Wafer Heating Device

Abstract

To provide a wafer heating device in which wiring is hardly sandwiched between a heater unit and a cooling plate when cooling the heater unit.SOLUTION: A wafer heating device includes: a heater unit that is equipped with an upper surface on which a wafer is placed, and a heater heating the wafer; a cooling plate that cools the heater unit; and wiring that is drawn from a lower surface of the heater unit. The cooling plate is configured to move between a state in which an upper surface of the cooling plate contacts with the lower surface of the heater unit and a state in which the upper surface of the cooling plate separates from the lower surface of the heater unit. The cooling plate is equipped with a recessed portion provided on the upper surface, and a first through-hole penetrating in a thickness direction from a position of a bottom portion of the recessed portion. The wiring is drawn to the lower surface side of the cooling plate through the recessed portion and the first through-hole while the heater unit and the cooling plate contact with each other.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 discloses a wafer heating apparatus that heats a wafer, for example, in a photolithography process. The wafer heating apparatus of Patent Document 1 includes a heater unit that heats the wafer, and a movable cooling module that cools the heater unit. The wafer is placed on the upper surface of the heater unit. The heater unit includes a heater that includes a resistance heating element. The movable cooling module is configured to be movable up and down. The heater unit is cooled by the movable cooling module coming into contact with the lower surface of the heater unit.

[0003] The heater unit includes wiring that supplies power to the resistive heating element. The wiring is drawn out from the underside of the heater unit. Since the wiring acts as a heat transmission path, there is a risk of cool spots being formed in the heater unit. To solve this problem, in the wafer heating device of Patent Document 2, a part of the wiring is fixed to the underside of the heater unit. By fixing the wiring to the heater unit, the wiring is heated by the heater unit. As a result, cool spots are less likely to be formed in the heater unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-129577 A [Patent Document 2] JP 2011-187257 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a wafer heating device equipped with a cooling plate, when the cooling plate comes into contact with the heater unit, there is a risk that the wiring may be pinched between the heater unit and the cooling plate. If the wiring is pinched between the heater unit and the cooling plate, the contact area between the heater unit and the cooling plate may decrease, slowing down the temperature drop rate of the heater unit. In addition, there is a risk that the insulating coating of the wiring pinched between the heater unit and the cooling plate may be damaged.

[0006] An object of the present disclosure is to provide a wafer heating apparatus that is unlikely to pinch wiring between a heater unit and a cooling plate when cooling the heater unit and that can stably cool the heater unit. [Means for solving the problem]

[0007] The wafer heating apparatus of the present disclosure is a heater unit including an upper surface on which a wafer is placed and a heater for heating the wafer; a cooling plate for cooling the heater unit; wiring drawn out from a lower surface of the heater unit; the cooling plate is configured to be movable between a state in which an upper surface of the cooling plate is in contact with a lower surface of the heater unit and a state in which the upper surface of the cooling plate is separated from the lower surface of the heater unit, The cooling plate includes a recess provided on an upper surface thereof and a first through hole extending from a bottom of the recess in a thickness direction thereof, The wiring passes through the recess and the first through hole and is drawn out to the lower surface side of the cooling plate when the heater unit and the cooling plate are in contact with each other. Effect of the Invention

[0008] The wafer heating apparatus of the present disclosure enables stable cooling of the heater unit. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a wafer heating apparatus according to the first embodiment. [Diagram 2] FIG. 2 is a partial enlarged view of the wafer heating apparatus according to the first embodiment. [Diagram 3] FIG. 3 is a partial enlarged view showing a state in which the cooling plate of the wafer heating apparatus shown in FIG. 2 is in contact with a heater unit. [Figure 4] FIG. 4 is a partial plan view of a cooling plate provided in the wafer heating apparatus according to the first embodiment. [Diagram 5] FIG. 5 is a partial plan view of a cooling plate different from that in FIG. [Figure 6] FIG. 6 is a schematic diagram of a wafer heating apparatus according to the second embodiment. [Figure 7] FIG. 7 is a plan view of a heater provided in the wafer heating apparatus according to the third embodiment. [Figure 8] FIG. 8 is a plan view of a cooling plate provided in the wafer heating apparatus according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Description of the embodiments of the present disclosure] The embodiments of the present disclosure are listed and described below.

[0011] <1> The wafer heating apparatus according to the embodiment includes: a heater unit including an upper surface on which a wafer is placed and a heater for heating the wafer; a cooling plate for cooling the heater unit; wiring drawn out from a lower surface of the heater unit; the cooling plate is configured to be movable between a state in which an upper surface of the cooling plate is in contact with a lower surface of the heater unit and a state in which the upper surface of the cooling plate is separated from the lower surface of the heater unit, The cooling plate includes a recess provided on an upper surface thereof and a first through hole extending from a bottom of the recess in a thickness direction thereof, The wiring passes through the recess and the first through hole and is drawn out to the lower surface side of the cooling plate when the heater unit and the cooling plate are in contact with each other.

[0012] In the wafer heating apparatus according to the embodiment, when the heater unit and the cooling plate are in contact with each other, the wiring is configured to be drawn out to the underside of the cooling plate through the recess and the first through hole in the cooling plate. Therefore, in the wafer heating apparatus according to the embodiment, the wiring is less likely to be pinched between the heater unit and the cooling plate. If the wiring is pinched between the heater unit and the cooling plate, there is a problem that the contact area between the heater unit and the cooling plate is reduced, and the wiring is damaged. The wafer heating apparatus according to the embodiment can significantly reduce the possibility of such problems occurring, and therefore it is possible to stably and repeatedly cool the heater unit.

[0013] <2> As one embodiment of the wafer heating apparatus according to the present invention, A part of an intermediate portion of the wiring is fixed to a lower surface of the heater unit, The intermediate portion may be disposed inside the recessed portion when the heater unit and the cooling plate are in contact with each other.

[0014] By fixing a part of the middle part of the wiring to the underside of the heater unit, the wiring is heated by the heater unit and heat is less likely to escape from the heater unit via the wiring. As a result, cool spots are less likely to form on the heater unit. In order for a part of the middle part of the wiring to be fixed to the underside of the heater unit, the middle part needs to be bent along the underside of the heater unit. <2> In the configuration, the intermediate portion of the bent wiring is arranged in the recess, so that the intermediate portion of the wiring is unlikely to be pinched between the heater unit and the cooling plate.

[0015] <3> The above form <2> As one embodiment of the wafer heating apparatus according to the present invention, The first through hole may be disposed below a portion where the intermediate portion is fixed to the heater unit.

[0016] The above form <3> In the configuration of (a), the wiring is guided to the first through hole without being excessively bent, and therefore the wiring is less likely to be damaged.

[0017] <4> As one embodiment of the wafer heating apparatus according to the present invention, the heater unit includes a support plate that supports the heater from below, the cooling plate is configured to be movable between a state in which an upper surface of the cooling plate is in contact with a lower surface of the support plate and a state in which the upper surface of the cooling plate is separated from the lower surface of the support plate, The support plate has a second through hole penetrating in a thickness direction, the recess is provided such that a continuous space is formed between an upper opening of the first through hole and a lower opening of the second through hole when the support plate and the cooling plate are in contact with each other, The wiring may be drawn out below the support plate through the second through hole.

[0018] By providing the heater unit with a support plate, the flatness of the wafer holding plate is well maintained, improving the temperature uniformity of the wafer holding plate. Because the support plate is a highly rigid body, the thickness of the heater unit including the wafer holding plate can be made thin. As a result, the heat capacity of the heater unit is reduced, improving the heating and cooling rates of the heater unit. In addition, the support plate can prevent the cooling plate from coming into direct contact with the heater. Therefore, even if the cooling plate comes into contact with the heater unit more frequently, the heater is less likely to be damaged.

[0019] <5> The above form <4> As one embodiment of the wafer heating apparatus according to the present invention, At room temperature, a projected outline of the second through hole is located inside an outline of an opening of the recess, The projected contour line may be a contour line obtained by projecting a contour line of the lower opening onto the cooling plate.

[0020] When the high-temperature heater unit comes into contact with the low-temperature cooling plate, the heater unit contracts and the cooling plate expands. At that time, there is a possibility that the wiring may come into contact with the inner wall of the recess. If the wiring is fixed to the lower surface of the heater unit, the fixed state of the wiring may change or the wiring may become detached if stress is applied to the wiring. The above-mentioned form in which the recess is larger than the projected outline of the second through hole <5> In this configuration, the wiring is less likely to come into contact with the inner wall of the recess.

[0021] <6> As one embodiment of the wafer heating apparatus according to the present invention, The cooling plate includes a body and an upper layer disposed on an upper surface of the body; The body is made of metal, The upper layer may be made of a material different from that of the main body.

[0022] Various effects can be obtained depending on the material of the upper layer. For example, if the upper layer is made of silicone resin, the adhesion between the heater unit and the cooling plate is increased, and the heater unit is cooled more quickly. In addition, when the heater unit and the cooling plate come into contact with each other, both the heater unit and the cooling plate are less likely to be damaged.

[0023] <7> As one embodiment of the wafer heating apparatus according to the present invention, The heater comprises a plurality of heating zones; the upper surface of the cooling plate comprises a plurality of cooling zones; Each cooling zone is a virtual area corresponding to each heating zone, An example of the embodiment is one in which the area Sa inside the outer circumferential contour of each cooling zone and the contact area Sb of each cooling zone with the heater unit satisfy Sb / Sa≧0.5.

[0024] A heater with multiple heating zones can reduce the uniform heating range of a wafer, which is the temperature variation across the wafer when the wafer is heated. <7> In the configuration, the contact area of ​​the cooling zone corresponding to each heating zone with the support plate is specified. When the entire lower surface of the heater unit and the upper surface of the cooling plate are in contact with each other, the area Sa of the cooling zone is equal to the contact area Sb. However, since recesses and holes are formed on the upper surface of the cooling plate, the contact area Sb is smaller than the area Sa of the cooling zone. If the contact area of ​​each cooling zone with the heater unit is equal to or larger than a predetermined value, the entire heater unit is cooled quickly.

[0025] <8> The above form <7> As one embodiment of the wafer heating apparatus according to the present invention, the plurality of cooling zones include a first cooling zone having the largest Sb / Sa and a second cooling zone having the smallest Sb / Sa; An embodiment in which the difference between Sb / Sa in the first cooling zone and Sb / Sa in the second cooling zone is 0.35 or less can be given.

[0026] The above form <8> In this configuration, the cooling speed of each heating zone is unlikely to vary, and the entire heater unit is therefore cooled uniformly in a short period of time.

[0027] <9> The above form <7> Or form <8> As one embodiment of the wafer heating apparatus according to the present invention, the plurality of cooling zones includes adjacent third and fourth cooling zones; the area inside the outer circumferential contour of the third cooling zone is smaller than the area inside the outer circumferential contour of the fourth cooling zone; the wiring includes a first wiring extending from the heating zone corresponding to the third cooling zone; the recess includes a first recess corresponding to the first wiring, At least a part of the first recess is disposed in the fourth cooling zone.

[0028] The above form <9> In this configuration, the contact area with the heater unit in the third cooling zone is prevented from becoming excessively small. By arranging a recess in the third cooling zone, the contact area with the heater unit in the third cooling zone is reduced. If a recess is further formed in the third cooling zone, which has an area smaller than the area of ​​the fourth cooling zone, the difference between the contact area with the heater unit in the third cooling zone and the contact area with the heater unit in the fourth cooling zone becomes even larger. By arranging a part of the recess provided in the third cooling zone in the fourth cooling zone, the difference in the contact area with the heater unit can be reduced. Therefore, the above form <9> The configuration of the above <7> and form <8> It is easy to meet the regulations.

[0029] [Details of the embodiment of the present disclosure] Hereinafter, specific examples of the wafer heating apparatus and the wafer holding plate according to the embodiment of the present disclosure will be described with reference to the drawings. The same reference numerals in the drawings indicate the same or corresponding parts. The size of the members shown in each drawing is expressed for the purpose of clarifying the description, and does not necessarily represent the actual size. Note that the present invention is not limited to these examples, but is indicated by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

[0030] <Embodiment 1> <Overall composition> The wafer heating apparatus 1 according to the embodiment shown in FIG. 1 to FIG. 3 is used for pre-baking in a photolithography process. Pre-baking is a heat treatment for volatilizing a solvent of a photoresist solution applied to the surface of a wafer 100. The wafer heating apparatus 1 includes a heater unit 10 for heating the wafer 100 and a cooling unit 11 for cooling the heater unit 10. A cooling plate 5 included in the cooling unit 11 is configured to be movable up and down, and cools the heater unit 10 as necessary. The partial enlarged view of FIG. 2 shows a state in which the cooling plate 5 is separated from the heater unit 10. The partial enlarged view of FIG. 3 shows a state in which the cooling plate 5 is in contact with the heater unit 10. Each component of the wafer heating apparatus 1 according to the embodiment will be described in detail below.

[0031] <Heater unit> The heater unit 10 of this example includes, in order from above, a wafer holding plate 2, a heater 3, and a support plate 4. As will be shown in a second embodiment described later, the support plate 4 is not essential.

[0032] [Wafer holding plate] The wafer holding plate 2 has a flat upper surface 2U on which the wafer 100 is placed. The upper surface 2U constitutes the upper surface 10U of the heater unit 10. In this example, the wafer holding plate 2 is a circular plate. The diameter of the circular plate need only be larger than the wafer 100 placed on the upper surface 10U, and is, for example, 200 mm or more and 400 mm or less. The planar shape of the wafer holding plate 2 is not limited to a circle, and may be, for example, a polygon such as a rectangle. It is preferable that the planar shape of the wafer holding plate 2 is similar to the planar shape of the wafer 100.

[0033] The material of the wafer holding plate 2 is preferably a material that has excellent thermal conductivity and is not easily deformed by heat. Preferred materials include copper, aluminum, or alloys containing these. The surface of the wafer holding plate 2 is preferably nickel-plated or anodized. Ceramics can also be used as the material of the wafer holding plate 2. Examples of ceramics include ceramics such as aluminum nitride, silicon carbide (SiC), aluminum oxide, and silicon nitride, as well as composites of these ceramics and silicon (Si). In particular, Si-SiC, which is a porous SiC body impregnated with metallic silicon, is preferred as the material of the wafer holding plate 2.

[0034] The wafer holding plate 2 may have protrusions, vacuum ports, lift pin holes, and the like (not shown). The protrusions are provided on the upper surface 2U. The protrusions form a minute gap between the upper surface 2U and the wafer 100. The vacuum ports and lift pin holes are holes that penetrate the wafer holding plate 2 in the thickness direction. When air is sucked from the gap between the upper surface 2U and the wafer 100 via the vacuum ports, the wafer 100 is corrected to a nearly flat state. The lift pin holes are holes through which lift pins that lift the wafer 100 from the upper surface 2U are inserted. Vacuum ports and lift pin holes are also provided in the heater 3 and the support plate 4, which will be described later.

[0035] In this embodiment, a temperature measuring element 25 is provided on the lower surface 2D of the wafer holding plate 2. The temperature of the wafer holding plate 2 measured by the temperature measuring element 25 is used to control the heater 3, which will be described later. The temperature measuring element 25 is disposed, for example, in a countersunk hole 20 provided on the lower surface 2D. An example of the temperature measuring element 25 is a temperature measuring element in which a platinum resistor is deposited on ceramics by vapor deposition. The temperature measuring element 25 is fixed, for example, with a silicone adhesive. A wiring 70 is connected to the temperature measuring element 25. The arrangement of the wiring 70 will be described later.

[0036] [heater] The heater 3 is a member that heats the wafer holding plate 2. The wafer 100 is heat-treated by the wafer holding plate 2 heated by the heater 3. The heater 3 includes a plate-shaped base material 31 made of an insulator and a circuit pattern 30 of a resistance heating element made of a metal. The base material 31 forms the outer shape of the heater 3. The base material 31 in this example is a disk-shaped base material having an outer diameter equal to that of the wafer holding plate 2. As shown in Figs. 2 and 3, in the heater 3 in this example, a circuit pattern is disposed inside the base material 31. The circuit pattern 30 is made of, for example, a thin metal film that generates heat when electricity is applied. An example of the circuit pattern 30 is a circuit pattern 30 formed by partially etching a stainless steel foil. An example of the base material 31 is a resin having excellent heat resistance such as polyimide. Other examples of the base material 31 include a mica sheet impregnated with a resin, ceramics, and the like. In this example, the heater 3 is fabricated by sandwiching the circuit pattern 30 between two polyimide sheets.

[0037] A blind hole 35 and a third through hole 36 are formed in the base material 31 of the heater 3. The blind hole 35 extends from the lower surface 3D of the heater 3 to a terminal of the circuit pattern 30. A wire 7 for supplying electricity is connected to the terminal. The wire 7 is disposed inside the blind hole 35. The third through hole 36 penetrates the base material 31 in the thickness direction. The upper end of the third through hole 36 opens into the countersunk hole 20. A wire 70 connected to the temperature measuring element 25 disposed in the countersunk hole 20 is disposed inside the third through hole 36. The blind hole 35 and the third through hole 36 may be filled with resin or the like.

[0038] [Support plate] The support plate 4 supports the heater 3 from below. The flatness of the wafer holding plate 2 is well maintained by the support plate 4, so that the uniform temperature of the wafer holding plate 2 is improved. The support plate 4 is a highly rigid body, so that the thickness of the heater unit 10 including the wafer holding plate 2 can be reduced. As a result, the heat capacity of the heater unit 10 is reduced, and the heating rate and the cooling rate of the heater unit 10 are improved. In this example, the lower surface 4D of the support plate 4 constitutes the lower surface 10D of the heater unit 10. The cooling plate 5 of the cooling unit 11 comes into contact with the lower surface 4D of the support plate 4 when the heater unit 10 is cooled. The support plate 4 prevents the cooling plate 5 from coming into direct contact with the heater 3, so that the heater 3 is less likely to be damaged. The support plate 4 in this example is a disk-shaped plate having the same outer diameter as the wafer holding plate 2. In this example, the support plate 4, the wafer holding plate 2, and the heater 3 are integrated by means of fastening screws (not shown) or the like. The support plate 4 is preferably made of ceramics, like the wafer holding plate 2.

[0039] The support plate 4 has a plurality of second through holes 45, 46 penetrating in the thickness direction. The second through holes 45 at positions corresponding to the terminals of the circuit pattern 30 are connected to the blind holes 35 of the heater 3. The wiring 7 connected to the circuit pattern 30 is disposed inside the second through hole 45 through the blind holes 35. The second through hole 46 at a position corresponding to the temperature measuring element 25 is connected to the third through hole 36 of the heater 3. The wiring 70 connected to the temperature measuring element 25 is disposed inside the second through hole 45 through the third through hole 36 as shown in FIG. 2. The second through holes 45, 46 in which the wiring 7, 70 are disposed may be filled with resin or the like.

[0040] <Cooling unit> The cooling unit 11 is configured to cool the heater unit 10 as necessary. The cooling unit 11 includes a cooling plate 5 and a cooling stage 6.

[0041] [Cooling stage] The cooling stage 6 is maintained at a low temperature by a refrigerant or the like. For example, a refrigerant flow passage is formed inside the cooling stage 6. The cooling stage 6 has a role of cooling the cooling plate 5. The cooling stage 6 also has a role of holding the heater unit 10 above the cooling stage 6. Specifically, the cooling stage 6 and the heater unit 10 are connected by a fixed shaft 60. The fixed shaft 60 passes through the cooling plate 5, and the cooling plate 5 is not fixed by the fixed shaft 60.

[0042] [Cooling plate] The cooling plate 5 is configured to be movable up and down. For example, the cooling plate 5 is attached to the tip of a rod of an air cylinder (not shown). When the heater unit 10 is cooled, the cooling plate 5, which is at a low temperature, moves upward via the cooling stage 6 and contacts the lower surface 4D of the support plate 4, i.e., the lower surface 10D of the heater unit 10. When the cooling plate 5 contacts the lower surface 10D of the heater unit 10, the heater unit 10 is quickly cooled and the temperature of the heater unit 10 is adjusted to a desired temperature. After the cooling of the heater unit 10 is completed, the cooling plate 5 leaves the lower surface 4D of the support plate 4 and descends to a position where it contacts the cooling stage 6.

[0043] The cooling plate 5 of this example includes a disk-shaped main body 50 and an upper layer 51 disposed on the upper surface of the main body 50. Unlike this example, the cooling plate 5 does not need to include the upper layer 51. The main body 50 is preferably made of a material having excellent thermal conductivity, such as a metal. The main body 50 of this example is made of an aluminum alloy.

[0044] The upper layer 51 has a function of improving the adhesion between the cooling plate 5 and the heater unit 10. In this example, the upper layer 51 is a resin sheet. The material of the upper layer 51 is preferably a flexible material mainly composed of silicone or fluorine. The upper layer 51, which has excellent flexibility, improves the adhesion between the cooling plate 5 and the heater unit 10, and improves the cooling efficiency of the heater unit 10 by the cooling plate 5. In addition, the upper layer 51, which has excellent flexibility, suppresses damage to the main body 50 of the cooling plate 5 and the heater unit 10 when the cooling plate 5 comes into contact with the heater unit 10.

[0045] The cooling plate 5 has recesses 52, 53 and first through holes 55, 56. The recesses 52 and 53 have the same configuration. The first through hole 55 and 56 have the same configuration. Therefore, in the following description, the recesses 52 and the first through hole 55 will be mainly described.

[0046] The recess 52 is a recess provided on the upper surface 5U of the cooling plate 5. The first through hole 55 is a through hole penetrating the cooling plate 5 in the thickness direction from the position of the bottom 52b of the recess 52. As shown in FIG. 3, the recess 52 is provided so that a continuous space is formed between the upper opening 55h of the first through hole 55 and the lower opening 45h of the second through hole 45 when the heater unit 10 and the cooling plate 5 are in contact with each other. The axis of the first through hole 55 and the axis of the second through hole 45 are disposed at different positions in the planar direction of the cooling plate 5. Unlike this example, the axis of the first through hole 55 and the axis of the second through hole 45 may coincide with each other.

[0047] 4 which is a partial top view of the cooling plate 5, at room temperature, it is preferable that the projected contour line 45v of the second through hole 45 is located inside the contour line of the opening 52h of the recess 52. The projected contour line 45v is a contour line obtained by projecting the contour line of the lower opening 45h of the second through hole 45 shown in FIG. 3 onto the cooling plate 5. The wiring 7 drawn into the inside of the recess 52 is led into the inside of the first through hole 55.

[0048] As shown in FIG. 5, the projected contour line 45v arranged inside the contour line of the opening 52h of the recess 52 may be multiple. In the example shown in FIG. 5, the contour shape of the opening 52h of the recess 52 is approximately V-shaped. The wiring 7 connected to the circuit pattern 30 shown in FIG. 3 and the wiring 70 connected to the temperature measuring element 25 shown in FIG. 3 are drawn into the interior of the recess 52. The wiring 7 and the wiring 70 arranged in the recess 52 are led into the interior of one first through hole 55. The contour shape of the opening 52h is not particularly limited. For example, the contour shape of the opening 52h may be approximately L-shaped or may be an elongated hole shape. In the case of the recess 52 having the elongated opening 52h, it is preferable that the first through hole 55 is arranged in the center of the recess 52 in the longitudinal direction, and the two projected contour lines 45v are arranged at both ends of the recess 52 in the longitudinal direction.

[0049] <Wiring> 2 and 3, the wiring 7 connected to the circuit pattern 30 is drawn out below the heater unit 10 through the second through hole 45. A part of the intermediate portion 7c of the wiring 7 drawn out from the second through hole 45 is fixed to the lower surface 10D of the heater unit 10. The wiring 7 drawn out from the second through hole 45 is drawn out to the lower surface 5D side of the cooling plate 5 through the first through hole 55 and connected to a power source (not shown). The first through hole 55 is disposed below the portion where the intermediate portion 7c is fixed to the lower surface 10D of the heater unit 10. Therefore, the wiring 7 is led to the first through hole 55 without the intermediate portion 7c being excessively bent.

[0050] The wiring 70 connected to the temperature measuring element 25 is pulled out below the support plate 4 via the second through hole 46. A part of the middle portion 70c of this wiring 70 is also fixed to the lower surface 10D of the heater unit 10. The wiring 70 pulled out from the second through hole 46 is pulled out to the lower surface 5D side of the cooling plate 5 via the first through hole 56 and connected to a temperature measuring device (not shown).

[0051] 3, in a state in which the heater unit 10 and the cooling plate 5 are in contact with each other, the middle portions 7c, 70c of the wirings 7, 70 are disposed inside the recesses 52, 53. That is, the wirings 7, 70 are not sandwiched between the heater unit 10 and the cooling plate 5, but are drawn out to the lower surface 5D side of the cooling plate 5 through the recess 52 and the first through hole 55 or the recess 53 and the first through hole 56.

[0052] The intermediate portion 7c of the wiring 7 and the intermediate portion 70c of the wiring 70 are fixed to the lower surface 10D of the heater unit 10 with, for example, an adhesive. Alternatively, the intermediate portions 7c, 70c may be fixed to the lower surface 10D with an adhesive sheet or the like. By fixing the intermediate portions 7c, 70c of the wiring 7, 70 to the lower surface 10D of the heater unit 10, cool spots are less likely to form in the heater unit 10.

[0053] In the wafer heating apparatus 1 of this embodiment, when the heater unit 10 and the cooling plate 5 are in contact with each other, the wirings 7, 70 are configured to pass through the recesses 52, 53 and the first through holes 55, 56 provided in the cooling plate 5 and be drawn out to the lower surface side of the cooling plate 5. Therefore, in the wafer heating apparatus 1, the wirings 7, 70 are unlikely to be pinched between the heater unit 10 and the cooling plate 5. This makes it possible to avoid problems caused by the wirings 7, 70 being pinched between the heater unit 10 and the cooling plate 5. Specific problems include a reduction in the contact area between the heater unit 10 and the cooling plate 5 and damage to the wirings 7, 70.

[0054] When the high-temperature heater unit 10 and the low-temperature cooling plate 5 come into contact with each other, the heater unit 10 contracts and the cooling plate 5 expands. At that time, the wiring 7, 70 may come into contact with the inner walls of the recesses 52, 53. If the wiring 7, 70 is subjected to stress due to contact with the inner walls, the fixed state of the wiring 7, 70 may change or the wiring 7, 70 may come off. As a result, a cool spot may be formed in the heater unit 10. To address this problem, in the wafer heating apparatus 1 of this embodiment, as shown in FIG. 4, the projected contour line 45v of the second through hole 45 is located inside the contour line of the opening 52h of the recess 52. Therefore, when the heater unit 10 contracts and the cooling plate 5 expands, the wiring 7, 70 is unlikely to come into contact with the inner walls of the recesses 52, 53.

[0055] <Embodiment 2> In the second embodiment, a wafer heating apparatus 1 including a heater unit 10 without a support plate 4 will be described with reference to Fig. 6. The configuration of the wafer heating apparatus 1 of this example other than the heater unit 10 is the same as that of the wafer heating apparatus 1 of the first embodiment.

[0056] In the wafer heating apparatus 1 of this example, the lower surface 3D of the heater 3 constitutes the lower surface 10D of the heater unit 10. Therefore, the wiring 7 drawn out from the blind hole 35 opening in the lower surface 3D of the heater 3 is led to the first through hole 55 of the cooling plate 5. Also, the wiring 70 drawn out from the third through hole 36 opening in the lower surface 3D of the heater 3 is led to the first through hole 56 of the cooling plate 5. In the wafer heating apparatus 1 of this example, the wiring 7, 70 is unlikely to be pinched between the heater unit 10 and the cooling plate 5 due to the presence of the recesses 52, 53 provided in the cooling plate 5.

[0057] 6, the circuit pattern 30 may be formed by metallization on the lower surface 2D of the wafer holding plate 2. In this case, after wiring 7, 70 is connected to the circuit pattern 30, the lower surface 2D including the circuit pattern 30 is coated with an insulating resin or the like to form the heater 3 integrated with the lower surface 2D. In this configuration, the blind hole 35 and the third through hole 36 are not formed in the heater 3.

[0058] <Embodiment 3> In the third embodiment, a wafer heating apparatus 1 in which a heater 3 in a heater unit 10 has multiple heating zones 8 will be described with reference to Figures 7 and 8. The basic configuration of the wafer heating apparatus 1 in the third embodiment is the same as that of the wafer heating apparatus 1 in the first embodiment. Therefore, for configurations not shown in Figures 7 and 8, refer to Figure 1.

[0059] The heater 3 of this example shown in FIG. 7 includes a plurality of heating zones 8. The plurality of heating zones 8 include three heating zones 8A arranged on the inner periphery side and six heating zones 8B arranged on the outer periphery side. The inner periphery side heating zone 8A is a fan shape with an inner angle of 120°. The three inner periphery side heating zones 8A have the same area. The outer periphery side heating zone 8B is a band shape having an inner periphery arc and an outer periphery arc with an inner angle of 60°. The six outer periphery side heating zones 8B have the same area. The area of ​​the inner periphery side heating zone 8A is smaller than the area of ​​the outer periphery side heating zone 8B. Each heating zone 8 has an independent circuit pattern. The circuit pattern is not shown in FIG. 7. The number of heating zones 8 and the shape of the heating zones 8 are not particularly limited.

[0060] The cooling plate 5 of this example shown in Fig. 8 includes a plurality of cooling zones 9. The plurality of cooling zones 9 include three cooling zones 9A arranged on the inner periphery side and six cooling zones 9B arranged on the outer periphery side. Each cooling zone 9 is a virtual area corresponding to each heating zone 8 shown in Fig. 7. More specifically, the cooling zone 9 is an area obtained by projecting the heating zone 8 in Fig. 7 onto the cooling plate 5 in Fig. 8. Therefore, the shape of each cooling zone 9 is congruent with the shape of the corresponding heating zone 8.

[0061] The cooling plate 5 is provided with a plurality of recesses 52 for receiving the wiring 7 of the circuit pattern 30. One wiring 7 is disposed in each recess 52. In Fig. 8, the recesses 53 for receiving the wiring 70 of the temperature measuring element 25, the holes for the lift pins, the vacuum port, etc. are not shown.

[0062] The number of recesses 52 in this example is the same as the number of heating zones 8 shown in Fig. 7. When multiple wirings 7 are arranged in one recess 52, the number of recesses 52 may be less than the number of heating zones 8.

[0063] If the contact area of ​​the cooling zone 9 with the heater unit 10 is small, it takes a long time to cool the heater unit 10. In order to improve the productivity of semiconductor chips, it is necessary to increase the cooling speed of the heater unit 10. In addition, in order to reuse the heater unit 10, the entire heater unit 10 needs to be at a predetermined temperature or lower. If there is variation in the cooling speed of each heating zone 8, the time until the heater unit 10 can be reused will be longer depending on the cooling time of the heating zone 8 with the slowest cooling speed. Therefore, it is preferable that the contact area of ​​each cooling zone 9 with the heater unit 10 satisfies at least one of the following conditions 1 and 2. Hereinafter, the "contact area of ​​the cooling zone 9 with the heater unit 10" may be simply expressed as the "contact area of ​​the cooling zone 9". ≪Condition 1≫ The area Sa inside the outer circumferential contour of each cooling zone 9 and the contact area Sb of each cooling zone 9 satisfy Sb / Sa≧0.5.

[0064] By each cooling zone 9 satisfying the above condition 1, when the cooling plate 5 contacts the heater unit 10, the heating zone 8 corresponding to each cooling zone 9 is quickly cooled. As a result, the time until the heater unit 10 can be reused is shortened. The larger Sb / Sa is, the faster the cooling rate of the heating zone 8 is. A preferable Sb / Sa is 0.6 or more, and a more preferable Sb / Sa is 0.7 or more.

[0065] ≪Condition 2≫ The difference ΔSb / Sa between Sb / Sa in the first cooling zone 91 and Sb / Sa in the second cooling zone 92 is 0.35 or less. Here, the first cooling zone 91 is the cooling zone 9 with the largest Sb / Sa among the multiple cooling zones 9. In this example, the cooling zone 9B on the outer periphery side is the first cooling zone 91. The second cooling zone 92 is the cooling zone 9 with the smallest Sb / Sa among the multiple cooling zones 9. In this example, the cooling zone 9A on the inner periphery side is the second cooling zone 92.

[0066] In the heater unit 10 having a plurality of heating zones 8, the heating zones 8 are intermittently heated by intermittent energization in order to maintain the heating zones 8 at a predetermined temperature. If there is variation in the cooling speed of each heating zone 8, the intermittent heating of the heating zones 8 that have reached the predetermined temperature will hinder the cooling of the heating zones 8 that have not yet reached the predetermined temperature. Therefore, if there is variation in the cooling speed of each heating zone 8, the cooling time of the entire heater unit 10 is likely to be long. On the other hand, if the plurality of cooling zones 9 satisfy the above condition 2, it is difficult for a large difference to occur in the cooling speed of each heating zone 8, and it is difficult for the time for each heating zone 8 to reach the predetermined temperature to vary. Therefore, the entire heater unit 10 is likely to be cooled uniformly, and the heater unit 10 is likely to quickly reach a predetermined temperature or lower. The smaller the difference ΔSb / Sa, the more preferable it is. A more preferable difference ΔSb / Sa is 0.30 or less, and a further more preferable difference ΔSb / Sa is 0.2 or less.

[0067] As a configuration that satisfies the above conditions 1 and 2, the size of the recesses 52 and the arrangement of the recesses 52 can be adjusted. In the cooling plate 5 of this example, some of the recesses 52 are provided so as to straddle the cooling zones 9, 9. Specifically, a first recess 54 that satisfies the following conditions is provided so as to straddle the third cooling zone 93 and the fourth cooling zone 94.

[0068] In this example, the multiple cooling zones 9 include adjacent third cooling zone 93 and fourth cooling zone 94. Here, the area inside the outer circumferential contour of the third cooling zone 93 is smaller than the area inside the outer circumferential contour of the fourth cooling zone 94. In this example, the cooling zone 9A on the inner circumferential side is the third cooling zone 93. The cooling zone 9B adjacent to the outer circumferential side of the third cooling zone 93 is the fourth cooling zone 94.

[0069] Of the wiring 7 arranged in each recess 52, the wiring 7 extending from the heating zone 8 corresponding to the third cooling zone 93 is the first wiring 71. The recess 52 in which the first wiring 71 is arranged is the first recess 54. In this example, a part of this first recess 54 is arranged in the fourth cooling zone 94. In this configuration, the first through hole 55 connecting to the first recess 54 is also arranged in the fourth cooling zone 94. By arranging a part of the first recess 54 in the fourth cooling zone 94 which is larger than the third cooling zone 93, the contact area of ​​the third cooling zone 93 is prevented from becoming too small compared to the contact area of ​​the fourth cooling zone 94. As a result, the above conditions 1 and 2 are easily satisfied.

[0070] Unlike this example, the entire first recess 54 may be disposed in the fourth cooling zone 94. To achieve such a configuration, for example, the axis of the second through hole 45 in Fig. 1 is tilted so that the first wiring 71 connected to the inner heating zone 8A in Fig. 7 is drawn to the outer cooling zone 9B in Fig. 8. Alternatively, the terminal of the inner heating zone 8A is provided at the position of the outer heating zone 8B.

[0071] <Test Example> In the test example, the effect of the difference ΔSb / Sa between Sb / Sa in the first cooling zone 91 and Sb / Sa in the second cooling zone 92 on the cooling time of the heater unit 10 was examined.

[0072] Wafer heating apparatuses 1 of Sample No. 1 to Sample No. 5 having multiple heating zones 8 and multiple cooling zones 9 were prepared. The only difference between these wafer heating apparatuses 1 was the value of the difference ΔSb / Sa. The ΔSb / Sa of the wafer heating apparatuses 1 of Sample No. 1, Sample No. 2, Sample No. 3, Sample No. 4, and Sample No. 5 were 0.1, 0.2, 0.3, 0.4, and 0.5, respectively. The Sb / Sa of the first cooling zone 91 and the Sb / Sa of the second cooling zone 92 of each sample are shown below. Sample No.1 Sb / Sa in the first cooling zone 91 is 0.6, and Sb / Sa in the second cooling zone 92 is 0.5. Sample No. 2 Sb / Sa in the first cooling zone 91 is 0.7, and Sb / Sa in the second cooling zone 92 is 0.5. Sample No.1 Sb / Sa in the first cooling zone 91 is 0.8, and Sb / Sa in the second cooling zone 92 is 0.5. Sample No.1 Sb / Sa in the first cooling zone 91 is 0.9, and Sb / Sa in the second cooling zone 92 is 0.5. Sample No.1 Sb / Sa in the first cooling zone 91 is 0.9, and Sb / Sa in the second cooling zone 92 is 0.4.

[0073] Electricity was applied to the heater 3 of the wafer heating device 1 of each sample, and the temperature of all heating zones 8 of the heater 3 was maintained at 150°C. The temperature of each heating zone 8 was measured by the temperature measuring element 25. Next, after the power supply to the heater 3 was stopped once, the cooling plate 5 of the cooling unit 11 was brought into contact with the support plate 4. Each heating zone 8 was cooled to 100°C±0.5°C. Each heating zone 8 was intermittently heated by intermittent power supply in order to maintain the temperature at 100°C±0.5°C. In this test, the cooling time until the temperature of all heating zones 8 of the heater 3 reached 100°C±0.5°C was measured. The results are shown in Table 1. The unit of cooling time is seconds (s).

[0074] [Table 1]

[0075] As shown in Table 1, it was clear that the smaller the difference ΔSb / Sa, the shorter the cooling time of the entire heater 3 in the wafer heating apparatus 1. In particular, the cooling times of the heaters 3 of samples No. 1, No. 2, and No. 3, in which the difference ΔSb / Sa was 0.35 or less, were 50 seconds or less. On the other hand, the cooling times of the heaters 3 of samples No. 4 and No. 5, in which the difference ΔSb / Sa was more than 0.35, were more than 70 seconds.

[0076] The reason why the cooling time of the heater 3 becomes shorter as the difference ΔSb / Sa becomes smaller is presumed to be as follows. The heating zone 8 cooled by the first cooling zone 91, which has the largest Sb / Sa, reaches 100°C earlier than the heating zone 8 cooled by the second cooling zone 92, which has the smallest Sb / Sa. As the difference ΔSb / Sa becomes smaller, the difference between the time at which the temperature of the heating zone 8 cooled by the first cooling zone 91 reaches 100°C and the time at which the temperature of the heating zone 8 cooled by the second cooling zone 92 reaches 100°C becomes smaller. Therefore, the number of times and the time of intermittent heating to maintain the heating zone 8 cooled by the first cooling zone 91 at 100°C are reduced. Therefore, the cooling time of the entire heater 3 is shortened. [Explanation of symbols]

[0077] 100 wafers 1 Wafer heating device 10 Heater unit, 10D bottom, 10U top 11 Cooling unit 2 Wafer holder plate 2D bottom, 2U top 20 counterbore, 25 temperature sensor 3 Heater 3D bottom side 30 Circuit pattern, 31 Substrate 35 blind hole, 36 third through hole 4 Support plate 4D bottom side 45,46 second through hole, 45h lower opening, 45v projected contour line 5 Cooling plate 5D bottom, 5U top 50 Main body, 51 Upper floor 52, 53 recess, 52b bottom, 52h opening, 54 first recess 55,56 First through hole, 55h upper opening 6 cooling stages, 60 fixed axis 7,70 wiring, 7c, 70c middle part, 71 first wiring 8 Heating Zones 9 Cooling Zone 91 First cooling zone, 92 Second cooling zone 93 Third cooling zone, 94 Fourth cooling zone

Claims

1. a heater unit including an upper surface on which a wafer is placed and a heater for heating the wafer; a cooling plate for cooling the heater unit; wiring drawn out from a lower surface of the heater unit; the cooling plate is configured to be movable between a state in which an upper surface of the cooling plate is in contact with a lower surface of the heater unit and a state in which the upper surface of the cooling plate is separated from the lower surface of the heater unit, The cooling plate includes a recess provided on an upper surface thereof and a first through hole extending from a bottom of the recess in a thickness direction thereof, the wiring is drawn through the recess and the first through hole to a lower surface side of the cooling plate when the heater unit and the cooling plate are in contact with each other, an upper surface of the cooling plate includes a cooling zone which is a virtual area corresponding to a heating zone of the heater; an area Sa of the inside of the outer circumferential contour of the cooling zone and a contact area Sb of the cooling zone with the heater unit satisfy Sb / Sa≧0.5; Wafer heating device.

2. The heating zone includes a plurality of heating zones, The cooling zone comprises a plurality of cooling zones; Each of the cooling zones corresponds to each of the heating zones.

2. The wafer heating apparatus of claim 1.

3. The plurality of cooling zones include a first cooling zone having the largest Sb / Sa ratio and a second cooling zone having the smallest Sb / Sa ratio, 3. The wafer heating apparatus according to claim 2, wherein a difference between Sb / Sa in the first cooling zone and Sb / Sa in the second cooling zone is 0.35 or less.

4. the plurality of cooling zones includes adjacent third and fourth cooling zones; the area inside the outer circumferential contour of the third cooling zone is smaller than the area inside the outer circumferential contour of the fourth cooling zone; the wiring includes a first wiring extending from the heating zone corresponding to the third cooling zone; the recess includes a first recess corresponding to the first wiring, The wafer heating apparatus according to claim 2 or 3, wherein at least a portion of the first recess is disposed in the fourth cooling zone.

5. A part of an intermediate portion of the wiring is fixed to a lower surface of the heater unit, 5. The wafer heating device according to claim 1, wherein the intermediate portion is disposed inside the recessed portion in a state in which the heater unit and the cooling plate are in contact with each other.

6. The wafer heating apparatus according to claim 5 , wherein the first through hole is disposed below a portion where the intermediate portion is fixed to the heater unit.

7. the heater unit includes a support plate that supports the heater from below, the cooling plate is configured to be movable between a state in which an upper surface of the cooling plate is in contact with a lower surface of the support plate and a state in which the upper surface of the cooling plate is separated from the lower surface of the support plate, The support plate has a second through hole penetrating in a thickness direction, the recess is provided such that a continuous space is formed between an upper opening of the first through hole and a lower opening of the second through hole when the support plate and the cooling plate are in contact with each other, The wafer heating device according to claim 1 , wherein the wiring is led out below the support plate through the second through hole.

8. At room temperature, a projected outline of the second through hole is located inside an outline of an opening of the recess, 8. The wafer heating apparatus according to claim 7, wherein the projected contour line is a contour line obtained by projecting a contour line of the lower opening onto the cooling plate.

9. The cooling plate includes a body and an upper layer disposed on an upper surface of the body; The body is made of metal, The wafer heating apparatus according to claim 1 , wherein the upper layer is made of a material different from that of the main body.

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