WO2022163214A1 - Heater control device - Google Patents
Heater control device Download PDFInfo
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- WO2022163214A1 WO2022163214A1 PCT/JP2021/047141 JP2021047141W WO2022163214A1 WO 2022163214 A1 WO2022163214 A1 WO 2022163214A1 JP 2021047141 W JP2021047141 W JP 2021047141W WO 2022163214 A1 WO2022163214 A1 WO 2022163214A1
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- temperature
- heating element
- power
- controller
- control device
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Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/46—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for heating the substrate
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/52—Controlling or regulating the coating process
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B1/00—Details of electric heating devices
- H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
- H05B1/0227—Applications
- H05B1/023—Industrial applications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/0004—Devices wherein the heating current flows through the material to be heated
Definitions
- the present disclosure relates to heater controllers.
- This application claims priority based on Japanese Patent Application No. 2021-12977 dated January 29, 2021, and incorporates all the descriptions described in the Japanese application.
- Patent Document 1 discloses a film forming apparatus for forming a metal thin film on a semiconductor wafer.
- This film forming apparatus includes a heating means provided on a mounting table, a temperature detecting section for detecting the temperature of the semiconductor wafer placed on the mounting table, a control means for controlling the amount of heat generated by the heating means, and a lower portion of the mounting table. and a support member that supports the
- the heating means includes a first heater and a second heater for respectively heating the central portion and the peripheral portion of the semiconductor wafer.
- the control means controls power supplied to the first heater based on the detected temperature value of the central portion of the mounting table. Further, the control means is configured to supply power to the second heater in a predetermined ratio with respect to the power supplied to the first heater.
- a heater control device of the present disclosure includes a substrate having a disk-like shape, a cylindrical support coaxially attached to the substrate, and a first heater disposed in an area including the center of the substrate. a heating element; at least one second heating element arranged concentrically with the first heating element; a temperature sensor for measuring a first temperature of the first heating element; at least one current sensor for measuring the supplied current; a first temperature regulator for outputting a first control signal such that the first temperature approaches a target temperature; A first power controller controlling a first power supplied to a heating element, a second power controller controlling a second power supplied to the second heating element, and determining the temperature of the second heating element A calculator.
- the substrate has a first surface on which an object to be heated is placed and a second surface facing the first surface.
- the tubular support is attached to the second surface.
- the temperature sensor is arranged inside the tubular support.
- the second power controller controls the second power using a phase control method so as to achieve a preset ratio with respect to the first power.
- the calculator obtains the temperature of the second heating element based on the measured value of the at least one current sensor.
- FIG. 1 is a functional block diagram of a heater control device according to Embodiment 1.
- FIG. FIG. 2 is a plan view of a substrate showing areas where heat generating elements are arranged.
- FIG. 3 is a vertical cross-sectional view showing the arrangement of heat generating elements within the substrate.
- FIG. 4 is an explanatory diagram of the phase control method.
- FIG. 5 is a flowchart showing a processing procedure up to outputting the second power in the first embodiment.
- FIG. 6 is a flowchart showing a processing procedure up to outputting the second temperature in the first embodiment.
- FIG. 7 is a graph showing an example of a temperature profile of a heating element according to Embodiment 1;
- FIG. 8 is a graph showing an example of the temperature profile of the heating element during temperature maintenance.
- FIG. 9 is a graph showing an enlarged example of the temperature profile in the processing state in FIG.
- FIG. 10 is a functional block diagram of a heater control device according to the second embodiment.
- FIG. 11 is a flowchart showing a processing procedure up to outputting the second power in the second embodiment.
- FIG. 12 is a plan view of a base material showing an arrangement region of a heating element in Modification 1.
- FIG. 13 is a vertical cross-sectional view of a base material showing an arrangement region of a heating element in Modification 1.
- FIG. FIG. 14 is a functional block diagram of a heater control device according to Modification 2.
- FIG. 15 is a functional block diagram of a heater control device according to Modification 3.
- FIG. 15 is a functional block diagram of a heater control device according to Modification 3.
- the power supplied to the first heater is controlled based on the value detected by the temperature detection unit.
- the second heater is supplied with electric power at a predetermined ratio to the electric power supplied to the first heater, but does not have a temperature detection section for detecting the temperature of the peripheral portion of the wafer. Therefore, it is desired to improve the heat uniformity by grasping the temperature of the second heater.
- One object of the present disclosure is to provide a multi-zone heater control device capable of grasping the temperature of the zone corresponding to each heating element without providing a temperature sensor for each heating element. .
- Another object of the present disclosure is to provide a multi-zone heater control device capable of controlling the temperature of a zone corresponding to each heating element without providing a temperature sensor for each heating element. to do.
- the temperature of the zone corresponding to each heating element can be grasped without providing a temperature sensor for each heating element.
- a heater control device includes a disk-shaped substrate, a cylindrical support coaxially attached to the substrate, and a center of the substrate. a first heating element arranged in a region containing; at least one second heating element arranged concentrically with the first heating element; a temperature sensor for measuring a first temperature of the first heating element; at least one current sensor for measuring current supplied to at least one second heating element; a first temperature regulator for outputting a first control signal such that the first temperature approaches a target temperature; a first power controller for controlling first power supplied to the first heating element according to a control signal; a second power controller for controlling second power supplied to the second heating element; a calculator for obtaining the temperature of a second heating element, the base material has a first surface on which a heating target is placed and a second surface facing the first surface, and the cylindrical support A body is attached to the second surface, the temperature sensor is located inside the tubular support, and the second power controller is a preset ratio to the first power.
- the second electric power is controlled by
- the first temperature of the first heating element is detected by the temperature sensor.
- the first power supplied to the first heating element is controlled based on the temperature detected by the temperature sensor.
- the temperature of the second heating element is obtained by the calculator based on the measured value of the current sensor. Therefore, the temperature of the second heating element can be grasped without a temperature sensor for detecting the temperature of the second heating element or the temperature of the zone in which the second heating element is arranged.
- the second power supplied to the second heating element is controlled to have a preset ratio to the first power. Since the second power is controlled by the phase control method, it can be controlled with high accuracy. As a result, the temperature of the second heating element can also be grasped with high precision.
- the calculator calculates the temperature of the second heating element using the first temperature, the second voltage of the second heating element, and a predetermined coefficient.
- the coefficient may be a coefficient representing the relationship between the resistance of the second heating element and the temperature of the second heating element.
- the resistance of the second heating element can be obtained using the current and the second voltage supplied to the second heating element. Furthermore, the temperature of the second heating element can be obtained by using the coefficient representing the relationship between the resistance of the second heating element and the temperature of the second heating element.
- the coefficient is selected from a plurality of predetermined coefficients according to the first temperature. It may be a coefficient.
- the temperature of the second heating element can be determined more accurately by using different coefficients according to the measurement result of the temperature sensor, that is, the first temperature of the first heating element.
- Electric power is supplied to the second heating element in a predetermined ratio to the electric power supplied to the first heating element. That is, the temperature of the second heating element is related to the temperature of the first heating element.
- the relationship between the temperature and resistance of the second heating element it is difficult to accurately determine the temperature of the second heating element depending on the temperature range with a coefficient obtained only from the relationship between the resistance at room temperature and the resistance at the maximum temperature. . Therefore, by using different coefficients according to the temperature of the first heating element, the temperature of the second heating element can be calculated more accurately.
- the plurality of coefficients are calculated when the temperature of the first heating element and the second heating element , at the time of temperature maintenance, and at the time of temperature decrease.
- the temperature of the second heating element can be obtained with higher accuracy than when the same coefficient is used in each step of raising the temperature of the second heating element, maintaining the temperature, and lowering the temperature.
- Each of the above stages has a significantly different temperature history. Therefore, it is difficult to accurately obtain the temperature of the second heating element if a common coefficient is used in each of these stages.
- the amount of temperature change per unit time is small compared to when the temperature is raised or lowered. Therefore, by using different coefficients according to different stages of the process from temperature increase to temperature decrease, the temperature of the second heating element can be obtained with higher accuracy.
- the coefficient is set to the value that the heating object is placed on the first surface when the temperature is maintained. It may be determined based on the first temperature measured in a state in which the temperature is not
- the coefficient can be obtained without conducting a preliminary test by placing the object to be heated on the first surface. Therefore, there is no need to prepare an object to be heated in the preliminary test.
- the preliminary test is a test in which the relationship between the temperature and the resistance of the second heating element is examined by heating the first heating element to the target temperature during temperature maintenance in order to obtain the above coefficient. If the required accuracy of the temperature of the second heating element is emphasized, the object to be heated must be prepared in order to perform a preliminary test by placing the object to be heated on the first surface of the base material. On the other hand, if the preliminary test is performed without placing the object to be heated on the first surface, the coefficient can be obtained without using the object to be heated.
- One form of the heater control device is an external heater that displays or transmits at least one of the temperature of the second heating element and the determination result as to whether the temperature of the second heating element is within an appropriate range to an external device.
- An output unit may be provided.
- the above embodiment can notify the user of the second temperature, which is the temperature of the second heating element, and the determination result.
- the external output unit include a second temperature indicator, an alarm device that outputs when the second temperature is out of a predetermined range, or a data output that communicates with other external devices. interface and the like.
- One form of the heater control device further includes a second temperature controller, and the second temperature controller adjusts the ratio so that the temperature of the second heating element approaches the target temperature. Outputting a second control signal, the second power controller may control the second power according to the ratio adjusted by the second control signal.
- the above form can adjust the above ratio and control the temperature of the second heating element with high accuracy.
- One form of the heater control device further includes a third temperature controller, and the third temperature controller adjusts the difference between the temperature of the second heating element and the first temperature to the temperature of the second heating element. output a third control signal for adjusting the ratio so that the difference between the respective target temperatures of the temperature and the first temperature, the second power controller outputs the adjusted by the third control signal
- the second power may be controlled according to the ratio.
- the above form can adjust the above ratio and accurately control the temperature of the second heating element.
- FIG. 1 A heater control device 1 according to a first embodiment will be described with reference to FIGS. 1 to 4.
- FIG. This heater control device 1 can be used in a film forming apparatus for forming a thin film on the surface of a wafer.
- a film forming apparatus includes a substrate 10 and a support 20 in a chamber in which atmospheric gas can be controlled. Illustration of the chamber is omitted.
- the heating elements 30 are not arranged in a part of the substrate 10 in the circumferential direction.
- the heater control device 1 includes a substrate 10 , a support 20 , multiple heating elements 30 , a temperature sensor 40 , a current sensor 50 and a controller 60 .
- the base material 10 has a first surface 10a on which the heating target W shown in FIG. 3 is placed, and a second surface 10b facing the first surface 10a.
- the first surface 10a side of the substrate 10 may be referred to as "upper”, and the second surface 10b side may be referred to as "lower”.
- a support 20 is attached below the substrate 10 .
- a plurality of heating elements 30 are arranged inside the base material 10 as shown in FIGS. 1 and 3 .
- the plurality of heating elements 30 includes a first heating element 31 and one or more second heating elements 32 .
- a temperature sensor 40 detects the temperature of the first heating element 31 .
- the current sensor 50 includes a first current sensor 51 that measures a first current flowing through the first heating element 31 and a second current sensor 52 that measures a second current flowing through the second heating element 32 .
- the controller 60 mainly controls power supplied to the first heating element 31 and the second heating element 32 .
- One of the features of the first embodiment is that the temperature sensor 40 is provided only in the first heating element 31 without providing a temperature sensor in the second heating element 32, so that the temperature of the second heating element 32 can be grasped. That's what it is. Each configuration will be described in more detail below.
- the substrate 10 has a disk-like shape.
- the substrate 10 has a first surface 10a and a second surface 10b.
- the first surface 10a and the second surface 10b face each other.
- a heating target W shown in FIG. 3 is placed on the first surface 10a.
- the object W to be heated is, for example, a wafer of silicon, a compound semiconductor, or the like.
- a support 20, which will be described later, is attached to the second surface 10b.
- the second surface 10b is provided with a plurality of holes into which a plurality of terminals 30t shown in FIG. 3 are fitted.
- the base material 10 is concentrically divided into a plurality of regions.
- the base material 10 of this example is divided into an inner region 10i and an outer region 10e.
- the inner region 10i is a circular region centered on the center of the substrate 10.
- the center of the base material 10 is the center of a circle formed by the outline of the base material 10 in plan view.
- the diameter of inner region 10i is 80% or less of the diameter of substrate 10 .
- the diameter of the inner region 10i may also be 50% or less of the diameter of the substrate 10.
- the diameter of inner region 10i may be 10% or more of the diameter of substrate 10 . Since the diameter of the first heating element 31 is 10% or more of the diameter of the substrate 10 , an area in which the first heating element 31 can be arranged in the center of the substrate 10 can be secured.
- the outer region 10e is an annular region located outside the inner region 10i. A plurality of heating elements 30, which will be described later, are arranged corresponding to the plurality of areas.
- the material of the base material 10 includes known ceramics. Examples of ceramics include aluminum nitride, aluminum oxide, and silicon carbide.
- the material of the base material 10 may be composed of a composite material of the above ceramics and metal. Examples of metals include aluminum, aluminum alloys, copper, copper alloys, and the like.
- the material of the base material 10 of this example is ceramics.
- the support 20 supports the base material 10 from the second surface 10b side, as shown in FIGS.
- the support 20 is attached to the second surface 10b so as to surround the terminals 30t when the heater control device 1 is viewed from the first surface 10a side.
- the shape of the support 20 is not particularly limited.
- the support 20 of this example is a cylindrical member.
- the support 20 is arranged concentrically with the substrate 10 .
- the base 10 and the support 20 are connected so that the center of the cylindrical support 20 and the center of the disk-shaped base 10 are coaxial.
- Both ends of the support 20 are provided with outwardly bent flanges 21 .
- a sealing member (not shown) is arranged between the flange portion 21 of the upper end portion and the second surface 10b. The interior of the support 20 is sealed by the sealing member.
- the second surface 10b and the flange portion 21 may be joined to maintain airtightness without using a sealing member.
- the chamber in which substrate 10 and support 20 are placed is typically filled with a corrosive gas. By keeping the inside of the support 20 airtight, the plurality of terminals 30t and the plurality of power lines 30c housed inside the support 20 can be isolated from the corrosive gas.
- the material of the support As for the material of the support 20, well-known ceramics can be mentioned as well as the material of the base material 10.
- the material of the support 20 and the material of the substrate 10 may be the same or different.
- Each of the multiple heating elements 30 is a heat source that heats the heating target W via the base material 10 .
- the first heating element 31 is arranged in a circular area including the center of the substrate 10, that is, the inner area 10i, as shown in FIGS.
- One or more second heating elements 32 are arranged concentrically with the substrate 10 and the first heating elements 31 .
- One or more second heating elements 32 are arranged in an annular region concentric with the center of the substrate 10, ie the outer region 10e.
- the first heating element 31 and one or more second heating elements 32 are spaced apart in the thickness direction of the substrate 10 .
- Each of the first heating element 31 and the second heating element 32 is connected to the power line 30c via the terminal 30t shown in FIG. Power is supplied from a power source (not shown) to each heating element 30 via the power line 30c.
- the shapes of the first heating element 31 and the second heating element 32 are not particularly limited.
- the shape of the outer peripheral outline of the first heating element 31 and the second heating element 32 is generally circular.
- a plurality of heating elements 30 are arranged concentrically with the substrate 10 and the support 20 . Therefore, the plurality of heating elements 30 are also arranged concentrically.
- concentric means that when the heater control device 1 is viewed from the first surface 10a side, the enveloping circles of the heating elements 30 have a common center and the enveloping circles have different diameters. . The center of this enveloping circle coincides with the center of the substrate 10 .
- the first heating element 31 and the second heating element 32 are shown in a simplified manner in FIGS. 1 and 3, the plurality of heating elements 30 are arranged concentrically.
- the term “center side” means the center side of the enveloping circle, and the term “outer side” means the side away from the center in the radial direction of the enveloping circle.
- the plurality of heating elements 30 includes one first heating element 31 and one or more second heating elements 32, as shown in FIGS. In this example, there is one second heating element 32 . As shown in Modification 1, which will be described later, a plurality of second heating elements 32 may be provided.
- the enveloping circle diameter of the one or more second heating elements 32 is larger than the enveloping circle diameter of the first heating element 31 .
- the heating elements 30 may be arranged so as to partially overlap in the radial direction of the enveloping circles, or may be arranged at intervals without overlapping. may be placed.
- Each heating element 30 is arranged inside the base material 10, as shown in FIGS. Each heating element 30 is arranged in a layered manner at intervals in the thickness direction of the substrate 10 . Each heating element 30 of this example is arranged in a layer parallel to the first surface 10a. The first heating element 31 is arranged in the first layer located closest to the first surface 10 a in the thickness direction of the base material 10 . By arranging the first heating element 31 on the first layer, a long length can be secured between the first heating element 31 and the second surface 10b. In addition, since the first heating element 31 is arranged in the first layer, the degree of freedom of the circuit pattern is high compared to the case where the first heating element 31 is arranged in a layer other than the first layer. .
- the first heating element 31 arranged in the first layer does not need to be arranged so as to avoid the terminal 30t connected to the second heating element 32 .
- the second heating element 32 is arranged closer to the second surface 10b than the first heating element 31 is.
- the individual second heating elements 32 are also arranged in layers with intervals in the thickness direction of the substrate 10 .
- each heating element 30 is not particularly limited as long as it can heat the object W to be heated to a desired temperature.
- the material of each heating element 30 includes known metals suitable for resistance heating. Examples of metals include one selected from the group consisting of stainless steel, nickel, nickel alloys, silver, silver alloys, tungsten, tungsten alloys, molybdenum, molybdenum alloys, chromium, and chromium alloys.
- Nickel alloys include, for example, nichrome.
- Each heating element 30 can be manufactured, for example, by combining a screen printing method and a hot press bonding method. In the case of this example, it can be manufactured by the following procedures. Three ceramic substrates and a screen mask to which each heating element 30 can be transferred are prepared. As the screen mask, a mask capable of forming each circuit pattern of the first heating element 31 and the second heating element 32 is used. A screen mask of a circuit pattern to be produced is placed on each of the two ceramic substrates. A paste to be the heating element 30 is applied to the ceramic substrate on which the screen mask is placed. A squeegee is used to transfer the heating element 30 to the ceramic substrate. After transferring the heating element 30, the screen mask is removed.
- the first substrate to which the first heating element 31 is transferred and the second substrate to which the second heating element 32 is transferred are obtained.
- the first substrate, the second substrate, and the ceramic substrate to which the heating element is not transferred are laminated in order and joined by hot pressing.
- Each heating element 30 is arranged inside the base material 10 by this bonding.
- the temperature sensor 40 is a sensor that measures the first temperature of the first heating element 31 .
- a commercially available thermocouple or resistance temperature detector can be used favorably.
- the temperature measuring resistor includes PT100, which is a platinum temperature measuring resistor.
- this temperature sensor 40 is inside the base material 10 .
- the temperature sensor 40 is arranged inside the base 10 in a region inside the inner peripheral surface of the support 20 when the base 10 is viewed from above.
- a temperature sensor is arranged inside a cylindrical support in the claims means that the temperature sensor is located inside the contour line of the inner peripheral surface of the support 20 when the support 20 is viewed in the axial direction. It means that 40 is located.
- the temperature sensor 40 is preferably arranged near the first heating element 31 .
- the temperature measured by the temperature sensor 40 installed near the first heating element 31 is not the temperature of the first heating element 31 itself, but the temperature of the inner region 10i of the substrate 10 where the first heating element 31 is arranged. be.
- the temperature of the inner region 10i is also regarded as the first temperature of the first heating element 31.
- the current sensor 50 is a sensor that detects current flowing through the heating element 30 .
- a first current sensor 51 that detects a first current flowing through the first heating element 31 and a second current sensor 52 that detects a second current flowing through the second heating element 32 are provided.
- the second current sensor 52 corresponds to the current sensor in claim 1 .
- the second current sensor 52 is provided for each second heating element 32 .
- the first current sensor 51 is provided on the power line 30c connected to the first heating element 31, and the second current sensor 52 is provided on the power line 30c connected to the second heating element 32, respectively.
- a sensor represented by a commercially available CT (Current Transmitter) can be used as the current sensor 50 .
- the first current or the second current is a value obtained by averaging the effective value of the current flowing through the first heating element 31 or the second heating element 32 within a predetermined period of time to remove electrical noise.
- the controller 60 controls each part necessary for the operation of the heater control device 1 . More specifically, the controller 60 has a first temperature controller 61 , a first power controller 63 , a second power controller 64 , a calculator 65 and a memory 66 . Controller 60 is typically implemented by a processor including a CPU (Central Processor Unit) or DSP (Digital Signal Processing). Typically, a processor includes a bus, a CPU connected to the bus, a ROM (Read-Only Memory), a RAM (Random Access Memory), an input/output I/F (Interface), and the like. One or more processors may be provided in the controller 60, or a plurality of processors may be provided.
- a processor Central Processor Unit
- DSP Digital Signal Processing
- a processor includes a bus, a CPU connected to the bus, a ROM (Read-Only Memory), a RAM (Random Access Memory), an input/output I/F (Interface), and the like.
- One or more processors may be provided in the
- the first temperature controller 61, the first power controller 63, the second power controller 64, the calculator 65, and the memory 66 may be configured as separate hardware, or may be part of one controller 60. It may be configured as a component.
- a memory 66 stores a program for causing the processor to execute a control procedure, which will be described later.
- the processor reads and executes programs stored in memory 66 .
- the program includes program codes for processing in the first temperature controller 61 , the first power controller 63 , the second power controller 64 and the calculator 65 .
- the first temperature controller 61 outputs a first control signal so that the first temperature approaches the target temperature.
- PID control can be used for the control by the first temperature controller 61 .
- PID control is a type of feedback control, and is a control method that controls an input value by three operations: the deviation (P) between the output value and the target value, its integration (I), and its differentiation (D). Smooth temperature control with little hunting can be performed by proportional action that outputs the manipulated variable according to the deviation. Integral action can automatically correct the offset. Differential action can speed up the response to disturbances.
- the target temperature is the temperature set by the user.
- the first temperature controller 61 performs PID calculation based on the target temperature and the current temperature of the first heating element 31 , that is, the first temperature, and outputs a first control signal to the first power controller 63 .
- the first power controller 63 controls the first power supplied to the first heating element 31 according to the first control signal.
- the first power controller 63 to which the first control signal is input supplies first power corresponding to the first control signal to the first heating element 31 .
- the first power is calculated by multiplying the first current and the first voltage.
- the first current is the measurement of the first current sensor 51 as described above.
- the first voltage is the voltage applied to the first heating element 31 . This first voltage is obtained by calculation as described later.
- the control of the first power is performed by the phase control method.
- the phase control method is a method of controlling the voltage applied to the load within the range of 0% to 100% by controlling the ignition phase angle every half cycle of the power supply frequency.
- a switching element is preferably used for the first power controller 63 .
- a specific example of the switching element is a triac.
- a triac is an element in which two thyristors are connected in anti-parallel so that bidirectional current can be controlled by opening and closing one gate.
- FIG. 4 shows the current waveform of the supply current from the power supply as a sine wave.
- the gate opens, turning on the triac and allowing current to flow.
- the current in the area indicated by hatching is output.
- the gate signal is a pulse signal with a constant width w. Even if the gate signal is removed, the triac remains on and current continues to flow. When the current flowing through the TRIAC becomes zero, the TRIAC automatically turns off and no current flows.
- the triac can output a desired current within a range of 0% to 100% of the first current.
- the output mode during phase control in this example is voltage proportional square control.
- the voltage proportional square control is a mode in which the square of the effective value Vrms of the output voltage is proportional to the manipulated variable MV corresponding to the degree of opening of the gate.
- the supply voltage from the power supply is also represented by a sine wave. Since the supply voltage from the power supply is known, the first voltage can also be grasped by calculation from the timing at which the gate signal is input with respect to the current waveform from the power supply as described above, in other words, the degree of opening of the gate. The computation of the first voltage and the computation of the first power are performed by the calculator 65, which will be described later.
- Different ratios can be set in a series of temperature profiles of temperature increase, temperature maintenance, and temperature decrease of the heating element 30. Normally, this ratio is different in each stage of temperature rising, temperature holding, and temperature dropping.
- the ratio between the time of temperature increase and the time of temperature decrease may differ depending on the temperature range from the start to the end of each stage. For example, between room temperature and 400° C., the first power:second power ratio is 1.0:0.8, and between 400° C. and 450° C., the first power:second power ratio is 1.0:0.8. 9. If the temperature rises at the same power ratio to a high temperature, the heat generating element 30 becomes too center-hot and may be damaged by thermal stress due to the difference in temperature distribution inside and outside the plane of itself. Therefore, it is preferable to increase the ratio of the second power at high temperatures.
- This control of the second power is also performed by the phase control method in the same way as the control of the first power.
- the second power is obtained by multiplying the second current and the second voltage.
- the second current is the measurement of second current sensor 52 .
- the second voltage can be calculated based on the degree of opening of the gate.
- the computation of the second voltage and the computation of the second power are also performed by the calculator 65, which will be described later.
- the calculator 65 performs various calculations required by the controller 60 . As described above, the computation of the first voltage, the first power, the second voltage, and the second power are all performed by the calculator 65 . Furthermore, the calculator 65 also calculates the second temperature, which is the temperature of the second heating element 32 .
- the second temperature of the second heating element 32 is obtained using the resistance of the second heating element 32 and a previously obtained coefficient representing the relationship between the resistance of the second heating element 32 and the temperature. That is, the second temperature is not a value measured using a temperature sensor, but a value calculated based on the power supplied to the first heating element 31 .
- the resistance of the second heating element 32 is obtained by dividing the second voltage of the second heating element 32 described above by the second current flowing through the second heating element 32 .
- the coefficients are obtained in advance by a preliminary test, which will be described later. This coefficient also includes a relational expression showing the relationship between the resistance of the second heating element 32 and the temperature.
- the coefficients are stored in memory 66 . If the relationship between the resistance of the second heating element 32 and the temperature is known in advance, and the resistance of the second heating element 32 is obtained, by referring to this resistance with the above relationship, the second Temperature can be calculated and obtained.
- the memory 66 can use various non-volatile memories suitably as memory which memorize
- the memory 66 may also include a volatile memory that temporarily stores values required for a series of operations.
- the heater control device 1 may include an external output section 70 and a transformer 80 .
- the external output unit 70 is a device that displays or transmits at least one of the second temperature of the second heating element 32 obtained as described above and the determination result as to whether or not the second temperature is within the appropriate range to an external device.
- the external output unit 70 may be a display that displays the second temperature in characters, or displays the change over time of the second temperature in a graph.
- Another external output unit 70 may be a device that outputs a processing result obtained by subjecting the second temperature to predetermined processing. Devices that indicate the result of this processing include an alarm device.
- the alarm device is, for example, a device that issues an alarm when the second temperature deviates from the set appropriate range.
- the warning is not particularly limited as long as it can notify the user of the abnormality of the second temperature.
- specific types of alarms include character display on a display, lighting of a lamp, and sounding of a buzzer.
- Still another external output unit 70 includes a communication device (not shown). This communication device communicates with an external device owned by a remote user. For example, information on the second temperature can be sent to an external device via a communication device, or the above alarm can be transmitted to the external device as a change in flag state via a communication device. The transmission of this information allows remote users to perceive the second temperature and alarm.
- the transformer 80 is a member for electromagnetically coupling a power source (not shown) and the controller 60 to supply electric power to the first heating element 31 and the second heating element 32 .
- the primary side of the transformer 80, that is, the power supply side, and the secondary side of the transformer 80, that is, the controller 60 side are not electrically connected and are insulated from each other. Since the power supply and the controller 60 are insulated, it is easy to control the power to each heating element 30 .
- power is supplied to each of the heating elements 30 by branching the power line 30 c on the secondary side to each of the first heating element 31 and the second heating element 32 . That is, the first heating element 31 and the second heating element 32 are not electrically insulated from each other. Since the first heating element 31 and the second heating element 32 are not insulated, the number of transformers 80 can be reduced compared to the case where both the heating elements 30 are insulated.
- the heater control device 1 may include an input section (not shown).
- the input unit is a device for inputting various conditions set by the user. Various conditions include a preset ratio to the first power to define the second power.
- Known input devices such as a numeric keypad, a keyboard, and a touch panel can be used for the input unit.
- Various conditions input from the input unit are stored in the memory 66 .
- ⁇ Processing procedure> The processing procedure of the heater control device 1 will be described with reference to FIGS. 5 and 6.
- FIG. Refer to FIG. 1 for each component.
- a processing procedure for outputting the first power and the second power to each heating element 30 will be described.
- step S ⁇ b>1 a first temperature is obtained from the temperature sensor 40 and a first current is obtained from the first current sensor 51 .
- the first temperature controller 61 outputs a first control signal so that the first temperature approaches the target temperature.
- the first power controller 63 outputs the first power corresponding to the first control signal to the first heating element 31 .
- step S ⁇ b>4 the calculator 65 calculates the second power, and the second power is output from the second power controller 64 to the second heating element 32 .
- a series of processes from step S1 to step S4 are repeated while the heater control device 1 is being driven.
- step S11 the second current sensor 52 acquires a second current.
- step S12 the computing unit 65 computes the second resistance, which is the resistance of the second heating element 32, from the second current and the second voltage.
- step S13 the computing unit 65 computes the second temperature using the computed second resistance and the previously obtained coefficient representing the relationship between the resistance of the second heating element 32 and the temperature.
- step S ⁇ b>14 the obtained second temperature is output to the external output section 70 .
- the preliminary test is a test for preliminarily obtaining a coefficient representing the relationship between the resistance of the second heating element 32 and the temperature. It is preferable to perform the preliminary test by different methods when the temperature is raised, when the temperature is lowered, and when the temperature is maintained. In other words, it is preferable to use different coefficients when raising and lowering the temperature and when maintaining the temperature.
- FIG. 7 is a graph showing temporal changes in the temperature of the first heating element 31 in the heater control device 1 of this example.
- the temperature of the heating element 30 rises at a substantially constant rate from room temperature to a predetermined holding temperature.
- the rate of temperature increase in this temperature increase process is selected such that the heating element 30 is not damaged.
- the temperature of the heating element 30 is held at a substantially constant temperature.
- the temperature holding process includes an idle state in which no wafer is placed on the substrate 10 and a processing state in which a wafer is placed on the substrate 10 and a film is formed on the wafer.
- minute temperature fluctuations occur due to the gas entering and exiting the film forming apparatus and the control of the electric power supplied to the heating elements 30 described above.
- the idling state is indicated by a straight line extending horizontally, but actually, as will be described later, the temperature fluctuates very slightly.
- wafers are moved in and out of the base material 10 and films are sequentially formed on a plurality of wafers, so that temperature fluctuations are greater than in the idle state.
- the temperature change in the process state is shown in FIG. 7 by the dashed line following the straight line in the idle state.
- the temperature of the heating element 30 drops at a substantially constant rate from the holding temperature to room temperature.
- the temperature drop rate in this temperature drop process is selected such that the heating element 30 is not damaged.
- the time of temperature increase and temperature decrease The amount of temperature change per unit time during temperature increase and temperature decrease is greater than that during temperature maintenance. During this temperature increase and temperature decrease, the film formation process on the wafer is not performed.
- the temperature range from the room temperature to the holding temperature or the temperature range from the holding temperature to the room temperature is divided into narrower temperature ranges, and the relationship between the resistance of the second heating element 32 and the temperature is calculated for each of the divided temperature ranges.
- Ask. the relationship between the resistance and the temperature of each of the first heating element 31 and the second heating element 32 is obtained for each of the temperature ranges separated from 50°C to 100°C. More specifically, when the temperature is rising, the first temperature range of 50 ° C. or higher and 100 ° C.
- the second temperature range of 100 ° C. or higher and 200 ° C. or lower, the third temperature range of 200 ° C. or higher and 300 ° C. or lower, 300 C. to 400.degree. C. and the fifth temperature range from 400.degree. C. to the holding temperature are obtained.
- An example of the holding temperature is 450°C.
- the first temperature range the relationship between resistance and temperature at two points of 50° C. and 100° C. is obtained.
- the relationship between the resistance of the second heating element 32 and the temperature should be obtained when the temperature is lowered, based on the same concept as when the temperature is raised.
- a different coefficient can be used for each temperature range.
- the temperature of the second heating element 32 can be obtained with high accuracy.
- the temperature of the second heating element 32 at the resistance R(Tr), that is, the room temperature Tr, and the holding temperature Tk of the second heating element 32 at the resistance R(Tk) are also expressed by a proportional relational expression.
- Tr ⁇ T ⁇ Tk and R(Tr) ⁇ R ⁇ R(Tk) Tr ⁇ T ⁇ Tk and R(Tr) ⁇ R ⁇ R(Tk).
- the resistance value at the intermediate temperature cannot be expressed by linear interpolation between the two points. It is difficult to accurately obtain the temperature of the second heating element.
- the rate of temperature change per unit time is very small compared to when the temperature is raised or lowered. Therefore, when maintaining the temperature, it is preferable to obtain the relationship between the resistance of the second heating element 32 and the temperature in a narrower temperature range than when raising or lowering the temperature. More specifically, the temperature of the second heating element 32 can be obtained accurately by using a coefficient corresponding to a minute temperature range, that is, the difference between the maximum temperature and the minimum temperature when the temperature is maintained.
- the temperature holding process includes two temperature profiles, the idle state without the heating target W and the processing state with the heating target W, as described above. This temperature profile will be explained based on FIG. FIG.
- the temperature of the first heating element 31 is the temperature obtained based on the resistance of the first heating element 31 obtained from the first current and the first voltage and the above coefficient.
- the temperature of the second heating element 32 is the temperature obtained based on the resistance of the second heating element 32 obtained from the second current and the second voltage and the above coefficient.
- This graph also shows the change over time of the measured value of the temperature sensor 40 . Both graphs have lines overlapping each other. Further, in this graph, Case 1 indicates the process of the idle state, and Case 2 indicates the process of the processing state.
- Method A processing state: with heating target
- the resistance value Rmax of each heating element 30 at the time of the maximum temperature Tmax and the resistance value Rmin of each heating element 30 at the time of the minimum temperature Tmin are obtained from the change over time of the measured value of the temperature sensor 40 within a predetermined time of the processing state. to confirm.
- the predetermined time is selected from a range of about 500 seconds to 1000 seconds.
- the predetermined time in this example is 600 seconds.
- a film is formed on one wafer within this predetermined time.
- FIG. 9 is an enlarged view of part of the temperature change in the processing state of FIG.
- the minimum temperature Tmin is the valley temperature from when the film-formed wafer is taken out to when the current wafer to be film-formed is placed on the substrate 10 .
- the maximum temperature Tmax is the peak temperature during the film formation process on the current wafer.
- FIG. 9 shows that the minimum temperature Tmin is 449.4°C and the maximum temperature Tmax is 450.3°C.
- the resistance value Rmax and the resistance value Rmin of each heating element 30 are the values obtained by dividing the first voltage at each time point by the first current, or the values obtained by dividing the second voltage at each time point by the second current. Using these maximum temperature Tmax, resistance value Rmax, minimum temperature Tmin, and resistance value Rmin, a relational expression between the temperature and resistance value of each heating element 30 is obtained. This relational expression is obtained from the same way of thinking as the relational expressions shown when the temperature is rising and when the temperature is falling.
- the above method obtains a relational expression based on the resistance value Rmax, the maximum temperature Tmax, the minimum temperature Tmin, and the resistance value Rmin in the processing state of the wafer. It can be grasped with high precision.
- the relationship between the resistance and the temperature of the heating element 30 can be obtained based on the temperature profile simulating the actual film formation. Thereby, the temperature of the second heating element 32 can be grasped with high accuracy.
- Method B processing state: with heating target
- the average resistance Rave within a predetermined time period is obtained from the change over time of the resistance value of each heating element 30 during the predetermined time period in the processing state.
- the predetermined time is appropriately selected, for example, from a range of approximately 5000 seconds to 10000 seconds. In this example, the predetermined time is 8000 seconds. Film formation is performed on 10 or more wafers within this predetermined time.
- the rate of change ⁇ R/R of the resistance of each heating element 30 within a predetermined period of time is set in advance.
- the maximum resistance Rmax and the minimum resistance Rmin within a predetermined time are obtained, and then the difference ⁇ R between the maximum resistance Rmax and the minimum resistance Rmin and the ratio ⁇ R/Rave of the difference ⁇ R to the average resistance Rave are obtained.
- this ratio ⁇ R/Rave be the rate of change ⁇ R/R.
- the rate of change ⁇ R/R is assumed to be 0.02 here.
- the average temperature Tave within a predetermined time period is obtained.
- the amount of temperature change ⁇ T within a predetermined period of time is set in advance.
- the temperature change amount ⁇ T the difference between the maximum temperature Tmax and the minimum temperature Tmin within a predetermined time is first obtained as the temperature change amount ⁇ T.
- the temperature change amount ⁇ T is 0.88° C. here.
- the ratio ⁇ R/R and the amount of temperature change ⁇ T are considered to be substantially constant for each heating element 30 unless the holding temperature changes significantly.
- the fact that the holding temperature does not change greatly means that the amount of change in the holding temperature is 100° C. or less, for example.
- the average resistance Rave and the average temperature Tave of each heating element 30 may be obtained. That is, the maximum resistance Rmax, the minimum resistance Rmin, the maximum temperature Tmax, and the minimum temperature Tmin from the next time onward are obtained as follows.
- ⁇ R Rave x 0.02
- Maximum resistance Rmax Rave+ ⁇ R/2
- Minimum resistance Rmin Rave- ⁇ R/2
- Maximum temperature Tmax Tave+ ⁇ T/2
- Minimum temperature Tmin Tave- ⁇ T/2
- the maximum resistance Rmax, minimum resistance Rmin, maximum temperature Tmax, and minimum temperature Tmin can be obtained using known resistance change rate ⁇ R/R and temperature change amount ⁇ T. Once these parameters are determined, the correlation between the resistance and temperature of the heating element 30 can be determined.
- the temperature of the second heating element 32 can be obtained more easily.
- Method C (idle state: no object to be heated) First, an average resistance Rave within a predetermined period of time is obtained from the change over time of the resistance value of each heating element 30 within a predetermined period of time in the idle state.
- the predetermined time is appropriately selected, for example, from a range of approximately 5000 seconds to 10000 seconds. In this example, the predetermined time is 10000 seconds.
- the rate of change ⁇ R/R of the resistance of each heating element 30 within a predetermined period of time is set in advance.
- the maximum resistance Rmax and the minimum resistance Rmin within a predetermined time are obtained, and then the difference ⁇ R between the maximum resistance Rmax and the minimum resistance Rmin and the ratio ⁇ R/Rave of the difference ⁇ R to the average resistance Rave are obtained.
- This ⁇ R/Rave is defined as the resistance change rate ⁇ R/R.
- the rate of change ⁇ R/R is assumed to be 0.02 here.
- the average temperature Tave within a predetermined time period is obtained.
- the amount of temperature change ⁇ T within a predetermined period of time is set in advance.
- the temperature change amount ⁇ T the difference between the maximum temperature Tmax and the minimum temperature Tmin within a predetermined time is first obtained as the temperature change amount ⁇ T.
- the temperature change amount ⁇ T is 0.88° C. here.
- the ratio ⁇ R/R and the amount of temperature change ⁇ T are considered to be substantially constant for each heating element 30 unless the holding temperature changes significantly.
- the fact that the holding temperature does not change greatly means that the amount of change in the holding temperature is 100° C. or less, for example.
- the average resistance Rave and the average temperature Tave of each heating element 30 may be obtained. That is, the maximum resistance Rmax, the minimum resistance Rmin, the maximum temperature Tmax, and the minimum temperature Tmin from the next time onward are obtained as follows.
- ⁇ R Rave x 0.02
- Maximum resistance Rmax Rave+ ⁇ R/2
- Minimum resistance Rmin Rave- ⁇ R/2
- Maximum temperature Tmax Tave+ ⁇ T/2
- Minimum temperature Tmin Tave- ⁇ T/2
- the maximum resistance Rmax, minimum resistance Rmin, maximum temperature Tmax, and minimum temperature Tmin can be obtained using known resistance change rate ⁇ R/R and temperature change amount ⁇ T.
- the temperature of the second heating element 32 can be obtained based on the coefficient obtained when there is no object W to be heated in the idle state, there is no need to prepare a wafer when obtaining the coefficient.
- waste of wafers can be reduced compared to the case of obtaining coefficients by forming films on wafers during the preliminary test. Once these parameters are determined, the correlation between the resistance and temperature of the heating element 30 can be determined.
- the temperature of the second heating element 32 can be obtained more easily.
- the heater control device can grasp the temperature of the zone corresponding to the second heating element 32 without providing the temperature sensor 40 on the second heating element 32 .
- a temperature sensor 40 detects the temperature of the first heating element 31 .
- the first electric power supplied to the first heating element 31 is controlled based on the temperature detected by the temperature sensor 40 .
- the second electric power supplied to the second heating element 32 is controlled to have a preset ratio to the first electric power.
- the temperature of the second heating element 32 is obtained by the calculator 65 based on the measured value of the second current sensor 52 . Therefore, the temperature of the second heating element 32 can be grasped without a temperature sensor for detecting the temperature of the second heating element 32 .
- the second power is controlled by the phase control method, it can be controlled with high precision. As a result, the temperature of the second heating element 32 can also be grasped with high accuracy.
- the first heating element 31 and the second heating element 32 are controlled by the first electric power and the second electric power. Control based on the power ratio is less susceptible to changes in resistance value due to self-heating of each heating element 30 than control based on the current ratio. From this point as well, the temperature of the second heating element 32 can be accurately grasped.
- Embodiment 2 Next, Embodiment 2 will be described based on FIG.
- the second temperature which is the temperature of the second heating element 32
- the temperature of the second heating element 32 can be controlled by controlling the second electric power by changing the ratio described above. Differences from the first embodiment will be mainly described below, and descriptions of common points with the first embodiment will be omitted.
- Embodiment 2 further includes a second temperature controller 62 .
- the second temperature controller 62 outputs a second control signal for adjusting the ratio so that the second temperature approaches the target temperature. Control for adjusting this ratio can also utilize PID control.
- second power controller 64 adjusts the ratio for determining the second power.
- the fluctuation range of this ratio can be set as appropriate, but it is preferably within about 5% of the ratio of the second power before the change.
- the second power ratio before change is 0.8, so the second power ratio after change is changed between 0.76 and 0.84. If the power fluctuates outside the fluctuation range of this ratio, an alarm device (not shown) issues an alarm to the user. This warning enables the user to detect an abnormality and take appropriate measures.
- step S21 the second temperature controller 62 outputs a second control signal for adjusting the ratio so that the second temperature approaches the target temperature.
- step S22 the calculator 65 calculates the second power according to the adjusted ratio. Second power is then output from the second power controller 64 to the second heating element 32 .
- the heater control device 1 of Embodiment 2 not only can the second temperature of the second heating element 32 be displayed on the external output unit 70, but also the temperature of the second heating element 32 can be controlled.
- Embodiment 3 Next, Embodiment 3 will be described.
- the ratio for obtaining the second power is controlled so that the difference between the second temperature and the first temperature is as zero as possible.
- the device configuration of Embodiment 3 is substantially the same as the device configuration of Embodiment 2 described in FIG.
- a third temperature controller 62a instead of the second temperature controller 62, a third temperature controller 62a is provided.
- the temperature Ts measured by the temperature sensor 40 is regarded as the temperature Th of the first heating element 31 itself and set as the first temperature. That is, strictly speaking, the temperature Th of the first heating element 31 is different from the temperature Ts measured by the temperature sensor 40 . This is because the temperature Ts transiently includes a temperature rise caused by the heat generated by the first heating element 31 itself.
- the difference between the second temperature and the first temperature is regarded as the difference in temperature distribution within the first surface 10a. Strictly speaking, the first temperature and the second temperature have different target temperatures.
- the third temperature adjuster 62a outputs a third control signal for adjusting the ratio so that the difference in temperature distribution becomes the difference between the target temperatures of the second temperature and the first temperature.
- a second power controller 64 controls the second power according to the ratio adjusted by the third control signal. This control of the second power enables more precise temperature control of each heating element 30 .
- an alarm device (not shown) issues an alarm to the user. This warning enables the user to detect an abnormality and take appropriate measures.
- FIG. Modification 1 is a configuration that can be applied to any of Embodiments 1 to 3.
- Each zone of the outer region 10e is a fan-shaped zone obtained by dividing the annular region into four equal parts.
- a second heating element 32 is arranged in each zone of the outer region 10e divided into four equal parts. That is, a first heat generating element 31 is provided in the inner area 10i, one second heat generating element 32 is provided in the intermediate area 10m, and four second heat generating elements 32 are provided in the outer area 10e.
- Each heating element 30 can independently control the power supplied.
- a current sensor (not shown) is provided on each power line 30c connected to each heating element 30. As shown in FIG.
- the heater control device 1 of Modified Example 1 by using the second power controller 64, it is possible to achieve uniform heating of the substrate 10 using more heating elements 30 than in Embodiments 1 and 2. .
- Modification 2 will be described based on FIG. Modification 2 is a modification of Embodiment 1, and has a configuration in which the first heating element 31 and the second heating element 32 are insulated.
- a first transformer 81 and a second transformer 82 are provided between the first heating element 31 and the power supply and between the second heating element 32 and the power supply, respectively. . That is, the primary sides of the first transformer 81 and the second transformer 82 are connected to the power line branched from the power supply. On the other hand, the secondary sides of the first transformer 81 and the second transformer 82 are connected to power lines 30c independent of each other. Therefore, the first heating element 31 and the second heating element 32 are insulated from each other.
- the first heating element 31 and the second heating element 32 can be more reliably insulated.
- Modification 3 will be described with reference to FIG. Modification 3 is a modification of Embodiment 2 or Embodiment 3, and has a configuration in which the first heating element 31 and the second heating element 32 are insulated.
- a first transformer 81 and a second transformer 82 are provided between the first heating element 31 and the power supply and between the second heating element 32 and the power supply, respectively. . That is, the primary sides of the first transformer 81 and the second transformer 82 are connected to the power line branched from the power supply.
- the secondary sides of the first transformer 81 and the second transformer 82 are connected to power lines 30c independent of each other. Therefore, the first heating element 31 and the second heating element 32 are insulated from each other.
- the first heating element 31 and the second heating element 32 can be more reliably insulated.
- heater control device 10 substrate 10a first surface 10b second surface 10i inner region 10m intermediate region 10e outer region 20 support 21 flange 30 heating element 31 first heating element 32 second heating element 30t terminal 30c power line 40 temperature sensor 50 Current sensor 51 First current sensor 52 Second current sensor 60 Controller 61 First temperature controller 62 Second temperature controller 62a Third temperature controller 63 First power controller 64 Second power controller 65 Computer 66 Memory 70 External output unit 80 Transformer 81 First transformer 82 Second transformer W Heating target w Width ⁇ Operation phase angle
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Abstract
Description
本出願は、2021年1月29日付の日本国出願の特願2021-12977に基づく優先権を主張し、前記日本国出願に記載された全ての記載内容を援用するものである。 The present disclosure relates to heater controllers.
This application claims priority based on Japanese Patent Application No. 2021-12977 dated January 29, 2021, and incorporates all the descriptions described in the Japanese application.
複数の発熱体を有するマルチゾーンヒータにおいて、ウエハ面内でのさらなる均熱性の向上が求められている。 [Problems to be Solved by the Present Disclosure]
In multi-zone heaters having a plurality of heating elements, there is a demand for further improvement in heat uniformity within the wafer surface.
上記ヒータ制御装置によれば、個々の発熱体に温度センサを設けることなく、各発熱体に対応するゾーンの温度を把握できる。 [Effect of the present disclosure]
According to the above heater control device, the temperature of the zone corresponding to each heating element can be grasped without providing a temperature sensor for each heating element.
以下、本開示の実施態様を列記して説明する。 [Description of Embodiments of the Present Disclosure]
Embodiments of the present disclosure are listed and described below.
本開示の実施形態に係るヒータ制御装置を図面に基づいて説明する。図中の同一符号は同一名称物を示す。各図面が示す部材の大きさや位置関係等は、説明を明確にする目的で表現されており、必ずしも実際の寸法関係等を表すものではない。 [Details of the embodiment of the present disclosure]
A heater control device according to an embodiment of the present disclosure will be described based on the drawings. The same reference numerals in the drawings indicate the same names. The sizes and positional relationships of members shown in each drawing are expressed for the purpose of clarifying the description, and do not necessarily represent the actual dimensional relationships.
図1から図4を参照して、実施形態1に係るヒータ制御装置1を説明する。このヒータ制御装置1は、ウエハの表面に薄膜を形成する成膜装置に利用できる。成膜装置は、雰囲気ガスの制御ができるチャンバー内に基材10及び支持体20を備える。チャンバーの図示は省略する。図1において、各発熱体30は基材10の周方向の一部に配置されていない箇所があるが、実際の装置では基材10の全体に満遍なく発熱体30が配置されている。 [Embodiment 1]
A
図1に示すように、ヒータ制御装置1は、基材10と、支持体20と、複数の発熱体30と、温度センサ40と、電流センサ50と、制御器60とを備える。基材10は、図3に示す加熱対象Wが載置される第一面10aと、第一面10aに向かい合う第二面10bとを備える。以下の説明では、基材10の第一面10a側を「上」とし、第二面10b側を「下」ということがある。支持体20は、基材10の下方に取り付けられている。複数の発熱体30は、図1及び図3に示すように、基材10の内部に配置されている。複数の発熱体30は、第一発熱体31と一つ以上の第二発熱体32とを備える。本例では、説明の便宜上、一つの第二発熱体32を備える場合を例として説明する。温度センサ40は第一発熱体31の温度を検知する。電流センサ50は、第一発熱体31に流れる第一電流を測定する第一電流センサ51と、第二発熱体32に流れる第二電流を測定する第二電流センサ52とを備える。制御器60は、主に第一発熱体31及び第二発熱体32に供給される電力を制御する。実施形態1の特徴の一つは、第二発熱体32には温度センサを設けることなく第一発熱体31のみに温度センサ40を設け、第二発熱体32の温度を把握できるように構成したことにある。以下、各構成をより詳しく説明する。 <Overall composition>
As shown in FIG. 1 , the
基材10は円板状の形状を有する。基材10は、第一面10aと第二面10bとを備える。第一面10aと第二面10bとは互いに向かい合っている。第一面10aには、図3に示す加熱対象Wが載置される。加熱対象Wは、例えばシリコンや化合物半導体等のウエハである。第二面10bには、後述する支持体20が取り付けられている。第二面10bには、図3に示す複数の端子30tが嵌め込まれる複数の穴が設けられている。 <Base material>
The
支持体20は、図1及び図3に示すように、基材10を第二面10b側から支持している。支持体20は、ヒータ制御装置1を第一面10a側から平面視したときに複数の端子30tを囲むように第二面10bに取り付けられている。支持体20の形状は、特に限定されない。本例の支持体20は、円筒状部材である。支持体20は、基材10と同心状に配置されている。本例では、円筒状の支持体20の中心と、円板状の基材10の中心とが同軸となるように、基材10と支持体20とが接続されている。 <Support>
The
複数の発熱体30の各々は、基材10を介して加熱対象Wを加熱する熱源である。第一発熱体31は、図1及び図3に示すように基材10の中心を含む円形領域、即ち内側領域10iに配置されている。一つ以上の第二発熱体32は、基材10及び第一発熱体31と同心状に配置されている。一つ以上の第二発熱体32は、基材10の中心と同心状の環状領域、即ち外側領域10eに配置されている。第一発熱体31と一つ以上の第二発熱体32とは、基材10の厚さ方向に間隔をあけて配置されている。第一発熱体31及び第二発熱体32の各々は、図3に示す端子30tを介して電力線30cにつながっている。この電力線30cを介して各発熱体30には図示しない電源から電力が供給される。 <First heating element and second heating element>
Each of the
温度センサ40は、第一発熱体31の第一温度を測定するセンサである。温度センサ40としては、市販の熱電対や測温抵抗体が好適に利用できる。測温抵抗体には、白金測温抵抗体であるPT100などが挙げられる。 <Temperature sensor>
The
電流センサ50は、発熱体30に流れる電流を検知するセンサである。本例では、第一発熱体31に流れる第一電流を検知する第一電流センサ51と、第二発熱体32に流れる第二電流を検知する第二電流センサ52とを備える。第二電流センサ52が請求項1における電流センサに相当する。第二発熱体32が複数ある場合、第二電流センサ52は、各第二発熱体32に設けられる。第一電流センサ51は第一発熱体31につながる電力線30cに、第二電流センサ52は第二発熱体32につながる電力線30cにそれぞれ設けられている。この電流センサ50は、市販のCT(Current Tansmitter)で代表されるセンサが利用できる。本例において、第一電流又は第二電流は、第一発熱体31又は第二発熱体32に流れる電流の実効値を所定時間内に平均化して電気的雑音を除去した値としている。 <Current sensor>
The
制御器60は、ヒータ制御装置1の動作に必要な各部の制御を行う。より具体的には、制御器60は、第一温度調節器61、第一電力制御器63、第二電力制御器64、演算器65及びメモリ66を備える。制御器60は、代表的には、CPU(Central Processor Unit)またはDSP(Digital Signal Processing)等を含むプロセッサによって実現される。代表的には、プロセッサは、バスと、バスに接続されたCPU、ROM(Read-Only Memory)、RAM(Random Access Memory)、入出力I/F(Interface)などを含む。プロセッサの数は、制御器60に一つ以上備えれられていればよく、複数備えられていてもよい。第一温度調節器61、第一電力制御器63、第二電力制御器64、演算器65及びメモリ66は、個別のハードウェアで構成されてもよいし、一つの制御器60の一部の構成要素として構成されてもよい。メモリ66には、後述する制御手順をプロセッサに実行させるためのプログラムが格納されている。プロセッサは、メモリ66に格納されたプログラムを読み出して実行する。プログラムは、第一温度調節器61、第一電力制御器63、第二電力制御器64、及び演算器65での処理に関するプログラムコードを含む。 <Controller>
The
第一温度調節器61は、上記第一温度が目標温度に近づくように第一制御信号を出力する。この第一温度調節器61での制御は、PID制御が利用できる。PID制御は、フィードバック制御の一種であり、入力値の制御を出力値と目標値との偏差(P)、その積分(I)、および微分(D)の3つの動作によって行う制御方法である。偏差に応じた操作量を出力する比例動作によりハンチングの小さい滑らかな温度制御が行える。積分動作でオフセットを自動的に修正できる。微分動作で外乱に対する応答を速くすることができる。 - First temperature controller The
第一電力制御器63は、第一制御信号に応じて第一発熱体31に供給される第一電力を制御する。第一制御信号が入力された第一電力制御器63は、第一制御信号に対応した第一電力を第一発熱体31に供給する。第一電力は、第一電流と第一電圧との積により演算される。第一電流は、上述したように第一電流センサ51の測定値である。第一電圧は、第一発熱体31に印加される電圧である。この第一電圧は後述するように演算により求められる。 - First power controller The
第二電力制御器64は、第二発熱体32に供給される第二電力を制御する。より具体的には、第二電力制御器64は、第一電力に対して予め設定された比率となるように第二電力を制御する。この比率は、ユーザが予め設定する比率である。例えば、第一電力:第二電力が1.0:0.8となるように比率が設定される。第二発熱体32が複数ある場合、個々の発熱体30の第二電力も第一電力に対して予め設定された比率となるように制御される。例えば、第二発熱体32が2つある場合、第一電力:第二電力A:第二電力B=1.0:0.8:0.6とする。第二電力Aは、2つの第二発熱体32の一方の第二電力である。第二電力Bは、2つの第二発熱体32の他方の第二電力である。 - Second power controller The
演算器65は、制御器60で必要な各種演算を行う。上述したように、第一電圧、第一電力、第二電圧、及び第二電力の演算はいずれも演算器65で行われる。さらに、演算器65は第二発熱体32の温度である第二温度の演算も行う。 ·Calculator The
メモリ66は、プログラムを記憶するメモリとして、各種不揮発性メモリが好適に利用できる。また、メモリ66は、一連の演算に必要な値を一時的に記憶する揮発性メモリを含んでいてもよい。 - Memory The
ヒータ制御装置1は、外部出力部70及びトランス80を備えてもよい。
外部出力部70は、上記のように求められた第二発熱体32の第二温度及び第二温度が適正範囲にあるか否かの判定結果の少なくとも一方を表示又は外部装置に送信する機器である。例えば、外部出力部70として、第二温度を文字で表示したり、第二温度の経時変化をグラフで表示したりするディスプレイが挙げられる。他の外部出力部70としては、第二温度に所定の処理を施した処理結果を出力する機器であってもよい。この処理結果を示す機器には、警報装置が挙げられる。警報装置は、例えば第二温度が設定された所定の適正範囲から外れた場合に警報を出す装置である。警報は、ユーザに第二温度の異常を知らせることができるものであれば特に限定されない。例えば、具体的な警報の種類としては、ディスプレイへの文字表示、ランプの点灯、ブザーの鳴動などが挙げられる。さらに他の外部出力部70としては、図示しない通信機器が挙げられる。この通信機器は、遠隔地のユーザが持つ外部装置との通信を行う。例えば、第二温度の情報を通信機器で外部装置へ送ったり、上記警報を通信機器でフラグの状態変化として外部装置に伝えたりすることができる。この情報の伝送により、遠隔地のユーザは第二温度や警報を認知できる。 <Other components>
The
The
図5、図6に基づいて、上記ヒータ制御装置1の処理手順を説明する。各構成部材については図1を参照する。
まず、図5に基づいて、第一電力及び第二電力を各発熱体30に出力するまでの処理手順を説明する。ステップS1において、温度センサ40から第一温度を取得し、さらに第一電流センサ51から第一電流を取得する。ステップS2では、第一温度が目標温度に近づくように第一温度調節器61が第一制御信号を出力する。ステップS3では第一電力制御器63は第一制御信号に対応した第一電力を第一発熱体31に出力する。そして、ステップS4では、演算器65で第二電力を演算し、さらに第二電力を第二電力制御器64から第二発熱体32に出力する。このステップS1からステップS4の一連の処理は、ヒータ制御装置1を駆動している間、繰り返して行われる。 <Processing procedure>
The processing procedure of the
First, based on FIG. 5, a processing procedure for outputting the first power and the second power to each
予備試験は、第二発熱体32の抵抗と温度との関係を表す係数を予め求めるための試験である。予備試験は、昇温時及び降温時と、温度保持時とで異なる手法により行うことが好適である。つまり、昇温時及び降温時と、温度保持時とで異なる係数を用いることが好適である。 <Preliminary test>
The preliminary test is a test for preliminarily obtaining a coefficient representing the relationship between the resistance of the
昇温時及び降温時では、温度保持時に比べて単位時間当たりの温度変化量が大きい。この昇温時及び降温時、ウエハへの成膜処理は行われない。この場合、室温から保持温度までの温度域又は保持温度から室温までの温度域をより狭い温度域ごとに区切り、区切られた各温度域ごとに第二発熱体32の抵抗と温度との関係を求める。例えば、50℃から100℃の範囲を有する区切られた温度域ごとに第一発熱体31及び第二発熱体32の各々の抵抗と温度との関係を求める。より具体的には、昇温時であれば、50℃以上100℃以下の第一温度域、100℃以上200℃以下の第二温度域、200℃以上300℃以下の第三温度域、300℃以上400℃以下の第四温度域、及び400℃以上保持温度以下の第五温度域の各々について第二発熱体32の抵抗と温度との関係を求める。保持温度の一例としては450℃が挙げられる。例えば、第一温度域においては、50℃と100℃の二点における抵抗と温度との関係を求める。ここで、二点の測定点、即ち低温側の抵抗R(T1)における第二発熱体32の温度T1と、高温側の抵抗R(T2)における第二発熱体32の温度T2とは、比例の関係式で表される。この関係式を用いれば、抵抗Rの第二発熱体32の温度Tは次式で求められる。
T={(T2-T1)/(R(T2)-R(T1))}×(R-R(T1))+T1
但し、T1≦T≦T2、R(T1)≦R≦R(T2)である。 ・At the time of temperature increase and temperature decrease The amount of temperature change per unit time during temperature increase and temperature decrease is greater than that during temperature maintenance. During this temperature increase and temperature decrease, the film formation process on the wafer is not performed. In this case, the temperature range from the room temperature to the holding temperature or the temperature range from the holding temperature to the room temperature is divided into narrower temperature ranges, and the relationship between the resistance of the
T={(T2−T1)/(R(T2)−R(T1))}×(RR(T1))+T1
However, T1≦T≦T2 and R(T1)≦R≦R(T2).
T={(Tk-Tr)/(R(Tk)-R(Tr))}×(R-R(Tr))+Tr
但し、Tr≦T≦Tk、R(Tr)≦R≦R(Tk)である。
この場合、室温と保持温度との二点から求めた第二発熱体32の抵抗と温度との関係式では、その中間の温度での抵抗値はその二点間の線形補間では表せないため、精度よく第二発熱体の温度を求めることは難しい。 On the other hand, for example, the temperature of the
T={(Tk−Tr)/(R(Tk)−R(Tr))}×(RR(Tr))+Tr
However, Tr≤T≤Tk and R(Tr)≤R≤R(Tk).
In this case, in the relational expression between the resistance and the temperature of the
温度保持時は、昇温時や降温時に比べて単位時間当たりの温度変化の割合はごく僅かである。よって、温度保持時は、昇温時や降温時よりも狭い温度帯域における第二発熱体32の抵抗と温度との関係を求めることが好ましい。より具体的には、温度保持時における最大温度と最小温度との差という微細な温度域に応じた係数を用いることで、正確に第二発熱体32の温度を求めることができる。温度保持過程には、上述したように加熱対象Wのないアイドル状態と加熱対象Wのある処理状態の2つの温度プロファイルが含まれる。この温度プロファイルを図8に基づいて説明する。図8は、第一発熱体の温度と第二発熱体の温度の経時変化を示すグラフである。第一発熱体31の温度は、第一電流と第一電圧とから求めた第一発熱体31の抵抗と上記係数とに基づいて求めた温度である。第二発熱体32の温度は、第二電流と第二電圧とから求めた第二発熱体32の抵抗と上記係数とに基づいて求めた温度である。このグラフでは、さらに温度センサ40の測定値の経時変化も併せて示している。いずれのグラフも互いに線が重なっている。さらにこのグラフでは、アイドル状態の過程をCase1とし、処理状態の過程をCase2として示している。このグラフに示すように、アイドル状態では、成膜装置のチャンバー内にガスの出入りが行われ、第一温度調節器61による温度制御の結果、ごく僅かの温度の上下動が認められる。これに対し、処理状態では、チャンバー内にウエハを出し入れするため、アイドル状態に比べてより大きな温度の上下動が認められる。図8のグラフは複数の線が重なって示されるため、例えば複数の線が重なって示されたアイドル状態における温度の振れ幅は大きく見える。しかし、個々のグラフの線の振れ幅はもっと小さい。特に、個々のグラフの振れ幅は、処理状態よりもアイドル状態の方が明確に小さい。このような温度保持過程においては、処理状態での温度プロファイルに基づいて係数を求める方法と、アイドル状態での温度プロファイルに基づいて係数を求める方法とがある。以下、それぞれを順に説明する。 ・During temperature retention During temperature retention, the rate of temperature change per unit time is very small compared to when the temperature is raised or lowered. Therefore, when maintaining the temperature, it is preferable to obtain the relationship between the resistance of the
まず、処理状態の所定時間内における温度センサ40の測定値の経時変化から、最大温度Tmaxの時点における各発熱体30の抵抗値Rmax、及び最小温度Tminの時点における各発熱体30の抵抗値Rminを確認する。所定時間は、500秒から1000秒程度の範囲から選択する。本例での所定時間は600秒である。この所定時間内に1枚のウエハに成膜が行われる。図9は、図8の処理状態における温度変化の一部を拡大して示したものである。最小温度Tminは、成膜処理済みのウエハが取り出され、今から成膜処理を行う現ウエハが基材10上に載置されるまでの間のバレー温度である。最大温度Tmaxは現ウエハに対して成膜処理が行われている間のピーク温度である。図9では、最小温度Tminが449.4℃、最大温度Tmaxが450.3℃であることを示している。各発熱体30の抵抗値Rmax及び抵抗値Rminは、上記各時点における第一電圧を第一電流で除した値、又は上記各時点における第二電圧を第二電流で除した値である。これら最大温度Tmax、抵抗値Rmax、最小温度Tmin、及び抵抗値Rminを用いて各発熱体30の温度と抵抗値の関係式を求める。この関係式は、昇温時及び降温時で示した関係式と同様の考え方により求められる。 Method A (processing state: with heating target)
First, the resistance value Rmax of each
まず、処理状態の所定時間内における各発熱体30の抵抗値の経時変化から、所定時間内の平均抵抗Raveを求める。所定時間は、例えば5000秒から10000秒程度の範囲から適宜選択する。本例では所定時間は8000秒である。この所定時間内には、10枚以上のウエハに成膜が行われている。次に、所定時間内の各発熱体30の抵抗の変化率ΔR/Rを予め設定しておく。最初に所定時間内の最大抵抗Rmax、最小抵抗Rminを求めておき、さらに最大抵抗Rmaxと最小抵抗Rminとの差分ΔR、及び差分ΔRの平均抵抗Raveに対する比率ΔR/Raveを求める。この比率ΔR/Raveを変化率ΔR/Rとする。例えば、ここでは変化率ΔR/Rを0.02とする。一方、温度センサ40の測定値についても同様に、所定時間内の平均温度Taveを求める。また、所定時間内における温度変化量ΔTを予め設定しておく。温度変化量ΔTも最初に所定時間内の最大温度Tmaxと最小温度Tminとの差分を温度変化量ΔTとして求めておく。例えば、ここでは温度変化量ΔTは0.88℃とする。比率ΔR/Rと温度変化量ΔTは、保持温度が大きく変わらなければ、発熱体30ごとにほぼ一定と考えられる。保持温度が大きく変わらないとは、例えば保持温度の変化量が100℃以下であることを言う。 Method B (processing state: with heating target)
First, the average resistance Rave within a predetermined time period is obtained from the change over time of the resistance value of each
ΔR=Rave×0.02
最大抵抗Rmax=Rave+ΔR/2
最小抵抗Rmin=Rave-ΔR/2
最大温度Tmax=Tave+ΔT/2
最小温度Tmin=Tave-ΔT/2 In subsequent film formation, the average resistance Rave and the average temperature Tave of each
ΔR = Rave x 0.02
Maximum resistance Rmax=Rave+ΔR/2
Minimum resistance Rmin=Rave-ΔR/2
Maximum temperature Tmax=Tave+ΔT/2
Minimum temperature Tmin=Tave-ΔT/2
まず、アイドル状態の所定時間内における各発熱体30の抵抗値の経時変化から、所定時間内の平均抵抗Raveを求める。所定時間は、例えば5000秒から10000秒程度の範囲から適宜選択する。本例では所定時間は10000秒である。次に、所定時間内の各発熱体30の抵抗の変化率ΔR/Rを予め設定しておく。最初に所定時間内の最大抵抗Rmax、最小抵抗Rminを求めておき、さらに最大抵抗Rmaxと最小抵抗Rminとの差分ΔR、及び差分ΔRの平均抵抗Raveに対する比率ΔR/Raveを求める。このΔR/Raveを抵抗変化率ΔR/Rとする。例えば、ここでは変化率ΔR/Rを0.02とする。一方、温度センサ40の測定値についても同様に、所定時間内の平均温度Taveを求める。また、所定時間内における温度変化量ΔTを予め設定しておく。温度変化量ΔTも最初に所定時間内の最大温度Tmaxと最小温度Tminとの差分を温度変化量ΔTとして求めておく。例えば、ここでは温度変化量ΔTは0.88℃とする。比率ΔR/Rと温度変化量ΔTは、保持温度が大きく変わらなければ、発熱体30ごとにほぼ一定と考えられる。保持温度が大きく変わらないとは、例えば保持温度の変化量が100℃以下であることを言う。 Method C (idle state: no object to be heated)
First, an average resistance Rave within a predetermined period of time is obtained from the change over time of the resistance value of each
ΔR=Rave×0.02
最大抵抗Rmax=Rave+ΔR/2
最小抵抗Rmin=Rave-ΔR/2
最大温度Tmax=Tave+ΔT/2
最小温度Tmin=Tave-ΔT/2 In subsequent film formation, the average resistance Rave and the average temperature Tave of each
ΔR = Rave x 0.02
Maximum resistance Rmax=Rave+ΔR/2
Minimum resistance Rmin=Rave-ΔR/2
Maximum temperature Tmax=Tave+ΔT/2
Minimum temperature Tmin=Tave-ΔT/2
次に、実施形態2を図10に基づいて説明する。実施形態1では、第二発熱体32の温度である第二温度を把握したり、第二温度が異常な温度となることを監視したりできる。これに対し、実施形態2では、上述した比率を変えることにより第二電力を制御することで、第二発熱体32の温度を制御することができる。以下、主に実施形態1との相違点について説明を行い、実施形態1との共通点の説明は省略する。 [Embodiment 2]
Next,
次に、実施形態3を説明する。実施形態3では、第二温度と第一温度との差が可及的にゼロになるように、第二電力を求めるための比率を制御する。実施形態3の装置構成は図10で説明される実施形態2の装置構成とほぼ同じである。実施形態3では、第二温度調節器62の代わりに第三温度調節器62aを備えている。実施形態2では、温度センサ40で測定した温度Tsを第一発熱体31自体の温度Thとみなして第一温度としている。つまり、厳密には第一発熱体31の温度Thは温度センサ40で測定される温度Tsとは異なる。これは、温度Tsには、第一発熱体31自身の発熱による温度上昇分が過渡的に含まれるためである。 [Embodiment 3]
Next, Embodiment 3 will be described. In Embodiment 3, the ratio for obtaining the second power is controlled so that the difference between the second temperature and the first temperature is as zero as possible. The device configuration of Embodiment 3 is substantially the same as the device configuration of
図12、図13に基づいて、変形例1を説明する。変形例1は実施形態1から実施形態3のいずれにおいても適用できる構成である。変形例1では、基材10において独立して温度制御されるゾーンが6つある。つまり、基材10には、基材10の中央部に位置する円形の内側領域10i、内側領域10iの外側に位置する中間領域10m、中間領域10mの外側に位置する外側領域10eが設けられている。さらに、変形例1では外側領域10eが基材10の周方向に分割されている。分割された外側領域10eに設けられる第二発熱体32の数は複数であればよい。本例での分割数は4つである。外側領域10eの各ゾーンは環状の領域を4等分した扇形のゾーンである。4等分された外側領域10eの各ゾーンには各々第二発熱体32が配置されている。つまり、内側領域10iには第一発熱体31が、中間領域10mには一つの第二発熱体32が、外側領域10eには4つの第二発熱体32が設けられている。各発熱体30は供給される電力を独立して制御できる。そして、各々の発熱体30につながる各電力線30cに図示しない電流センサが設けられている。 [Modification 1]
図14に基づいて変形例2を説明する。変形例2は実施形態1の変形例であり、第一発熱体31と第二発熱体32とを絶縁した構成である。 [Modification 2]
図15に基づいて変形例3を説明する。変形例3は実施形態2又は実施形態3の変形例であり、第一発熱体31と第二発熱体32とを絶縁した構成である。
図15に示すように、変形例3では、第一発熱体31と電源との間及び第二発熱体32と電源との間にそれぞれ第一トランス81と第二トランス82とが設けられている。つまり、第一トランス81と第二トランス82の一次側は電源から分岐された電力線につながっている。一方、第一トランス81と第二トランス82の二次側は互いに独立した電力線30cにつながっている。そのため、第一発熱体31と第二発熱体32とは互いに絶縁されている。 [Modification 3]
Modification 3 will be described with reference to FIG. Modification 3 is a modification of
As shown in FIG. 15, in Modification 3, a
10 基材
10a 第一面
10b 第二面
10i 内側領域
10m 中間領域
10e 外側領域
20 支持体
21 フランジ部
30 発熱体
31 第一発熱体
32 第二発熱体
30t 端子
30c 電力線
40 温度センサ
50 電流センサ
51 第一電流センサ
52 第二電流センサ
60 制御器
61 第一温度調節器
62 第二温度調節器
62a 第三温度調節器
63 第一電力制御器
64 第二電力制御器
65 演算器
66 メモリ
70 外部出力部
80 トランス
81 第一トランス
82 第二トランス
W 加熱対象
w 幅
θ 操作位相角
1
Claims (8)
- 円板状の形状を有する基材と、
前記基材に同軸状に取り付けられた筒状の支持体と、
前記基材の中心を含む領域に配置された第一発熱体と、
前記第一発熱体と同心状に配置された少なくとも一つの第二発熱体と、
前記第一発熱体の第一温度を測定する温度センサと、
前記少なくとも一つの第二発熱体に供給される電流を測定する少なくとも一つの電流センサと、
前記第一温度が目標温度に近づくように第一制御信号を出力する第一温度調節器と、
前記第一制御信号に応じて前記第一発熱体に供給される第一電力を制御する第一電力制御器と、
前記第二発熱体に供給される第二電力を制御する第二電力制御器と、
前記第二発熱体の温度を求める演算器とを備え、
前記基材は、加熱対象が載置される第一面と、前記第一面と向かい合う第二面とを有し、
前記筒状の支持体は、前記第二面に取り付けられ、
前記温度センサは、前記筒状の支持体の内側に配置され、
前記第二電力制御器は、前記第一電力に対して予め設定された比率となるように前記第二電力を位相制御方式により制御し、
前記演算器は、前記少なくとも一つの電流センサの測定値に基づいて前記第二発熱体の温度を求める、
ヒータ制御装置。 a substrate having a disk-like shape;
a cylindrical support coaxially attached to the substrate;
a first heating element arranged in a region including the center of the base material;
at least one second heating element arranged concentrically with the first heating element;
a temperature sensor that measures the first temperature of the first heating element;
at least one current sensor measuring the current supplied to the at least one second heating element;
a first temperature regulator that outputs a first control signal so that the first temperature approaches a target temperature;
a first power controller that controls the first power supplied to the first heating element according to the first control signal;
a second power controller that controls the second power supplied to the second heating element;
A calculator for obtaining the temperature of the second heating element,
The base material has a first surface on which a heating target is placed and a second surface facing the first surface,
The tubular support is attached to the second surface,
The temperature sensor is arranged inside the tubular support,
The second power controller controls the second power by a phase control method so as to achieve a preset ratio with respect to the first power,
The computing unit obtains the temperature of the second heating element based on the measured value of the at least one current sensor;
heater controller. - 前記演算器は、前記第一温度、前記第二発熱体の第二電圧、及び予め定めた係数を用いて前記第二発熱体の温度を演算し、
前記係数は、前記第二発熱体の抵抗と前記第二発熱体の温度との関係を表す係数である、請求項1に記載のヒータ制御装置。 The calculator calculates the temperature of the second heating element using the first temperature, the second voltage of the second heating element, and a predetermined coefficient,
2. The heater control device according to claim 1, wherein said coefficient is a coefficient representing the relationship between the resistance of said second heating element and the temperature of said second heating element. - 前記係数は、予め定めた複数の係数から前記第一温度に応じて選択された係数である、請求項2に記載のヒータ制御装置。 The heater control device according to claim 2, wherein the coefficient is selected from a plurality of predetermined coefficients according to the first temperature.
- 前記複数の係数は、前記第一発熱体及び前記第二発熱体の昇温時、温度保持時、及び降温時で異なる、請求項3に記載のヒータ制御装置。 4. The heater control device according to claim 3, wherein the plurality of coefficients are different when the temperature of the first heating element and the second heating element is increased, when the temperature is maintained, and when the temperature is decreased.
- 前記係数は、前記温度保持時に、前記第一面に前記加熱対象が載置されていない状態で測定された前記第一温度に基づいて求められる、請求項4に記載のヒータ制御装置。 5. The heater control device according to claim 4, wherein said coefficient is obtained based on said first temperature measured in a state in which said object to be heated is not placed on said first surface when said temperature is maintained.
- 前記第二発熱体の温度及び前記第二発熱体の温度が適正範囲にあるか否かの判定結果の少なくとも一方を表示又は外部装置に送信する外部出力部を備える、請求項1から請求項5のいずれか1項に記載のヒータ制御装置。 6. An external output unit that displays or transmits at least one of the temperature of the second heating element and the determination result as to whether or not the temperature of the second heating element is within an appropriate range to an external device. The heater control device according to any one of Claims 1 to 3.
- さらに第二温度調節器を備え、
前記第二温度調節器は、前記第二発熱体の温度が目標温度に近づくように前記比率を調整するための第二制御信号を出力し、
前記第二電力制御器は、前記第二制御信号により調整された前記比率に応じて前記第二電力を制御する、請求項1から請求項6のいずれか1項に記載のヒータ制御装置。 Further equipped with a second temperature controller,
The second temperature controller outputs a second control signal for adjusting the ratio so that the temperature of the second heating element approaches the target temperature;
The heater control device according to any one of claims 1 to 6, wherein said second power controller controls said second power according to said ratio adjusted by said second control signal. - さらに第三温度調節器を備え、
前記第三温度調節器は、前記第二発熱体の温度と前記第一温度との差が前記第二発熱体の温度と第一温度のそれぞれの目標温度の差になるように前記比率を調整するための第三制御信号を出力し、
前記第二電力制御器は、前記第三制御信号により調整された前記比率に応じて前記第二電力を制御する、請求項1から請求項6のいずれか1項に記載のヒータ制御装置。
Further equipped with a third temperature controller,
The third temperature controller adjusts the ratio so that the difference between the temperature of the second heating element and the first temperature is the difference between the target temperatures of the second heating element and the first temperature. output a third control signal for
The heater control device according to any one of claims 1 to 6, wherein said second power controller controls said second power according to said ratio adjusted by said third control signal.
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US20200255945A1 (en) * | 2018-05-07 | 2020-08-13 | Lam Research Corporation | Use of voltage and current measurements to control dual zone ceramic pedestals |
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