Wafer temperature control device and wafer temperature control method

Abstract

To suppress the occurrence of overshoot.SOLUTION: A wafer temperature control device comprises: a placement section which has a placement surface on which a wafer is placed; a temperature adjustment section which is capable of heating and cooling the placement section; multiple temperature sensors which are provided on the placement section; and a temperature control device which controls the temperature adjustment section. The temperature control device includes: multiple operation amount change amount calculation sections which are provided for each of the multiple temperature sensors, and calculate an operation amount change amount of the temperature adjustment section on the basis of a detected temperature and a target temperature of the temperature sensor; a selection and switching section which can switch from a state where the operation amount change amount calculated by one operation amount change amount calculation section is selected to a state where the operation amount change amount calculated by the other operation amount change amount calculation section is selected; and an operation amount calculation section which calculates the operation amount of the temperature adjustment section on the basis of the operation amount change amount selected by the selection and switching section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for controlling a wafer temperature. [Background technology]

[0002] Patent Document 1 discloses a temperature control device for a wafer prober. This temperature control device controls the temperature of the wafer to a target temperature and also controls the temperature distribution within the wafer surface. The temperature control device of Patent Document 1 includes a stage on which the wafer can be placed and which is divided into a plurality of regions in a plan view, a temperature adjustment unit provided in each region of the stage and capable of independently adjusting the temperature of each region, and a temperature sensor provided in each region of the stage for detecting the temperature of each region. When a local thermal disturbance is applied to a chip on the wafer by energizing it, the temperature control device of Patent Document 1 suppresses the local thermal disturbance and settles the temperature to a target temperature by the temperature sensor and temperature adjustment unit provided in the region where the local thermal disturbance is applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-125685 Summary of the Invention [Problem to be solved by the invention]

[0004] In a temperature control device such as that in Patent Document 1, when the position to which the local thermal disturbance is applied is changed, the temperature sensor is also switched. However, after the temperature sensor is switched, an overshoot may occur when the detected temperature of the switched temperature sensor is settled to the target temperature range by PID control. The present invention has been made in view of the above problems, and an object of the present invention is to provide a wafer temperature control device and a wafer temperature control method that are capable of suppressing the occurrence of overshoot. [Means for solving the problem]

[0005] A wafer temperature control device according to one embodiment of the present invention comprises a mounting section having a mounting surface on which a wafer is placed, a temperature adjustment section capable of heating and cooling the mounting section, a plurality of temperature sensors provided on the mounting section, and a temperature control device controlling the temperature adjustment section, wherein the temperature control device comprises a plurality of manipulated variable change calculation sections provided for each of the plurality of temperature sensors and calculating an manipulated variable change amount of the temperature adjustment section based on a detected temperature of the temperature sensor and a target temperature, a selection / switching section that selects either a state in which an manipulated variable change amount calculated by one of the manipulated variable change calculation sections is selected or a state in which an manipulated variable change amount calculated by another of the manipulated variable change calculation sections is selected, and a manipulation variable calculation section that calculates an manipulated variable of the temperature adjustment section based on the manipulation variable change amount selected by the selection / switching section.

[0006] A wafer temperature control method according to one embodiment of the present invention includes a temperature monitoring step of detecting wafer temperatures at multiple locations; a manipulated variable change calculation step of calculating an manipulated variable change for each location based on the wafer temperatures at the multiple locations detected by the temperature monitoring step and a target temperature; a selection / switching step of switching from a state in which an manipulated variable change for one location is selected among the manipulated variable changes for each location calculated by the manipulated variable change calculation step to a state in which an manipulated variable change for another location is selected; a manipulated variable calculation step of calculating an manipulated variable for the wafer temperature based on the manipulated variable change selected by the selection / switching step; and a temperature adjustment step of adjusting the wafer temperature based on the manipulated variable calculated by the manipulated variable calculation step. Effect of the Invention

[0007] According to the present invention, the occurrence of overshoot can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a temperature control device 1. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 4 is a control block diagram of a manipulated variable change amount calculation unit. [Figure 6] FIG. 4 is a control block diagram of a manipulation amount calculation unit. [Figure 7] 3 is a flowchart of a temperature control method according to an embodiment. [Figure 8] 5 is a graph showing temperature changes and manipulated variables of a main temperature sensor and a sub temperature sensor in the embodiment. [Figure 9] FIG. 4 is a control block diagram of a control device in a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, as an example of a wafer temperature control device, a temperature control device for controlling the temperature of a wafer on which a chip is formed, the electrical characteristics of which are inspected by passing an electric current through the wafer (the temperature of the wafer locally heated by passing an electric current through the wafer) to a target temperature will be described. For example, the wafer is formed in a disk shape.

[0010] <Temperature control device> Fig. 1 is a block diagram of a temperature control device 1. Fig. 2 is a plan view showing the arrangement of a temperature detection unit 4. In Fig. 2, a wafer W is indicated by a dashed line. As shown in FIG. 1, the temperature control device 1 includes a mounting unit 2, a temperature adjustment unit 3, and a temperature detection unit 4 ( The temperature control device 1 includes a temperature adjusting device (see FIG. 3 ) and a control device 5. Each element of the temperature control device 1 is controlled by the control device 5.

[0011] <Placement section> The mounting portion 2 has a mounting surface 10 on which a wafer W can be mounted. The mounting portion 2 is formed in a disk shape having the mounting surface 10 on a first surface 11. As shown in FIG. 2, the mounting surface 10 is formed in a circular shape in a plan view. For example, the outer diameter of the mounting surface 10 is set to be equal to or larger than the outer diameter of the wafer W. The mounting surface 10 is partitioned into a plurality of regions 21-24 (for example, four in this embodiment) in a plan view. These multiple regions 21-24 are arranged in the circumferential direction of the mounting surface 10 which is circular in a plan view. The regions 21-24 in this embodiment are fan-shaped, which are obtained by equally dividing the mounting surface 10 which is circular in a plan view in the circumferential direction. The regions 21-24 are arranged in the order of the regions 21-24 in a left-handed (counterclockwise) direction in a plan view.

[0012] FIG. 3 is a cross-sectional view of the placement section and the temperature adjustment section. As shown in Fig. 3, the mounting portion 2 has a recess 13 that opens to a second surface 12 opposite to the first surface 11. The recess 13 does not open to the first surface 11 (mounting surface 10). A plurality of recesses 13 are provided in each of the plurality of regions 21 to 24 (see Fig. 2). For example, two recesses 13 are provided in each of the regions 21 to 24.

[0013] <Temperature adjustment section> The temperature adjustment unit 3 can heat and cool the placement unit 2. For example, the temperature adjustment unit 3 adjusts the temperature of the placement unit 2 for each of the multiple regions 21 to 24 independently. For example, the temperature adjustment unit 3 includes a thermoelectric element 30 such as a Peltier element. For example, the thermoelectric element 30 is provided in each of the multiple regions 21 to 24. For example, when the multiple thermoelectric elements 30 are energized, each of the regions 21 to 24 can be heated and cooled independently. Each of the thermoelectric elements 30 in each of the regions 21 to 24 is controlled by the control device 5 (see FIG. 1). For example, a thermoelectric element 321 (see FIG. 4) is arranged in the region 21, a thermoelectric element 322 (see FIG. 4) is arranged in the region 22, a thermoelectric element 323 (see FIG. 4) is arranged in the region 23, and a thermoelectric element 324 (see FIG. 4) is arranged in the region 24.

[0014] The temperature adjustment section 3 is in contact with the second surface 12 of the mounting section 2. The temperature adjustment section 3 has through holes 31 that communicate with the recesses 13. A plurality of through holes 31 are provided corresponding to the recesses 13. For example, two through holes 31 are provided in each of the regions 21 to 24.

[0015] Operation amount calculation section The temperature control device 1 of this embodiment includes a cooling unit 35 that cools the temperature adjustment unit 3. For example, the cooling unit 35 is a water-cooled plate and has cooling paths 36 through which cooling water can flow. The cooling paths 36 are provided in each of the multiple regions 21 to 24. The cooling unit 35 can independently cool each of the regions 21 to 24, for example, by driving a pump (not shown) to flow cooling water through each cooling path 36. For example, the pump corresponding to the cooling path 36 of each of the regions 21 to 24 is controlled by the control device 5 (see FIG. 1). The cooling unit 35 has an insertion hole 37 that is connected to the through hole 31 of the temperature adjustment unit 3. A plurality of insertion holes 37 are provided corresponding to the through holes 31. For example, two of the plurality of insertion holes 37 are provided in each of the regions 21 to 24.

[0016] <Temperature detection section> The temperature detection unit 4 detects the temperatures of the regions 21 to 24 (see FIG. 2). For example, the temperature detection unit 4 includes a temperature sensor 40 such as a resistance temperature detector (RTD) or a thermocouple (TC). A plurality of temperature sensors 40 are provided in each of the regions 21 to 24. For example, as shown in FIG. 2, two temperature sensors 40 are provided in each of the regions 21 to 24. As shown in FIG. 3, the temperature sensors 40 are disposed in the recess 13 of the mounting unit 2 through the insertion hole 37 of the cooling unit 35 and the through hole 31 of the temperature adjustment unit 3.

[0017] The temperature sensors 40 are spaced apart from one another in both the circumferential and radial directions of the mounting surface 10 in a plan view. The temperature sensors 40 are spaced apart from one another in each of the regions 21-24 in a plan view. For example, two temperature sensors 40 in each of the regions 21-24 are arranged at the same position in the radial direction and at the same intervals in the circumferential direction. The detected temperatures of each temperature sensor 40 are input to the control device 5 (see FIG. 1).

[0018] For example, the two temperature sensors 40 arranged in each of the regions 21 to 24 are composed of a main temperature sensor and a sub-temperature sensor. As shown in FIG. 2, for example, a main temperature sensor 41m and a sub-temperature sensor 41s are arranged in the region 21. A main temperature sensor 42m and a sub-temperature sensor 42s are arranged in the region 22. A main temperature sensor 43m and a sub-temperature sensor 43s are arranged in the region 23. A main temperature sensor 44m and a sub-temperature sensor 44s are arranged in the region 24. For example, the main temperature sensors 41m to 44m are arranged at the same position in the regions 21 to 24. The main temperature sensors 41m to 44m may be arranged at an optimum position (for example, the center of gravity) for uniformly heating and cooling the regions 21 to 24. For example, the sub-temperature sensors 41s to 44s are arranged at the same position in the regions 21 to 24. The sub-temperature sensors 41s to 44s may be arranged in such a way that the range in each of the regions 21 to 24 other than the main temperature sensors 41m to 44m can be appropriately observed with a given number of sensors.

[0019] <Control device> FIG. 4 is a control block diagram of the control device. The control device 5 controls the temperature adjustment unit 3 based on the temperatures detected by the multiple temperature sensors 40. For example, the control device 5 controls the temperature adjustment unit 3 by a speed-type Proportional Integral Derivative Controller (PID controller) in order to set the temperatures detected by the temperature sensors 40 to a target temperature SV. As shown in FIG. 4, the control device 5 includes multiple manipulated variable change amount calculation units 51, a selection / switching unit 52, and multiple manipulated variable calculation units 53.

[0020] <Operation amount change amount calculation section> FIG. 5 is a control block diagram of the operation amount change amount calculation unit. An operation amount change calculation unit 51 is provided for each of the plurality of temperature sensors 40. In this embodiment, the operation amount change calculation unit 51 includes main operation amount change calculation units 511m-514m connected to the main temperature sensors 41m-44m, and secondary operation amount change calculation units 511s-514s connected to the secondary temperature sensors 41s-44s. A deviation e(k) (where "k" indicates the current sampling time) obtained by subtracting a target temperature SV from each detected temperature of the main temperature sensors 41m-44m and the secondary temperature sensors 41s-44s by a subtractor 54 is input to the main operation amount change calculation units 511m-514m and the secondary operation amount change calculation units 511s-514s. 5, manipulated variable change calculation section 51 uses deviation e(k) and deviation e(k-1) from one sampling time before to calculate the current amount of change dP(k) in the P term, the amount of change dI(k) in the I term, and the amount of change dD(k) in the D term. Manipulated variable change calculation section 51 further adds up the amount of change dP(k) in the P term, the amount of change dI(k) in the I term, and the amount of change dD(k) in the D term to find the current amount of change in manipulated variable ΔMV(k).

[0021] The selection / switching unit 52 is capable of switching from a state in which the operation amount change ΔMV(k) calculated by one operation amount change calculation unit 51 is selected to a state in which the operation amount change ΔMV(k) calculated by another operation amount change calculation unit 51 is selected. As shown in Fig. 4, the selection / switching unit 52 of the embodiment is capable of switching between a state in which the operation amount change ΔMV(k) calculated by the operation amount change calculation unit 51 connected to the main temperature sensor is selected and a state in which the operation amount change ΔMV(k) calculated by the operation amount change calculation unit 51 connected to the sub temperature sensor is selected.

[0022] In the embodiment, the selection / switching unit 52 switches the selection state of two operation amount changes ΔMV(k) which are the calculation results of the main operation amount change calculation unit and the sub operation amount change calculation unit corresponding to the main temperature sensor and the sub temperature sensor installed in the same region, for example. That is, the selection / switching unit 52 in the embodiment selects either the operation amount change ΔMV(k) calculated by the main operation amount change calculation unit or the operation amount change ΔMV(k) calculated by the sub operation amount change calculation unit. For example, the selection / switching unit 52 in the embodiment is capable of selecting / switching individually for each corresponding region. For example, when the position where the disturbance is applied changes within the same region, the selection / switching unit 52 in the embodiment switches the selection state to use the detection result of the temperature sensor 40 closer to the position where the disturbance is applied.

[0023] <Operation amount calculation section> FIG. 6 is a control block diagram of the operation amount calculation unit. The operation amount calculation unit 53 calculates the operation amount MV(k) of the temperature adjustment unit 3 based on the operation amount change amount ΔMV(k) selected by the selection / switching unit 52. The operation amount calculation unit 53 is provided for each of the plurality of thermoelectric elements 30 provided for each of the regions 21 to 24. For example, in the embodiment, as the plurality of operation amount calculation units 53, an operation amount calculation unit 531 corresponding to the region 21, an operation amount calculation unit 532 corresponding to the region 22, an operation amount calculation unit 533 corresponding to the region 23, and an operation amount calculation unit 534 corresponding to the region 24 are provided. As shown in FIG. 4, an operation amount change amount ΔMV1 is input to the operation amount calculation unit 531 as the operation amount change amount ΔMV(k), an operation amount change amount ΔMV2 is input to the operation amount calculation unit 532, an operation amount change amount ΔMV3 is input to the operation amount calculation unit 533, and an operation amount change amount ΔMV4 is input to the operation amount calculation unit 534.

[0024] As shown in Fig. 6, the operation amount calculation unit 53 calculates the current operation amount MV(k) by adding the operation amount change amount ΔMV(k) selected by the selection / switching unit 52 to the operation amount MV(k-1) of one sampling time before. As shown in Fig. 4, the operation amount calculation unit 531 outputs the operation amount MV1 to the thermoelectric element 321 as the operation amount MV(k), the operation amount calculation unit 532 outputs the operation amount MV2 to the thermoelectric element 322, the operation amount calculation unit 533 outputs the operation amount MV3 to the thermoelectric element 323, and the operation amount calculation unit 534 outputs the operation amount MV4 to the thermoelectric element 324. Note that the operation amount calculation unit 53 may have an anti-windup circuit (not shown).

[0025] <Temperature control method> FIG. 7 is a flowchart of a temperature control method according to an embodiment. As shown in FIG. 7, the temperature control method of the embodiment includes a temperature monitoring step S01, a wafer mounting step S02, a wafer inspection step S03, a manipulated variable change calculation step S04, a selection / switching step S05, a manipulated variable calculation step S06, and a temperature adjustment step S07.

[0026] In the temperature monitoring step S01, the temperature is monitored at a plurality of locations in at least one of the plurality of regions 21 to 24. For example, in the temperature monitoring step S01, the temperature is monitored at a plurality of locations in each of the plurality of regions 21 to 24. For example, in the temperature monitoring step S01, all of the plurality of temperature sensors 40 provided in each of the plurality of regions 21 to 24 are constantly monitored. After the temperature monitoring step S01, the process proceeds to the wafer placement step S02.

[0027] In the wafer placing step S02, a wafer W is placed on a placing surface 10 having a plurality of regions 21 to 24. For example, in the wafer placing step S02, a disk-shaped wafer W is placed so as to be entirely overlapped on the placing surface 10 which is circular in a plan view. After the wafer placing step S02, the process proceeds to a wafer inspection step S03.

[0028] In the wafer inspection process S03, the process starts inspection of the wafer W placed on the placement surface 10. For example, local heat input occurs as a disturbance application due to the inspection of the wafer W. After the wafer inspection process S03 starts, the process proceeds to a manipulated variable change amount calculation process S04.

[0029] In the manipulated variable change calculation step S04, the manipulated variable change ΔMV(k) for each location is calculated based on the detected temperatures (wafer temperatures) at the multiple locations detected in the temperature monitoring step S01 and the target temperature SV. For example, in the embodiment, the manipulated variable change calculation unit 51 calculates the manipulated variable change ΔMV(k) by adding the change dP(k) of the P term, the change dI(k) of the I term, and the change dD(k) of the D term.

[0030] In the selection / switching step S05, among the operation amount changes of each location calculated in the operation amount change calculation step S04, a state in which the operation amount change of one location is selected is switched to a state in which the operation amount change of another location is selected. In the embodiment, as described above, a state in which one of the two operation amount changes ΔMV(k) calculated based on the detected temperatures of the main temperature sensor and the sub-temperature sensor installed in the same area is selected. Also, as necessary, a state in which one of the two operation amount changes ΔMV(k) is selected is switched to a state in which the other is selected. For example, in the selection / switching step S05 of the embodiment, the operation amount change ΔMV(k) is selected / switched for each of the areas 21 to 24.

[0031] In the manipulated variable calculation step S06, a manipulated variable MV(k) for adjusting the temperature is calculated based on the manipulated variable change amount ΔMV(k) selected in the selection and switching step S05. For example, in the embodiment, the manipulated variable calculation unit 53 calculates the current manipulated variable MV(k) by adding the manipulated variable change amount ΔMV(k) to the manipulated variable MV(k-1) one sampling time before.

[0032] In the temperature adjustment step S07, the wafer temperature is adjusted based on the operation amount MV(k) calculated in the operation amount calculation step S06. That is, the wafer W is heated or cooled by the calculated operation amount MV using the thermoelectric element 30 in the area corresponding to the operation amount MV.

[0033] Fig. 8 is a graph showing temperature changes and manipulated variables of the main temperature sensor and the sub temperature sensor in the embodiment. In Fig. 8, the temperature changes and manipulated variables in the embodiment are shown by solid lines, and the temperature changes and manipulated variables in the comparative example are shown by lines other than the solid lines (dashed lines, one-dot chain lines, and two-dot chain lines). Fig. 8 also shows an example in which the temperature sensor 40 for feedback control of the temperature of the region 21 is switched from the main temperature sensor 41m to the sub temperature sensor 41s. Also, Fig. 8 shows an example in which the detected temperature of the main temperature sensor 41m is higher than the detected temperature of the sub temperature sensor 41s.

[0034] As shown in FIG. 8, in a state where the detected temperature of the main temperature sensor 41m is settled at the target temperature SV, the main temperature sensor 41m is switched to the sub temperature sensor 41s (at the time of "sensor switching" in FIG. 8). The selection / switching unit 52 switches from a state where the controlled variable change amount ΔMV(k) of the main controlled variable change amount calculation unit 511m is selected to a state where the controlled variable change amount ΔMV(k) of the sub controlled variable change amount calculation unit 511s is selected. At this time, the controlled variable MV1 output from the controlled variable calculation unit 531 of the embodiment is calculated by speed-type PID control, so that it gradually increases over time, and the rate of increase decreases over time, until it reaches a predetermined peak value. Thereafter, the controlled variable MV1 gradually decreases over time, and the rate of decrease also gradually decreases, until it becomes the same constant controlled variable MV as before the sensor switching time. By controlling the thermoelectric element 321 by such a controlled variable MV1, the detected temperature of the sub temperature sensor 41s gradually increases from the sensor switching time and is settled without exceeding the target temperature SV.

[0035] 9 is a control block diagram of a control device in a comparative example. In the comparative example, the same parts as those in the embodiment are denoted by the same reference numerals. The temperature control device in the comparative example includes a mounting section 2 (see FIG. 3), a temperature adjustment section 3 (see FIG. 3), a temperature detection section 4 (see FIG. 3), and a control device 105 (see FIG. 9). As in the above embodiment, the temperature control device in the comparative example has a mounting surface 10 (see FIG. 2) partitioned into four regions 21 to 24, and each region includes one main temperature sensor and one sub-temperature sensor constituting the temperature detection section 4. That is, the region 21 includes a main temperature sensor 41m and a sub-temperature sensor 41s, the region 22 includes a main temperature sensor 42m and a sub-temperature sensor 42s, the region 23 includes a main temperature sensor 43m and a sub-temperature sensor 43s, and the region 24 includes a main temperature sensor 44m and a sub-temperature sensor 44s.

[0036] The control device 105 controls the temperature adjustment unit 3 (thermoelectric elements 30) based on the temperatures detected by the multiple temperature sensors 40. For example, the control device 105 controls the temperature adjustment unit 3 (thermoelectric elements 30) by PID control (Proportional Integral Derivative Controller) to set the temperature detected by the temperature sensor 40 to the target temperature SV. As shown in FIG. 9, the control device 105 includes a selection / switching unit 152, a subtractor 54, and operation amount calculation units 153-156. The selection / switching unit 152 is capable of switching between the main temperature sensor and the sub-temperature sensor for each region and selecting one of the detected temperatures. The detected temperature selected by the selection / switching unit 152 is input to the operation amount calculation units 153-156 via the subtractors 54 for each region. The operation amount calculation units 153-156 calculate the operation amounts MV1-MV4 of the temperature adjustment unit 3 by PID control based on the input from the subtractor 54.

[0037] As shown in Fig. 8, in the comparative example having the above configuration, when the selection / switching unit 152 switches from the main temperature sensor 41m to the sub-temperature sensor 41s, a so-called switching shock occurs. Specifically, the manipulated variable MV1 of the thermoelectric element 321 (shown by a dashed line in Fig. 8) rises almost vertically from the time of sensor switching, and when it reaches a peak value (for example, more than twice MV1) higher than the peak of the manipulated variable MV1 described above, it suddenly drops and becomes lower than the manipulated variable MV before the time of sensor switching, and then becomes the constant manipulated variable MV1 before the time of sensor switching. When the thermoelectric element 321 is controlled by the manipulated variable MV of such a comparative example, the detected temperature of the sub-temperature sensor 41s (shown by a dashed line in Fig. 8) rises sharply from the time of sensor switching, exceeds (overshoots) the target temperature SV, and then is settled at the target temperature SV.

[0038] <Action and effect> As described above, the wafer temperature control device 1 of this embodiment includes the mounting part 2 having the mounting surface 10 on which the wafer W is mounted, the temperature adjustment part 3 capable of heating and cooling the mounting part 2, a plurality of temperature sensors 40 provided on the mounting part 2, and the control device 5 for controlling the temperature adjustment part 3. The control device 5 includes a plurality of manipulated variable change calculation parts 51 provided for each of the plurality of temperature sensors 40 and calculating an manipulated variable change ΔMV(k) of the temperature adjustment part 3 based on the detected temperatures of the temperature sensors 40 and a target temperature SV, a selection / switching part 52 capable of switching from a state in which an manipulated variable change ΔMV(k) calculated by one manipulated variable change calculation part 51 is selected to a state in which an manipulated variable change ΔMV calculated by another manipulated variable change calculation part 51 is selected, and a manipulated variable calculation part 53 for calculating the manipulated variable MV(k) of the temperature adjustment part 3 based on the manipulated variable change ΔMV(k) selected by the selection / switching part 52. According to this configuration, when switching from a state in which a manipulated variable change ΔMV(k) calculated by one manipulated variable change calculation unit 51 is selected to a state in which a manipulated variable change ΔMV(k) calculated by another manipulated variable change calculation unit 51 is selected, the amount of change in the manipulated variable MV(k) at the time of switching can be made smaller than when the manipulated variable MV(k) is switched. This makes it possible to suppress the wafer temperature from overshooting the target temperature SV without extending the time required for the temperature of the wafer W to be settled at the target temperature SV.

[0039] Furthermore, in this embodiment, the plurality of temperature sensors 40 are made up of main temperature sensors 41m-44m and sub temperature sensors 41s-44s, and the plurality of manipulated variable change calculation units 51 include main manipulated variable change calculation units 511m-514m that calculate the manipulated variable change ΔMV(k) of the temperature adjustment unit 3 based on the detected temperatures of the main temperature sensors 41m-44m and the target temperature SV, and sub manipulated variable change calculation units 511s-514s that calculate the manipulated variable change ΔMV(k) of the temperature adjustment unit 3 based on the detected temperatures of the sub temperature sensors 41s-44s and the target temperature SV. The selection / switching unit 52 selects either the manipulated variable change ΔMV(k) calculated by the main manipulated variable change calculation units 511m-514m or the manipulated variable change ΔMV(k) calculated by the sub manipulated variable change calculation units 511s-514s. This makes it possible to reduce the amount of change in the manipulated variable MV(k) when switching between temperature control based on the main temperature sensor and temperature control based on the sub-temperature sensor, thereby preventing the wafer temperature from overshooting the target temperature SV.

[0040] In this embodiment, the mounting surface 10 is partitioned into a plurality of regions 21-24 in a plan view, and the thermoelectric elements 30, main temperature sensors 41m-44m, and sub temperature sensors 41s-44s of the temperature adjustment unit 3 are provided for each of the regions 21-24. A manipulated variable calculation unit 53 is provided for each of the plurality of thermoelectric elements 321-324 of the temperature adjustment unit 3, main manipulated variable change calculation units 511m-514m are provided for each of the plurality of main temperature sensors 41m-44m, and sub manipulated variable change calculation units 511s-514s are provided for each of the plurality of sub temperature sensors 41s-44s. The selection / switching unit 52 selects, for each of the multiple regions 21-24, either the operation amount change amount ΔMV(k) calculated by the main operation amount change amount calculation units 511m-514m or the operation amount change amount ΔMV(k) calculated by the secondary operation amount change amount calculation units 511s-514s, and outputs the selected operation amount change amount to the operation amount calculation units 531-534. According to this configuration, since there is no need to provide the same number of operation amount calculation units 531 to 534 as the temperature sensor 40 and the operation amount change amount calculation unit 51, the circuit configuration of the control device 5 can be simplified.

[0041] Furthermore, in this embodiment, the control device 5 performs speed-type PID control by the operation amount change amount calculation section 51 and the operation amount calculation section 53. This makes it possible to reduce the deviation between the temperature of the wafer W and the target temperature SV, and quickly settle the temperature of the wafer W at the target temperature SV.

[0042] The wafer temperature control method of this embodiment includes a temperature monitoring step S01 for detecting wafer temperatures at multiple locations; a manipulated variable change calculation step S04 for calculating a manipulated variable change ΔMV(k) for each location based on the wafer temperatures at the multiple locations detected by the temperature monitoring step S01 and a target temperature SV; a selection / switching step S05 for switching from a state in which the manipulated variable change ΔMV(k) for one location is selected among the manipulated variable change ΔMV(k) for each location calculated by the manipulated variable change calculation step S04 to a state in which the manipulated variable change ΔMV(k) for another location is selected; a manipulated variable calculation step S06 for calculating a manipulated variable MV(k) for adjusting the temperature based on the manipulated variable change ΔMV(k) selected by the selection / switching step S05; and a temperature adjustment step S07 for adjusting the temperature of the wafer W based on the manipulated variable MV(k) calculated by the manipulated variable calculation step S06. According to this configuration, the amount of change in the manipulated variable MV(k) at the time of switching can be made smaller than when the manipulated variable MV(k) is switched, and this makes it possible to suppress the wafer temperature from overshooting the target temperature SV without extending the time it takes for the temperature of the wafer W to be settled at the target temperature SV.

[0043] (Modification of the above embodiment) In the above-described embodiment, the mounting surface is formed in a circular shape in a plan view, but the present invention is not limited thereto. For example, the mounting surface may be formed in a rectangular shape in a plan view. For example, the shape of the mounting surface in a plan view can be changed according to required specifications, such as the shape of the wafer W.

[0044] In the above embodiment, an example has been described in which the temperature sensors 40 are arranged at a distance from each other in the circumferential direction and the radial direction of the mounting surface in a plan view, but this is not limited thereto. For example, the temperature sensors 40 do not have to be arranged at a distance from each other in the circumferential direction and the radial direction of the mounting surface in a plan view. For example, the arrangement of the temperature sensors 40 can be changed according to required specifications.

[0045] In the above embodiment, the four regions 21 to 24 are arranged side by side in the circumferential direction in a sector shape, but the present invention is not limited to this. For example, the shape and arrangement of each region can be changed according to the required specifications.

[0046] In the above embodiment, an example has been described in which a plurality of temperature sensors 40 are provided in each of the plurality of regions 21 to 24, but this is not limiting. For example, the number and positions of the temperature sensors 40 can be changed according to required specifications.

[0047] In the above-described embodiment, an example was given in which the control device 5 monitors the detected temperatures of multiple temperature sensors 40 provided in a specified area, and selects the detected temperature with the largest temperature change per unit time from the multiple monitored detected temperatures, but this is not limited to this.

[0048] In the above-described embodiment, an example has been described in which the mounting portion 2 is formed in a plate shape having the mounting surface 10 on the first surface 11, but this is not limiting. For example, the mounting portion 2 may be formed in a block shape having the mounting surface 10 on the first surface 11. For example, the shape of the mounting portion 2 can be changed according to required specifications.

[0049] In the above-described embodiment, an example has been described in which the temperature adjustment unit 3 is provided on the second surface 12 of the mounting unit 2 opposite to the side on which the mounting surface 10 is provided, but this is not limiting. For example, the temperature adjustment unit 3 may be built into the mounting unit 2. For example, the installation mode of the temperature adjustment unit 3 can be changed according to required specifications.

[0050] In the above-described embodiment, an example has been described in which the temperature sensor 40 is disposed in the recess 13 of the mounting unit 2 through the through-hole 31 of the temperature adjustment unit 3, and the temperature of the region is detected through the recess 13 of the mounting unit 2, but this is not limiting. For example, the temperature sensor 40 may detect the temperature of the region without passing through the recess 13 of the mounting unit 2. For example, the temperature sensor 40 may be a non-contact temperature sensor. For example, the aspect of the temperature sensor 40 can be changed according to required specifications.

[0051] In the above-described embodiment, the temperature control device 1 for controlling the temperature of a wafer W having chips whose electrical characteristics are inspected by energizing (the temperature of the wafer W locally heated by energizing) to a target temperature SV has been given as an example of a wafer temperature control device, but the present invention is not limited to this. For example, the temperature control device 1 may be applied to a temperature control device for controlling the temperature of a wafer W that does not have chips whose electrical characteristics are inspected by energizing to a target temperature SV. For example, the temperature control device 1 may be applied to a temperature control device for controlling the temperature of a wafer W such as a silicon wafer to a target temperature SV. For example, the temperature control device 1 may be used in a dry process. For example, the manner of use of the temperature control device can be changed according to the required specifications.

[0052] In the above embodiment, an example in which speed-type PID control is performed has been described, but the present invention is not limited to this. For example, PD control or the like may be performed instead of PID control.

[0053] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention, and the above-described embodiments can also be combined as appropriate. [Explanation of symbols]

[0054] 1...Temperature control device 2...Placement section 3...Temperature adjustment section 4...Temperature detection section 5...Control device 10...Placement surface 11...First surface 12...Second surface 13...Recess 21-24...Area 30...Thermoelectric element 31...Through hole 35...Cooling section 36...Cooling path 37...Insertion hole 40...Temperature sensor 41m-44m...Main temperature sensor 41s-44s...Sub-temperature sensor 51...Operation quantity change amount calculation section 52...Selection / switching section 53...Operation quantity calculation section 54...Subtractor 321-324...Thermoelectric element 511m-514m...Main operation quantity change amount calculation section 511s-514s...Sub-operation quantity change amount calculation section S01...Temperature monitoring process S02...Wafer placement process S03...Wafer inspection process S04...Operation quantity change amount calculation process S05...Selection / switching process S06…Operation amount calculation process S07…Temperature adjustment process SV…Target temperature W…Wafer

Claims

1. a mounting portion having a mounting surface on which a wafer is placed; A temperature adjusting unit capable of heating and cooling the placement unit; A plurality of temperature sensors provided on the mounting portion; A temperature control device that controls the temperature adjustment unit, The temperature control device includes: a plurality of operation amount change amount calculation units provided for each of the plurality of temperature sensors, the operation amount change amount of the temperature adjustment unit being calculated based on the detected temperatures of the temperature sensors and a target temperature; a selection / switching unit capable of switching from a state in which an operation amount change amount calculated by one of the operation amount change calculation units is selected to a state in which an operation amount change amount calculated by another of the operation amount change calculation units is selected; an operation amount calculation unit that calculates an operation amount of the temperature adjustment unit based on the operation amount change amount selected by the selection / switching unit; A wafer temperature control device comprising:

2. The plurality of temperature sensors include a main temperature sensor and a sub-temperature sensor, The plurality of operation amount change amount calculation units include a main operation amount change amount calculation unit that calculates an operation amount change amount of the temperature adjustment unit based on the detected temperature of the main temperature sensor and a target temperature; a sub manipulated variable change calculation unit that calculates a manipulated variable change amount of the temperature adjustment unit based on the detected temperature of the sub temperature sensor and a target temperature, The selection / switching unit is Selecting one of the operation amount change amount calculated by the main operation amount change amount calculation unit and the operation amount change amount calculated by the auxiliary operation amount change amount calculation unit The apparatus for controlling the temperature of a wafer according to claim 1 .

3. The placement surface is divided into a plurality of regions in a plan view, the temperature adjusting unit, the main temperature sensor, and the sub-temperature sensor are provided for each of the regions, The operation amount calculation unit is provided for each of the plurality of temperature adjustment units, the main operation amount change amount calculation unit is provided for each of the plurality of main temperature sensors, the secondary manipulated variable change amount calculation unit is provided for each of the plurality of secondary temperature sensors, The selection / switching unit is For each of the plurality of regions, one of the operation amount change amount calculated by the main operation amount change amount calculation unit and the operation amount change amount calculated by the sub operation amount change amount calculation unit is selected and output to the operation amount calculation unit. The apparatus for controlling the temperature of a wafer according to claim 2 .

4. The temperature control device includes: The operation amount change amount calculation unit and the operation amount calculation unit perform speed-type PID control. The apparatus for controlling the temperature of a wafer according to claim 1 .

5. a temperature monitoring step of detecting the wafer temperatures at a plurality of locations; an operation amount change calculation step of calculating an operation amount change amount for each of the plurality of locations based on the wafer temperatures and the target temperature detected by the temperature monitoring step; a selection / switching step of switching from a state in which an amount of change in operation at one location is selected to a state in which an amount of change in operation at another location is selected among the amount of change in operation at each location calculated in the amount of change in operation calculation step; a manipulated variable calculation step of calculating a manipulated variable for adjusting a temperature based on the manipulated variable change amount selected in the selection / switching step; and a temperature adjusting step of adjusting the wafer temperature based on the operation amount calculated by the operation amount calculating step. A method for controlling the temperature of a wafer.

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