Heater and wafer heating device

Abstract

To provide a heater capable of easily uniformizing the temperature of the outermost periphery of a first surface of a substrate.SOLUTION: A heater heating a wafer is provided, comprising a circular substrate comprised of an insulating sheet, and a plurality of heat generating circuits provided inside the substrate, a first surface of the substrate is radially divided into a plurality of heating areas, each of the plurality of heating areas has an annular outer area located on the outermost periphery of the first surface, and at least one of the heat generating circuits is provided at a portion of the substrate corresponding to the outer area, and at least a part of the first terminal and second terminal of the heat generating circuit corresponding to the outer area is provided outside an overlap region of the wafer in the substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a heater and a wafer heating apparatus. [Background technology]

[0002] A heater unit for heating a wafer used in a coater / developer apparatus is disclosed in Patent Document 1. The heater unit for heating a wafer has a heat generating module.

[0003] The heat generating module includes an insulating sheet and a plurality of heat generating circuits disposed inside the insulating sheet, the surface of the insulating sheet being divided into a plurality of heating zones by the plurality of heat generating circuits.

[0004] The multiple heating zones include, in order from the center of the surface of the insulating sheet toward the outside in the radial direction, multiple central fan-shaped heating zones, multiple intermediate fan-shaped heating zones, and multiple peripheral fan-shaped heating zones. The multiple central fan-shaped heating zones are aligned in the circumferential direction at the center of the surface of the insulating sheet. The multiple intermediate fan-shaped heating zones are aligned in the circumferential direction on the outer periphery side of the multiple central fan-shaped heating zones. The multiple peripheral fan-shaped heating zones are aligned in the circumferential direction at the outermost periphery of the surface of the insulating sheet.

[0005] In the heat generating module, one heat generating circuit is provided for each heating zone in order to control the temperature of each heating zone independently. Also, in the heat generating module, one temperature sensor is provided for each heating zone in order to measure the temperature of each heat generating circuit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-71349 A Summary of the Invention [Problem to be solved by the invention]

[0007] An electrode that supplies power to the heating circuit is connected to each of the first and second terminals of each heating circuit. Typically, in any heating zone, the first terminal, the second terminal, and the temperature sensor are provided inside the overlapping area of ​​the wafer on the insulating sheet. The overlapping area is defined as follows: A cylindrical surface formed by the outer peripheral surface of the wafer that is arranged concentrically with the insulating sheet is extended in a direction perpendicular to the surface of the insulating sheet. At that time, the extended cylindrical surface is extended so as to intersect with the surface of the insulating sheet. The area on the surface of the insulating sheet that is surrounded by the extended cylindrical surface is defined as the overlapping area.

[0008] In each heating zone, the first terminal and the second terminal have a lower heat density than the portion of the heat generating circuit other than the first terminal and the second terminal. Also, the portion where the temperature sensor is provided cannot be provided with a heat generating circuit. Therefore, the portion where the first terminal, the second terminal, and the temperature sensor are provided is likely to become a localized cool spot.

[0009] The above-mentioned multiple central fan-shaped heating zones and multiple intermediate fan-shaped heating zones are located on the central side of the surface of the insulating sheet, and therefore heat is less likely to be dissipated than the peripheral fan-shaped heating zone. That is, the multiple peripheral fan-shaped heating zones are located on the outer periphery of the surface of the insulating sheet, and therefore heat is more likely to be dissipated than the multiple central fan-shaped heating zones and multiple intermediate fan-shaped heating zones. The peripheral fan-shaped heating zone is more likely to be affected by cool spots than the multiple central fan-shaped heating zones and multiple intermediate fan-shaped heating zones. The outer periphery side of the surface of the insulating sheet where the peripheral fan-shaped heating zone is located has a larger surface area than the central side of the surface of the insulating sheet, and therefore the temperature is more likely to decrease due to the effect of heat dissipation. The peripheral fan-shaped heating zone faces the chamber in which the wafer heating heater unit is mounted, and therefore the temperature is more likely to decrease due to the effect of heat dissipation. Therefore, the temperature distribution of the peripheral fan-shaped heating zone is likely to be non-uniform.

[0010] An object of the present disclosure is to provide a heater that can easily make the temperature of the outermost periphery on a first surface of a substrate uniform, and a wafer heating device including the heater. [Means for solving the problem]

[0011] The heater of the present disclosure is a heater for heating a wafer, and comprises a circular base material made of an insulating sheet and a plurality of heating circuits provided inside the base material, a first surface of the base material is radially divided into a plurality of heating areas, the plurality of heating areas have an annular outer area located at the outermost periphery of the first surface, at least one of the heating circuits is provided at a location on the base material corresponding to the outer area, and at least a portion of the first terminal and second terminal of the heating circuit corresponding to the outer area is provided outside the overlapping area of ​​the wafer on the base material.

[0012] The wafer heating apparatus of the present disclosure includes a holder having an upper surface on which a wafer is placed, and a heater for heating the holder, the heater being the heater of the present disclosure described above. Effect of the Invention

[0013] The heater of the present disclosure easily makes the temperature of the outermost periphery on the first surface of the substrate uniform.

[0014] The wafer heating apparatus of the present disclosure facilitates uniform temperature across the wafer. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view showing an outline of a wafer heating apparatus according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing an outline of a heater provided in the wafer heating apparatus according to the embodiment. [Diagram 3] FIG. 3 is an enlarged plan view of region A in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Description of the embodiments of the present disclosure First, the embodiments of the present disclosure will be listed and described.

[0017] (1) A heater according to one embodiment of the present disclosure is a heater for heating a wafer, comprising a circular base material made of an insulating sheet and a plurality of heating circuits provided inside the base material, a first surface of the base material is radially divided into a plurality of heating areas, the plurality of heating areas have an annular outer area located at the outermost periphery of the first surface, at least one of the heating circuits is provided in a location on the base material corresponding to the outer area, and at least a portion of a first terminal and a second terminal of the heating circuit corresponding to the outer area are provided outside an overlapping area of ​​the wafer on the base material.

[0018] In the outer area, the heater has at least a portion of the first terminal and the second terminal, which serve as cool spots, located outside the overlapping area of ​​the wafer on the substrate, making it easy to make the temperature of the outermost periphery on the first surface of the substrate uniform.

[0019] (2) In one embodiment of the heater, the outer area is circumferentially divided into a plurality of fan-shaped outer zones, one heating circuit is provided at a location on the substrate corresponding to each of the plurality of outer zones, and at least a portion of a first terminal and a second terminal of the heating circuit corresponding to each of the plurality of outer zones is provided outside the overlapping region.

[0020] The greater the number of outer zones, the greater the number of first terminals and second terminals that become cool spots. The greater the number of outer zones, the more difficult it becomes to make the temperature of the outermost periphery of the substrate uniform if the cool spots are provided inside the overlapping region.

[0021] In the heater, the number of first terminals and second terminals that become cool spots is large in the outer area. Nevertheless, in the heater, at least a part of the first terminals and second terminals are provided outside the overlapping area in each outer zone, so that it is easy to make the temperature of the outermost periphery on the first surface of the substrate uniform.

[0022] (3) In one embodiment of the heater of (2) above, all of the first terminals and the second terminals corresponding to each of the plurality of outer zones may be provided outside the overlapping region.

[0023] The heater described above tends to make the temperature of the outermost periphery on the first surface of the substrate more uniform.

[0024] (4) As one embodiment of the heater of (2) or (3) above, the heating circuit corresponding to each of the plurality of outer zones may have a circuit portion connecting the first terminal and the second terminal, and the circuit portion may have an inner circuit portion provided inside the overlapping region and an outer circuit portion provided outside the overlapping region.

[0025] The heater has an outer circuit portion in the heat generating circuit of each outer zone, and therefore the heater can heat the outer zone uniformly up to the outer periphery compared to a case where the circuit portion is composed of only an inner circuit portion. Therefore, the heater can make the temperature of the outermost periphery on the first surface of the substrate more uniform. The inner circuit portion and the outer circuit portion are preferably connected in series between the first terminal and the second terminal.

[0026] (5) As one embodiment of the heater, at least one hole is provided in a portion of the base material corresponding to the outer area, the hole being a hole for providing a temperature sensor, and at least a portion of the hole is provided outside the overlapping area of ​​the wafer in the base material.

[0027] Since at least a part of the hole that becomes the cool spot is provided on the outside of the overlapping region of the wafer in the base material, the heater can easily make the temperature of the outermost periphery on the first surface of the base material uniform.

[0028] (6) As one embodiment of the heater of (5) above, the outer area is circumferentially divided into a plurality of fan-shaped outer zones, one hole is provided in a location on the substrate corresponding to each of the plurality of outer zones, and at least a portion of the hole corresponding to each of the plurality of outer zones is provided outside the overlapping region.

[0029] The heater described above tends to make the temperature of the outermost periphery on the first surface of the substrate more uniform.

[0030] (7) In one embodiment of the heater of (6) above, all of the holes corresponding to each of the plurality of outer zones may be provided outside the overlapping region.

[0031] The heater described above tends to make the temperature of the outermost periphery on the first surface of the substrate more uniform.

[0032] (8) A wafer heating apparatus according to one embodiment of the present disclosure includes a holding stage having an upper surface on which a wafer is placed, and a heater for heating the holding stage, the heater being any one of the heaters described above in (1) to (7).

[0033] The wafer heating device, by including the heater, can easily make the temperature uniform on the outer periphery of the wafer, and therefore can easily make the temperature uniform over the entire wafer.

[0034] Details of the embodiments of the present disclosure DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will now be described in detail with reference to the accompanying drawings, in which like reference numerals refer to like objects.

[0035] <<Embodiment>> [Wafer Heating Device] A wafer heating apparatus 1 according to an embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram of a vertical section of the wafer heating apparatus 1. The vertical section refers to a section of the wafer heating apparatus 1 cut along a plane along the stacking direction of the holding table 2 and the heater 3 of the wafer heating apparatus 1. The thicknesses of the holding table 2, the heater 3, the support plate 6, the first cooling plate 71, and the second cooling plate 72 in FIG. 1 are shown diagrammatically and do not necessarily correspond to the actual thicknesses. The thicknesses refer to the lengths along the stacking direction. FIG. 2 is a plan view showing an outline of the heater 3. FIG. 2 is a view showing the first surface 41 of the base material 4 in the heater 3 as viewed from a direction perpendicular to the first surface 41. FIG. 3 is a plan view showing an enlarged view of the area A surrounded by a dashed circle shown in FIG. 2. In the following description, the first surface 41 side of the base material 4 may be expressed as "upper" and the opposite second surface 42 side as "lower".

[0036] As shown in Fig. 1, the wafer heating apparatus 1 of this embodiment includes a holding table 2 and a heater 3. The holding table 2 has an upper surface on which a wafer 100 is placed and a lower surface in contact with the heater 3. The heater 3 heats the holding table 2. One of the features of the wafer heating apparatus 1 of this embodiment is that the heater 3 has a specific structure. The wafer heating apparatus 1 of this embodiment further includes a support plate 6 and a cooling unit 7. Each component will be described in detail below.

[0037] [heater] The heater 3 heats the wafer 100 via the holding table 2. The wafer 100 is arranged concentrically with the holding table 2. The heater 3 in this embodiment is sandwiched between the holding table 2 and a support plate 6 from above and below. The heater 3 includes a base material 4 and a heating circuit 5.

[0038] (base material) The substrate 4 covers the heating circuit 5. The substrate 4 is made of an insulating sheet. The planar shape of the substrate 4 is circular, as shown in FIG. 2. The substrate 4 is arranged concentrically with the holding table 2. The outer diameter of the substrate 4 is larger than the outer diameter of the wafer 100, as shown in FIG. 1. The substrate 4 forms the outer shape of the heater 3. A first surface 41 of the substrate 4 is in contact with the holding table 2. A second surface 42 of the substrate 4 in this embodiment is in contact with the support plate 6.

[0039] The first surface 41 is virtually divided into a plurality of heating areas in the radial direction. Each heating area may be composed of a single heating zone, or may be divided into a plurality of heating zones in the circumferential direction. The number of heating areas and the number of heating zones in each heating area can be appropriately selected according to the required temperature distribution. The heating zone refers to a virtual section on the first surface 41 including a unit of the heat generating circuit 5 capable of independently controlling the temperature. The number of heating zones corresponds to the number of the heat generating circuits 5 capable of independently controlling the temperature. For example, when the number of heating zones in a certain heating area is two, the number of heat generating circuits 5 corresponding to the certain heating area is two, and one heat generating circuit 5 is provided at a location corresponding to each heating zone on the substrate 4. The first terminal 51 and the second terminal 52 of the heat generating circuit 5 shown in FIG. 3 are provided in each heating zone. In this embodiment, the electrode 95 shown in FIG. 1 is connected to the first terminal 51 and the second terminal 52.

[0040] 2, the first surface 41 has at least an inner area 46 and an outer area 48. The inner area 46 is a circular heating area located in a region including the center of the first surface 41. The outer area 48 is an annular heating area located on the outermost periphery of the first surface 41.

[0041] The outer peripheral edge of the outer area 48 in this embodiment is located on the outer peripheral edge of the first surface 41. The outer area 48 in this embodiment includes a region located inside the overlapping region 410 of the wafer 100 and a region located outside the overlapping region 410. That is, the outer peripheral edge of the overlapping region 410 is located between the inner peripheral edge and outer peripheral edge of the outer area 48.

[0042] The overlapping region 410 is defined as follows: A cylindrical surface formed by the outer peripheral surface of the wafer 100 arranged concentrically with the substrate 4 is extended in a direction perpendicular to the first surface 41. At that time, the extended cylindrical surface is extended so as to intersect with the first surface 41. The overlapping region 410 is an area of ​​the first surface 41 that is surrounded by the extended cylindrical surface.

[0043] Unlike this embodiment, the outer periphery of the outer area 48 may be located inside the outer periphery of the first surface 41. Furthermore, the outer periphery of the outer area 48 may coincide with the outer periphery of the overlapping region 410. In this case, the outer area 48 has a region located inside the overlapping region 410 of the wafer 100, but does not have a region located outside the overlapping region 410.

[0044] The first surface 41 may further include a middle area 47. The middle area 47 is an annular heating area located between the inner area 46 and the outer area 48. The number of middle areas 47 may be one or more.

[0045] The first surface 41 of this embodiment has an inner area 46, a middle area 47, and an outer area 48. The middle area 47 of this embodiment has a first middle area 471 and a second middle area 472. The inner area 46 of this embodiment is composed of one circular inner zone 461. The first middle area 471 of this embodiment is composed of three sector-shaped first middle zones 471a. The second middle area 472 of this embodiment is composed of three sector-shaped second middle zones 472a. The outer area 48 of this embodiment is composed of eight sector-shaped outer zones 481. Each outer zone 481 includes an area located inside the overlapping area 410 and an area located outside the overlapping area 410.

[0046] In this embodiment, one first hole 43 is provided at a location in the base material 4 corresponding to each heating zone. As shown in FIG. 1, the first hole 43 is a hole for providing a temperature sensor 90. That is, the number of first holes 43 corresponds to the number of temperature sensors 90. In this embodiment, the number of temperature sensors 90 corresponds to the number of heat generating circuits 5, that is, the number of heating zones. When a certain heating area is divided into a plurality of heating zones, one first hole 43 is provided at a location in the base material 4 corresponding to each heating zone. When a certain heating area is divided into a plurality of heating zones, unlike this embodiment, there may be a heating zone in which one first hole 43 is provided and a heating zone in which no first hole 43 is provided.

[0047] The temperature sensor 90 measures the temperature of the holding table 2. An example of the type of the temperature sensor 90 is a temperature sensing resistor or a thermocouple. A lead wire 91 is connected to the temperature sensor 90. The hole for providing the temperature sensor 90 includes a case where the temperature sensor 90 itself is disposed inside the first hole portion 43, and a case where the temperature sensor 90 is not disposed inside the first hole portion 43, but the lead wire 91 of the temperature sensor 90 is disposed inside the first hole portion 43.

[0048] The first hole 43 in this embodiment is a through hole. The through hole is provided along the up-down direction of the base material 4.

[0049] At least a portion of the first holes 43 corresponding to each outer zone 481 is provided outside the overlapping region 410 as shown in Fig. 2. In each outer zone 481, at least a portion of the first holes 43 serving as cool spots is provided outside the overlapping region 410, so that it is easy to make the temperature of the outermost periphery of the first surface 41 uniform. In order to make the temperature of the outermost periphery uniform, it is particularly preferable that all of the first holes 43 corresponding to each outer zone 481 are provided outside the overlapping region 410 as in this embodiment.

[0050] Examples of the material of the base material 4 include polyimide, silicon, epoxy, and phenol.

[0051] (heating circuit) The heat generating circuit 5 is a heat source for heating the wafer 100 shown in FIG. 1. The heat generating circuit 5 is provided inside the base material 4. At least one heat generating circuit 5 is provided at a location corresponding to each heating area in the base material 4. When the heating area is divided into a plurality of heating zones, one heat generating circuit 5 is provided at a location corresponding to each heating zone in the base material 4. Each heat generating circuit 5 can independently control the temperature. Each heat generating circuit 5 has one first terminal 51 and one second terminal 52. As shown in FIG. 3, each heat generating circuit 5 has a circuit portion 55 connecting the first terminal 51 and the second terminal 52. The layout of the pattern of the circuit portion 55 in each heat generating circuit 5 is not particularly limited and can be appropriately selected according to the heating temperature and the required temperature distribution. For example, a pattern in which a circular arc portion and a straight portion are combined is used as the pattern of the circuit portion 55.

[0052] At least a part of the first terminal 51 and the second terminal 52 of the heating circuit 5 corresponding to each outer zone 481 is provided outside the overlapping region 410 as shown in FIG. 2. Since at least a part of the first terminal 51 and the second terminal 52 in each outer zone 481 is provided outside the overlapping region 410, it is easy to make the temperature of the outermost periphery on the first surface 41 uniform. In order to make the temperature of the outermost periphery uniform, it is particularly preferable that all of the first terminals 51 and all of the second terminals 52 corresponding to each outer zone 481 are provided outside the overlapping region 410. The first terminal 51 and the second terminal 52 are connected to the electrode 95 shown in FIG. 1. The electrode 95 supplies power to the heating circuit 5. The electrode 95 is connected to a lead wire 96.

[0053] As shown in FIG. 3, the circuit portion 55 of the heat generating circuit 5 corresponding to each outer zone 481 preferably has an outer circuit portion 552 in addition to an inner circuit portion 551. The inner circuit portion 551 is a portion provided inside the overlapping region 410. The outer circuit portion 552 is a portion provided outside the overlapping region 410. The outer circuit portion 552 makes it easier to heat the temperature uniformly over the outer periphery of each outer zone 481 compared to when the circuit portion 55 is composed of only the inner circuit portion 551. Therefore, it is easier to make the temperature of the outer area 48 uniform. The first terminal 51 and the second terminal 52 are connected to both ends of the outer circuit portion 552. In this embodiment, both ends of the outer circuit portion 552 are located on the outermost periphery.

[0054] The shapes of the first terminal 51 and the second terminal 52 can be appropriately selected and may be, for example, a rectangular shape, a circular shape, a rectangular ring shape, or a ring shape. In this embodiment, the first terminal 51 and the second terminal 52 have the same rectangular shape. An electrode 95 is connected to the lower surface of the first terminal 51. Unlike this embodiment, the first terminal 51 and the lead wire 96 may be directly connected to each other without the electrode 95 being interposed therebetween.

[0055] 1, a second hole 44 is provided in the substrate 4 such that the bottom surface of the first terminal 51 is exposed from the substrate 4. An electrode 95 is connected to the bottom surface of the first terminal 51 within the upper end of the second hole 44. A portion of the lead wire 96 is also provided inside the second hole 44. The arrangement of the electrode 95 and the lead wire 96 is similar to that of the second terminal 52.

[0056] Unlike this embodiment, the electrode 95 may be entirely provided inside the substrate 4. In that case, a part of the lead wire 96 is also provided inside the substrate 4. Alternatively, a part of the electrode 95 may be provided inside the substrate 4, and the remaining part of the electrode 95 may be provided outside the substrate 4. In that case, the entire lead wire 96 is provided outside the substrate 4.

[0057] The material of the heating circuit 5 is not particularly limited as long as it can heat the wafer 100 to a desired temperature. Examples of the material of the heating circuit 5 include known metals suitable for resistance heating. An example of the metal is one selected from the group consisting of stainless steel, nickel, nickel alloy, silver, silver alloy, tungsten, tungsten alloy, molybdenum, molybdenum alloy, chromium, and chromium alloy. An example of the nickel alloy is nichrome. An example of the shape of the heating circuit 5 is a foil shape.

[0058] The heater 3 can be produced by sandwiching the upper and lower surfaces of the heat generating circuit 5 between insulating films as base materials and thermocompression bonding.

[0059] [Holding stand] 1, the holder 2 has a mounting surface on the upper surface thereof on which the wafer 100 is placed. The holder 2 is configured in a disk shape. The outer diameter of the holder 2 is larger than the outer diameter of the wafer 100. The lower surface of the holder 2 is in contact with the upper surface of the heater 3. The holder 2 may have a known configuration.

[0060] A plurality of first recesses 21 are provided on the underside of the holding base 2. A temperature sensor 90 is fixed to the bottom of each first recess 21. That is, the number of first recesses 21 is the same as the number of temperature sensors 90. The first recesses 21 are formed at locations that communicate with the first hole portions 43. An adhesive can be used to fix the temperature sensors 90 to the bottom.

[0061] The material of the retaining material is a metal, a ceramic, or a ceramic composite material. Examples of metals include copper, a copper alloy, aluminum, and an aluminum alloy. A plating layer may be provided on the surface of the metal. An example of the plating layer is nickel. An example of a ceramic is silicon carbide or aluminum nitride. An example of a ceramic composite material is Si-SiC or Al-SiC.

[0062] [Support plate] The support plate 6 supports the heater 3 from below. The support plate 6 has a circular shape. The upper surface of the support plate 6 is in contact with the lower surface of the heater 3. The support base may have a known structure.

[0063] The support plate 6 has a plurality of through holes. The plurality of through holes include a first through hole 61 and a second through hole 62 shown in FIG. 1. A lead wire 91 of a temperature sensor 90 is passed through the first through hole 61. The number of the first through holes 61 is the same as the number of the temperature sensors 90. The first through holes 61 are provided along the vertical direction of the support plate 6. The first through holes 61 are formed at locations that communicate with the first hole portion 43. A lead wire 96 of an electrode 95 is passed through the second through hole 62. When the first terminal 51 and the second terminal 52 are close to each other as shown in FIG. 3, the number of the second through holes 62 shown in FIG. 1 may be the same as the number of the heating circuits 5 or the number of the electrodes 95. When the first terminal 51 and the second terminal 52 are close to each other as shown in FIG. 3, the lead wire 96 of the electrode 95 connected to the first terminal 51 and the lead wire 96 of the electrode 95 connected to the second terminal 52 may be passed through one second through hole 62. Although not shown in the drawings, when the first terminal 51 and the second terminal 52 are separated from each other, the number of the second through holes 62 may be the same as the number of the electrodes 95. The second through holes 62 are provided along the up-down direction of the support plate 6. The second through holes 62 are formed at locations that communicate with the second hole portions 44.

[0064] The support plate 6 and the holding table 2 are mechanically connected. For example, screws (not shown) can be used for the mechanical connection. A known fixing method can be used for fixing the support plate 6 and the holding table using screws, so explanation and illustration will be omitted.

[0065] The support plate 6 is supported by a plurality of legs 8. In this embodiment, each leg 8 is fixed to a first cooling plate 71, which will be described later. A known fixing method can be used for fixing the support plate 6 to each leg 8 and the method for fixing each leg 8 to the first cooling plate 71, and therefore explanation and illustration thereof will be omitted. Note that each leg 8 may be fixed to the bottom of a case (not shown) instead of the first cooling plate 71.

[0066] The material of the support plate 6 is ceramic or a ceramic composite material. An example of the ceramic is the same as the ceramic described in the material of the holding material. An example of the ceramic composite material is the same as the ceramic composite material described in the material of the holding material.

[0067] [Cooling unit] The cooling unit 7 cools the support plate 6, the heater 3, and the holding table 2. A known configuration can be used for the cooling unit 7. The cooling unit 7 has a first cooling plate 71 and a second cooling plate 72.

[0068] (First cooling plate) The first cooling plate 71 cools the second cooling plate 72. A refrigerant flow path (not shown) is provided inside the first cooling plate 71. The first cooling plate 71 is cooled by the refrigerant flowing through the flow path. The first cooling plate 71 is fixed to the bottom of a case (not shown) or the like.

[0069] The first cooling plate 71 has a plurality of through holes (not shown). The plurality of through holes includes a hole through which a rod of an air cylinder (described later) is passed and a hole through which the leg part 8 is fixed. A detailed description of the plurality of through holes will be omitted.

[0070] (Second cooling plate) The second cooling plate 72 cools the support plate 6, the heater 3, and the holding table 2. The second cooling plate 72 moves up and down between the first cooling plate 71 and the support plate 6. The second cooling plate 72 is moved up and down by a lifting mechanism (not shown). An example of the lifting mechanism is an air cylinder. The air cylinder has a rod that moves up and down. Unlike the first cooling plate 71, the second cooling plate 72 does not have a flow path through which the refrigerant flows. The second cooling plate 72 itself is cooled by contacting the first cooling plate 71. The cooled second cooling plate 72 cools the heater 3 through the support plate 6 by contacting the support plate 6. Unlike this embodiment, the cooling unit 7 does not need to have the second cooling plate 72. In that case, it is preferable to lift and lower the first cooling plate 71.

[0071] The second cooling plate 72 has a plurality of through holes. The plurality of through holes include a first through hole 721, a second through hole 722, and a third through hole 723. The first through hole 721 is provided with a lead wire 91 of the temperature sensor 90. The number of the first through holes 721 is the same as the number of the temperature sensors 90. The first through holes 721 are provided along the vertical direction of the second cooling plate 72. The first through holes 721 are provided at positions that communicate with the first through holes 61 of the support plate 6 when the upper surface of the second cooling plate 72 is brought into contact with the lower surface of the support plate 6. The lead wire 96 of the electrode 95 is provided through the second through hole 722. The number of the second through holes 722 may be the same as or different from the number of the second through holes 62. The second through holes 722 are provided along the vertical direction of the second cooling plate 72. The second through holes 722 are formed at locations that communicate with the second through holes 62 of the support plate 6 when the upper surface of the second cooling plate 72 and the lower surface of the support plate 6 are brought into contact with each other. The legs 8 are passed through the third through holes 723. The diameter of the third through holes 723 is larger than the diameter of the legs 8. Therefore, the second cooling plate 72 can be raised and lowered along the axial direction of the legs 8. The number of the third through holes 723 is the same as the number of the legs 8. The third through holes 723 are provided along the up-down direction of the second cooling plate 72.

[0072] Metals having high thermal conductivity can be used as the material of the first cooling plate 71 and the second cooling plate 72. Examples of the metals include aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, magnesium, magnesium alloys, titanium, titanium alloys, and stainless steel.

[0073] A cushion layer (not shown) may be provided on the upper surface of the second cooling plate 72. Unlike this embodiment, when the cooling unit 7 does not have the second cooling plate 72, a cushion layer may be provided on the upper surface of the first cooling plate 71. The cushion layer is preferably made of a material having excellent flexibility, heat resistance, and thermal conductivity. The cushion layer is composed of, for example, foamed metal, metal mesh, graphite sheet, or resin sheet. Examples of resin include fluororesin, polyimide resin, and silicone resin. The resin sheet may contain a filler such as carbon.

[0074] The wafer heating apparatus 1 includes the heater 3 that can easily make the temperature of the outermost periphery of the first surface 41 of the substrate 4 uniform, and therefore can easily make the temperature of the wafer 100 uniform over the entire area of ​​the wafer 100. Therefore, the wafer heating apparatus 1 can be suitably used in a coater / developer apparatus.

[0075] Test Example In a test example, the temperature uniformity of the outer area of ​​the substrate attached to the heater was examined.

[0076] [Sample No. 1] The heater of sample No. 1 is similar to the heater 3 of the embodiment described with reference to Figures 1 to 3. That is, in the heater of sample No. 1, all of the first terminals and all of the second terminals of the heating circuits corresponding to each outer zone and all of the holes are provided outside the overlapping region of the wafer.

[0077] [Sample No. 101] The heater of sample No. 101 differs from the heater of sample No. 1 in that all of the first terminals and all of the second terminals and all of the holes of the heating circuits corresponding to each outer zone are provided inside the overlapping region of the wafer. Except for the above, the heater of sample No. 101 was the same as the heater of sample No. 1.

[0078] [Evaluation of temperature uniformity] The temperature uniformity in the outer area of ​​the substrate was evaluated by calculating the difference between the maximum and minimum temperatures in the outer area. This evaluation was performed by supplying power to each heating circuit and setting the first surface temperature to 150°C. A 29-point wafer temperature measurement system manufactured by KLA-Tencor was used for the measurement.

[0079] For the heater of sample No. 1, the difference between the maximum and minimum temperatures in the outer area was 0.06°C. In contrast, for the heater of sample No. 101, the difference between the maximum and minimum temperatures in the outer area was 0.14°C. It was found that the heater of sample No. 1 was able to make the temperature in the outer area more uniform than the heater of sample No. 101.

[0080] The present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0081] 1 Wafer heating device 2 holding base, 21 first recess 3 Heater 4 substrate, 41 first surface, 410 overlapping region, 42 second surface 43 First hole, 44 Second hole 46 Inner Area, 461 Inner Zone 47 Middle Area 471 First Middle Area, 471a First Middle Zone 472 Second Middle Area, 472a Second Middle Zone 48 Outer Area, 481 Outer Zone 5 heating circuit, 51 first terminal, 52 second terminal 55 circuit section, 551 inner circuit section, 552 outer circuit section 6 Support plate, 61 first through hole, 62 second through hole 7 cooling unit, 71 first cooling plate, 72 second cooling plate 721 First through hole, 722 Second through hole, 723 Third through hole 8 legs 90 Temperature sensor, 91 Lead wire, 95 Electrode, 96 Lead wire 100 wafers Area A

Claims

1. A heater for heating a wafer, A circular base material made of an insulating sheet; A plurality of heating circuits are provided inside the base material, the first surface of the substrate is radially divided into a plurality of heating areas; the plurality of heating areas includes an annular outer area located on the outermost periphery of the first surface, At least one heating circuit is provided in a portion of the base material corresponding to the outer area, At least a portion of the first terminal and the second terminal of the heating circuit corresponding to the outer area is provided outside the overlapping area of ​​the wafer in the base material, At least one hole is provided in a portion of the base material corresponding to the outer area, The hole is a hole for providing a temperature sensor, At least a portion of the hole is provided outside an overlapping region of the wafer in the base material. heater.

2. The outer area is divided into a plurality of fan-shaped outer zones in the circumferential direction, The base material is provided with one heating circuit at a location corresponding to each of the plurality of outer zones, The heater according to claim 1 , wherein at least a portion of the first terminal and the second terminal of the heating circuit corresponding to each of the plurality of outer zones is provided outside the overlapping region.

3. The heater according to claim 2 , wherein all of the first terminals and the second terminals corresponding to each of the plurality of outer zones are provided outside the overlapping region.

4. the heat generating circuit corresponding to each of the plurality of outer zones has a circuit portion connecting the first terminal and the second terminal, The circuit unit includes: an inner circuit portion provided inside the overlapping region; The heater according to claim 2 or 3, further comprising: an outer circuit portion provided outside the overlapping region.

5. The outer area is divided into a plurality of fan-shaped outer zones in the circumferential direction, The base material is provided with one hole at a location corresponding to each of the plurality of outer zones, The heater according to claim 1 , wherein at least a portion of the hole portion corresponding to each of the plurality of outer zones is provided outside the overlapping region.

6. The heater according to claim 5 , wherein all of the holes corresponding to each of the plurality of outer zones are provided outside the overlapping region.

7. a support table having an upper surface on which a wafer is placed; a heater for heating the holding table; The heater is a heater according to any one of claims 1 to 6. Wafer heating device.

8. A support having an upper surface on which a wafer is placed; A heater provided on a lower surface of the support table; a support plate that supports the heater from below, The heater is a heater according to any one of claims 1 to 6, the temperature sensor is fixed to the support table at the position of the hole provided in the heater; Wafer heating device.

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