Wafer heating device
By connecting the circuit patterns of the wafer heating device in the same phase and optimizing the configuration, the problem of increased leakage current was solved, enabling higher temperature wafer heating and a more uniform circuit design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUMITOMO ELECTRIC INDUSTRIES LTD
- Filing Date
- 2025-12-25
- Publication Date
- 2026-07-21
AI Technical Summary
In existing wafer heating devices, the central heating circuit and the peripheral heating circuit are connected to different phases of a three-phase AC power supply, resulting in increased leakage current.
By connecting the first and second circuit patterns to the same phase of a three-phase AC power supply, the configuration of the circuit patterns is optimized, the potential difference is reduced, and a heating element is placed in the internal parallel plane of the mounting plate to reduce the overlap and distance between the circuit patterns.
It effectively reduces leakage current, increases the temperature at which thin films are formed on the wafer surface, reduces the overlapping area of circuit patterns and the number of components, and reduces voltage imbalance.
Smart Images
Figure CN122438201A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to wafer heating apparatus. Background Technology
[0002] Patent Document 1 discloses a substrate mounting stage for heating a semiconductor substrate, having an upper surface on which a semiconductor substrate is mounted. The substrate mounting stage is circular. The upper surface of the substrate mounting stage has a circular central region centered on the center of the upper surface, and an annular outer peripheral region disposed around the outer periphery of the central region. A heating circuit for heating the semiconductor substrate is embedded in a plane parallel to the upper surface inside the substrate mounting stage. The heating circuit has a central heating circuit disposed in the plane corresponding to the central region, and an outer peripheral heating circuit disposed in the plane corresponding to the outer peripheral region. The central heating circuit is disposed in the plane closer to the upper surface than the outer peripheral heating circuit. Power is supplied to the central heating circuit and the outer peripheral heating circuit from an external power source.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent Document 1: International Publication No. 2019 / 008889 Summary of the Invention
[0006] The technical problem that the invention aims to solve
[0007] Generally, the external power supply is a three-phase AC power supply, with the central heating circuit and the peripheral heating circuit connected to different phases of the three-phase AC power supply. When the central heating circuit and the peripheral heating circuit are arranged in different planes with partial overlap in a direction orthogonal to the upper surface, the connection of the central heating circuit and the peripheral heating circuit to different phases creates a potential difference between the two circuits. Due to this potential difference, the leakage current between the two circuits may increase.
[0008] One of the purposes of this disclosure is to provide a wafer heating device that can reduce leakage current.
[0009] Solutions for solving technical problems
[0010] The wafer heating apparatus disclosed herein includes a heater comprising: a mounting plate having an upper surface for mounting a wafer; and a heating element disposed within a plane parallel to the upper surface of the mounting plate. The heater is configured to receive power from a three-phase AC power supply. The heating element has a plurality of circuit patterns. The plurality of circuit patterns includes a first circuit pattern and a second circuit pattern that are adjacent to each other. The first circuit pattern and the second circuit pattern are connected to the same phase of the three-phase AC power supply.
[0011] Invention Effects
[0012] The wafer heating device disclosed herein can reduce leakage current. Attached Figure Description
[0013] Figure 1 This is a schematic longitudinal cross-sectional view showing the wafer heating apparatus of Embodiment 1.
[0014] Figure 2 This is a first schematic cross-sectional view of the mounting plate in the wafer heating apparatus of Embodiment 1.
[0015] Figure 3 This is a second schematic cross-sectional view of the mounting plate in the wafer heating apparatus of Embodiment 1.
[0016] Figure 4 yes Figure 1 A magnified view of region A.
[0017] Figure 5 This is a schematic longitudinal cross-sectional view showing the wafer heating apparatus of Embodiment 2.
[0018] Figure 6 This is a schematic cross-sectional view of the mounting plate in the wafer heating apparatus of Embodiment 3.
[0019] Figure 7 This is a schematic longitudinal cross-sectional view showing the wafer heating apparatus of Embodiment 3.
[0020] Figure 8 This is a schematic longitudinal cross-sectional view showing the wafer heating apparatus of Embodiment 4. Detailed Implementation
[0021] [Description of embodiments of this disclosure]
[0022] First, we will describe the implementation aspects of this disclosure.
[0023] (1) A wafer heating apparatus according to one aspect of the present disclosure includes a heater, the heater comprising: a mounting plate having an upper surface for mounting a wafer; and a heating element disposed in a plane parallel to the upper surface within the mounting plate. The heater is configured to receive power from a three-phase AC power supply. The heating element has a plurality of circuit patterns. The plurality of circuit patterns have a first circuit pattern and a second circuit pattern adjacent to each other. The first circuit pattern and the second circuit pattern are connected to the same phase of the three-phase AC power supply.
[0024] The wafer heating device described in (1) reduces the potential difference between the first and second circuit patterns by connecting the first and second circuit patterns to the same phase, compared to the case where they are connected to different phases. Therefore, the wafer heating device described in (1) can reduce leakage current. The lower the volume resistivity of the portion disposed between multiple circuit patterns, the greater the leakage current; the higher the temperature, the lower the volume resistivity. That is, the higher the temperature, the greater the leakage current. Because the wafer heating device described in (1) can reduce leakage current, it can heat the wafer to a relatively high temperature when forming a thin film on the wafer surface.
[0025] (2) In the wafer heating device of (1) above, the shortest distance between the first circuit pattern and the second circuit pattern may be less than 15 mm.
[0026] If the first circuit pattern and the second circuit pattern are connected to different phases, and the minimum distance is 15 mm or less, a potential difference is easily generated between the first circuit pattern and the second circuit pattern. However, the wafer heating apparatus of (2) described above can reduce the potential difference between the first circuit pattern and the second circuit pattern even if the minimum distance is set to 15 mm or less by connecting the first circuit pattern and the second circuit pattern to the same phase. Therefore, the wafer heating apparatus of (2) described above can set the minimum distance to 15 mm or less.
[0027] (3) In the wafer heating apparatus of (1) or (2) above, the first circuit pattern and the second circuit pattern may be arranged in the same plane.
[0028] Although the first circuit pattern and the second circuit pattern of the wafer heating device described above (3) are arranged in the same plane parallel to the upper surface, leakage current can be reduced. Moreover, the wafer heating device described above (3) can reduce the thickness of the substrate.
[0029] (4) In the wafer heating apparatus of (1) or (2) above, the first circuit pattern may be disposed in a first surface parallel to the upper surface, and the second circuit pattern may be disposed in a second surface further away from the upper surface than the first surface.
[0030] Although the wafer heating device described above (4) is configured such that the first circuit pattern and the second circuit pattern partially overlap in a direction orthogonal to the upper surface, it can reduce leakage current.
[0031] (5) In the wafer heating apparatus of (4) above, the wafer heating apparatus may also have a region in which the first circuit pattern and the second circuit pattern repeat in a direction orthogonal to the upper surface. When viewed from above in a direction perpendicular to the upper surface, the ratio of the overlapping area SA of the first region where the first circuit pattern is arranged and the second region where the second circuit pattern is arranged to the larger of the total area of the first region and the total area of the second region, SA / SB×100%, is 3% or more.
[0032] The larger the repeating area SA, the more likely the leakage current will increase. That is, if the ratio is 3% or more, the leakage current will increase more easily due to the large repeating area SA. Even if the ratio is 3% or more, the wafer heating device of (5) described above can reduce the leakage current compared with the case where the first circuit pattern and the second circuit pattern are connected to different phases.
[0033] (6) In any of the above (1) to (5) wafer heating devices, the number of heaters may be multiple, and at least two of the multiple heaters are connected to different phases of the three-phase AC power supply.
[0034] The wafer heating device described in (6) above can prevent the load from concentrating on a specific phase by connecting at least two of the multiple heaters to different phases of a three-phase AC power supply. That is, the wafer heating device described in (6) above can reduce voltage imbalance.
[0035] Details of the embodiments disclosed herein
[0036] Hereinafter, embodiments of the wafer heating apparatus of this disclosure will be described based on the accompanying drawings. The shapes, dimensions, and positional relationships shown in the drawings are for illustrative purposes only and do not necessarily represent actual shapes, dimensions, and positional relationships. The same reference numerals in the drawings denote the same names of objects.
[0037] [Implementation Method 1]
[0038] <Wafer Heating Device>
[0039] Reference Figures 1 to 4 The wafer heating apparatus 1 of Embodiment 1 will be described below. Figure 1 As shown, the wafer heating apparatus 1 of Embodiment 1 includes a heater 2. The heater 2 is configured to receive power from a three-phase AC power supply 6 (hereinafter simply referred to as power supply 6). The heater 2 can be used in a film-forming apparatus to form a thin film on the surface of a wafer 100. The heater 2 allows a spray head to be sprayed into a chamber (not shown) within the wafer. Figure 1The upper surface 31 of the mounting plate 3 shown is fixed to the mounting platform face-to-face. The heater 2 includes the mounting plate 3, the heating element 4, and the shaft 5. Figure 1 As shown, the mounting plate 3 has an upper surface 31 for mounting the wafer 100 and a lower surface 32 that is the opposite surface of the upper surface 31. Figures 1 to 3 As shown, the heating element 4 is disposed inside the mounting plate 3. The mounting plate 3 is supported by a shaft 5. A power supply 6 supplies power to the heating element 4. One feature of the wafer heating device 1 in Embodiment 1 is the connection method between the heating element 4 and the power supply 6.
[0040] Heater
[0041] [Placement plate]
[0042] A wafer 100 is mounted on the upper surface 31 of the mounting plate 3. The wafer 100 is, for example, a silicon or compound semiconductor wafer. An axis 5 is fixed on the lower surface 32 of the mounting plate 3. The shape of the mounting plate 3 in this example is circular when viewed from above. The material of the mounting plate 3 is, for example, ceramic. The ceramic is, for example, aluminum nitride, silicon nitride, silicon carbide, or alumina. Among these ceramics, aluminum nitride, which has high thermal conductivity, is suitable for the mounting plate 3. The mounting plate 3 can also be formed from a composite material of the above-mentioned ceramic and metal. The metal forming the composite material is, for example, aluminum, aluminum alloy, copper, or copper alloy. The material of the mounting plate 3 in this example is ceramic.
[0043] The upper surface 31 is virtually divided into multiple heating regions in a direction away from its center. A heating region is a virtual partition on the upper surface 31 that includes circuit pattern units capable of independent temperature control. The number of heating regions corresponds to the number of circuit patterns capable of independent temperature control. For example, if there are two heating regions, there are two circuit patterns. In this example, the upper surface 31 is divided into an inner region and an outer peripheral region. The inner region is a circular region concentric with the center of the mounting plate 3. The outer peripheral region is an annular region concentric with the center of the mounting plate 3. The outer peripheral region is an annular region surrounding the inner region.
[0044] [Fever body]
[0045] The heating element 4 is a heat source for heating the wafer 100 mounted on the upper surface 31 of the carrier plate 3. The material of the heating element 4 is not particularly limited as long as it can heat the wafer 100 to the desired temperature. The material of the heating element 4 is a metal suitable for resistance heating. The metal forming the heating element 4 is, for example, selected from the group consisting of stainless steel, nickel, nickel alloys, silver, silver alloys, tungsten, tungsten alloys, molybdenum, molybdenum alloys, chromium, and chromium alloys. For example, a nickel-chromium alloy is used as a nickel alloy.
[0046] The heating element 4 is disposed within a plane parallel to the upper surface 31 inside the mounting plate 3. The heating element 4 has multiple circuit patterns disposed on different planes in a manner that partially overlaps in a direction orthogonal to the upper surface 31. In this example, there are two circuit patterns. The heating element 4 in this example has the following... Figure 1 , Figure 2 The first circuit pattern 41 arranged in the first surface as shown, and as shown in the figure Figure 1 , Figure 3 The second circuit pattern 42 is shown disposed on the second surface. Figure 2 , Figure 3 For ease of explanation, only circuit diagrams 41 and 42 are marked with shaded lines. This will be explained later. Figure 6 The same applies to China. For example... Figure 1 As shown, the second surface is farther away from the upper surface 31 than the first surface. That is, the second circuit pattern 42 is positioned farther away from the upper surface 31 than the first circuit pattern 41. The first circuit pattern 41 is positioned in the region of the first surface corresponding to the inner region of the upper surface 31. The second circuit pattern 42 is positioned in the region of the second surface corresponding to the outer peripheral region of the upper surface 31. It should be noted that the first circuit pattern 41 and the second circuit pattern 42 can also be arranged with their positions reversed. The above description can be understood as the first circuit pattern 41 being positioned in the second surface and the second circuit pattern 42 being positioned in the first surface.
[0047] The shortest distance between the first circuit pattern 41 and the second circuit pattern 42 is, for example, 15 mm or less. Unlike this example, if the first circuit pattern 41 and the second circuit pattern 42 are connected to different phases and the aforementioned shortest distance is 15 mm or less, a potential difference is easily generated between the first circuit pattern 41 and the second circuit pattern 42. However, the wafer heating apparatus 1 in this example connects the first circuit pattern 41 and the second circuit pattern 42 to the same phase, thereby reducing the potential difference between the first circuit pattern 41 and the second circuit pattern 42 even when the aforementioned shortest distance is set to 15 mm or less, compared to the case where they are connected to different phases. Therefore, the wafer heating apparatus 1 in this example can set the aforementioned shortest distance to 15 mm or less. The aforementioned shortest distance is 10 mm or less or 5.0 mm or less. The aforementioned shortest distance is, for example, 1.0 mm or more. The aforementioned shortest distance is 1.0 mm or more and 15 mm or less, 1.0 mm or more and 10 mm or less, or 1.0 mm or more and 5.0 mm or less.
[0048] like Figure 4As shown, the distance L between the first circuit pattern 41 and the second circuit pattern 42 in a direction orthogonal to the upper surface 31 is, for example, 1.0 mm or more and 10.0 mm or less. If the distance L is 1.0 mm or more, the resistance value of the portion disposed between the first circuit pattern 41 and the second circuit pattern 42 increases, thus reducing the leakage current between the two circuit patterns 41 and 42. If the distance L is 10.0 mm or less, the second circuit pattern 42 will not be too far away from the upper surface 31, thus allowing for more uniform heating of the wafer 100. The distance L can also be 2.0 mm or more and 7.0 mm or less, or 3.0 mm or more and 6.0 mm or less.
[0049] like Figure 2 The diagram shows the first circuit pattern 41, as follows: Figure 3 The diagram shows the second circuit pattern 42. Figure 2 , Figure 3 The circuit diagrams 41 and 42 are schematic examples of wiring methods and are not limited to... Figure 2 , Figure 3 The structure. For example, the second circuit pattern 42 may not be a linear pattern like the straight section 421 described later, but a semi-circular pattern including each second terminal 72a, 72b.
[0050] exist Figure 2 In the first circuit pattern 41, the two first terminals 71a and 71b that supply power to the first circuit pattern 41 are connected to the first circuit pattern 41 near the center of the mounting plate 3. The first circuit pattern 41 is formed by a plurality of concentric curved portions 411 and straight portions 412 that connect adjacent curved portions 411 to each other in a single stroke.
[0051] In this example, the width W1 of the straight portion 412 is the same as the width of the curved portion 411. The width W1 is, for example, 0.5 mm or more and 10.0 mm or less. Width W1 refers to the length, viewed from a direction orthogonal to the upper surface 31, along a direction orthogonal to the length direction of the straight portion 412. If the width W1 is 0.5 mm or more, the repeating area SA, as described later, tends to increase, thus increasing the leakage current. However, as described later, the wafer heating device 1 in this example can reduce the leakage current. That is, the wafer heating device 1 in this example can reduce the leakage current even if the width W1 is 0.5 mm or more. If the width W1 is 10.0 mm or less, the heat density tends to increase. The width W1 can also be 2.5 mm or more and 6.5 mm or less, or 3.0 mm or more and 6.0 mm or less.
[0052] exist Figure 3In this example, the connection points of the two second terminals 72a and 72b supplying power to the second circuit pattern 42 are located near the center of the mounting plate 3, and near the connection points of the first terminals 71a and 71b with the first circuit pattern 41. The second circuit pattern 42 is formed in a single-stroke shape by a first straight section 421, a plurality of concentric curved sections 422, and a second straight section 423. The first straight section 421 extends in a straight line from the connection points of each second terminal 72a and 72b with the second circuit pattern 42 towards the vicinity of the outer peripheral edge of the mounting plate 3. The second straight section 423 connects adjacent curved sections 422 to each other. Each first straight section 421 overlaps with the inner region in a direction orthogonal to the upper surface 31. In this example, each first straight section 421 is connected to the curved section 422 located at the outermost periphery. In this example, the width W2 of the second straight section 423 is the same as the width and width W1 of the curved section 422. In this example, the width W3 of each first straight section 421 is larger than the width W2. Widths W2 and W3 are lengths observed from a direction orthogonal to the upper surface 31, along a direction orthogonal to the length direction of each section 422, 423. Because width W3 is larger than width W2, it is easier to reduce the heat density of each first straight section 421. Therefore, the influence of the heat generated by each first straight section 421 on the temperature of the inner region of the upper surface 31 is more easily reduced.
[0053] In this example, the first circuit pattern 41 and the first straight section 421 partially overlap in a direction orthogonal to the upper surface 31. As described later, the first circuit pattern 41 and the second circuit pattern 42 are connected to the same phase of the power supply 6, which is the R phase in this example. Specifically, the first terminal 71a and the second terminal 72a are connected to the R phase in this example, and the first terminal 71b and the second terminal 72b are connected to the S phase of the power supply 6. Therefore, although the first circuit pattern 41 and the second circuit pattern 42 partially overlap, the leakage current can be reduced. The wafer heating device 1 in this example, which can reduce leakage current, can also eliminate the need for an insulation transformer between the semiconductor element 10 and the power supply 6, as described later, thus reducing the number of components. The lower the volume resistivity of the portion disposed between the first circuit pattern 41 and the second circuit pattern 42, the greater the leakage current; the higher the temperature, the lower the volume resistivity. That is, the higher the temperature, the greater the leakage current. For example, the volume resistivity of aluminum nitride is 10 at 450°C. 6 Ω·cm or more and 10 11 Below Ω·cm, at 550℃, it is 10 5 Ω·cm or more and 10 9 Below Ω·cm, at 650℃, it is 10 4 Ω·cm or more and 10 8The volume resistivity is approximately below Ω·cm. Thus, in aluminum nitride, the higher the temperature, the lower the volume resistivity, and therefore, the higher the temperature, the easier it is for leakage current to increase. The wafer heating device 1 in this example can reduce leakage current, and therefore, when forming a thin film on the surface of wafer 100, it can heat wafer 100 to a relatively high temperature.
[0054] When viewed from above in a direction perpendicular to the upper surface 31, the ratio of the overlapping area SA of the first region C1 where the first circuit pattern 41 is arranged and the second region C2 where the second circuit pattern 42 is arranged to the larger of the areas SA / SB of the total area S1 of the first region C1 and the total area S2 of the second region C2, is, for example, 3% or more. The first region C1 refers to the entire region surrounded by the outer contour line C11 and the inner contour line C12 of the first circuit pattern 41. That is, the first region C1 includes, in addition to the curved portion 411 itself and the straight portion 412 itself, the area between the curved portions 411 and the area between the straight portions 412. The second region C2 refers to the entire region surrounded by the outer contour line C21 and the inner contour line C22 of the second circuit pattern 42. The second region C2, in addition to the first straight portion 421 itself, the curved portion 422 itself, and the second straight portion 423 itself, also includes the area between the first straight portions 421, the area between the curved portions 422, and the area between the first straight portion 421 and the second straight portion 423. Figure 2 , Figure 3 For ease of explanation, and to distinguish them from the outlines of the first circuit pattern 41 and the second circuit pattern 42, the outer outlines C11 and C21 are made larger than their respective outlines and represented by double-dotted lines, although they actually overlap with their outlines. Similarly, to distinguish them from the outlines of the first circuit pattern 41 and the second circuit pattern 42, the inner outlines C12 and C22 are made smaller than their respective outlines and represented by double-dotted lines, although they actually overlap with their outlines. It should be noted that, in special configurations where the area occupied by the circuit pattern in each region C1 and C2 is small (e.g., less than 3%), the total area of the first circuit pattern 41 projected when viewed from above can be set as S1, the total area of the second circuit pattern 42 projected when viewed from above as S2, and the overlapping area of the first circuit pattern 41 and the second circuit pattern 42 as SA.
[0055] The larger the repeating area SA, the more likely the leakage current will increase. That is, if the ratio is 3% or more, the leakage current is more likely to increase due to the large repeating area SA. However, as described later, the wafer heating device 1 in this example can reduce the leakage current. The ratio can also be 10% or more or 20% or more. There is no particular upper limit to the ratio. In practical designs, the ratio is, for example, less than 100%, or 90% or less. The ratio can also be 80% or less or 50% or less. The ratio can be 3% or more and 90% or less, 10% or more and 90% or less, or 20% or more and 90% or less.
[0056] 〔axis〕
[0057] Shaft 5 supports mounting plate 3. In this example, shaft 5 is cylindrical. Shaft 5 and mounting plate 3 are arranged concentrically. That is, shaft 5 is connected to mounting plate 3 in such a way that the center of the cylindrical shaft 5 is coaxial with the center of the circular mounting plate 3. The material of shaft 5 is selected from one of the ceramic groups described in the material section of mounting plate 3, or from one of the composite material groups. The material of shaft 5 may be the same as or different from the material of mounting plate 3. In this example, the material of shaft 5 is ceramic.
[0058] Three-phase AC power supply
[0059] A three-phase AC power supply 6 supplies power to the heating element 4. This power supply 6 is connected to the heating element 4 via terminals 7 and power lines 8. Terminals 7 are first terminals 71a and 71b connected to each end of the first circuit pattern 41, and second terminals 72a and 72b connected to each end of the second circuit pattern 42. Power lines 8 are first power lines 81a and 81b connected to each of the first terminals 71a and 71b, and second power lines 82a and 82b connected to each of the second terminals 72a and 72b. Terminals 7 and power lines 8 are disposed inside the shaft 5. The chamber where the heater 2 is disposed is typically filled with corrosive gas. By disposing of terminals 7 and power lines 8 inside the shaft 5, terminals 7 and power lines 8 can be isolated from the corrosive gas.
[0060] The power supply 6 is connected in a delta configuration. The R phase of power supply 6 is connected to the first circuit pattern 41 and the second circuit pattern 42 via a first power line 81a and a second power line 82a. The first power line 81a and the second power line 82a are combined and connected to the R phase. A semiconductor element 10 is connected to the first power line 81a and the second power line 82a, which switches between continuously energizing and de-energizing the heating element 4. The semiconductor element 10 is, for example, a thyristor. The S phase of power supply 6 is grounded via a grounding wire 9. A first power line 81b and a second power line 82b are connected to this grounding wire 9. The first power line 81b and the second power line 82b are combined and connected to the grounding wire 9. Power line 8 is not connected to the T phase of power supply 6.
[0061] [Implementation Method 2]
[0062] Reference Figure 5 , Figure 6 The wafer heating apparatus 1 of Embodiment 2 will be described below. Figure 5 As shown, the wafer heating device 1 of Embodiment 2 differs from the wafer heating device 1 of Embodiment 1 in that the first circuit pattern 41 and the second circuit pattern 42 are arranged on the same plane. The following description focuses on the differences from Embodiment 1. Descriptions of the same structures are omitted. These aspects are also the same in Embodiments 3 and 4 described later.
[0063] like Figure 6 As shown, the first circuit pattern 41 and the second circuit pattern 42 do not overlap in a direction orthogonal to the upper surface 31. Figure 6 In this configuration, the connection points of the two second terminals 72a and 72b that supply power to the second circuit pattern 42 are located near the outer periphery of the mounting plate 3. That is, the connection points of the second terminals 72a and 72b with the second circuit pattern 42 are located away from the connection points of the first terminals 71a and 71b with the first circuit pattern 41.
[0064] In this example, the shortest distance between the first circuit pattern 41 and the second circuit pattern 42 is the closest distance within a single plane. Figure 6 In this example, the distance between the outermost periphery of the first circuit pattern 41 and the innermost periphery of the second circuit pattern 42 is the shortest distance. If this shortest distance is 15 mm or less, the leakage current between the first circuit pattern 41 and the second circuit pattern 42 is likely to increase. The wafer heating apparatus 1 in this example connects the first circuit pattern 41 and the second circuit pattern 42 to the same phase, thereby reducing the leakage current between them even if the shortest distance is 15 mm or less, compared to the case where they are connected to different phases. Therefore, the wafer heating apparatus 1 in this example can set the shortest distance to 15 mm or less.
[0065] [Implementation Method 3]
[0066] Reference Figure 7 The wafer heating device 1 of Embodiment 3 will be described. The main difference between the wafer heating device 1 of Embodiment 3 and the wafer heating device 1 of Embodiment 1 is that the heating element 4 has three or more circuit patterns.
[0067] [Placement plate]
[0068] In this example, the upper surface 31 of the mounting plate 3 is divided into three heating zones. In addition to the inner and outer peripheral zones similar to those in Embodiment 1, the upper surface 31 in this example also has an outermost peripheral zone. The outermost peripheral zone is a ring-shaped region concentric with the center of the mounting plate 3. The outermost peripheral zone is a ring-shaped region surrounding the outer peripheral zone.
[0069] [Fever body]
[0070] In this example, there are three heating elements 4. In addition to the first circuit pattern 41 and the second circuit pattern 42, which are the same as in Embodiment 1, the heating element 4 in this example also has a third circuit pattern 43. The third circuit pattern 43 is disposed within a third surface. The third surface is parallel to the upper surface 31 and is farther away from the upper surface 31 than the second surface. That is, the third circuit pattern 43 is disposed at a position farther away from the upper surface 31 than the second circuit pattern 42. The first circuit pattern 41, the second circuit pattern 42, and the third circuit pattern 43 partially overlap in a direction orthogonal to the upper surface 31. The third circuit pattern 43 is connected to the power supply 6 via two third terminals 73a and 73b connected to each end, and two third power lines 83a and 83b connected to each terminal 73a and 73b. The first circuit pattern 41, the second circuit pattern 42, and the third circuit pattern 43 are connected to the same phase, for example, the R phase, of the power supply 6.
[0071] In this example, the regions where the first circuit pattern 41 and the second circuit pattern 42 overlap, as well as the regions where the second circuit pattern 42 and the third circuit pattern 43 overlap, can also be considered in the same way as in Embodiment 1.
[0072] [Implementation Method 4]
[0073] <Wafer Heating Device>
[0074] Reference Figure 8 The wafer heating apparatus 1 of Embodiment 4 will now be described. The main difference between the wafer heating apparatus 1 of Embodiment 4 and the wafer heating apparatus 1 of Embodiment 1 is that the number of heaters 2 is multiple.
[0075] In this example, there are two heaters 2. The structure of each heater 2 is the same as that of the heater 2 in Embodiment 1. Figure 8The first circuit pattern 41 and the second circuit pattern 42 of the first heater 2 shown in the left figure are connected to the same phase of the power supply 6, which is phase R in this example. Figure 8 The first circuit pattern 41 and the second circuit pattern 42 of the second heater 2 shown in the right figure are connected to the same phase of the power supply 6 but a different phase from that of the first heater 2, which is the T phase in this example. Specifically, the R phase of the power supply 6 is connected to the first circuit pattern 41 and the second circuit pattern 42 of the first heater 2 via the first power line 81a and the second power line 82a. The T phase of the power supply 6 is connected to the first circuit pattern 41 and the second circuit pattern 42 of the second heater 2 via the first power line 81a and the second power line 82a. The S phase of the power supply 6 is grounded via the grounding wire 9. The first power line 81b and the second power line 82b of the first heater 2, and the first power line 81b and the second power line 82b of the second heater 2 are connected to the grounding wire 9.
[0076] In the wafer heating device 1 of this example, the first circuit pattern 41 and the second circuit pattern 42 of the first heater 2 are connected to the same phase of the power supply 6, and the first circuit pattern 41 and the second circuit pattern 42 of the second heater 2 are also connected to the same phase of the power supply 6. Therefore, the wafer heating device 1 of this example can reduce the leakage current of the first heater 2 and the second heater 2. Furthermore, by connecting the first heater 2 and the second heater 2 to different phases of the power supply 6, the wafer heating device 1 of this example can prevent the load from concentrating on a specific phase. Therefore, the wafer heating device 1 of this example can reduce voltage imbalance.
[0077] By having multiple heaters 2, with at least two heaters 2 connected to different phases, load dispersion can be achieved compared to the case where all heaters 2 are connected to the same phase. When there are three heaters 2, each connected to a different phase, it is easiest to prevent load concentration in a specific phase. Even when there are four or more heaters 2, it is best to connect as many heaters 2 as possible to other phases.
[0078] [Experimental Example]
[0079] In the experimental example, the difference in leakage current was studied when the first and second circuit patterns of the heater were connected to the same phase of the power supply versus when they were connected to different phases.
[0080] <Sample No. 1>
[0081] The wafer heating device for sample No. 1 is a reference. Figures 1 to 4 The wafer heating apparatus 1 described in Embodiment 1. The volume resistivity of the aluminum nitride in the mounting plate 3 constituting Sample No. 1 is 10⁻⁶ at 450°C. 9 Ω·cm, 10 at 550℃8 Ω·cm, 10 at 650℃ 7 Ω·cm. The first circuit pattern 41 and the second circuit pattern 42 are arranged in different planes. The width W1 of the first circuit pattern 41, the width W2 of the curved portion 422 and the second straight portion 423 of the second circuit pattern 42 are set to 3mm. Figure 4 The distance L shown is set to 4mm. The first circuit pattern 41 and the second circuit pattern 42 are connected to the same phase of the power supply 6, which is phase R in this example.
[0082] <Sample No. 101>
[0083] The wafer heating device of sample No. 101 is the same as that of sample No. 1, except that the first circuit pattern 41 is connected to the R phase of the power supply 6 and the second circuit pattern 42 is connected to the T phase of the power supply 6.
[0084] <Measurement of Leakage Current>
[0085] A voltage obtained by phase control of an AC voltage of 200V was applied to the first circuit pattern 41 and the second circuit pattern 42, and the leakage current (mA) was measured at temperatures of the mounting plate 3 at 450°C, 550°C, and 650°C. The actual applied voltage ranged from 100V to 180V. The temperature of the mounting plate 3 was measured using a thermocouple (not shown) embedded in the mounting plate 3. The leakage current is the leakage current between the first circuit pattern 41 and the second circuit pattern 42. The leakage current was measured using a commercially available AC leakage current clamp meter capable of measuring AC current to the mA unit. Specifically, the leakage current was measured by clamping the first power line 81a and the first power line 81b together with the AC leakage current clamp meter, and by clamping the second power line 82a and the second power line 82b together with the AC leakage current clamp meter. The results are shown in Table 1.
[0086]
[0087] As shown in Table 1, when the temperature of the mounting plate 3 is any one of 450℃, 550℃, and 650℃, the leakage current of sample No.1 is lower than that of sample No.101. The higher the temperature of the mounting plate 3, the greater the reduction in leakage current of sample No.1 relative to sample No.101.
[0088] It should be noted that the present invention is not limited to the structure shown in the embodiments, but is defined by the claims and is intended to include all modifications with the same meaning and scope as the claims.
[0089] The number of heaters can also be three or more. For example, in the case of four heaters, the first and second circuit patterns of two of the four heaters are connected to the R phase of the power supply, and the first and second circuit patterns of the remaining two heaters are connected to the T phase of the power supply.
[0090] Explanation of reference numerals in the attached figures
[0091] 1. Wafer heating device
[0092] 2 heaters
[0093] 3. Mounting plate
[0094] 31 Upper surface
[0095] 32 Lower surface
[0096] 4. Heating element
[0097] 41 First Circuit Pattern
[0098] 411 Bending section
[0099] 412 Straight Section
[0100] 42 Second Circuit Pattern
[0101] 421 First Straight Section
[0102] 422 Bending section
[0103] 423 Second straight section
[0104] 43 Third Circuit Pattern
[0105] 5-axis
[0106] 6. Three-phase AC power supply (power supply)
[0107] 7 terminals
[0108] 71a, 71b First Terminal
[0109] 72a, 72b Second Terminal
[0110] 73a, 73b Third Terminal
[0111] 8 Power lines
[0112] 81a, 81b First Electric Power Line
[0113] 82a, 82b Second Power Line
[0114] 83a, 83b Third Power Line
[0115] 9. Grounding wire
[0116] 10 Semiconductor Components
[0117] 100 wafers
[0118] Area A
[0119] C1 First Area
[0120] C11 Outer contour line
[0121] C12 inner contour line
[0122] C2 Second Area
[0123] C21 Outer contour line
[0124] C22 inner contour line
[0125] L distance
[0126] W1, W2, W3 widths.
Claims
1. A wafer heating device, The device includes a heater comprising: a mounting plate having an upper surface for mounting a wafer; and a heating element disposed within a plane of the mounting plate parallel to the upper surface. The heater is configured to receive power from a three-phase AC power source. The heating element has multiple circuit patterns. The plurality of circuit patterns have a first circuit pattern and a second circuit pattern that are adjacent to each other. The first circuit pattern and the second circuit pattern are connected to the same phase of the three-phase AC power supply.
2. The wafer heating apparatus according to claim 1, wherein, The shortest distance between the first circuit pattern and the second circuit pattern is less than 15mm.
3. The wafer heating apparatus according to claim 1 or 2, wherein, The first circuit pattern and the second circuit pattern are disposed in the same plane.
4. The wafer heating apparatus according to claim 1 or 2, wherein, The first circuit pattern is disposed in a first plane parallel to the upper surface. The second circuit pattern is disposed in a second surface that is further away from the upper surface than in the first surface.
5. The wafer heating apparatus according to claim 4, wherein, The wafer heating device has a region where the first circuit pattern and the second circuit pattern repeat in a direction orthogonal to the upper surface. When viewed from above in a direction perpendicular to the upper surface, the ratio of the overlapping area SA of the first region with the first circuit pattern and the second region with the second circuit pattern to the larger of the total area of the first region and the total area of the second region, SA / SB×100%, is 3% or more.
6. The wafer heating apparatus according to claim 1 or 2, wherein, The number of heaters is multiple. At least two of the plurality of heaters are connected to different phases of the three-phase AC power supply.