand having a wafer mounting surface and a coolant flow path provided inside the mounting stand, the flow path having a first flow path extending radially of the mounting stand, an arc-shaped second flow path provided in an outer peripheral region of the mounting stand, and a plurality of third flow paths arranged in parallel to connect the first flow path and the second flow path, the first flow path having a first open end provided on an outer surface of the mounting stand and a first closed end provided inside the mounting stand, and the second flow path having a second open end provided on the outer surface. Effect of the Invention

[0009] The above-described wafer holder allows efficient cooling of the wafer. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic vertical sectional view of a wafer holder according to the first embodiment. [Figure 2A] 2A is a top view of a first member of the wafer holder of FIG. 1. FIG. [Figure 2B] 1. FIG. 2B is a bottom view of a second member of the wafer holder shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2A. [Figure 4]FIG. 4 is an assembly explanatory diagram of the mounting table shown in a cross section taken along line IV-IV of FIGS. 2A and 2B. [Diagram 5] FIG. 5 is a perspective view showing the arrangement of flow paths in a mounting stage of the wafer holder of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Description of the embodiments of the present disclosure] The embodiments of the present disclosure are listed and described below.

[0012] (1) A wafer holding stand according to one embodiment of the present disclosure is a wafer holding stand including a disk-shaped mounting table, the mounting table having a wafer mounting surface and a coolant flow path provided inside the mounting table, the flow path including a first flow path extending radially of the mounting table, an arc-shaped second flow path provided in an outer peripheral region of the mounting table, and a plurality of third flow paths arranged in parallel to connect the first flow path and the second flow path, the first flow path having a first open end provided on an outer surface of the mounting table and a first closed end provided inside the mounting table, and the second flow path having a second open end provided on the outer surface.

[0013] The wafer holder of the above embodiment includes three flow paths, the first flow path, the second flow path, and the third flow path, and therefore a sufficient contact area between the coolant and the mounting table can be ensured. With this contact area, the wafer on the mounting table can be efficiently cooled. The first flow path circulates the coolant in a radial direction between a first open end provided on the outer surface of the mounting table and a first closed end located inside the mounting table. The second flow path circulates the coolant in a circumferential direction in the outer peripheral region of the mounting table. The third flow path circulates the coolant through a plurality of flow paths arranged in parallel to connect the first flow path and the second flow path. By including the three flow paths, it is easy to configure the flow paths over the entire area of ​​the mounting table. In other words, the entire surface of the wafer placed on the mounting table can be uniformly cooled. In addition, it is also possible to cool the wafer in a very short time.

[0014] (2) In one embodiment of the wafer holder, the first opening end and the second opening end are provided on the outer surface at positions facing each other in the radial direction.

[0015] The first and second opening ends are provided at positions facing each other in the radial direction on the outer surface of the mounting table, which makes it easy to arrange the second flow path symmetrically with respect to the first flow path. In other words, the first flow path for introducing or discharging the coolant into or from the mounting table and the second flow path for introducing or discharging the coolant to the outside of the mounting table are provided symmetrically, which makes it easy to cool the mounting table uniformly without bias.

[0016] (3) In one embodiment of the wafer holder, the first opening end is an inlet for a coolant, and the second opening end is an outlet for the coolant.

[0017] The first opening end is an inlet for the coolant, and the second opening end is an outlet for the coolant, so that the coolant flows through the first flow path, the third flow path, and the second flow path in that order. In the mounting table, the coolant temperature is lower the further upstream. By introducing the coolant in the radial direction through the first flow path, a low-temperature coolant can be supplied to a region including the center of the mounting table. Next, the coolant is circulated from the first flow path to the multiple third flow paths toward the second flow path in the outer periphery region. Then, the coolant is discharged from the second flow path through the second opening end. By introducing a low-temperature coolant into a region including the center of the mounting table, which is likely to become relatively hot, and circulating a relatively high-temperature coolant in the outer periphery region, which is likely to be cooled originally, the mounting table can be efficiently cooled. In turn, the wafer can also be efficiently cooled.

[0018] (4) In one embodiment of the wafer holder, the first closed end is located distal from the first open end to a center of the holder.

[0019] According to the wafer holder of the above embodiment, the first closed end is located farther from the first open end than the center of the mounting table, so that the first flow path can have a length equal to or greater than the radius of the mounting table. In other words, the coolant can circulate over a sufficient range in the radial direction of the mounting table. This allows the mounting table, and therefore the wafer, to be efficiently cooled.

[0020] (5) In one embodiment of the wafer holder, the first flow path and the third flow path are disposed so as to intersect at right angles.

[0021] Since the first flow path and the third flow path are perpendicular to each other, the third flow path can be easily provided evenly over a wide area of ​​the mounting table. This makes it possible to efficiently cool the wafer. It is difficult for the third flow path to be connected only to the second flow path without being connected to the first flow path. This effect will be described in detail later.

[0022] (6) In one embodiment of the wafer holder, the first flow path has a width greater than a width of the third flow path.

[0023] The wafer holder of the above embodiment has a relatively wide first flow passage, which allows the coolant to flow quickly in the radial direction including the center of the holder. Also, the wafer holder has a relatively narrow third flow passage, which makes it easy to form a large number of third flow passages and increases the contact area between the coolant and the holder. The configuration of the first and third flow passages allows the wafer to be cooled efficiently.

[0024] (7) In one embodiment of the wafer holder, the third flow paths are disposed symmetrically with respect to the first flow path.

[0025] In the wafer holder of the above embodiment, the third flow paths are arranged symmetrically with respect to the first flow path, which makes it easier to cool the area between the first flow path and the second flow path evenly, thereby making it possible to more efficiently cool the wafer.

[0026] (8) In one embodiment of the wafer support stand, the support stand is a joint between a disk-shaped first member and a disk-shaped second member, the first member having a first groove forming the first flow path and a second groove forming the second flow path, the second member having a plurality of third grooves forming the third flow path, and the joint is configured such that the third groove overlaps both the first groove and the second groove.

[0027] In the above-described wafer holder, the first member and the second member are joined together to form a wafer holder that is easily configured to have a superior wafer cooling efficiency.

[0028] (9) In one embodiment of the wafer holder related to the above embodiment (8), the second member has a first main surface which is a supporting surface for the wafer and a second main surface opposite the first main surface, and the second main surface has the plurality of third grooves.

[0029] In the above-described wafer holder, the wafer mounting surface is provided on the first main surface, and the third flow path is provided on the second main surface. In other words, the third flow path is disposed in the second member, which is closer to the wafer mounting surface, of the first and second members, and thus the wafer can be cooled efficiently. Furthermore, by eliminating the heat transfer interface between the wafer mounting surface and the third flow path, the wafer can be cooled more efficiently. In addition, the protrusions that form the inner surface of the third groove act as supports, thereby ensuring the rigidity of the mounting table.

[0030] (10) In one embodiment of the wafer support table, the wafer support table is made of copper or a copper alloy.

[0031] The wafer holder of the above embodiment can efficiently cool the wafer since the mounting table is made of copper or a copper alloy, which has excellent thermal conductivity.

[0032] (11) In one embodiment of the wafer holder, the width of each of the third flow paths is not less than 0.1 mm and not more than 5.0 mm.

[0033] If the width of each of the third flow paths is 0.1 mm or more, the flow resistance of the coolant does not become too large. Furthermore, if the width of each of the third flow paths is 5.0 mm or less, it is easy to increase the number of third flow paths and to increase the contact area between the coolant and the mounting table. This increase in contact area allows the wafer to be cooled more efficiently. The width of each of the third flow paths is preferably 0.3 mm or more and 2.0 mm or less, and more preferably 0.3 mm or more and 1.3 mm or less. If the width is 0.3 mm or more, processing of the third flow paths is not excessively difficult. If the width is 2.0 mm or less, and even more preferably 1.3 mm or less, it is easy to increase the number of grooves.

[0034] (12) In one embodiment of the wafer holder, the parallel spacing of the third flow paths is equal to or greater than 0.1 mm and equal to or less than 5.0 mm.

[0035] If the parallel spacing of the third flow paths is 0.1 mm or more, the thickness of the protrusions provided between adjacent third flow paths will not be excessively thin. Therefore, when a probe is pressed against a wafer to inspect the wafer circuit, it is easy to ensure sufficient rigidity of the mounting table against the pressing. If the parallel spacing of the third flow paths is 5.0 mm or less, it is easy to ensure a sufficient number of third flow paths. In other words, it is easy to increase the contact area between the refrigerant and the mounting table, and the wafer can be cooled more efficiently. The parallel spacing of the third flow paths is preferably 0.3 mm or more and 2.0 mm or less, more preferably 0.3 mm or more and 1.3 mm or less.

[0036] [Details of the embodiment of the present disclosure] A wafer holder according to an embodiment of the present disclosure will be described with reference to the drawings. Here, the following description will be given using a wafer holder constituting a prober as an example. A prober is an inspection device that controls a wafer placed on a mounting table to a predetermined temperature and measures the electrical performance of each chip before cutting a semiconductor wafer on which circuits are formed into individual chips. The same reference numerals in the figures indicate the same objects. The sizes and positional relationships of the members shown in each drawing are expressed for the purpose of clarifying the description and do not necessarily represent the actual dimensional relationships. First, an overview of the wafer holder will be described, and then the configuration of the mounting table, which is one of the components of the wafer holder, will be described in detail.

[0037] [Embodiment 1] <Wafer holder> 1, the wafer holder 1 includes a mounting table 10, a temperature adjustment unit 30, a support member 40, a warpage prevention plate 20, and a base plate 50. The warpage prevention plate 20, the temperature adjustment unit 30, the support member 40, and the base plate 50 form a support structure for the mounting table 10. One of the features of the wafer holder 1 of this embodiment is that the mounting table 10 includes a first flow path 11, a second flow path 12, and a third flow path 13, each having a specific structure. First, the mounting table 10 will be described, and then the warpage prevention plate 20, the temperature adjustment unit 30, the support member 40, and the base plate 50 will be described.

[0038] <Placement table> As shown in FIG. 1, the mounting table 10 is a member through which a coolant for cooling the wafer flows. The mounting table 10 in this example also functions as a chuck top that adsorbs the mounted wafer. The overall shape of the mounting table 10 is a shape that matches the shape of the wafer, and is usually configured in a disk shape. In the following description, the center refers to the center of the outer edge of the mounting table 10 in a plan view, the first member 10A or the second member 10B described later. The radial direction refers to the radial direction of the mounting table 10 in a plan view, the first member 10A or the second member 10B described later. The circumferential direction refers to the circumferential direction of the mounting table 10 in a plan view, the first member 10A or the second member 10B described later. The size of the mounting table 10 is such that there is a small amount of space around the wafer when it is mounted on it. Examples of the size of the wafer include a diameter of 200 mm, a diameter of 300 mm, and a diameter of 450 mm.

[0039] The material of the mounting table 10 may be a metal, a nonmetal, or a composite of a metal and a nonmetal, which have excellent thermal conductivity. The higher the thermal conductivity of the material of the mounting table 10, the more preferable it is. Examples of metals include copper, copper alloys, silver, silver alloys, aluminum, and aluminum alloys. In particular, copper or copper alloys, which have excellent thermal conductivity, are preferable. Examples of nonmetals include silicon and ceramics. Examples of ceramics include aluminum nitride and silicon carbide. Examples of composites include a composite of silicon and silicon carbide, a composite of aluminum and silicon carbide, and a composite of aluminum, silicon, and silicon carbide. The material of the mounting table 10 in this example is oxygen-free copper. That is, both the first member 10A and the second member 10B described later are made of oxygen-free copper.

[0040] The thermal conductivity of the material constituting the mounting table 10 is preferably 100 W / m·K or more. This thermal conductivity is more preferably 200 W / m·K or more, 300 W / m·K or more, and particularly preferably 400 W / m·K or more. The thermal conductivity of aluminum is approximately 230 W / m·K, that of copper is approximately 400 W / m·K, and that of silver is approximately 420 W / m·K. The thermal conductivity of silicon carbide is approximately 200 W / m·K, and that of aluminum nitride is approximately 150 W / m·K.

[0041] The mounting table 10 is preferably subjected to a surface treatment. Examples of the surface treatment include plating. Specific examples of plating include Ni plating and Ni-P plating. Examples of plating methods include electrolytic plating and electroless plating. The surface treatment in this example is Ni-P plating by electroless plating. When copper containing oxygen-free copper is used for the mounting table 10, Ni plating or Ni-P plating is preferably performed. Since copper is easily diffused into silicon, which is a constituent material of the wafer, the diffusion can be suppressed by performing Ni plating or Ni-P plating. As a result, the reliability of the device obtained from the wafer can be ensured. The area where the surface treatment is performed preferably includes the wafer mounting surface 10s of the mounting table 10.

[0042] The mounting table 10 has a disk-shaped first member 10A and a disk-shaped second member 10B. The mounting table 10 is formed by joining the first member 10A and the second member 10B. The first member 10A has a coolant inlet 10i, a coolant outlet 10o, a first flow path 11, and a second flow path 12. The second member 10B has a wafer mounting surface 10s, a wafer suction mechanism, and a third flow path 13. In the following description, the longitudinal direction of the first flow path 11 may be referred to as the X direction, and among the directions perpendicular to the X direction, the upper side of Figures 2A and 2B may be referred to as the Y1 direction, and the lower side of Figures 2A and 2B may be referred to as the Y2 direction.

[0043] (First member) A first flow passage 11 and a second flow passage 12 are formed on the surface of the first member 10A facing the second member 10B, that is, on the upper surface of FIG. 1. The first flow passage 11 is a flow passage extending in the radial direction from the outer peripheral surface of the first member 10A, as shown in FIG. 2A. The "flow passage extending in the radial direction" may be a straight flow passage or a non-straight flow passage, such as a meandering wave-shaped flow passage. In other words, it is sufficient that the straight line connecting both ends of the first flow passage 11 is generally along the radial direction. The shape of the first flow passage 11 can be designed according to the characteristics of the refrigerant used, mainly the viscosity and the required flow rate. In terms of the low occurrence of pressure loss, the first flow passage 11 is preferably a straight flow passage. Such a first flow passage 11 is formed by processing a first groove 11r on the surface of the first member 10A facing the second member 10B. The processing of this first groove 11r can be easily performed by, for example, cutting.

[0044] One end of the first flow passage 11 is a first opening end 11s that opens to the outer surface of the first member 10A. The first opening end 11s can be provided at any suitable location on the outer surface of the first member 10A as long as it can be opened. In this example, the first opening end 11s is provided on the outer peripheral surface of the first member 10A. Unlike this example, the first opening end 11s may be provided on the lower surface of the first member 10A. The lower surface of the first member 10A refers to the surface of the first member 10A opposite to the second member 10B. For example, the first opening end 11s can be provided in the center of the lower surface of the first member 10A. This first opening end 11s corresponds to the inlet 10i for the refrigerant. The other end of the first flow passage 11 is a first closed end 11e that closes the tip of the first flow passage 11. This other end is provided on the outer peripheral surface of the first member 10A slightly closer to the center than the position facing the first opening end 11s across the center of the first member 10A. In other words, the first closed end 11e is located on the distal side of the center of the first member 10A from the first opening end 11s. The first closed end 11e is provided on the inner circumferential side of the second flow passage 12 described later. That is, the first closed end 11e and the second flow passage 12 are separated from each other. In other words, the other end of the first flow passage 11 does not communicate with the second flow passage 12. Since the first closed end 11e closes the tip of the first flow passage 11, the flow of the refrigerant introduced into the first flow passage 11 can be blocked by the first closed end 11e. As a result, the refrigerant in the first flow passage 11 can be smoothly guided to the second flow passage 12 through the third flow passage 13. As long as the first closed end 11e is separated from the second flow passage 12, it is preferable that the first closed end 11e is close to the second flow passage 12. This is because the refrigerant can be circulated over a wider range in the radial direction by providing the first flow passage 11 over almost the entire length in the radial direction. The first flow passage 11 in this example is a linear flow passage having a uniform width in the longitudinal direction. The width of first flow passage 11 does not have to be uniform in the longitudinal direction. For example, the cross-sectional area of ​​first flow passage 11 may be changed so that the width gradually increases or decreases from first open end 11s to first closed end 11e. In addition, a partially protruding convex portion may be provided midway along first flow passage 11 as a guide for the refrigerant to third flow passage 13.

[0045] The cross-sectional shape of the first flow passage 11 is not particularly limited. In this example, the cross-sectional shape of the first flow passage 11 is rectangular. The width of the first flow passage 11 is preferably larger than the width of a third flow passage 13 described later. With this configuration, the coolant can be circulated quickly in the radial direction including the center of the mounting table 10.

[0046] As shown in FIG. 2A, the second flow passage 12 is an arc-shaped flow passage provided in the outer peripheral region of the first member 10A. The "outer peripheral region" is a region between the outer edge of the first member 10A in plan view and a concentric circle having a diameter of 80% of the diameter of the first member 10A. The "arc-shaped flow passage" may be an arc-shaped flow passage along a circumference concentric with the outer edge of the first member 10A, or a curved flow passage having a path partially deviated from the circumference concentric with the outer edge of the first member 10A, such as a meandering wave-shaped flow passage. In other words, it is sufficient that the path of the central axis along the longitudinal direction of the second flow passage 12 approximately overlaps with the circumference concentric with the outer edge of the first member 10A. Such a second flow passage 12 is formed by processing an arc-shaped second groove 12r in the first member 10A. The processing of the second groove 12r can be easily performed by, for example, cutting processing.

[0047] The second flow passage 12 is preferably provided as close as possible to the outer peripheral surface of the first member 10A. The length of the second flow passage 12 is preferably provided in a range as long as possible in the circumferential direction of the outer peripheral region. This is to allow the coolant to spread over a wider range in the circumferential direction of the mounting table 10. The second flow passage 12 in this example is a C-shaped flow passage having a uniform width in the longitudinal direction. The first flow passage 11 passes through a region corresponding to a slit in this C-shaped flow passage. That is, in the vicinity of the first opening end 11s in FIG. 2A, one end of the second flow passage 12 is disposed in the Y1 direction of the first flow passage 11, and the other end of the second flow passage 12 is disposed in the Y2 direction of the first flow passage. The middle part of the second flow passage 12 is disposed in a region on the outer peripheral side of the first closed end 11e. The middle part of this second flow passage 12 is provided with a second opening end 12s that communicates with the outer peripheral surface of the first member 10A. That is, the first opening end 11s and the second opening end 12s are provided on the outer circumferential surface of the mounting table 10 at positions facing each other across the center of the mounting table 10. The second opening end 12s corresponds to the outlet 10o of the refrigerant. The second opening end 12s can be provided at any position in the longitudinal direction of the second flow passage 12. In this example, the second opening end 12s is provided at the center of the C-shaped second flow passage 12. Meanwhile, both ends of the C-shaped second flow passage are configured as second closed ends 12e whose ends are closed.

[0048] The cross-sectional shape of the second flow passage 12 is not particularly limited. In this example, the cross-sectional shape of the second flow passage 12 is rectangular. The width of the second flow passage 12 is preferably larger than the width of the third flow passage 13 described later in order to ensure a necessary cross-sectional area. This configuration makes it easy to quickly circulate the refrigerant along the circumferential direction. In addition, when the refrigerant flows from a plurality of third flow passages 13 to the second flow passage 12, the refrigerant in the third flow passage 13 is easily collected in the second flow passage 12. The width of the second flow passage 12 may be narrower than the width of the first flow passage 11 or may be the same. In addition, the width of the second flow passage 12 may not be uniform in the longitudinal direction. For example, the width may be gradually changed from both ends toward the second opening end 12s. The depth of the second flow passage 12 is not limited to be constant, and may be gradually changed from the second closed end 12e toward the second opening end 12s.

[0049] A pipe 14 is inserted into the first open end 11s and the second open end 12s. This pipe 14 is an end of a piping that constitutes a circulation path of the refrigerant. In this example, stainless steel is used as the material for the pipe 14. The piping is provided with a cooling means for the refrigerant and a pump for pressure-feeding the refrigerant, both of which are not shown.

[0050] (Second member) As shown in FIG. 1, the second member 10B is provided with a wafer suction mechanism on the first main surface 10t, which is the wafer mounting surface 10s. A specific example of the suction mechanism includes a groove provided on the wafer mounting surface 10s and an exhaust path 10c for exhausting from the groove. A specific example of the groove includes a plurality of annular grooves 10r provided on the wafer mounting surface 10s, as shown in FIG. 1. These annular grooves 10r are provided concentrically. An exhaust port 10e is formed on the bottom surface of each annular groove 10r. This exhaust port 10e extends in the thickness direction of the second member 10B and is connected to the exhaust path 10c. The exhaust path 10c is, for example, a linear flow path extending along the radial direction inside the second member 10B. One end of the exhaust path 10c is a closed end, and the other end is opened on the side surface of the second member 10B. An exhaust pipe (not shown) is connected to this opening, and the exhaust pipe is further connected to an exhaust pump (not shown). By driving the exhaust pump, the air is exhausted from the annular groove 10r through the exhaust path 10c and the exhaust pipe, and the wafer can be adsorbed onto the mounting surface 10s. Note that the mechanism for holding the wafer on the mounting surface 10s is not limited to the above-mentioned vacuum chuck, and may be an electrostatic chuck or a mechanical clamp.

[0051] A plurality of third flow paths 13 are provided on the second main surface 10b, which is the surface of the second member 10B opposite to the mounting surface 10s. The third flow paths 13 are flow paths that connect the above-mentioned first flow paths 11 and the second flow paths 12. As shown in FIG. 2B, the third flow paths 13 are flow paths that extend in a direction perpendicular to the X direction that is the direction along the first flow paths 11. In this example, the linear third flow paths 13 are arranged in parallel in the X direction along the first flow paths 11. Specifically, the third flow paths 13 located on the first opening end 11s side and the second opening end 12s side are the shortest, and the third flow paths 13 located in the middle between these two are the longest. These third flow paths 13 can be formed by processing third grooves 13r in the second main surface 10b. The processing of the third grooves 13r can be easily performed by, for example, cutting.

[0052] The direction in which the third flow passage 13 extends may be a direction intersecting with the first flow passage 11. However, it is preferable that the third flow passage 13 is disposed so as to be perpendicular to the first flow passage 11. For example, assume that the first flow passage 11 is linear over almost the entire length in the radial direction, and the second flow passage 12 is arc-shaped over almost the entire length in the circumferential direction, and a plurality of third flow passages 13 are provided so as to intersect the first flow passage 11 obliquely. The first flow passage 11 is provided at a location that is a circumferential break in the second flow passage 12. Also, the communication location between the second flow passage 12 and the third flow passage 13 is located closer to the first closed end 11e than the communication location between the first flow passage 11 and the third flow passage 13, relative to the first opening end 11s. In that case, the third flow passage 13 that is connected only to the second flow passage 12 may be generated between the first opening end 11s and the center of the mounting table 10. On the other hand, if the first flow passage 11 and the third flow passage 13 are perpendicular to each other, the second flow passage 12 can be provided in substantially the entire region between the first flow passage 11 and the third flow passage 13.

[0053] The third flow path 13 in this example is composed of a series of third grooves 13r extending in a direction perpendicular to the X direction. If the third groove 13r is a series of grooves, it is easy to process. As will be described later with reference to FIG. 4, when the first member 10A and the second member 10B are joined, the first flow path 11, the second flow path 12, and the third flow path 13 are arranged as shown in FIG. 5. The middle part of the third groove 13r and the first groove 11r constituting the first flow path 11 intersect with each other. At this intersection, the first flow path 11 and the third flow path 13 are communicated with each other. In addition, both ends of the third groove 13r also overlap with the second groove 12r constituting the second flow path 12. At this overlap, the third flow path 13 and the second flow path 12 are communicated with each other. Unlike this example, the third flow path 13 may be composed of a third groove 13r divided into two in the middle, rather than a series of third grooves 13r, as long as it communicates with the first flow path 11. For example, the third flow passage 13 may be divided into a third groove 13r extending in the Y1 direction and a third groove 13r extending in the Y2 direction across the central axis of the first flow passage 11.

[0054] The width of each of the third flow paths 13 may be 0.1 mm or more and 5.0 mm or less. If the width of each of the third flow paths 13 is 0.1 mm or more, the flow resistance of the refrigerant does not become too large. In addition, if the width of each of the third flow paths 13 is 5.0 mm or less, it is easy to increase the number of the third flow paths 13 and to increase the contact area between the refrigerant and the mounting table 10. This width is preferably 0.3 mm or more and 2.0 mm or less, and more preferably 0.3 mm or more and 1.2 mm or less. If this width is 0.3 mm or more, it is not difficult to process the third flow paths 13. The width of this third flow path 13 may be 0.5 mm or more and 1.0 mm or less. In this example, the width of each of the third flow paths 13 is uniform in the longitudinal direction. However, the width of each of the third flow paths 13 does not have to be uniform in the longitudinal direction. For example, the groove width of the third flow path 13 may be structured so as to gradually narrow toward the periphery in each of the central region of the mounting table 10, the peripheral region of the mounting table 10, and an intermediate region located between the central region and the peripheral region, or may be structured so as to gradually widen toward the periphery. Note that the depth of the third flow path 13 may be changed in order to appropriately design the cross-sectional area of ​​the third flow path 13 and obtain the desired performance.

[0055] The number of the third flow paths 13 is preferably large. This is because the contact area between the refrigerant and the second member 10B can be increased. However, if the number of the third flow paths 13 is large, the parallel interval of the third flow paths 13 becomes small. The parallel interval of the third flow paths 13 refers to the interval between adjacent third flow paths 13, that is, the width of the protrusions formed between adjacent third flow paths 13. The parallel interval of the third flow paths 13 can be 0.1 mm or more and 5.0 mm or less. If the parallel interval of the third flow paths 13 is 0.1 mm or more, the thickness of the protrusions provided between adjacent third flow paths 13 does not become excessively thin. Therefore, when the probe of the prober is pressed against the wafer to inspect the circuit of the wafer, it is easy to ensure sufficient rigidity of the mounting table 10 against the above pressing. If the parallel interval of the third flow paths 13 is 5.0 mm or less, it is easy to ensure a sufficient number of the third flow paths 13. The parallel spacing may be 0.3 mm or more and 2.0 mm or less, further 0.3 mm or more and 1.2 mm or less, and particularly 0.5 mm or more and 1.0 mm or less.

[0056] The width of the third flow paths 13 and the parallel interval of the third flow paths 13 may be the same or different. In this example, the width of the third flow paths 13 and the parallel interval of the third flow paths 13 are the same. When the width and the parallel interval are the same, the third flow paths 13 and the protrusions are arranged in a well-balanced manner.

[0057] A coolant flows through the first flow path 11, the second flow path 12, and the third flow path 13. In order to uniformly cool the mounting table 10, it is desirable that the first flow path 11, the second flow path 12, and the third flow path 13 are not arranged in a biased manner. For example, it is preferable to arrange the second flow path 12 and the third flow path 13 symmetrically with respect to the first flow path 11. The coolant flowing through such flow paths is not particularly limited as long as it is a material that does not substantially react with the material constituting the mounting table 10. For example, gas such as nitrogen or dry air, or liquid such as water, oil, ethylene glycol aqueous solution, or fluorine-based liquid can be used as the coolant. In this example, the coolant flows in the order of the first opening end 11s, the first flow path 11, the third flow path 13, the second flow path 12, and the second opening end 12s.

[0058] <How to assemble the mounting stand> Next, a description will be given of a method for assembling the mounting table 10. As shown in FIG. The above-mentioned first member 10A and second member 10B are prepared. A brazing material is placed on at least one of the surfaces of the first member 10A on which the first groove 11r and the second groove 12r are formed and the surface of the second member 10B on which the third groove 13r is formed. As the brazing material, for example, a sheet-like silver brazing material can be used. A specific example of the silver brazing material is BAg-8. BAg-8 has a composition containing 72 mass% silver (Ag) and 28 mass% copper (Cu). For example, BAg-8 having a thickness of 0.05 mm can be used. A pipe 14 is disposed at each of the first opening end 11s and the second opening end 12s. The first member 10A and the second member 10B are overlapped so that the first groove 11r of the first member 10A and the third groove 13r of the second member 10B are perpendicular to each other. In this state, the first member 10A and the second member 10B are heated while a load is applied to them. The first member 10A and the second member 10B are brazed together by this heating.

[0059] ≪Support structure≫ The above-described mounting table 10 is supported by a support structure to constitute a wafer holder 1. The support structure includes a base plate 50, a support member 40, and a temperature adjustment unit 30, and also includes a warp prevention plate 20 as necessary.

[0060] (Base plate) The base plate 50 is a member that serves as a base for supporting the mounting table 10, the support member 40, the temperature adjustment unit 30, and the warp prevention plate 20. The material of this base plate 50 may be any of aluminum nitride, silicon carbide, a composite of silicon and silicon carbide, a composite of aluminum and silicon carbide, and a composite of aluminum, silicon, and silicon carbide.

[0061] (Support member) The support member 40 is a member that supports the mounting table 10 on the base plate 50. When the warp prevention plate 20 is present, the support member 40 supports the warp prevention plate 20 on the base plate 50. The shape of the support member 40 can be columnar, cylindrical, or the like. The columnar or cylindrical support member 40 passes through a hole provided in the temperature adjustment unit 30 to support the warp prevention plate 20 or the mounting table 10. The outer diameter of the columnar or cylindrical support member 40 is sufficiently smaller than the outer diameter of the warp prevention plate 20 or the outer diameter of the mounting table 10. By using the columnar or cylindrical support member 40, the contact area between the support member 40 and the warp prevention plate 20 or the contact area between the support member 40 and the mounting table 10 can be reduced. This suppresses heat conduction to the base plate 50 via the support member 40, thereby maintaining the thermal uniformity of the mounting table 10. Furthermore, by using the columnar or cylindrical support member 40, a space can be formed between the temperature adjustment unit 30 and the base plate 50, which will be described below. This space contributes to heat insulation between the base plate 50 and the mounting table 10. The support member 40 in this example is a cylindrical body. It is preferable to provide a plurality of support members 40 so as to support the mounting table 10 or the warp prevention plate 20 in a well-balanced manner. The material of the support member 40 may be any of alumina, mullite alumina, mullite, cordierite, steatite, and silicon nitride.

[0062] (Temperature control unit) The temperature adjustment unit 30 is a unit for heating or cooling the wafer to a predetermined temperature. In this example, the temperature adjustment unit 30 is provided on the lower surface of the warp prevention plate 20. The temperature adjustment unit 30 includes a cooling section 31 and a heating section 32. A flow path for a coolant is configured in the cooling section 31. This coolant may be different from the coolant flowing through the flow path of the mounting table 10, or the same coolant may be used. A heater such as a resistance heating element is disposed in the heating section 32. In this example, the cooling section 31 is disposed on the lower surface of the warp prevention plate 20, and the heating section 32 is disposed on the lower surface of the cooling section 31. Conversely, the heating section 32 may be disposed on the lower surface of the warp prevention plate 20, and the cooling section 31 may be disposed on the lower surface of the heating section 32. In addition, the cooling section 31 may be disposed above the warp prevention plate 20, and the heating section 32 may be disposed below the warp prevention plate 20. The mounting table 10 is mainly used to efficiently cool the heated wafer. On the other hand, the cooling unit 31 is used to adjust the temperature of the wafer to a predetermined temperature by operating together with the heating unit 32, or to control the temperature of the wafer to below the freezing point without operating the heating unit 32.

[0063] (Warp prevention plate) The warp prevention plate 20 is a member for suppressing the occurrence of warping of the mounting table 10 due to heat during wafer inspection. The warp prevention plate 20 may be provided as necessary and is not an essential member. When the warp prevention plate 20 is not provided, the support member 40 supports the mounting table 10. Examples of materials for the warp prevention plate 20 include alumina, mullite alumina, mullite, cordierite, steatite, silicon nitride, silicon carbide, or composites of these ceramics and metals.

[0064] The above-described wafer holder 1 provides the following advantages. The wafer placement table 10 has the above-mentioned first flow path 11, second flow path 12, and third flow path 13, so that the wafer can be cooled efficiently. Since the second flow passage 12 and the third flow passage 13 are arranged symmetrically with respect to the first flow passage 11, the wafer can be cooled uniformly. By appropriately selecting the width of the third flow paths 13 and the parallel spacing of the third flow paths 13, it is possible to ensure a sufficient contact area between the refrigerant and the mounting table 10 while also ensuring sufficient rigidity of the mounting table 10. Since the wafer can be cooled efficiently, the wafer holder 1 is particularly effective when the device to be inspected is one with a high heat density. An example of a device with a high heat density is a CPU. It goes without saying that the wafer holder 1 is also effective for inspecting devices with a low heat density, such as memories.

[0065] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the scope of the claims. For example, the inlet 10i and the outlet 10o of the coolant may be interchanged. That is, the coolant may flow in the order of the second opening end 12s, the second flow path 12, the third flow path 13, the first flow path 11, and the first opening end 11s. In addition, the first member 10A and the second member 10B may be configured upside down. That is, the first member 10A may have the wafer mounting surface 10s, the first flow path 11, and the second flow path 12, and the second member 10B may have the third flow path 13. [Explanation of symbols]

[0066] 1 Wafer holder 10. Placement table 10A First member 10B Second member 10s Placement surface 10t First main surface 10r Annular groove 10e Exhaust port 10c Exhaust duct 10i entrance 10o exit 10b Second main surface 11 First flow path 11r First groove 11s First open end 11e First closed end 12 Second flow path 12r second groove 12s 2nd open end 12e Second closed end 13 Third flow path 13r third groove 14 Pipes 20 Anti-warping board 30 Temperature Control Unit 31 Cooling section 32 Heating section 40 Support member 50 Base plate

Claims

1. A wafer holder having a disk-shaped mounting table, the mounting table has a wafer mounting surface and a coolant flow path provided inside the mounting table, The flow path is A first flow path extending in a radial direction of the mounting table; an arc-shaped second flow path provided in an outer circumferential region of the mounting table; a plurality of third flow paths arranged in parallel so as to connect the first flow path and the second flow path; The first flow path is A first opening end provided on an outer surface of the mounting table; a first closed end provided inside the mounting table; The second flow passage has a second open end provided on the outer surface, the third flow paths are disposed at positions different from the first flow paths in a direction along a thickness of the mounting table, Each of the third flow paths intersects with the first flow path when the mounting table is viewed in a plan view. Wafer holder.

2. 2. The wafer holder according to claim 1, wherein the first opening end and the second opening end are provided at positions on the outer surface facing each other.

3. 3. The wafer holder according to claim 1, wherein the first opening end is an inlet for a coolant, and the second opening end is an outlet for the coolant.

4. 4. The wafer holder of claim 1, wherein the first closed end is located farther from the first open end than the center of the holder.

5. 5. The wafer holder according to claim 1, wherein the first flow path and the third flow path are disposed so as to intersect at right angles with each other.

6. 6. The wafer holder of claim 1, wherein a width of the first flow passage is greater than a width of the third flow passage.

7. 7. The wafer holder according to claim 1, wherein the third flow paths are disposed symmetrically with respect to the first flow path.

8. the mounting base is a joint body of a disk-shaped first member and a disk-shaped second member, The first member includes a first groove that constitutes the first flow path and a second groove that constitutes the second flow path, The second member includes a plurality of third grooves that constitute the third flow path, 8. The wafer holder according to claim 1, wherein the bonded body is configured such that the third groove overlaps both the first groove and the second groove.

9. The second member is a first main surface which is a surface on which the wafer is placed; a second main surface facing the first main surface, 9. The wafer holder according to claim 8, wherein the second main surface is provided with the plurality of third grooves.

10. 10. The wafer support table according to claim 1, wherein the support table is made of copper or a copper alloy.

11. 11. The wafer holder of claim 1, wherein each of the third flow paths has a width of 0.1 mm or more and 5.0 mm or less.

12. 12. The wafer holder according to claim 1, wherein the parallel spacing of the third flow paths is equal to or greater than 0.1 mm and equal to or less than 5.0 mm.

13. A wafer holder having a disk-shaped mounting table, the mounting table has a wafer mounting surface and a coolant flow path provided inside the mounting table, The flow path is A first flow path extending in a radial direction of the mounting table; an arc-shaped second flow path provided in an outer circumferential region of the mounting table; a plurality of third flow paths arranged in parallel so as to connect the first flow path and the second flow path; The first flow path is A first opening end provided on an outer surface of the mounting table; a first closed end provided inside the mounting table; The second flow passage has a second open end provided on the outer surface, The mounting base includes a joint body of a disk-shaped first member and a disk-shaped second member, The first member includes a first groove that constitutes the first flow path, The second member includes a plurality of third grooves that constitute the third flow path, The joint is configured such that the third groove overlaps the first groove. Wafer holder.

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