Temperature control unit

Abstract

The temperature regulating unit (1) of the present invention comprises: a temperature regulating unit body (2); a temperature regulating part (3) arranged inside the temperature regulating unit body (2) and raising or lowering the surface temperature of the temperature regulating unit body (2) on the side where the temperature regulating object (100) is located; and a thin film temperature measuring resistor part (4) formed within a certain range within the temperature regulating unit body (2) and on the side where the temperature regulating object (100) is located, and arranged on a side closer to the temperature regulating object (100) than the temperature regulating part (3), and formed by a thermal spray film. The temperature regulating unit can accurately measure the average temperature within the temperature regulating surface.

Description

Technical Field

[0001] The present invention is applicable to a temperature control unit including a temperature measuring resistor for measuring the temperature of a temperature control object. Background Art

[0002] In recent years, in semiconductor manufacturing processes, microfabrication of substrates is generally performed by dry methods such as dry etching under vacuum or reduced pressure. In the case of dry etching using plasma, the substrate inputs heat from the plasma. Since the temperature of the substrate affects the etching rate, if its temperature distribution is uneven, the etching depth will vary. Therefore, it is necessary to adjust the temperature so that the temperature of the substrate is uniform within the surface, and it is necessary to accurately grasp the substrate temperature for accurate temperature control.

[0003] Patent document 1 describes an electrostatic attraction device, which includes: a substrate having a plurality of coolant grooves, a high resistance layer formed on the substrate, a plurality of heaters formed by thermally spraying a conductor in the high resistance layer, and a plurality of electrostatic attraction electrodes formed by thermally spraying a conductor in the high resistance layer. In the electrostatic attraction device, a depression is provided on the substrate, and an armored thermocouple for obtaining temperature information is fixed in the depression by a fixing fixture. Patent document 1 describes that the armored thermocouple is contacted by a spring with a certain pressing load, so the reliability of the measurement result is high.

[0004] Patent document 2 describes an evaluation device for a substrate mounting device that fixes and controls the temperature of a substrate to be processed, which includes an airtight chamber, an evaluation substrate having a heating resistor heating body, and a temperature measuring mechanism for measuring the temperature of the evaluation substrate. A temperature probe having a plurality of thermocouple elements is mounted on the resistance heating body. In addition, it is also described that the substrate is exposed from an opening through which the temperature probe embedded in the resistance heating body is taken out, and infrared light emitted from the opening of the resistance heating body is measured by a radiation thermometer disposed inside or outside the airtight chamber.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2007-088411

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-155140 Summary of the invention

[0009] -Problems that the invention needs to solve-

[0010] In the case where a sheathed thermocouple is set in a depression of a substrate as shown in Patent Document 1, and in the case where multiple thermocouple elements are installed on a heat-generating resistance heating body as shown in Patent Document 2, the position where the thermocouple is arranged will become a thermal abnormal point, which will be different from the original temperature of the substrate, so it is difficult to accurately measure the average temperature of the entire substrate. Furthermore, these thermocouples are usually arranged through holes set from the back side of the substrate, and the distance from the substrate is far, so there is a big difference between the measured temperature and the actual temperature of the substrate. In addition, in the method of measuring the temperature of the substrate by detecting infrared light with a radiation thermometer set inside or outside the airtight chamber, when there are other heat sources such as plasma light-emitting components or halogen heaters, these heat sources hinder the temperature measurement of infrared light, making it difficult to measure the accurate temperature of the substrate. It should be noted that such a problem is not limited to the field of semiconductor manufacturing processes, and the same problem will occur when thermocouples are used in other fields or when there are other heat sources.

[0011] The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a temperature control unit that can accurately measure the average temperature within a temperature control surface.

[0012] -Solutions to solve the problem-

[0013] The temperature regulating unit of the present invention includes: a temperature regulating unit body; a temperature regulating portion, which is arranged inside the temperature regulating unit body and raises or lowers the surface temperature of the temperature regulating unit body on the side where the temperature regulating object is located; and a thin film temperature measuring resistor portion, which is formed inside the temperature regulating unit body and within a certain range within the surface on the side where the temperature regulating object is located, and is arranged on a side closer to the temperature regulating object than the temperature regulating portion, and is formed by a thermal spray film.

[0014] According to the temperature regulating unit of the present invention, since the temperature measuring resistor part is arranged on a side closer to the temperature regulating object than the temperature regulating part, there is almost no difference between the measured temperature and the actual temperature of the temperature regulating object. In addition, since the temperature measuring resistor part is formed by a thermal spraying film, a thinner temperature measuring resistor part can be formed, thereby shortening the distance between the temperature regulating object and the temperature regulating part. Furthermore, since the temperature measuring resistor part is formed within a certain range within the surface of the temperature regulating object side of the temperature regulating unit body, there is no thermal abnormal point as when using a thermocouple, thereby accurately measuring the average temperature within the temperature regulating surface. Furthermore, if the obtained temperature information is fed back, the temperature of the temperature regulating object can be controlled with higher accuracy.

[0015] The thin film temperature measuring resistor part can be formed into a strip pattern with a folded part on the same surface. The number of folded parts can be single, but preferably multiple. Thus, a temperature measuring surface can be formed over a wide range.

[0016] Preferably, the thin film temperature measuring resistor portion is made of a metal or alloy containing Al. In this case, compared with other metals or alloys, the change in resistance value over time during long-term use is smaller, and the reliability of measurement is high.

[0017] The temperature regulating portion may be a thermal sprayed film formed into a band-shaped pattern with a folded portion on the same surface. The number of folded portions may be single, but preferably multiple. Thus, a temperature regulating surface can be formed over a wide range. In addition, since the temperature regulating portion can be formed by a thin film, the thickness of the entire temperature regulating unit can be reduced.

[0018] In the case where the temperature regulating part is composed of a plurality of structural parts, a part of each of the plurality of structural parts can constitute a power supply terminal part connected to the power supply terminal, and in the case where the thin film temperature measuring resistor part is composed of a plurality of structural parts, a part of each of the plurality of structural parts can constitute a resistance value measuring terminal part connected to the resistance value measuring terminal. Thus, temperature regulation control and temperature measurement can be performed within a desired range, increasing the design variation. In this case, preferably, each structural part of the temperature regulating part and each structural part of the thin film temperature measuring resistor part are configured to correspond to each other in the thickness direction of the temperature regulating unit. Thus, the temperature regulating surface can be divided into a plurality of regions, and the temperature of each region can be measured, so that each region can be individually and precisely temperature controlled.

[0019] In the temperature control unit, for example, the temperature control unit body may include a substrate portion and an insulating layer formed on the surface of the substrate portion, and the thin film temperature measuring resistor portion may be disposed within the insulating layer. Thus, the substrate portion may be made of a conductive material, increasing the design variation. In addition, the temperature control surface may be made insulating, or may have a surface protection function.

[0020] -Effects of the Invention-

[0021] According to the present invention, there is almost no difference between the measured temperature and the actual temperature of the temperature control object. In addition, since there is no thermal abnormal point as in the case of using a thermocouple, the average temperature in the temperature control surface can be accurately measured. Furthermore, if the accurate temperature information obtained from the temperature measuring resistor is fed back, the temperature of the temperature control object can be controlled with higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic cross-sectional view of a temperature adjustment unit according to one embodiment of the present invention.

[0023] Figure 2 Yes Figure 1 A perspective view of a temperature regulation unit is shown with a portion cut away.

[0024] Figure 3 Graph showing a thin film temperature measuring resistor portion formed by a thermal spray film, wherein the thermal spray film is formed by thermal spray materials of Al, Ni, and Ni-Al alloy, respectively. Figure 3 (a) shows the temperature dependence of the resistance of the thin film temperature measuring resistor. Figure 3 (b) shows the change in the resistance value of the thin film temperature measuring resistor over time.

[0025] Figure 4 This is a graph showing the temperature change trend of a temperature measuring resistor formed by Al thermal spraying film when heated at 150°C. Figure 4 (a) shows the temperature change trend when heated at 150°C for 50 hours. Figure 4 (b) shows the temperature change trend when heated at 150°C for 100 hours.

[0026] Figure 5 (a) is a top view showing a pattern of a temperature control unit, Figure 5 (b) is a plan view showing a pattern of the thin film temperature measuring resistor portion.

[0027] Figure 6 Yes Figure 5 A three-dimensional diagram of a temperature adjustment unit including a temperature adjustment portion and a thin film temperature measuring resistor portion.

[0028] Figure 7 is a cross-sectional schematic diagram showing the structure of a temperature control unit, Figure 7 (a) shows the structure of the temperature control unit when the thin film temperature measuring resistor is arranged on the side closer to the temperature control object than the temperature control part. Figure 7 (b) shows the structure of the temperature adjustment unit when the thin-film temperature measuring resistor portion is provided on the side farther from the temperature adjustment target than the temperature adjustment portion.

[0029] Figure 8 Is Figure 7 Comparative results of temperature measurements performed on each test piece are shown.

[0030] Fig. 9 This is a graph comparing the temperature measured by a thermocouple installed at an arbitrary point on the temperature measurement surface with the average temperature measured by a thin film temperature measuring resistor portion formed over a wide area over the entire temperature measurement surface.

[0031] Fig.10 Yes Fig. 9 The infrared thermal imager (IR) photograph of the thin film temperature resistor during the temperature change shown.

[0032] Fig.11 It is a perspective view showing an example in which the temperature adjustment unit is formed in a ring shape.

[0033] Fig.12This is a perspective view showing an example in which the temperature adjustment unit is formed in a disk shape.

[0034] Fig.13 This is a schematic diagram showing an example of using a heating wire instead of a thermal spray film as a temperature control unit. Fig.13 (a) is a cross-sectional view, Fig.13 (b) is a partially cut-away stereogram.

[0035] Fig.14 This is a schematic diagram showing an example of using a refrigerant fluid instead of a thermal spray film as a temperature control unit. Fig.14 (a) is a cross-sectional view, Fig.14 (b) is a partially cut-away stereogram.

[0036] Fig.15 This is a schematic cross-sectional view showing an example in which a temperature control unit is applied to an electrostatic chuck. DETAILED DESCRIPTION

[0037] Hereinafter, embodiments of the temperature adjustment unit of the present invention will be described. Figure 1 is a schematic cross-sectional view of a temperature adjustment unit 1 according to one embodiment of the present invention, Figure 2 Yes Figure 1 A partially cutaway perspective view of the temperature regulating unit 1 shown. The temperature regulating unit 1 is configured to include: a temperature regulating unit body 2; a temperature regulating portion 3, which is disposed inside the temperature regulating unit body 2 and is used to raise and lower the surface temperature of the temperature regulating object 100 of the temperature regulating unit body 2; and a thin film temperature measuring resistor portion 4, which is disposed inside the temperature regulating unit body 2 and is used to measure the surface temperature of the temperature regulating object 100. The temperature regulating portion 3 can be used as a heat medium for heating the temperature regulating object 100, or as a coolant for cooling the temperature regulating object 100. Whether the temperature regulating portion 3 is used as a heat medium or a coolant depends on the temperature of the temperature regulating object 100 and its surrounding temperature.

[0038] The temperature regulating unit body 2 is constituted to include a base material portion 2a and an insulating layer 2b formed on the surface of the base material portion 2a. The temperature regulating portion 3 and the thin film temperature measuring resistor portion 4 are both arranged in the insulating layer 2b. The temperature regulating portion 3 and the thin film temperature measuring resistor portion 4 can be buried in the interior of an insulating layer, or can be arranged to be sandwiched between multiple insulating layers. The temperature regulating object 100 is placed on the upper surface of the temperature regulating unit body 2. It should be noted that in order to illustrate these schematic diagrams, the insulating layer 2b of the temperature regulating portion 3 and the thin film temperature measuring resistor portion 4, which are provided as the main parts, is drawn thicker than the actual thickness in the figures.

[0039] Figure 1 and Figure 2The temperature regulating unit body 2 shown is configured as a cylinder with a specified height and diameter. The base material portion 2a of the temperature regulating unit body 2 is made of a single material such as a metal bulk body, and is a solid basic structure of the temperature regulating unit 1. In this embodiment, the temperature regulating unit body 2 can be other shapes such as a columnar, plate-shaped, disc-shaped, bowl-shaped, cylindrical, annular (ring-shaped), cone-shaped, etc. in addition to a cylindrical shape, and can also be a three-dimensional shape with steps in part. The temperature regulating portion 3 and the thin film temperature measuring resistor portion 4 are arranged in a form corresponding to the shape of the temperature regulating unit body 2. When the temperature regulating unit body 2 is configured as a hollow cylinder, the temperature regulating portion 3 and the thin film temperature measuring resistor portion 4 can be respectively arranged on the inner circumference and outer circumference of the temperature regulating unit body 2, for example.

[0040] As the constituent material of the substrate portion 2a, for example, conductive materials such as aluminum alloys, titanium alloys, copper alloys, stainless steel, or insulating materials such as ceramic sintered bodies can be listed. The insulating layer 2b can be formed by a film forming method such as a thermal spraying method, a PVD method, a CVD method, or by laminating a sintered body. The constituent material of the insulating layer 2b is not particularly limited, as long as it is a material that imparts insulating properties, but preferably a material that takes into account both the required thermal conductivity and insulation, or a material that has both plasma resistance and wear resistance. The insulating layer 2b does not need to be a single layer, and can also be composed of multiple layers.

[0041] The thickness of the insulating layer 2b is, for example, 20-2000 μm. The thickness of the insulating layer 2b can be, for example, 100-10000 μm in the case of multilayer stacking. The heat removal efficiency can be adjusted by changing the thickness or material of the insulating layer 2b. As constituent materials of the insulating layer 2b, oxide-based ceramics, nitride-based ceramics, fluoride-based ceramics, carbide-based ceramics, boride-based ceramics, compounds containing them, or mixtures thereof can be cited.

[0042] Examples of oxide-based ceramics include Al2O3, TiO2, SiO2, Cr2O3, ZrO2, Y2O3, MgO, CaO, and La2O3. Examples of nitride-based ceramics include TiN, TaN, AlN, BN, Si3N4, HfN, NbN, YN, ZrN, Mg3N2, and Ca3N2. Examples of fluoride-based ceramics include LiF, CaF2, BaF2, YF3, AlF3, ZrF4, and MgF2. Examples of carbide-based ceramics include TiC, WC, TaC, B4C, SiC, HfC, ZrC, VC, and Cr3C2. Examples of boride-based ceramics include TiB2, ZrB2, HfB2, VB2, TaB2, NbB2, W2B5, CrB2, and LaB6.

[0043] The temperature control unit 3 provided in the insulating layer 2b has a specific resistance value that can be used as a heat medium (heater), and heats the temperature control object 100 at room temperature placed on the upper surface of the temperature control unit body 2 to a predetermined temperature by applying a predetermined voltage and passing a current.

[0044] The temperature control unit 1 of this embodiment may further include a flow path for circulating a cooling fluid (refrigerant) inside the base portion 2a. By adjusting the flow rate and speed of the cooling fluid, the temperature control of the temperature control object 100 is made easier.

[0045] From the viewpoint of improving the temperature uniformity in the temperature control area, the temperature control portion 3 is formed into a long and narrow strip pattern having a plurality of folded portions on the same surface. In addition, the temperature control portion 3 has a plurality of repeated patterns arranged in parallel at predetermined intervals. Thus, a pseudo temperature control surface is formed by the temperature control portion 3, so that the temperature of the temperature control object 100 can be uniformly controlled over a wide range.

[0046] The thickness of the temperature regulating part 3 is preferably in the range of 10-1000 μm. If the thickness of the temperature regulating part 3 is less than 10 μm, the film formation may be unstable. In addition, if the thickness of the temperature regulating part 3 is greater than 1000 μm, the heat generation may be reduced and the efficiency may be reduced.

[0047] The line width of the temperature adjustment portion 3 is preferably in the range of 1 to 5 mm. Setting the line width of the temperature adjustment portion 3 to 1 mm or more can reduce the possibility of line breakage, and setting the line width to 5 mm or less can reduce temperature unevenness in the temperature adjustment area.

[0048] The interlinear distance of the temperature control part 3 is preferably in the range of 0.5-50 mm. By setting the interlinear distance of the temperature control part 3 to 0.5 mm or more, short circuits can be avoided, and by setting the interlinear distance to 50 mm or less, temperature unevenness in the temperature control area can be reduced.

[0049] The constituent material of the temperature regulating part 3 is not limited as long as it can be used as a temperature regulating component, but it is preferably a material composed of a metal element monomer selected from Mo, W, Ta, Cr, Ti, Al, Si, Ni, Nb, Fe, Cu, Ag, Pt, an alloy containing one or more of these metal elements, a conductive compound containing one or more of these metal elements, or a mixture thereof.

[0050] The temperature regulating part 3 is formed by, for example, a thermal spray film. By thermal spraying, a thin film can be continuously and uniformly coated without being limited by the size and shape of the substrate part 2a. The thermal spraying method can be any one of atmospheric plasma spraying, reduced pressure plasma spraying, water plasma spraying, arc spraying, high-speed flame spraying, low-speed flame spraying, and cold spraying.

[0051] The pattern of the temperature regulating part 3 can be produced by masking the surface of the insulating layer formed on the substrate part 2a into a pattern in advance and then thermally spraying the entire surface. It can also be produced by masking the surface of the thermally sprayed film into a pattern after thermally spraying the entire surface, and then using mechanical processing or spray processing to remove unnecessary thermally sprayed films.

[0052] A portion of the temperature regulating portion 3 is extended to the side of the base material portion 2a, and the extended portion becomes the power supply terminal portion 11, which is connected to the power supply terminal. The power supply terminal is connected to an external power supply that supplies power to the temperature regulating portion 3. Thus, power can be supplied to the temperature regulating portion 3 without providing a power supply mechanism that passes through the base material portion 2a.

[0053] The power supply terminal portion 11 of the temperature regulating portion 3 is formed by a thermal spray film having a relatively thin film thickness, and therefore the connection method with the external power supply can be listed as: a connection structure in which the end of an external power supply cable is joined, a connection structure in which the end of the power supply cable is connected via a power supply socket, and a connection structure in which the end of the power supply cable is directly pressed. As methods for joining the power supply cable, soldering, brazing, welding, etc. can be listed. When a power supply socket is used, it is preferred to weld the power supply socket to the power supply terminal portion 11. When the power supply cable is directly pressed onto the power supply terminal portion 11, a structure such as a screw stopper for fixing the power supply cable is required.

[0054] The thin film temperature measuring resistor 4 for measuring the temperature of the temperature control object 100 is formed in the insulating layer 2b of the temperature control unit body 2 over a certain range on the surface (temperature measuring surface) on the side where the temperature control object 100 is located. The thin film temperature measuring resistor 4 is provided on the side closer to the temperature control object 100 than the temperature control unit 3.

[0055] The thin film temperature measuring resistor part 4 has a specific resistance value that can be used as a temperature measuring resistor. A temperature measuring resistor is a device that measures temperature based on the resistance value when a direct current flows, and uses a resistor whose resistance value changes constantly as the temperature changes. By pre-drawing a standard curve of the temperature measuring resistor used, the temperature can be calculated from the actually measured resistance value. By successively reading the resistance value of the thin film temperature measuring resistor part 4, the temperature of the upper surface (temperature adjustment surface) of the temperature adjustment unit body 2 can be measured in real time.

[0056] From the viewpoint of being able to measure temperature over a wide range, the thin film temperature measuring resistor portion 4 is formed into a thin and long strip pattern having a plurality of folded portions on the same surface. In addition, the thin film temperature measuring resistor portion 4 has a plurality of repeated patterns arranged in parallel at predetermined intervals. Thus, a pseudo temperature measuring surface is formed by the thin film temperature measuring resistor portion 4, so that the average temperature in the temperature regulating surface can be measured more accurately.

[0057] The thickness of the thin film temperature measuring resistor portion 4 is preferably in the range of 10-1000 μm. If the thickness of the thin film temperature measuring resistor portion 4 is less than 10 μm, the film formation may be unstable. In addition, if the thickness of the thin film temperature measuring resistor portion 4 is greater than 1000 μm, the resistance value becomes too small to obtain an appropriate value.

[0058] The line width of the thin film temperature measuring resistor 4 is preferably in the range of 1-5 mm. By setting the line width of the thin film temperature measuring resistor 4 to 1 mm or more, disconnection can be reduced, and by setting the line width to 5 mm or less, an appropriate resistance value can be easily obtained.

[0059] The interline distance of the thin film temperature measuring resistor 4 is preferably in the range of 0.5-50 mm. By setting the interline distance of the thin film temperature measuring resistor 4 to 0.5 mm or more, short circuits can be avoided, and by setting the interline distance to 50 mm or less, an appropriate resistance value can be easily obtained.

[0060] The constituent material of the thin film temperature measuring resistor portion 4 is not limited as long as it can be used as a material for a temperature measuring resistor, and can be selected from metal element monomers, alloys containing more than one of these metal elements, conductive compounds containing more than one of these metal element monomers and alloys, or mixtures thereof. Among them, the material consisting of the metal or alloy containing Al is particularly preferred. The metal or alloy containing Al has a smaller time-dependent change in resistance value due to repeated heat loads than other metals or alloys, and even if used for a long time, the accuracy of temperature measurement is not easy to decrease.

[0061] The thin film temperature measuring resistor part 4 is formed by a thermal spraying film. By thermal spraying, the thin film can be continuously and uniformly coated without being limited by the size and shape of the substrate part 2a. The thermal spraying method can be any one of atmospheric plasma spraying, reduced pressure plasma spraying, water plasma spraying, arc spraying, high speed flame spraying, low speed flame spraying, and cold spraying.

[0062] The pattern of the thin film temperature measuring resistor part 4 can be produced by masking the surface of the insulating layer formed on the substrate part 2a into a pattern in advance and then thermally spraying the entire surface. It can also be produced by masking the surface of the thermal sprayed film into a pattern after thermally spraying the entire surface, and then using mechanical processing or spray processing to remove excess thermal sprayed film.

[0063] A portion of the thin film temperature measuring resistor 4 is extended to the side of the substrate 2a, and the extended portion becomes a resistance value measuring terminal 12, which is connected to the resistance value measuring terminal. The resistance value measuring terminal reads the resistance value of the thin film temperature measuring resistor 4 and is connected to an external measuring device that converts the resistance value into temperature. Thus, the resistance value of the thin film temperature measuring resistor 4 can be measured without setting a measuring mechanism that penetrates the substrate 2a.

[0064] The thin film temperature measuring resistor part 4 is formed by a thin thermal spray film, so the connection method with the external measuring device can be listed as: a connection structure in which the end of the external connection cable is joined, a connection structure in which the end of the connection cable is connected via a connection socket, and a connection structure in which the end of the connection cable is directly pressed. As a method of joining the connection cable, soldering, brazing, welding, etc. can be listed. In the case of directly pressing the connection cable onto the resistance value measurement terminal part 12, a structure such as a screw stopper for fixing the connection cable is required.

[0065] The thermal spray powder used to form the temperature regulating part 3 and the thin film temperature measuring resistor part 4 can be, for example, a thermal spray powder with a particle size range of 5-80 μm. If the particle size is too small, the fluidity of the powder decreases and it cannot be stably supplied, and the thickness of the film tends to become uneven. On the other hand, if the particle size is too large, the film is formed in an incompletely molten state, and there is a possibility that the film becomes too porous and the film becomes rough.

[0066] The average porosity of the thermal sprayed film constituting the temperature regulating portion 3 and the thin film temperature measuring resistor portion 4 is preferably in the range of 1-10%. The average porosity can be adjusted by the thermal spraying method or the thermal spraying conditions. If the porosity is less than 1%, the influence of the residual stress existing in the thermal sprayed film increases, and peeling or cracking may occur easily. If the porosity is greater than 10%, various gases used in, for example, the semiconductor manufacturing process can easily invade the thermal sprayed film, and the durability may decrease. The average porosity can be measured as follows: observe the cross-section of the thermal sprayed film with an optical microscope, binarize the observed image, regard the black area inside the film as the pore part, and calculate the area ratio of the black area to the entire area.

[0067] For the temperature regulating unit 1, by further providing a control mechanism, the temperature control of the temperature regulating object 100 can be performed more strictly. The control mechanism inputs the detection signal detected by the thin film temperature measuring resistor part 4 into the control part, converts the detection signal into temperature information based on the pre-calculated standard curve data, and determines the voltage applied to the temperature regulating part 3 based on the temperature information.

[0068] like Figure 1 , Figure 2 As shown, by setting the thin film temperature measuring resistor part 4 on the side closer to the temperature control object 100 than the temperature control part 3, there is almost no difference between the measured temperature and the actual temperature of the temperature control object 100. Since the thin film temperature measuring resistor part 4 is formed within a certain range within the temperature measurement surface, there is no thermal abnormal point as when using a thermocouple, so that the average temperature of the temperature control surface can be accurately measured. In addition, by feeding back the obtained temperature information, temperature control can be performed with high precision.

[0069] Figure 3 Graph showing a thin film temperature measuring resistor portion formed by a thermal spray film, wherein the thermal spray film is formed by thermal spray materials of Al, Ni, and Ni-Al alloy, respectively. Figure 3 (a) shows the temperature dependence of the resistance of the thin film temperature measuring resistor. Figure 3 (b) shows the change of the resistance value of the thin film temperature measuring resistor over time. Figure 3 The graph (a) showing the temperature dependence of resistance shows that the rate of change of resistance value with temperature change is constant, and this curve serves as a standard curve for converting the resistance value of a temperature measuring resistor into temperature. Table 1 shows the average temperature coefficient α.

[0070] [Table 1]

[0071] α[1 / ℃] Al thermal spraying <![CDATA[3.05×10 -3 ]]> Ni thermal spraying <![CDATA[6.72×10 -3 ]]> Ni-Al alloy thermal spraying <![CDATA[1.42×10 -3 ]]>

[0072] exist Figure 3 In the measurement of the resistance value change over time of (b), the resistance value after heating at 200°C for a certain period of time and then maintaining at 80°C for 30 minutes was measured, and the resistance value was plotted. The sampling time was after heating for 1 hour, 3 hours, 6 hours, 9 hours, 12 hours, 19 hours, 26 hours, and 33 hours. Figure 3As shown in the curve, the change rate of the resistance value of the Ni thermal spray film is -1.66% after 33 hours. Although it can be used at this level, the change rate of the resistance value of the Al thermal spray film is 0.03% after 33 hours, and the change rate of the resistance value of the Ni-Al alloy thermal spray film is 0.24% after 33 hours, which are both very small. It can be seen that in the case of the Al thermal spray film and the Ni-Al alloy thermal spray film, the time-dependent change of the resistance value is small even after long-term use, and the reliability is higher.

[0073] In order to evaluate the characteristics of the temperature measuring resistor formed by the Al thermal spraying film, a comparative test was conducted with Pt100 (Japanese Industrial Standard JIS-C1604) which is standardized as a temperature measuring resistor. Specifically, the test pieces of Pt100 and the temperature measuring resistor formed by the Al thermal spraying film were placed in a constant temperature bath, and the temperature measured by Pt100 and the temperature measured by the temperature measuring resistor formed by the Al thermal spraying film were compared when the temperature of the constant temperature bath reached 25°C, 50°C, 100°C, and 150°C, respectively. The results are shown in Table 2. It can be seen that there is almost no error in the measured temperature between Pt100 and the temperature measuring resistor formed by the Al thermal spraying film.

[0074] [Table 2]

[0075] [℃]

[0076] <![CDATA[Standard temperature / T Pt100 > <![CDATA[Measured temperature / T 热喷涂 > error 24.50 24.48 0.02 49.80 49.80 0.00 99.95 99.97 0.02 149.55 149.53 0.02

[0077] In addition, test pieces of temperature measuring resistors formed of Pt100 and Al thermal sprayed films were placed in a constant temperature chamber and subjected to a stability test when kept at a high temperature for a certain period of time. Figure 4 This is a graph showing the temperature change trend of a temperature measuring resistor formed by Al thermal spraying film when heated at 150°C. Figure 4 (a) shows the temperature change trend when heated at 150°C for 50 hours. Figure 4 (b) shows the temperature change trend when heated at 150°C for 100 hours. Figure 4 As shown in Table 3, when a temperature measuring resistor formed by an Al thermal spray film is heated at 150°C for a certain period of time, there is almost no difference in the measured values ​​before and after heating after 50 hours and after 100 hours. In addition, the same test conditions were also carried out for Pt100, and the measured temperatures before and after heating were compared. The results are shown in Table 3. It can be seen that there is almost no error in the measured temperatures before and after heating between Pt100 and the temperature measuring resistor formed by an Al thermal spray film.

[0078] [Table 3]

[0079]

[0080] Figure 5 (a) is a top view showing a pattern of the temperature adjustment unit 3, Figure 5 (b) is a plan view showing one pattern of the thin film temperature measuring resistor section 4 . Figure 6 Yes Figure 5 A three-dimensional diagram of a temperature control unit 1 including a temperature control unit 3 and a thin film temperature measuring resistor unit 4. Figure 6 In the figure, for the convenience of explanation, the thin film temperature measuring resistor part 4 and the temperature regulating part 3 can be seen from above. In this example, a part of the temperature regulating part 3 is extended outward, and the extended part constitutes a power supply terminal part 11 connected to the power supply terminal on the same surface. In addition, a part of the thin film temperature measuring resistor part 4 is extended outward, and the extended part constitutes a resistance value measuring terminal part 12 connected to the resistance value measuring terminal on the same surface. The band-shaped pattern part with a folded part of the temperature regulating part 3 is formed, for example, with a line width of 1.2 mm, a line spacing of 2 mm, and a resistance value of 20Ω. In addition, the band-shaped pattern part with a folded part of the thin film temperature measuring resistor part 4 is formed, for example, with a line width of 1 mm, a line spacing of 1 mm, and a resistance value of 10Ω. In addition, in the thickness direction of the temperature regulating unit 1, the thin film temperature measuring resistor part 4 and the temperature regulating part 3 are configured to correspond to each other via an insulating layer. That is, the area where the temperature adjustment unit 3 adjusts the temperature coincides with the area where the thin film temperature measuring resistor unit 4 measures the temperature when viewed from above. Therefore, by feeding back the temperature information obtained by the thin film temperature measuring resistor unit 4 to the temperature adjustment unit 3, temperature control can be performed with high accuracy.

[0081] like Figure 5 and Figure 6 As shown in the figure, although the temperature regulating part 3 and the thin film temperature measuring resistor part 4 are formed to overlap each other via the insulating layer, the temperature regulating part 3 and the thin film temperature measuring resistor part 4 are not formed in the same pattern, but are formed in patterns of different directions and lengths. Specifically, the thin film temperature measuring resistor part 4 spans the part where the temperature regulating part 3 exists and the part where the temperature regulating part 3 does not exist, that is, the strip-shaped part of the temperature regulating part 3 and the strip-shaped part of the thin film temperature measuring resistor part 4 are cross-arranged when viewed from above, thereby being able to more accurately measure the average temperature in the plane.

[0082] The following shows the results of comparative verification of the temperature measurement accuracy when the positional relationship between the temperature adjustment unit 3 and the thin film temperature measuring resistor unit 4 in this embodiment is changed. Figure 7 is a cross-sectional schematic diagram showing the structure of a temperature control unit, Figure 7 (a) shows the structure of the temperature control unit when the thin film temperature measuring resistor section 4 is arranged on the side closer to the temperature control object than the temperature control section 3. Figure 7 (b) shows the structure of the temperature control unit when the thin film temperature measuring resistor section 4 is arranged on the side farther from the temperature control object than the temperature control section 3. Figure 7In the schematic diagram of (a), an insulating layer 2b composed of multiple layers is formed on the base material part 2a, and an insulating layer 2c, a temperature regulating part 3, an insulating layer 2d, a thin film temperature measuring resistor part 4, and an insulating layer 2e are sequentially arranged from the side of the base material part 2a, and a thermocouple 20 is further arranged on the surface of the outermost layer, that is, the insulating layer 2e. Figure 7 In the schematic diagram of (b), an insulating layer 2b composed of multiple layers is formed on the substrate portion 2a, and an insulating layer 2c, a thin film temperature measuring resistor portion 4, an insulating layer 2d, a temperature regulating portion 3, and an insulating layer 2e are arranged in sequence from the substrate portion 2a side, and a thermocouple 20 is further arranged on the surface of the outermost layer, i.e., the insulating layer 2e. Figure 7 (a) is an embodiment of the present invention, Figure 7 (b) is a comparative example.

[0083] Prepare Figure 7 (a) shows a test piece and Figure 7 (b) shows a test piece, and the temperature of the temperature adjustment part 3 of each test piece is adjusted to 50°C, 100°C, and 150°C, respectively, and maintained for a certain period of time. In each test piece, the temperature adjustment part 3, the thin film temperature measuring resistor part 4, and the insulating layer 2b are all formed by thermal spraying, and the material of the insulating layers 2c, 2d, and 2e is Al2O3, the material of the temperature adjustment part 3 is W, and the material of the thin film temperature measuring resistor part 4 is Al. The thickness of the temperature adjustment part 3 is 150μm, the thickness of the thin film temperature measuring resistor part 4 is 80μm, the thickness of the insulating layers 2c, 2d, and 2e is 100μm, and the total thickness is 300μm.

[0084] Figure 8 Is Figure 7 Comparative results of temperature measurements performed on each test piece are shown. Figure 8 TCs is the temperature measured by the thermocouple 20 , and RTD is the temperature measured by the thin film temperature measuring resistor unit 4 . Figure 8 middle, Figure 8 (a) shows the case where the thin film temperature measuring resistor part 4 is the upper layer and the temperature adjustment part 3 is the lower layer. Figure 8 (b) shows the case where the temperature regulating part 3 is the upper layer and the thin film temperature measuring resistor part 4 is the lower layer. Although the thickness of the insulating layer 2b is extremely thin, only 300μm, the difference between TCs and RTD is very small when the thin film temperature measuring resistor part 4 is the upper layer in each case of being maintained at 50°C, maintained at 100°C, and maintained at 150°C. That is, it can be seen that regardless of the distance from the temperature measurement object, the positional relationship between the temperature regulating part 3 and the thin film temperature measuring resistor part 4 is: when the thin film temperature measuring resistor part 4 is set on the side closer to the temperature measurement object than the temperature regulating part 3, the temperature of the temperature measurement object can be measured more accurately.

[0085] The following shows the results of a verification experiment on the measurement accuracy of the in-plane average temperature of the thin-film temperature measuring resistor portion 4 in the present embodiment. Fig. 9 This is a graph comparing the temperature measured by a thermocouple set at any point in the temperature measuring surface with the average temperature measured by a thin film temperature measuring resistor formed over a wide range over the entire temperature measuring surface. In this test, the measured temperature after 220 seconds after the start of heating was shown as 150°C in the case of the thermocouple and 200°C in the case of the thin film temperature measuring resistor. In addition, the average temperature in the surface measured by the infrared thermal imager (IR) at the same time was 205°C. Therefore, although the temperature measurement at one point sometimes differs greatly from the actual average temperature in the surface, the average temperature can be accurately measured by using the thin film temperature measuring resistor over a wide range in the temperature regulating surface.

[0086] Fig.10 Yes Fig. 9 The infrared thermal imager (IR) photograph of the thin film temperature measuring resistor 4 during the temperature change shown. The thermocouple is set at a point (+) on the periphery of the temperature measuring surface. Fig.10 The three images are photographs of the temperature measured by the thermocouple at (a) 50°C, (b) 100°C, and (c) 150°C. For ease of comparison, the temperature measured by the thermocouple, the average temperature measured by the thin film temperature measuring resistor unit of the present embodiment, and the average temperature measured by the infrared thermal imager (IR) are shown together in Table 4. It can be seen that although there are differences between the thin film temperature measuring resistor unit and the infrared thermal imager of the present embodiment relative to the temperature measured by the thermocouple, the measured temperatures in the case of the thin film temperature measuring resistor unit and the infrared thermal imager (IR) of the present embodiment are similar. This shows that the thin film temperature measuring resistor unit of the present embodiment can more accurately measure the average temperature in the surface than the thermocouple. In addition, the thin film temperature measuring resistor unit of the present embodiment is different from the infrared thermal imager (IR) and can measure the temperature even in the presence of other heat sources such as plasma light-emitting components or halogen heaters. That is, the thin film temperature measuring resistor unit of the present embodiment can measure the average temperature in the surface with the same degree of accuracy as the infrared thermal imager (IR) even in the presence of other heat sources.

[0087] [Table 4]

[0088]

[0089] The disclosed embodiments and examples are examples of the temperature control unit involved in the present invention and are not restrictive. Parts of the features of the embodiments and examples can be extracted and combined with each other. The size, shape, and structural material of the thin film temperature measuring resistor part, the temperature control part, and the temperature control unit body can be changed as long as the effect of the present invention is not impaired.

[0090] Fig.11 2 is a perspective view showing an example in which the temperature control unit is formed into a ring shape. Fig.11In the figure, for the convenience of explanation, the thin film temperature measuring resistor section is shown when observed from above. In the temperature regulating unit 25, independent structural parts 26a, 26b, 26c, and 26d constituting the thin film temperature measuring resistor section 26 are arranged in each of the four equally divided regions. A part of each structural part 26a, 26b, 26c, and 26d is extended around the side of the substrate part, and their front ends independently constitute the terminal parts 28a and 28b for measuring the resistance value. In addition, in the lower layer of each of the structural parts 26a, 26b, 26c, and 26d of the thin film temperature measuring resistor section 26, four different temperature regulating parts independent of each other are arranged through an insulating layer. Thus, the temperature can be precisely controlled individually in the four independent regions constituting the temperature regulating unit 25.

[0091] Fig.12 2 is a perspective view showing an example in which the temperature control unit is formed in a disk shape. Fig.12 In the figure, for the sake of convenience, the thin film temperature measuring resistor part is shown when viewed from above. In the temperature control unit 30, the thin film temperature measuring resistor part 31 is composed of four different structural parts 31a, 31b, 31c, and 31d that are independent of each other. Specifically, the thin film temperature measuring resistor part 31 is circular as a whole, and is composed of a circular structural part 31d containing the center of the circle, and three structural parts 31a, 31b, and 31c that divide the periphery of the structural part 31d into three parts. Fig.12 In the structure of the temperature control unit 30 shown in the figure, a part of each structure part 31a, 31b, 31c, 31d is extended outward on the same surface, and their front end parts independently constitute the terminal parts 32a, 32b, 32c, 32d for measuring the resistance value. In addition, four different temperature control parts independent of each other are provided in the lower layer of each structure part 31a, 31b, 31c, 31d of the thin film temperature measuring resistor part 31 through an insulating layer. Thus, the temperature can be controlled precisely in four independent regions constituting the temperature control unit 30.

[0092] Fig.13 1 is a schematic diagram showing an example of using a heating wire instead of a thermal spray film as a temperature control section of a temperature control unit. Fig.13 (a) is a cross-sectional view, Fig.13 (b) is a partially cut-away stereogram. Fig.13In the figure, for the sake of convenience of explanation, the thin film temperature measuring resistor part is shown when viewed from above. The temperature regulating unit 40 is in the shape of a ring, and three ring-shaped heating wires 5 (43) are also buried inside the base material part 2a. The heating wire 5 (43) is, for example, a nickel-chromium alloy wire, and the outer periphery is covered with a heat-resistant insulator. An insulating layer 2b is formed on the upper surface of the base material part 2a, and a thin film temperature measuring resistor part 41 formed by a thermal sprayed film is formed in the insulating layer 2b. A portion of the thin film temperature measuring resistor part 41 is extended around the side of the base material part 2a, and its front end portion constitutes a terminal part 42 for measuring the resistance value. In Fig.13 In the illustrated embodiment, the thin film temperature measuring resistor section 41 is also provided on the side closer to the temperature adjustment target than the temperature adjustment section 43, and can similarly perform temperature measurement with high accuracy.

[0093] Fig.14 This is a schematic diagram showing an example of using a refrigerant fluid instead of a thermal spray film as a temperature control section provided in a temperature control unit. Fig.14 (a) is a cross-sectional view, Fig.14 (b) is a partially cut-away stereogram. Fig.14 In the figure, for the sake of convenience of explanation, the thin film temperature measuring resistor part is shown when viewed from above. The temperature regulating unit 50 is annular in shape, and an annular cavity is also provided inside the substrate part 2a, through which the refrigerant fluid 6 (53) passes. The refrigerant fluid 6 (53) can be a liquid or a gas. A through hole connected to the two ends of the cavity is provided in a part of the substrate part 2a, and the refrigerant fluid 6 (53) can flow in and out from the through hole. An insulating layer 2b is formed on the upper surface of the substrate part 2a, and a thin film temperature measuring resistor part 51 formed by a thermal spray film is formed in the insulating layer 2b. A part of the thin film temperature measuring resistor part 51 is extended around the side of the substrate part 2a, and its front end portion constitutes a terminal part 52 for measuring the resistance value. In Fig.14 In the illustrated embodiment, the thin film temperature measuring resistor portion 51 is also provided on the side closer to the temperature adjustment object than the temperature adjustment portion 53, and the temperature can be measured with high accuracy in the same manner.

[0094] Fig.15 1 is a schematic cross-sectional view showing an example in which a temperature control unit is applied to an electrostatic chuck. Fig.15In the temperature control unit 65 shown, the temperature control unit 3, the thin film temperature measuring resistor unit 4, and the electrode unit 66 are formed in order from the side of the substrate unit 2a in the insulating layer 2b formed on the upper surface of the substrate unit 2a. The electrode unit 66 is formed by a thermal spraying film, and the thermal spraying film is formed into a band-shaped pattern having a plurality of folded portions like the thin film temperature measuring resistor unit 4. A part of the electrode unit 66 extends to the side of the substrate unit 2a, and its front end constitutes a power supply terminal unit 67 connected to the power supply terminal. By applying a predetermined voltage to the electrode unit 66, the temperature control object (for example, a Si wafer substrate) 100 placed on the upper surface of the temperature control unit 65 is attracted and fixed.

[0095] The scope of the present invention is not limited to the implementation modes and examples, and all changes within the equivalent scope of the claims are included in the protection scope of the present invention.

[0096] -Industrial Applicability-

[0097] The temperature control unit of the present invention is not limited to the field of semiconductor manufacturing processes, but can be applied to products in any field as long as uniform temperature control within a surface is required.

[0098] -Explanation of symbols-

[0099] 1, 25, 30, 40, 50, 65: Temperature adjustment unit

[0100] 2: Temperature control unit body

[0101] 2a: Base material

[0102] 2b, 2c, 2d, 2e: Insulation layer

[0103] 3, 43, 53: Temperature regulation unit

[0104] 4, 26, 31, 41, 51: Thin film temperature measuring resistor

[0105] 5: Heating wire

[0106] 6: Refrigerant fluid

[0107] 11, 67: Power supply terminal

[0108] 12, 28a, 28b, 32a, 32b, 32c, 32d: Resistance measurement terminals

[0109] 20: Thermocouple

[0110] 26a, 26b, 26c, 26d, 31a, 31b, 31c, 31d: Structural parts of the thin film temperature measuring resistor part

[0111] 66: Electrode

[0112] 100: Temperature measurement object

Claims

1. A temperature adjustment unit, wherein: The temperature regulating unit comprises: Temperature regulating unit body; a temperature regulating part, which is arranged inside the temperature regulating unit body and raises or lowers the surface temperature of the temperature regulating unit body on the side where the temperature regulating object is located; and A thin film temperature measuring resistor portion, which is formed in a certain range within the surface of the temperature regulating unit body and on the side where the temperature regulating object is located, and is arranged on a side closer to the temperature regulating object than the temperature regulating portion, and is formed by a thermal spray film; The temperature regulating unit body comprises a substrate portion, the upper surface of the substrate portion being a side where the temperature regulating object is located; The temperature regulating portion is disposed on a side closer to the temperature regulating object than the base material portion; A portion of the thin film temperature measuring resistor portion is extended to the side of the base portion, and the extended portion becomes a resistance value measuring terminal portion and is connected to the resistance value measuring terminal; The resistance value measuring terminal reads the resistance value of the thin film temperature measuring resistor portion and is connected to an external measuring device that converts the resistance value into temperature.

2. The temperature adjustment unit according to claim 1, wherein: The thin film temperature measuring resistor portion is formed in a strip-shaped pattern having a folded portion on the same surface.

3. The temperature adjustment unit according to claim 1 or 2, wherein: The thin film temperature measuring resistor portion includes a metal or an alloy containing Al.

4. The temperature adjustment unit according to claim 1 or 2, wherein: The temperature adjustment portion is formed of a thermal sprayed film formed in a band-shaped pattern having a folded portion on the same surface.

5. The temperature adjustment unit according to claim 1 or 2, wherein: The temperature adjustment unit includes a plurality of structural parts, and a part of each of the plurality of structural parts constitutes a power supply terminal part. The thin film temperature measuring resistor section includes a plurality of structural sections, and a portion of each of the plurality of structural sections constitutes a resistance value measuring terminal section.

6. The temperature adjustment unit according to claim 5, wherein: The structural parts of the temperature adjustment portion and the structural parts of the thin-film temperature measuring resistor portion are arranged to correspond to each other in the thickness direction of the temperature adjustment unit.

7. The temperature adjustment unit according to claim 1 or 2, wherein: The temperature adjustment unit body has an insulating layer formed on the surface of the base material portion, and the thin film temperature measuring resistor portion is provided in the insulating layer.

Images