Temperature control device and method, semiconductor device manufacturing apparatus, and article manufacturing method

Abstract

The present application provides a temperature control device and method, a semiconductor device manufacturing apparatus, and an article manufacturing method that are advantageous in maintaining control accuracy of secondary temperature control and reducing peak current generated in multiple heaters for secondary temperature control. The temperature control device includes a first control unit that controls a cooler that performs primary temperature control of a temperature control medium, and a second control unit that controls power supplied to each of multiple heaters that perform secondary temperature control of the temperature control medium by PWM control. The second control unit determines a timing at which a pulse in PWM control of each of the multiple heaters is ON in such a manner that a total current value of the multiple heaters does not exceed a prescribed limit value, the first control unit determines a correction value for the target temperature based on an operation amount for each of the multiple heaters output from the second control unit, and corrects the target temperature using the determined correction value.

Description

Technical Field

[0001] This invention relates to a temperature control device and method, a semiconductor device manufacturing apparatus, and a method for manufacturing articles. Background Technology

[0002] Manufacturing equipment, such as exposure apparatus, used in the production processes of semiconductor devices and display devices, demands high productivity. With this increasing productivity in recent years, the heat generated from drive components (heat-generating parts), such as linear motors, has increased. Temperature-regulating media, such as water, antifreeze, or inactive liquids, are used for cooling these heat-generating parts. The temperature-regulating media, which absorbs heat generated by the heat-generating parts and has increased in temperature, undergoes a heat exchange with chilled water supplied from the equipment via a refrigerator based on frequency conversion control and heat bypass gas control, achieving primary temperature control.

[0003] The high-precision temperature control required for device manufacturing equipment cannot be achieved solely through primary temperature control based on refrigerators and heat exchangers, as described above. Therefore, secondary temperature control is performed near the heat-generating part using precision heaters with high responsiveness and accuracy. One method for adjusting the output of the precision heater is PWM (Pulse Width Modulation), which changes the ratio of the energizing time from the power supply to the precision heater per unit time. PWM is widely used as a heater control method because it allows for relatively inexpensive equipment construction and is easy to control. The power supply for the precision heater is the same as the equipment power supply used in the semiconductor factory where the device manufacturing equipment is located.

[0004] Here, in order to suppress the current flowing in the precision heater used for secondary temperature control, it is necessary to reduce the rated output value of the precision heater. Therefore, it is important to suppress the control temperature difference ΔT between primary and secondary temperature control. As an example of solving this problem, Patent Document 1 discloses a technique for changing the target temperature of primary temperature control based on a drive command to the drive unit that serves as the heat source of the device.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5641709 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] According to the technology in Patent Document 1, when the output of a precision heater is controlled in a PWM manner, the average current flowing in multiple precision heaters can be reduced per unit time. However, since the energizing time of multiple precision heaters is repeated within the PWM control cycle, the effect of reducing peak current cannot be expected.

[0010] Since the power supply for device manufacturing equipment is determined by peak current, an increase in peak current may lead to an increase in the power supply capacity of the equipment in the factory where the device manufacturing equipment is located. To reduce peak current, a method is considered that the energizing time of multiple precision heaters is not repeated by extending the PWM control cycle. However, in this case, extending the PWM control cycle may lead to increased temporal non-uniformity of heat generated in the precision heaters, resulting in a decrease in temperature stability in secondary temperature control.

[0011] This invention provides a technique that helps maintain the control accuracy of temperature control and reduces the peak current generated in multiple heaters.

[0012] Solution for solving the problem

[0013] According to a first aspect of the present invention, a temperature regulating device is provided, characterized in that the temperature regulating device comprises: a cooler for primary temperature regulation by cooling a temperature regulating medium; a first control unit for controlling the cooler based on a deviation between a target temperature and a current temperature; a plurality of heaters for secondary temperature regulation by providing heat generated according to the supplied power to the temperature regulating medium cooled by the cooler; and a second control unit for controlling the power supply to each of the plurality of heaters by PWM control, wherein the second control unit determines the time when the pulse in the PWM control of each of the plurality of heaters is ON such that the total current value of the plurality of heaters does not exceed a predetermined limit value, and the first control unit determines a correction value for the target temperature based on the operation amount of each of the plurality of heaters output from the second control unit, and corrects the target temperature using the determined correction value.

[0014] According to a second aspect of the present invention, a temperature control method is provided, characterized in that the temperature control method comprises: a first step of performing a primary temperature control of a cooling temperature control medium based on the deviation between a target temperature and a current temperature; and a second step of performing a secondary temperature control of the cooling temperature control medium cooled by the primary temperature control by performing PWM control on the power supply to each of a plurality of heaters, wherein the second step includes a step of determining the time when the pulse in the PWM control of each of the plurality of heaters is ON, such that the total current value of the plurality of heaters does not exceed a predetermined limit value; and the first step includes a step of determining a correction value for the target temperature based on the operation amount of each of the plurality of heaters output in the secondary temperature control, and correcting the target temperature using the determined correction value.

[0015] According to a third aspect of the present invention, a device manufacturing apparatus is provided having a plurality of heating elements, characterized in that the device manufacturing apparatus includes a temperature control device according to the first aspect described above, and the plurality of heaters are disposed between the cooler and the plurality of heating elements.

[0016] In one technical solution, the aforementioned third-party device manufacturing apparatus can be configured as a photolithography apparatus for forming patterns on a substrate.

[0017] According to a fourth aspect of the present invention, a method for manufacturing an article is provided, characterized in that the method comprises: a step of forming a pattern on a substrate using the photolithography apparatus; and a step of processing the substrate on which the pattern is formed, thereby manufacturing an article using the processed substrate.

[0018] The effects of the invention

[0019] According to the present invention, a technique is provided that is beneficial for maintaining the control accuracy of temperature control and reducing the peak current generated in multiple heaters. Attached Figure Description

[0020] Figure 1 This is a diagram illustrating an example of the structure of a device manufacturing apparatus.

[0021] Figure 2 This is a diagram showing an example of the structure of a temperature control device.

[0022] Figure 3 This is a block diagram of a secondary temperature control system.

[0023] Figure 4 This is a flowchart representing the control process at the moment when the pulse becomes ON in PWM control.

[0024] Figure 5 This diagram illustrates the generation of peak current caused by the repetition of the ON pulse period in PWM control.

[0025] Figure 6 This is a block diagram of a primary temperature control system.

[0026] Figure 7 This is a diagram illustrating the effects of the first embodiment.

[0027] Figure 8 This is a block diagram of a primary temperature control system.

[0028] Figure 9 This is a flowchart illustrating the control process at the moment when the pulse becomes ON in the PWM control of the second embodiment.

[0029] Figure 10 This is a diagram illustrating the effects of the second embodiment.

[0030] Figure 11 This is a flowchart of the temperature control method. Detailed Implementation

[0031] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiments do not limit the technical solutions covered by the claims. Although multiple features are described in the embodiments, these multiple features are not all limited to those essential to the invention; in addition, multiple features can be combined arbitrarily. Furthermore, in the drawings, the same or identical structures are labeled with the same reference numerals, and repeated descriptions are omitted.

[0032] [First Implementation Method]

[0033] Figure 1 This diagram schematically illustrates the structure of a device manufacturing apparatus according to a first embodiment of the temperature control device of the present invention. Here, an example of a photolithography apparatus configured to form a pattern on a substrate will be described. The photolithography apparatus includes an imprinting apparatus, an exposure apparatus, etc. The imprinting apparatus forms a pattern on a substrate by curing imprinting material while a mold (reticule) is in contact with imprinting material supplied to the substrate. The exposure apparatus forms a latent image corresponding to the pattern of the reticule on the photoresist supplied to the substrate by exposing it through a reticule, which serves as an exposure mask. Hereinafter, an example of a photolithography apparatus configured as an exposure apparatus will be described to provide a concrete example.

[0034] exist Figure 1 In this process, light emitted from a light source (not shown), such as an ArF excimer laser or a KrF excimer laser, is provided to an illumination optical system 2. The illumination optical system 2 uses the light from the light source to illuminate a portion of the intermediate mask (original) 1 using slit light (light whose cross-sectional shape is defined by the slit). While illuminating the intermediate mask 1 with slit light, the intermediate mask 1 and the wafer (substrate) 9 are simultaneously scanned using an intermediate mask stage 3 and a wafer stage 10. As a result of this simultaneous scanning, the entire pattern of the intermediate mask 1 is transferred to the wafer 9 via a projection optical system 4 held by a stage 5.

[0035] The intermediate mask stage 3 includes an intermediate mask holding section for holding the intermediate mask 1 and a drive section (e.g., an actuator such as a linear motor) for driving the intermediate mask holding section. The intermediate mask holding section is driven by the drive section on the stage 14. The wafer stage 10 includes a wafer holding section for holding the wafer 9 and a drive section (e.g., an actuator such as a linear motor) for driving the wafer holding section. The wafer holding section is driven by the drive section on the stage 15.

[0036] The positional relationship between the intermediate mask stage 3 and the wafer stage 10 is measured in real time by measuring instruments including a reference mirror 11 and a laser interferometer 12. Based on this measurement, the stage control device 13 performs positioning and synchronization control of the intermediate mask 1 and the wafer 9. During exposure, the wafer stage 10 can be controlled to ensure that the surface of the wafer 9 is aligned with the focal plane of the projection optical system 4. Here, the surface position of the wafer 9 (position and tilt in the vertical direction) is measured by an optical focusing sensor (not shown), and the measurement result is provided to the stage control device 13.

[0037] The main body of the device fabrication apparatus (exposure apparatus) is housed in an environmental chamber (not shown), and the environment surrounding the main body can be maintained at a specified temperature. Air that has been individually temperature-adjusted is blown into the space surrounding the intermediate mask stage 3, the wafer stage 10, the laser interferometer 12, and the space surrounding the projection optical system 4, thereby maintaining the ambient temperature with higher precision.

[0038] When the intermediate mask stage 3 and the wafer stage 10 are driven, a large amount of heat is generated from the driving section. The driving section drives the controlled object according to the command from the stage control device 13, and the heat generated from the driving section depends on the driving mode (control information used to control the driving section).

[0039] The heat generated by the drive unit causes expansion or deformation of the wafer stage 10 (wafer 9) or the intermediate mask stage (intermediate mask 1). This expansion or deformation causes positional shifts or tilting of the reference mirror 11, potentially introducing errors in the measurement results of the measuring instruments, including the laser interferometer 12. Furthermore, the expansion or deformation of wafer 9 or intermediate mask 1 can deform the pattern formed on wafer 9. Additionally, if the temperature of the intermediate mask stage 3 or wafer stage 10 changes, the temperature of the surrounding air will also change. If this temperature-changed air flows within the optical path of the laser interferometer 12, it can cause measurement errors due to fluctuations caused by changes in refractive index. Therefore, the heat generated by the drive unit should be rapidly recovered.

[0040] To recover heat generated by multiple driving units (multiple heat-generating units) such as the intermediate mask stage 3 and the wafer stage 10, and to maintain a constant temperature, cooling flow paths 6a and 6d are respectively arranged inside or around the driving units. Furthermore, to reduce the impact of heat (radiative heat, exposure heat, etc.) that cannot be recovered in cooling flow paths 6a and 6d, cooling flow paths 6b and 6c are respectively arranged inside or around the projection optical system 4 and the stage 5. Temperature-adjusted heat flows through cooling flow paths 6a, 6b, 6c, and 6d. Figure 2The temperature-regulating medium 30 (liquid, gas, or other fluid) is shown. Cooling flow paths 6a, 6b, 6c, 6d and connected pipes 32a, 32b, 32c, 32d together form the circulation path of the temperature-regulating medium 30. The temperature-regulating medium 30 is supplied and recovered by the temperature-regulating device 100 via pipes 32a, 32b, 32c, 32d. Furthermore, although the structure in which cooling flow paths are arranged inside or around the intermediate mask stage 3, wafer stage 10, projection optical system 4, and stage 5 has been described here, it is also possible to... Figure 1 Cooling flow paths are configured inside or around other units not shown.

[0041] Next, refer to Figure 2 The following describes a structural example of the temperature control device 100. The temperature control device 100 includes a heat exchanger 24, which functions as a cooler, for primary temperature control by cooling the temperature control medium 30, and a primary temperature control unit 21, which functions as a first control unit, for controlling the heat exchanger 24. The temperature control device 100 further includes: a plurality of heaters that perform secondary temperature control by providing heat generated according to the supplied electricity to the temperature control medium 30 cooled by the heat exchanger 24; and a second control unit that controls the power supply to each of these plurality of heaters via PWM control. In the following embodiment, the second control unit is illustrated as including secondary temperature control units 26a, 26b, 26c, and 26d.

[0042] The temperature-regulating medium 30, temporarily stored in the housing 29, is pumped by 31 and transported via pipe 32 to the heat exchanger 24 (cooler). The heat exchanger 24 can be, for example, a plate heat exchanger. In the plate heat exchanger, the temperature-regulating medium 30 and cooling water 27 flow in a convection manner through plates, facilitating heat exchange between them. The temperature of the temperature-regulating medium 30 after passing through the heat exchanger 24 is measured by a temperature sensor 22 (first temperature sensor) disposed on the pipe 32, and the measured value is provided to the primary temperature control unit 21 (first control unit) of the temperature control unit 20.

[0043] Additionally, the operating parameters of the secondary temperature control units 26a, 26b, 26c, and 26d (second control units), described later, are provided to the primary temperature control unit 21. Based on the operating parameters of the temperature sensor 22 and the secondary temperature control units 26a-26d, the primary temperature control unit 21 adjusts the opening of the control valve 23. This adjusts the flow rate of the cooling water 27 supplied to the heat exchanger 24, thereby adjusting the temperature of the temperature regulating medium 30. The cooling water 27 is typically supplied by a plant device (not shown) via piping 25. The heat exchanger 24 can be a plate heat exchanger as described above, or it can be a temperature regulating unit utilizing a Peltier element, or a temperature regulating unit of a refrigeration machine with variable cooling capacity including hot gas bypass.

[0044] A temperature-regulating medium 30, whose temperature is controlled by a primary temperature control unit 21 to match the target temperature, is supplied via pipe 32 to the interior or periphery of the cooling objects 40a, 40b, 40c, and 40d. In this embodiment, the cooling objects 40a to 40d correspond to the intermediate mask stage 3, the projection optics system 4, the stage 5, and the wafer stage 10, respectively, but are not limited thereto. The number of cooling objects and their associated structures can also be increased or decreased.

[0045] Multiple heaters, including heaters 28a, 28b, 28c, and 28d, are arranged between the heat exchanger 24 and the objects being cooled 40a-40d. Additionally, temperature sensors 29a, 29b, 29c, and 29d (multiple second temperature sensors) are respectively disposed on pipes 32a, 32b, 32c, and 32d to measure the temperature of the temperature-regulating medium 30 passing through the interior or periphery of the objects being cooled 40a-40d. Alternatively, temperature sensors 29a-29d may be positioned at locations other than those measuring the temperature of the temperature-regulating medium 30, but capable of measuring the temperature of specific parts of the objects being cooled 40a-40d.

[0046] Temperature is measured by temperature sensors 29a-29d, and the measured values ​​are provided to secondary temperature control units 26a, 26b, 26c, and 26d of the temperature control unit 20, respectively. The secondary temperature control units 26a-26d control the output of multiple heaters, including heaters 28a, 28b, 28c, and 28d, via a timing control unit 41 and switches 42a, 42b, 42c, and 42d, to keep the measured values ​​based on temperature sensors 29a-29d constant. Heaters 28a-28d are connected to a power supply 43 via switches 42a-42d. The power supply 43 can use AC power from factory equipment or DC power from a device manufacturing apparatus. Furthermore, switches 42a-42d can utilize solid-state relays (SSRs). Switches 42a-42d adjust the energizing time of heaters 28a-28d based on the operating amount of the secondary temperature control units 26a-26d, which is converted into PWM control signals by the timing control unit 41. Furthermore, PWM is an abbreviation for Pulse Width Modulation, which refers to the method of controlling the on-time (ON period) and off-time (OFF period) per unit of time. By performing PWM control, the heat generated by the heaters 28a to 28d in each PWM control cycle can be adjusted. As a result, the temperature of the temperature-regulating medium 30 in the heaters 28a to 28d is adjusted.

[0047] As described above, the temperature control device 100 includes multiple second temperature sensors (temperature sensors 29a to 29d) that measure the temperature of the temperature control medium passing through different objects. The second control unit, including the secondary temperature control unit (26a to 26d), includes multiple control systems that perform secondary temperature control on multiple heaters (heaters 28a to 28d) assigned to different objects. Figure 3 This is a block diagram of a secondary temperature control system including a secondary temperature control unit 26a. The secondary temperature control unit 26a calculates the deviation Err2a based on the target temperature SP2a stored in the memory 53 and the measured value PV2a based on the temperature sensor 29a, and supplies it to the PID compensator 54a.

[0048] Err2a=SP2a-PV2a ···(1)

[0049] The PID compensator 54a calculates the operating quantity MV2a based on the deviation Err2a and supplies it to the timing control unit 41. The timing control unit 41 converts the operating quantity MV2a into a PWM control signal through physical quantity conversion, thereby controlling the ON timing of the PWM pulse and controlling the on / off switch 42a. When the energizing time of the heater 28a changes through the on / off switch 42a, the heat generated in the heater 28a changes. When the temperature regulating medium 30 passes through the heater 28a, the heat generated by the heater 28a moves to the temperature regulating medium 30, thereby changing the temperature of the temperature regulating medium 30. The temperature regulating medium 30 after passing through the heater 28a further recovers heat when passing through the cooling flow path 6a arranged inside or around the cooling object 40a, thereby further changing its temperature. Finally, the temperature of the temperature regulating medium 30 is measured by the temperature sensor 29a, and the measured value is fed back to the secondary temperature control unit 26a.

[0050] The block diagram of the secondary temperature control system, including the secondary temperature control unit 26a, has been described above. The secondary temperature control units 26b to 26d also have the same block diagram as the secondary temperature control unit 26a described above.

[0051] Figure 4 A flowchart of the control process for the moment when the pulse becomes ON in PWM control (pulse ON moment) is shown. In S101, the timing control unit 41 converts the operating quantities MV2a~MV2d of the secondary temperature control unit 26a~26d from operating quantities to the period when the pulse is ON in PWM control (pulse ON period) based on equation (2).

[0052] During the pulse ON period, ON_i = MV2i / 100 × PWM_cyc ···(2)

[0053] Where i is a notation (one of a, b, c, d) that identifies one of the secondary temperature control units 26a to 26d. MV2i is the operating quantity (in %) of the secondary temperature control unit determined by i. PWM_cyc is the PWM control period (in seconds).

[0054] In S102, the timing control unit 41 determines the sequence of ON_a to ON_d during the pulse ON period based on either or both of the length of the pulse ON period and the rated output value of the heater. Hereinafter, for the sake of simplicity, the sequence of pulse ON will be described as the first pulse (duration ON_a), the second pulse (duration ON_b), the third pulse (duration ON_c), and the fourth pulse (duration ON_d).

[0055] In S103, the timing control unit 41 calculates time T1 using equation (3).

[0056] T1=PWM_cyc-(ON_a + ON_b + ON_c + ON_d) ···(3)

[0057] In S104, the timing control unit 41 determines whether time T1 is 0 or higher. If T1 is 0 or higher, it determines that the first pulse (ON_a) to the fourth pulse (ON_d) can be turned on sequentially without repetition within the PWM control cycle. In this case, the process proceeds to S105. In S105, the timing control unit 41 opens the switches 42a to 42d sequentially according to the order determined in S102.

[0058] On the other hand, when T1 is less than 0, it is impossible to sequentially turn on the first to fourth pulses without repetition within the PWM control cycle. In this case, the process proceeds to S106. In S106, the timing control unit 41 calculates time T2 using equation (4).

[0059] T2=PWM_cyc-(ON_a + ON_b + ON_c) ···(4)

[0060] In S107, the timing control unit 41 determines whether time T2 is 0 or higher. If T2 is 0 or higher, it determines that the first pulse (ON_a) and the second pulse (ON_b) can be turned on sequentially without repetition within the PWM control cycle. In this case, the process proceeds to S108. In S108, the timing control unit 41 opens the switches corresponding to the first pulse (ON_a) and the second pulse (ON_b) sequentially according to the order determined in S102. Then, in S109, the timing control unit 41 opens the switches corresponding to the third pulse (ON_c) and the fourth pulse (ON_d) simultaneously according to the order determined in S102.

[0061] If it is determined in S107 that T2 is less than 0, the process proceeds to S110. In S110, the timing control unit 41 calculates time T3 using equation (5).

[0062] T3=PWM_cyc-(ON_a + ON_b)···(5)

[0063] In S111, the timing control unit 41 determines whether time T3 is 0 or higher. If T3 is 0 or higher, it is determined that the first pulse (ON_a) can be turned on within the PWM control cycle. In this case, the process proceeds to S112. In S112, the timing control unit 41 opens the switch corresponding to the first pulse (ON_a) in the order determined in S102. After the first pulse falls, in S113, the timing control unit 41, based on the turn-on sequence determined in S102, simultaneously opens the switches corresponding to the second pulse (ON_b) to the fourth pulse (ON_d).

[0064] If it is determined in S111 that T3 is less than 0, the process proceeds to S114. In S114, the timing control unit 41 opens the switches corresponding to the first pulse (ON_a) to the fourth pulse (ON_d) simultaneously, without following the order determined in S102.

[0065] As described above, the timing control unit 41 controls the energizing time of the heaters 28a to 28d based on the operating parameters of the secondary temperature control units 26a to 26d.

[0066] Here, the problem of the accompanying peak current will be explained. If, during the period before the temperature-regulating medium 30 is controlled at a constant temperature by the primary temperature control unit 21 and the temperature sensors 29a-29d detect the temperature of the temperature-regulating medium 30, there is no thermal interference other than the heat generated by the heaters 28a-28d, then the operating parameters of the secondary temperature control units 26a-26d become constant. In this case, the ON period of the PWM control pulse does not change, and S105 can always be selected based on the target temperature of both the primary and secondary temperature controls. However, from Figure 2 and Figure 3 As can be seen, since the heat recovered by the temperature regulating medium 30 from the cooled objects 40a to 40d constantly changes depending on the operating state of the device manufacturing apparatus, the operating parameters of the secondary temperature control unit 26a to 26d also vary. Therefore, depending on the operating state of the device manufacturing apparatus, it may sometimes become a process other than S105.

[0067] Next, examples of choosing S108 to S109 instead of S105 will be given. Figure 5This represents the current temperature PV1 of the temperature-regulating medium 30, which is temperature-controlled by a primary temperature control system; the currents Ia, Ib, Ic, and Id flowing in heaters 28a, 28b, 28c, and 28d; and their total current Isum. For simplicity, it is assumed that the rated output values ​​of heaters 28a to 28d are the same.

[0068] Figure 5 (A) represents the time-series change of the temperature PV1 of the temperature-regulating medium 30, which is temperature-controlled by the primary temperature control system. In the figure, the horizontal axis represents time, and the vertical axis represents temperature. Additionally, the dashed lines represent the target temperature SP1 of the primary temperature control unit 21 and the target temperatures SP2a to SP2d of the secondary temperature control units 26a to 26d. The solid lines represent the temperature PV1 measured by the temperature sensor 22. For simplicity, the target temperatures SP2a to SP2d of the secondary temperature control units 26a to 26d are all set to the same value, SP2. The primary temperature control system performs temperature control to make the temperature PV1 match the target temperature SP1. The deviation ΔT between the target temperature SP2 and the temperature PV1 is the temperature that should be increased in the secondary temperature control system. The temperature-regulating medium 30 is heated by the heat generated by the heaters 28a to 28d and the heat recovered from the cooling objects 40a to 40d, increasing the temperature by ΔT.

[0069] Figure 5 (B) represents the time-series variation of the current Ia flowing in heater 28a. In the figure, the horizontal axis represents time, and the vertical axis represents current. The current Ia flows through heater 28a during ON_a in the PWM control cycle (PWM_cyc).

[0070] Figure 5 (C) represents the time-series variation of the current Ib flowing in heater 28b. After heater 28a is energized, current Ib flows through heater 28b during the ON_b period.

[0071] Figure 5 (D) represents the time-series change of the current Ic flowing in heater 28c. After heater 28b is energized, during the ON_c period, current Ic flows through heater 28c.

[0072] Figure 5 (E) represents the time series variation of the current Id flowing in heater 28d. Similar to heater 28c, heater 28d also has a current Id flowing during the ON_d period after heater 28b has finished being energized.

[0073] Figure 5(F) represents the time-series variation of the total current Isum, Ia to Id, when heaters 28a to 28d are energized. As can be seen from the figure, a peak current occurs at the points where the energization times of heaters 28c and 28d overlap. The power supply specifications for the device manufacturing facility need to be determined based on this peak current. Therefore, to cope with such peak currents, it may be necessary to increase the power supply capacity of the equipment in the plant where the device manufacturing facility is located.

[0074] Figure 6 This is a block diagram of a primary temperature control system including the primary temperature control unit 21 in the first embodiment. The physical quantity converter 50 converts the operating quantities of the secondary temperature control units 26a to 26d into the pulse ON period of the PWM according to equation (1). The arithmetic unit 51 calculates Tco, which represents the correction time, based on the pulse ON period obtained from the physical quantity converter 50 and equations (6) to (8). As can be seen from equation (6), Tco represents the excess of the period (total period) relative to the PWM control cycle when the pulse ON periods of the switches 42a to 42d are opened sequentially.

[0075] Tco = (ON_a + ON_b + ON_c + ON_d)-PWM_cyc ···(6)

[0076] When Tco≤0, Tco =0 ···(7)

[0077] When Tco > 0, Tco = Tco ···(8)

[0078] The physical quantity converter 52 converts the pulse ON period into a temperature correction amount PV1co (correction value) by applying the correction time Tco calculated by the arithmetic unit 51 to the following equation (9).

[0079] PV1co = A·Tco ···(9)

[0080] Here, A is a constant, determined based on at least one of the rated output values ​​of heaters 28a to 28d and the flow rate of the temperature-regulating medium 30 flowing through the cooling objects 40a to 40d.

[0081] Thus, in one example, the correction value is determined by multiplying the value (Tco) representing the excess amount of the total pulse ON period relative to the PWM control cycle by a constant (A). The primary temperature control unit 21 then determines the primary temperature correction amount PV1co based on the total pulse ON period for each heater. The primary temperature control unit 21 applies the temperature PV1 measured by the temperature sensor 22 and the primary temperature correction amount PV1co to equation (10). Then, the primary temperature control unit 21 applies the target temperature SP1 stored in the memory 53 to equation (11). The primary temperature control unit 21 thus calculates the deviation Err1' at any time and supplies it to the PID compensator 54.

[0082] PV1'=PV1-PV1co ···(10)

[0083] Err1'=PV1'-SP1 ···(11)

[0084] The PID compensator 54 calculates the operating amount MV1' for controlling the cooling based on the heat exchanger 24 according to the deviation Err1' and outputs it to the control valve 23. As shown in equation (10), the corrected temperature PV1' becomes a temperature below the temperature PV1 measured by the temperature sensor 22. Therefore, the deviation Err1' obtained according to equation (11) becomes a value below the deviation Err1 obtained based on equation (12) and according to the target temperature SP1 and the temperature PV1 measured by the temperature sensor 22.

[0085] Err1 = PV1 - SP1 ···(12)

[0086] Control valve 23 controls the opening of valve 56 via actuator 55 according to deviation Err1'. Since deviation Err1' is less than deviation Err1, the opening of valve 56 decreases, and the flow rate of cooling water 27 flowing into heat exchanger 24 decreases. Therefore, the amount of heat exchange between temperature regulating medium 30 and cooling water 27 in heat exchanger 24 decreases, and the temperature of temperature regulating medium 30 passing through heat exchanger 24 becomes higher than the target temperature SP1. The temperature of temperature regulating medium 30 is measured again by temperature sensor 22, and its measurement value is fed back to primary temperature control unit 21. Furthermore, in the above example, it was explained in the form of subtracting the primary temperature correction amount PV1co from the temperature PV1 measured by temperature sensor 22 (Equation (10)), but even if the primary temperature correction amount PV1co is added to the target temperature SP1 of primary temperature control unit 21, the same effect can be obtained. Specifically, by substituting equation (10) into equation (11), we obtain Err1' = PV1 - (SP1 + PV1co). Therefore, the primary temperature correction amount PV1co is added to the target temperature SP1 of the primary temperature control unit 21, and the result of the addition is subtracted from the temperature PV1 to obtain the deviation Err1'. Thus, in this embodiment, the primary temperature control unit 21 corrects the target temperature (SP1) using the correction value (PV1co). That is, from... Figure 6 It can be seen that the PID compensator 54 outputs the operating quantity MV1' for controlling the cooling based on the heat exchanger 24, based on the deviation Err1' between the temperature measured by the temperature sensor 22 and the target temperature after correction using the temperature correction amount PV1co.

[0087] In addition, if the primary temperature correction PV1co indicates that one of the multiple secondary temperature control units cannot perform temperature control, the primary temperature control unit 21 may provide the deviation Err1 shown in equation (12) to the PID compensator 54 instead of the deviation Err1' shown in equation (11).

[0088] According to this embodiment, the temperature of the temperature-regulating medium 30 is changed in the primary temperature control system so that the total ON time of the multiple PWM control pulses in the secondary temperature control system is less than the PWM control cycle. Therefore, the timing control unit 41 can always select S105 to sequentially open the switches 42a to 42d. (Refer to...) Figure 7 The effects of this study will be explained. Figure 7 This represents the temperature PV1 of the temperature-regulating medium 30, which is controlled by a primary temperature control system; the current flowing in heaters 28a to 28d; and their total current. Figure 5 Similarly, for the sake of simplicity, the rated output values ​​of heaters 28a to 28d are the same, and the target temperatures SP2a to SP2d of the secondary temperature control units 26a to 26d are all set to the same value SP2.

[0089] Figure 7 (A) represents the time-series change of the temperature PV1 of the temperature-regulating medium 30, which is controlled by the primary temperature control system. In the figure, the horizontal axis represents time, and the vertical axis represents temperature. Additionally, the dashed lines represent the target temperature SP1 of the primary temperature control unit 21 and the target temperatures SP2a to SP2d of the secondary temperature control units 26a to 26d. The solid line represents the temperature PV1 measured by the temperature sensor 22. The thick line represents the correction temperature PV1'. The correction temperature PV1' is controlled by the primary temperature control system to match the target temperature SP1. However, the actual temperature PV1 is always higher than the correction temperature PV1' by the primary temperature correction amount PV1co, therefore the temperature difference ΔT' between the target temperature SP2 and the temperature PV1 is greater than... Figure 5 The temperature difference ΔT is small. The temperature difference ΔT' is the temperature that should be increased in the secondary temperature control system, achieved by the heat generated by heaters 28a to 28d and the heat recovered from the cooled object 40a to 40d. If the heat recovered from the cooled object 40a to 40d is... Figure 5 Under the same conditions, less heat needs to be generated in heaters 28a to 28d. That is, the ON period of the switch is shortened.

[0090] Figure 7 (B) represents the time-series variation of the current Ia flowing in heater 28a. In the figure, the horizontal axis represents time T, and the vertical axis represents current A. The current Ia flows through heater 28a during time ON_a' in the PWM control cycle (PWM_cyc).

[0091] Figure 7 (C) represents the time series variation of the current Ib flowing in heater 28b. After heater 28a is energized, current Ib flows through heater 28b during the time ON_b'.

[0092] Figure 7 (D) represents the time series variation of the current Ic flowing in heater 28c. After heater 28b is energized, current Ic flows through heater 28c during the time ON_c'.

[0093] Figure 7 (E) represents the time series variation of the current Id flowing in heater 28d. After heater 28c is energized, current Id flows through heater 28d during the time ON_d'.

[0094] Figure 7 (F) represents the time-series variation of the total current Isum, Ia to Id, when heaters 28a to 28d are energized sequentially. As can be seen from the figure, since the energizing times of heaters 28a to 28d are not repeated, no current is generated. Figure 5The peak current shown in (F) is the peak current.

[0095] As described above, according to this embodiment, the ON timing of the pulses in the PWM control of each of the multiple heaters is determined such that the total current value of the multiple heaters does not exceed a predetermined limit. In the above embodiment, the predetermined limit refers to the maximum value among the rated currents of each of the multiple heaters. In this embodiment, by changing the ON timing of the pulses of each heater and the temperature of the temperature regulating medium 30 in the primary temperature control system, the total value of the ON period of the PWM control pulses is made less than or equal to the PWM control cycle, thereby preventing the repetition of the energizing time of the multiple heaters in the secondary temperature regulation. This suppresses the generation of excessive peak current. Furthermore, since the repetition of the energizing time of the multiple heaters can be prevented without extending the PWM control cycle, the controllability of the secondary temperature regulation can be prevented.

[0096] Figure 11 The flowchart illustrates a temperature control method according to one embodiment. The temperature control method includes a first step S1, which involves cooling the temperature control medium 30 based on the deviation between a target temperature SP1 and the current temperature PV1. The temperature control method also includes a second step S2, which involves supplying power to each heater 28a-28d via PWM control to perform a second temperature control, heating the temperature control medium 30 that has been cooled by the first temperature control.

[0097] Here, the second step S2 includes step S21, which determines the timing of the pulse ON period in the PWM control of each of the heaters 28a to 28d, such that the total current value of the heaters 28a to 28d does not exceed a predetermined limit. Furthermore, the first step S1 includes step S11, which corrects the target temperature SP1. In step S11, a correction value (primary temperature correction amount PV1co) for the target temperature SP1 is determined based on the operation amounts MV2a to MV2d output in the secondary temperature adjustment for the heaters 28a to 28d respectively, and the target temperature SP1 is corrected using this determined correction value.

[0098] [Second Implementation]

[0099] Figure 8 This is a block diagram of the primary temperature control system in the second embodiment. Figure 6The difference in the block diagram of the primary temperature control system described in the previous embodiment is that a selector 57 is added between the physical quantity converter 50 and the arithmetic unit 51. In the first embodiment, the correction time Tco is calculated according to equations (6) to (8) regardless of the rated output values ​​of heaters 28a to 28d and the respective durations of ON_a to ON_d during the pulse ON period. However, in reality, there are many cases where the rated output values ​​of heaters 28a to 28d differ, and the energizing current is also different depending on the difference in the rated output values ​​of each heater. As an example, let the energizing current of heaters 28c and 28d be H, the energizing current of heater 28b be twice H, and the energizing current of heater 28a be four times H. In this case, since the current flowing in heater 28a is at its maximum value, even if heaters 28b, 28c, and 28d are energized simultaneously, the current of heater 28a will not be exceeded. In this embodiment, similar to the first embodiment, the timing of the pulse ON in the PWM control of each of the multiple heaters is determined in such a way that the total current value of the multiple heaters does not exceed a predetermined limit value. Here, the specified limit value refers to the maximum value among the rated currents of the multiple heaters. Therefore, in this case, the specified limit value is 4 times the value of H, which is the energizing current of heater 28a.

[0100] Selector 57 selects the longest of ON_b, ON_c, and ON_d during the ON pulse period and outputs its duration as ON_cmp to arithmetic unit 51. Arithmetic unit 51 calculates the correction time Tco'' according to equations (13) to (15).

[0101] Tco'' = (ON_a + ON_cmp)-PWM_cyc ···(13)

[0102] When Tco''≤0, Tco'' =0 ···(14)

[0103] When Tco'' > 0, Tco'' = Tco'' ··· (15)

[0104] Furthermore, the combination of signals input to selector 57 is not limited to... Figure 8 The signal shown can also be changed according to the rated output value of the heater.

[0105] Figure 9 A flowchart illustrating the control processing at the moment the pulse becomes ON in the PWM control of the second embodiment is shown. Figure 9In step S101, the timing control unit 41 converts the operating quantities MV2a to MV2d of the secondary temperature control units 26a to 26d from operating quantities to pulse ON periods according to the above formula (2). In step S102, the timing control unit 41 determines the sequence of ON_a to ON_d during the pulse ON periods according to the rated output value of the heater. In step S103, the timing control unit 41 calculates time T1 using the above formula (3). In step S112, the timing control unit 41 opens the switch corresponding to the first pulse (ON_a) according to the sequence determined in step S102. After the first pulse falls, in step S113, the timing control unit 41 opens the switches corresponding to the second pulse (ON_b) to the fourth pulse (ON_d) simultaneously based on the conduction sequence determined in step S102. Alternatively, the contents of steps S102 and S103 can be changed according to the rated output value of the heater.

[0106] Reference Figure 10 This explains the effects of this implementation method. Figure 10 This indicates the temperature of the temperature-regulating medium 30, which is temperature-controlled by a primary temperature control system, the current flowing in heaters 28a to 28d, and their combined current.

[0107] Figure 10 (A) represents the time-series change of the temperature of the temperature-regulating medium 30, which is controlled by the primary temperature control system. In the figure, the horizontal axis represents time, and the vertical axis represents temperature. Additionally, the dashed lines represent the target temperature SP1 of the primary temperature control unit 21 and the target temperatures SP2a to SP2d of the secondary temperature control units 26a to 26d. The solid lines (thin lines) represent the temperature PV1 measured by the temperature sensor 22, and the thick lines represent the correction temperature PV1''. The correction temperature PV1'' is controlled by the primary temperature control system to match the target temperature SP1. However, the actual temperature PV1 is always higher than the correction temperature PV1'' by the primary temperature correction amount PV1co'', therefore, the temperature difference ΔT'' between the target temperature SP2 and the temperature PV1 is greater than... Figure 5 The temperature difference ΔT is small.

[0108] Figure 10 (B) represents the time-series variation of the current Ia flowing in heater 28a. In the figure, the horizontal axis represents time and the vertical axis represents current. During the time ON_a'' of the PWM control cycle (PWM_cyc), the current H×4 flows through heater 28a.

[0109] Figure 10 (C) represents the time series variation of the current Ib flowing in heater 28b. After the energization of heater 28a ends, during the time ON_b'', the current H×2 flows through heater 28b.

[0110] Figure 10 (D) represents the time series variation of the current Ic flowing in heater 28c. Similar to heater 28b, heater 28c has a current H flowing during the time ON_c'' after the energization of heater 28a ends.

[0111] Figure 10 (E) represents the time series variation of the current Id flowing in heater 28d. Similar to heaters 28b and 28c, heater 28d experiences a current H flowing during the time ON_d'' after the energization of heater 28a ends.

[0112] Figure 10 (F) represents the time series variation of the total current Isum of currents Ia to Id when heaters 28a to 28d are energized. According to the figure, the energizing time of heaters 28b to 28d is repeated, but the total current value will not exceed the energizing current of heater 28a with the largest rated output value, i.e., H×4. Therefore, an excessively large peak current will not be generated.

[0113] As described above, in this embodiment, the total duration of the pulse ON periods is selectively calculated based on the multiple pulse ON periods of the secondary temperature control and the rated output value of the heater. Then, based on this total duration, the temperature of the temperature-regulating medium 30 controlled by the primary temperature control system is changed to be within or below the PWM control cycle. Therefore, even if the energizing times of the multiple heaters under secondary temperature control are repeated, the generation of excessive peak current can be suppressed. Furthermore, compared to the first embodiment, the control processing based on the pulse ON timing of the timing control unit 41 can be simplified.

[0114] [Implementation Method of Item Manufacturing]

[0115] The article manufacturing method of this invention is suitable for manufacturing articles such as microdevices, semiconductor devices, and components with fine structures. The article manufacturing method of this embodiment includes a step of transferring a pattern from a master template onto a substrate using the aforementioned device manufacturing apparatus (exposure apparatus, imprinting apparatus, drawing apparatus, etc.), and a step of processing the substrate on which the pattern has been transferred in this step. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, encapsulation, etc.). Compared to conventional methods, the article manufacturing method of this embodiment is advantageous in at least one aspect of article performance, quality, productivity, and production cost.

[0116] This invention is not limited to the embodiments described above, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are appended to disclose the scope of this invention.

[0117] Explanation of reference numerals in the attached figures

[0118] 20: Temperature control unit; 21: Primary temperature control unit; 24: Heat exchanger (cooler); 26a, 26b, 26c, 26d: Secondary temperature control unit; 28a, 28b, 28c, 28d: Heater; 30: Temperature regulating medium; 40a, 40b, 40c, 40d: Cooling object; 41: Timing control unit; 100: Temperature regulating device.

Claims

1. A temperature regulating device, characterized in that, This temperature control device has the following features: The cooler performs primary temperature regulation by cooling the temperature-regulating medium; The first control unit controls the cooler based on the deviation between the target temperature and the current temperature; Multiple heaters perform secondary temperature regulation by providing heat generated according to the supplied power to the temperature regulating medium that has been cooled by the cooler. as well as The second control unit controls the power supply to each of the plurality of heaters via PWM control. The second control unit determines the timing of the ON pulse in the PWM control of each of the plurality of heaters, such that the total current value of the plurality of heaters does not exceed a predetermined limit. The first control unit adjusts the target temperature using a correction value based on a total period calculated by summing the periods of the plurality of heaters.

2. The temperature regulating device according to claim 1, characterized in that, The specified limit value is the maximum value among the rated currents of the plurality of heaters.

3. The temperature regulating device according to claim 1, characterized in that, The first control unit determines the correction value by multiplying the value representing the excess amount of the total period relative to the PWM control cycle by a constant.

4. The temperature regulating device according to claim 3, characterized in that, The constant is based on at least one of the rated output values ​​of the plurality of heaters and the flow rate of the temperature-regulating medium flowing through the object being cooled.

5. The temperature regulating device according to claim 1, characterized in that, The temperature control device also includes a first temperature sensor that measures the temperature of the temperature control medium passing through the cooler. The first control unit includes a PID compensator, which outputs an operating amount for controlling cooling based on the cooler, based on the deviation between the temperature measured by the first temperature sensor and the target temperature adjusted using a correction value for adjusting the target temperature.

6. The temperature regulating device according to claim 1, characterized in that, The temperature control device also has multiple second temperature sensors that measure the temperature of the temperature control medium passing through different objects. The second control unit includes multiple control systems, which perform secondary temperature adjustment on the multiple heaters assigned to the different objects, and each of the multiple control systems includes: A PID compensator outputs an operating amount for controlling heater-based heating based on the deviation between the temperature measured by a second temperature sensor and the target temperature; and The timing control unit converts the operational quantity output from the PID compensator into a PWM control signal and controls the timing.

7. A temperature control method, characterized in that, This temperature control method has the following characteristics: The first step involves adjusting the temperature of the cooling medium based on the deviation between the target temperature and the current temperature; and The second step involves performing secondary temperature regulation by applying PWM control to the power supply to each of the multiple heaters, thereby heating the temperature-regulating medium that has been cooled by the primary temperature regulation. The second step includes determining the timing of the ON pulse period in the PWM control of each of the plurality of heaters, such that the total current value of the plurality of heaters does not exceed a predetermined limit. The first step includes adjusting the target temperature using a correction value based on a total period calculated by summing the periods of the plurality of heaters.

8. A semiconductor device manufacturing apparatus having multiple heat-generating units, characterized in that, The semiconductor device manufacturing apparatus includes the temperature control device as described in any one of claims 1 to 6. The plurality of heaters are disposed between the cooler and the plurality of heating elements.

9. The semiconductor device manufacturing apparatus according to claim 8, characterized in that, The semiconductor device manufacturing apparatus is configured as a photolithography apparatus for forming patterns on a substrate.

10. A method for manufacturing an article, characterized in that, The method for manufacturing this item has the following characteristics: The process of forming a pattern on a substrate using the photolithography apparatus of claim 9; and The process of processing the substrate on which the pattern is formed. Articles are manufactured using the processed substrate.

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