JPH08273995A - Substrate cooling device - Google Patents

Abstract

PURPOSE: To cool a substrate under the same temperature condition even when the temperature of cooling water is changed by drive-controlling an electronic cooling element so as to permit the endothermic quantity of a cooling means per unit time from a substrate placing member to be a prescribed fixed value, in response to the cooling medium temperature detected by a cooling medium temperature detecting means. CONSTITUTION: A control part 22 controls a Peltier element 15 according to the cooling water temperature detected by a sensor 18 so that the heat absorbed per unit time from a heat sink 11 by a Peltier element 15 and a heat dissipating plate 14 can be constant to cool a substrate efficiently. The device is provided with a second table memory 31, which stores the drive-control element quantity of the Peltier element 15, and a temperature control part 26, which controls the plate temperature of the cooling plate 5. The drive element control quantity is the duty ratio of the supply current for driving the Peltier element 15 for each cooling water temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display device,
In the photolithography process, a substrate such as a substrate for an optical disk is provided with a cooling means in order to cool the substrate which has been heated to a high temperature before and after the photoresist coating and developing processes to a target temperature near room temperature. The present invention relates to a substrate cooling device that cools a substrate by placing the substrate in contact with or close to a cooling plate.

[0002]

2. Description of the Related Art As a substrate cooling device of this type, for example,
A device as shown in FIG. 11 is known. This device
A cooling plate 104 that is provided in the processing chamber 100 and includes a heat transfer plate 101, a Peltier element 102, and a heat dissipation plate 103, and a through hole 1 formed in the cooling plate 104.
A plurality of substrate support pins 105 that can be moved up and down through 04a and an air cylinder 106 that raises and lowers each substrate support pin 105 are provided. When cooling the substrate W in a high temperature state, the substrate W is carried in by a substrate transfer robot (not shown) in a state where each substrate support pin 105 is raised, and then each substrate support pin 105 is lowered. Thus, the substrate W is placed on the cooling plate 104 and the cooling of the substrate W is started. At this time, the Peltier device 10 is controlled by proportional calculus (PID) control or the like.
By driving No. 2, as shown in the time chart of FIG. 12, the plate temperature T _P of the cooling plate 104 is maintained at the same temperature as the target temperature T _S for cooling the substrate W.

[0003]

However, the above-mentioned conventional apparatus has the following problems. That is, cooling water is circulated inside the heat dissipation plate 103 through a supply / discharge pipe (not shown), and radiates the heat of the Peltier element 102. Since ordinary tap water is usually used as the cooling water, it is difficult to strictly control the temperature of the supplied cooling water, and the temperature greatly changes due to changes in temperature. This change in the cooling water temperature causes the Peltier element 102.
Will affect the cooling capacity of. That is, even if the same amount of current is supplied to the Peltier element 102 from the drive unit (not shown), if the temperature of the cooling water that radiates the heat of the Peltier element 102 changes, the cooling capacity of the Peltier element 102 will be affected by the variable factors. receive. For example, when high-temperature cooling water is supplied, the cooling capacity is low even if the same current is supplied to the Peltier element 102, while when low-temperature cooling water is supplied, the same current is supplied. Even so, the cooling capacity becomes high. As a result, the cooling history of the substrate temperature T _W of the substrate W varies, which adversely affects the quality of the substrate.

Further, in such a substrate cooling device, as shown in FIG.
As shown in FIG. 2, when the high temperature substrate W is placed on the cooling plate 104 at the cooling start time t ₁ , the substrate temperature T _W of the substrate _W is pulled and the plate temperature T _P temporarily rises. Of course, at this time, the Peltier element 102 of the cooling plate 104 is controlled by the PID control so as to reach the target temperature TS for cooling. However, even in that case, the cooling capacity of the Peltier element 102 can be increased as much as possible. Since this is not possible, it is inevitable that the temperature of the cooling plate 104 temporarily becomes higher than the target temperature TS for cooling. Therefore, since the time t _P until the plate temperature T _P returns to the target temperature T _S becomes long, the time t for cooling the substrate W to the target temperature T _S
W also becomes long, and as a result, the throughput of the entire apparatus is reduced.

The present invention has been made in view of such circumstances, and even if the temperature of the cooling water changes, the substrate can be cooled under the same temperature condition, and the substrate is processed. An object of the present invention is to provide a substrate cooling device capable of stabilizing the quality. It is another object of the present invention to provide a substrate cooling device that can cool a substrate at high speed to shorten the cooling time and can cool the substrate under stable conditions.

[0006]

The present invention has the following constitution in order to achieve such an object. Claim 1
The substrate cooling device according to, cools the substrate mounting member by a cooling means comprising an electronic cooling element, and a heat radiating means for radiating the heat of the electronic cooling element by circulating a refrigerant,
In a substrate cooling device that cools the substrate by placing the substrate in contact with or close to the substrate placing member, a coolant temperature detecting means for detecting the temperature of the coolant flowing through the heat radiating means,
A control unit that drives and controls the electronic cooling / heating element such that the amount of heat absorbed by the cooling unit per unit time with respect to the substrate mounting member becomes a predetermined constant value in accordance with the coolant temperature detected by the coolant temperature detection unit. It is characterized by having and.

A substrate cooling device according to a second aspect is the first aspect.
In the above, the control means, with respect to the fluctuation of the refrigerant temperature,
Based on the refrigerant temperature detected by the refrigerant temperature detecting means, the memory means storing the drive control element amount of the electronic cooling / heating element for keeping the heat absorption amount per unit time of the cooling means at a predetermined constant value, and corresponding It is characterized by comprising a reading means for reading the drive control element amount, and a drive control means for driving and controlling the electronic cooling / heating element based on the drive control element amount read by the reading means.

A substrate cooling device according to a third aspect is the second aspect.
In the above, the storage means is a table memory that stores a plurality of refrigerant temperatures and drive control element amounts of the electronic cooling / heating elements corresponding to the respective refrigerant temperatures.

A substrate cooling device according to a fourth aspect is the second aspect.
Alternatively, in claim 3, the drive control element amount of the electronic cooling / heating element is a duty ratio of a current supplied to the electronic cooling / heating element.

According to a fifth aspect of the present invention, there is provided a substrate cooling device which cools a substrate mounting member by means of a cooling means including an electronic cooling element and a heat radiating means for radiating heat of the electronic cooling element by circulating a cooling medium. In a substrate cooling device that cools the substrate by placing the substrate on or in close proximity to the substrate placing member, a placement detecting unit that detects placement of the substrate on the substrate placing member, and the heat radiating unit. Refrigerant temperature detecting means for detecting the temperature of the refrigerant flowing through, the fluctuation of the refrigerant temperature, the amount of heat absorbed per unit time of the cooling means, the refrigerant of a predetermined upper limit temperature to be passed through the heat radiating means Storage means for storing the drive control element amount of the electronic cooling / heating element for equalizing the maximum heat absorption amount per unit time with respect to the substrate mounting member of the cooling means when circulating, and the coolant temperature detecting hand. Based on the refrigerant temperature detected by the reading means for reading the corresponding drive control element amount, and when the substrate is placed on the substrate placing member, the drive control element amount read by the reading means Drive control means for controlling the drive of the electronic cooling / heating element based on the above.

[0011]

According to the substrate cooling apparatus of the first aspect, the cooling means comprises the electronic cooling element and the heat radiating means for radiating the heat of the electronic cooling element by circulating the refrigerant. The refrigerant temperature detecting means detects the temperature of the refrigerant flowing through the heat radiating means, and in accordance with the refrigerant temperature, the control means causes the amount of heat absorbed by the cooling means for the substrate mounting member per unit time to be a predetermined constant value. In addition, since the electronic cooling and heating element is driven and controlled,
The substrate placed on the substrate placing means is also cooled under constant conditions.

In the substrate cooling device according to the second aspect of the present invention, the storage means has a drive control element for the electronic cooling element for keeping the amount of heat absorbed by the cooling means per unit time at a predetermined constant value with respect to fluctuations in the refrigerant temperature. I remember the amount. The read-out means reads out the drive control element amount corresponding to the coolant temperature detected by the coolant temperature detecting means, and the drive control means determines the heat absorption amount per unit time of the cooling means with respect to the substrate mounting member based on the drive control element amount. The electronic cooling / heating element is drive-controlled so as to be a constant value.

In the substrate cooling apparatus according to the third aspect of the present invention, the storage means including the table memory stores a plurality of refrigerant temperatures and the drive control element amounts of the electronic cooling / heating elements corresponding to the respective refrigerant temperatures. The read-out means reads out the drive control element amount corresponding to the coolant temperature detected by the coolant temperature detecting means, and the drive control means determines the heat absorption amount per unit time of the cooling means with respect to the substrate mounting member based on the drive control element amount. The electronic cooling / heating element is drive-controlled so as to be a constant value.

In the substrate cooling apparatus according to the fourth aspect, the duty ratio of the current supplied to the electronic cooling / heating element is used as the drive control element amount of the electronic cooling / heating element in the storage means.

According to the substrate cooling device of the fifth aspect, the cooling means comprises the electronic cooling element and the heat radiating means for radiating the heat of the electronic cooling element by circulating the refrigerant.
With respect to the fluctuation of the refrigerant temperature, the amount of heat absorbed per unit time of the cooling means, with respect to the substrate mounting member of the cooling means when the refrigerant having a predetermined upper limit temperature that is circulated in the heat radiating means flows. The drive control element amount of the electronic cooling element for equalizing the maximum heat absorption amount per unit time is stored in the storage means. The temperature of the refrigerant flowing through the heat radiating means is detected by the refrigerant temperature detecting means, and according to the detected refrigerant temperature, the heat absorption amount per unit time of the cooling means with respect to the substrate mounting member is an electron for making the maximum heat absorption amount. The drive control element amount of the cooling / heating element is read by the reading means.
When the substrate is placed on the substrate placing member, the electronic cooling / heating element is controlled by the drive control unit based on the drive control element amount read by the reading unit. Electronic cooling element
The cooling means is driven so as to maximize the amount of heat absorbed per unit time within a range that does not impair a constant cooling condition even if the refrigerant temperature fluctuates.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall vertical cross-sectional view showing an embodiment of a substrate cooling device according to the present invention, and FIG. 2 is a plan view of a main part thereof. A substrate cooling device 2 is provided below the housing 1, and a substrate heating device 3 is provided above the substrate cooling device 2.

In the substrate cooling device 2, a cooling plate 5 is provided in the processing chamber 4, and a plurality of substrate support pins 7 are vertically movable through through holes 6 formed in the cooling plate 5. Further, FIG. As shown, a plurality of proximity balls 8 are provided on the cooling plate 5 to form a predetermined gap (proximity gap) for uniform cooling between the surface of the cooling plate 5 and the substrate W. ing.

An air cylinder 10 is interlockingly connected to a support member 9 that integrally holds each substrate support pin 7, and the substrate support pin 7 is moved up and down by the expansion and contraction of the air cylinder 10. The substrate W is loaded and unloaded by a substrate transfer robot (not shown) in a state where each substrate support pin 7 is raised, and each substrate support pin 7 is lowered to place the substrate W on the cooling plate 5. It can be mounted on and supported by each proximity ball 8.

The cooling plate 5 is an aluminum heat transfer plate 11 on which a substrate W is placed, and a water-cooled aluminum heat dissipation plate 1 in which a water supply pipe 12 and a drain pipe 13 are connected.
4 and a Peltier element 15 for quenching interposed between the heat transfer plate 11 and the heat dissipation plate 14. The heat radiating plate 14 circulates cooling water to radiate the heat of the Peltier element 15. A plate temperature sensor 16 for measuring the plate temperature T _P of the cooling plate 5 cooled by the Peltier element 15 is provided near the center of the heat transfer plate 11. A cooling water temperature sensor 18 is connected to the water supply pipe 12 of the heat dissipation plate 14 to measure the temperature of the cooling water flowing from the water supply pipe 12 to the heat dissipation plate 14.

Next, the configuration of the control system will be described with reference to the block diagram of FIG. As shown in FIG. 3, the plate temperature sensor 16, the cooling water temperature sensor 18, an input unit 20 for inputting each set value described later, and a transfer control unit 21 for outputting a signal for sending the substrate W are connected to the control unit 22. At the same time, the control unit 22 is connected to a substrate elevating drive unit 27 that drives the air cylinder 10 via the solenoid valve 17 and the like, and a cooling drive unit 28 for the Peltier element 15.

In the input unit 20, the operator inputs necessary set values such as the set temperature of the cooling plate 5 from a keyboard or the like, and outputs the set values thus input to the control unit 22 for setting. It has become. Each set value will be described later.

In the transfer controller 21, for example, the substrate W loaded by the substrate transfer robot is used as the cooling plate 5.
The timing when the substrate W is lifted above the substrate support pin 7 is time-controlled in advance, and when the timing comes, it is considered that the substrate W is mounted on the substrate support pin 7 and the substrate sending signal is sent to the controller 22. It is designed to output to.

The control section 22 includes a controller 23, a first set temperature storage section 24 for storing a first set temperature T _S1 which is a target temperature for cooling the substrate W, and a temperature rising peak T of the cooling plate 5. The first table memory 30 in which the second set temperature T _S2 associated with _H is stored, and the Peltier element 15 and the heat radiating plate with respect to the variation of the cooling water temperature TN detected by the cooling water temperature sensor 18. The second table memory 31 in which the amount of drive control elements of the Peltier element 15 for keeping the amount of heat absorbed from the heat transfer plate 11 per unit time by the unit 14 is maintained at a predetermined constant value, and the cooling plate 5.
And a temperature control unit 26 for controlling the plate temperature T _P of the plate. The second set temperature T _S2 and the drive control element amount stored in the table memories 30 and 31 are experimentally determined in advance. The drive element control amount stored in the second table memory 31 is, specifically, a plurality of cooling water temperatures T.
With respect to N, it is the value of the duty ratio of the supply current for driving the Peltier device 15 corresponding to each temperature. Details will be described later.

The controller 23 is composed of a so-called microcomputer, and has a writing function for storing the first set temperature T _S1 given from the input section 20 in the first set temperature storage section 24 and a substrate sending signal from the transfer control section 21. A placement detection function of detecting the placement of the substrate W on the cooling plate 5 by reception, and a duty ratio corresponding to the temperature of the cooling water detected by the cooling water temperature sensor 18 are selectively read from the second table memory 31. The duty ratio read function for outputting to the temperature control unit 26 and the plate temperature sensor 16
The peak detection function of detecting the peak of the temperature rise of the cooling plate 5 detected by the second setting temperature TS2 corresponding to the detected temperature rising peak temperature TH is selectively read out from the first table memory 30. Cooling plate 5 with temperature determination function and plate temperature sensor 16
Determination function for determining that the temperature of the cooling plate 5 has reached the determined second set temperature TS2, and the first set temperature stored in the first set temperature storage unit 24 when the temperature of the cooling plate 5 reaches the second set temperature TS2. The set temperature TS1 of PID control is read out and output as a target temperature for PID control to a temperature control unit 26 which will be described later.
A PID control instructing function for instructing the start of D control, a time counting function for timing the elapse of a preset cooling processing time tE, and a substrate elevating / lowering according to a time counting result of the time counting function and a substrate sending signal from the transfer control unit 21. The control unit 27 has a pin control function for outputting a pin lowering command for raising and lowering the substrate support pin 7 and a pin raising command. The output of the duty ratio set by the duty ratio reading function to the temperature control unit 26 also serves as an instruction to start the duty control to the temperature control unit 26.

The temperature control unit 26 also comprises a so-called microcomputer. The temperature control unit 26 has a PID control function containing a known program for PID control and a duty control function containing a known program for duty control. These two functions are selected by the control of the controller 23. In the PID control function, the Peltier element 15 is PID controlled to a predetermined target temperature by referring to the plate temperature TP of the cooling plate 5 measured by the plate temperature sensor 16 and outputting a control signal to the cooling drive unit 28. . The target temperature at which the temperature control unit 26 should perform PID control of the Peltier device 15 is the set temperature output from the controller 23. For example, from the controller 23 to the first set temperature TS1
Is output, the Peltier element 15 is PID-controlled so as to reach the first set temperature TS1. Further, in the duty control function, a control signal corresponding to the duty ratio output from the controller 23 is output to the cooling drive unit 28 to duty control the current output to the Peltier element 15, and the Peltier element 15 is controlled to a normal state described later. Drive with the maximum cooling output. Further, the temperature control unit 26 constantly inputs the plate temperature TP of the cooling plate 5 measured by the plate temperature sensor 16 and transmits it to the controller 23 as well.
In this embodiment, the controller 23 and the temperature control unit 2
Although each of the functions 6 is realized by a single microcomputer, a plurality of circuits each having these functions may be separately provided.

Due to these functions and configurations, the control unit 22 controls the Peltier element 15 and the heat radiating plate 14 for the heat transfer plate 11 per unit time according to the temperature of the cooling water detected by the cooling water temperature sensor 18. The Peltier element 15 is controlled so that the heat absorption amount becomes a predetermined constant value.

In the cooling control of this embodiment, the plate temperature T _P is lower than the target temperature (first set temperature T _S1 ) from the time when the substrate W is placed on the cooling plate 5 (second temperature). The substrate W is cooled at high speed by driving and controlling the Peltier element 15 at the maximum cooling output so that the set temperature T _S2 ) of the plate temperature T _S2 ) is controlled to suppress the temperature rise of the plate temperature T _P. Then, this maximum cooling output is normalized so that the amount of heat absorbed per unit time becomes constant with respect to the fluctuation of the cooling water temperature, and even if the temperature of the cooling water fluctuates, the same stable temperature for the substrate is obtained. It can be cooled under the conditions. Further, the plate temperature T _P is controlled under optimum conditions, and when the substrate temperature T _W approaches the target temperature, the approach is quickly converged to efficiently cool the substrate W. This will be specifically described below.

The cooling control operation with the above configuration will be described with reference to the flow charts of FIGS. 4 and 5 and the time chart of FIG. 6 showing the control executed by the controller 23. In FIG. 6, (a) shows the transfer timing of the substrate W by raising and lowering the substrate indicating pin 7, and (b) is a time chart. The substrate temperature TW of the substrate _{W is shown} by a solid line and the plate temperature T _P of the cooling plate 5 is shown. Is indicated by a broken line. In addition,
At the cooling start time t ₁ , the substrate W is placed on the cooling plate 5 to start cooling, and immediately after that, the substrate temperature T
_{Since W} is a high temperature, in FIG. 6B, the substrate temperature T _W immediately after that is omitted.

Step 1: First, each set value is input from the input unit 20. As each set value, the first set temperature T _S1
As the target temperature for cooling the substrate W, the substrate cooling time t _E from the cooling start t ₁ to the cooling end t ₂ of the substrate W, and the like depending on the type of the substrate W and the capacity of the Peltier element 15. It is determined experimentally in advance. The controller 23 stores the first set temperature T _S1 among the set values in the first set temperature storage unit 24. First set temperature T
_S1 is a target temperature for cooling the substrate W, for example, 20
℃ is set. The substrate cooling time tE is stored in the memory inside the controller 23.

Step 2: Next, the controller 23
Before the substrate W is placed on the cooling plate 5, that is, before the cooling start t _{1 of the} substrate W is started, P
The first set temperature T _S1 is output as the target temperature for ID control. As a result, the first set temperature TS1 is set as the target temperature for PID control of the Peltier element 15 in the temperature control unit 26.
As shown in, the Peltier element 15 is driven by the PID control function so that the plate temperature T _P of the cooling plate 5 becomes the first set temperature T _S1 . As a result, before the substrate W is placed on the cooling plate 5, the plate temperature T _P of the cooling plate 5 is the target temperature T _S1 for cooling the substrate in advance.
Will be maintained.

Steps 3, 4, 5: Next, the controller 23 determines whether or not a substrate sending-out signal has been issued from the transfer control unit 21. That is, it is determined whether the substrate W has been loaded onto the substrate support pins 7. When the substrate W is loaded onto the substrate support pins 7, the controller 23 issues a pin lowering command to the substrate lift drive unit 27, and the substrate support pins 7 are lowered by contraction of the air cylinder 10 and the substrate W is moved.
Are placed on each proximity ball 8 on the cooling plate 5. As a result, the substrate W1 is placed close to the cooling plate 5, and the cooling operation of the substrate W1 is started from this time (time t1). The controller 23 determines whether or not the pin lowering is completed, and when completed, moves to the next step 6.

Steps 6, 7, 8: Next, the controller 23 causes the cooling water temperature sensor 18 via the temperature controller 26.
The temperature T _N of the cooling water flowing through the water supply pipe 12 measured at is read. The duty ratio of the output current value is determined from the second table memory 31 based on the read cooling water temperature T _N , and the Peltier element 15 is driven with the normalized maximum cooling output based on this.

Here, the normalized maximum cooling output will be described. Even if a constant current is supplied, the Peltier element 15 arranged on the plate 5 is affected by the ambient temperature, the cooling water temperature of the radiator plate 14, the cooling water flow rate, the plate temperature, etc., and its cooling capacity changes. Have characteristics. Of these, the ambient temperature is less affected because the cooling plate 5 is used near room temperature, and the flow rate of the cooling water can be made almost constant by providing a regulator or a flow rate adjusting valve. Further, the plate temperature may change slightly during the process, but as long as the same type of substrate is processed at the same temperature, the plate temperature changes in the same trajectory for all the substrates. The problem of homogeneity does not arise.

However, since tap water is usually used as the cooling water, it is difficult to control the temperature T _N to be constant, and the temperature greatly changes due to changes in temperature. This change in the cooling water temperature affects the cooling capacity of the Peltier element 15. That is, the cooling drive unit 2
Even if a constant current is supplied from 8 to the Peltier element 15, if the cooling water temperature T _N for radiating the heat of the Peltier element 15 changes, the cooling capacity of the Peltier element 15 is affected by the variable element. For example, when high-temperature cooling water is supplied, even if the maximum current is supplied to the Peltier element 15, the cooling capacity is low, while when low-temperature cooling water is supplied, the same current is supplied. Even if supplied, the cooling capacity becomes high.

Therefore, by controlling the side temperature of the cooling water and controlling the duty ratio of the current output to the Peltier element 15 based on the temperature, the cooling capacity is always constant regardless of the temperature of the cooling water. The maximum cooling output is corrected to obtain Hereinafter, a specific description will be given with reference to FIGS. 7 and 8. Figure 7 is a cooling water temperature T _N, shows the relationship between the heat absorption amount Q per unit time from the heat transfer plate 11 by heat radiating plate 14 and the Peltier element 15, FIG. 8 (a) reference coolant temperature T _N is 8 shows the output control state of the current i when the temperature becomes, for example, 30 ° C., and FIG. 8B shows the output control state of the current i when the cooling water temperature T _N changes to 20 ° C.

As shown in FIG. 7, generally, the cooling water temperature T
_{When N} rises, the heat absorption amount Q, which is the cooling capacity of the Peltier element 15 and the heat dissipation plate 14, decreases. For example, assuming that the maximum heat absorption amount Q when the cooling water temperature is 20 ° C. is 100%, if the same current is applied at the cooling water temperature 30 ° C., the cooling water temperature 20
When the heat absorption amount Q is 80% at 80 ° C., as shown in FIG. 8A, the cooling capacity at the cooling water temperature of 30 ° C. is used as a reference, and at the cooling water temperature of 20 ° C. , Fig. 8
As shown in (b), the current i supplied to the Peltier element 15 is divided at an appropriate time period S, the output is duty-controlled to 80%, and the heat absorption amount Q when the reference cooling water temperature is 30 ° C. Adjust to. That is, when the reference cooling water temperature is 30 ° C., a current having a constant value a is applied to the Peltier element 1.
5 continuously. On the other hand, when the cooling water temperature is 20 ° C., ON / OFF control is performed in a pulsed manner so that 80 (ON state) vs. 20 (OFF state) in the time period S.
A current having a constant value a is supplied to the Peltier device 15 at a ratio of. In this way, the current of constant value a is turned on and off in a pulsed manner.
Since only FF control is performed, the maximum cooling output can be easily corrected. Thereby, even if the cooling water temperature T _N changes, a constant large cooling capacity can always be obtained. This is called the normalized maximum cooling output. The duty ratio associated with the cooling water temperature T _N derived from the graph shown in FIG. 7 is experimentally obtained in advance. The standard cooling water temperature T _N of 30 ° C.
It is the upper limit temperature of the cooling water supplied to No. 4 and is predetermined. When the upper limit temperature is reached, the Peltier element 1
The maximum heat absorption amount is the heat absorption amount Q per unit time when 5 is driven with the maximum capacity, that is, when the maximum current a that can be supplied is continuously supplied.

Steps 9 and 10: When the cooling of the substrate W is started, the controller 23 sequentially reads the plate temperature T _P of the cooling plate 5 measured by the plate temperature sensor 16 via the temperature controller 26. Controller 23
As shown in FIG. 6 (b), the plate temperature T _P is read by reading the plate temperature T _P at regular time intervals and comparing the temperature T _Pn of the previous measurement with the temperature T _{Pn + 1 of the present} measurement to determine the plate temperature T _P.
Has reached the peak of temperature rise. That is, if the temperature T _{Pn +1} measured this time is lower than the temperature T _Pn measured last time, it is determined that the plate temperature T _P has reached the temperature rising peak. Incidentally, it referred to as temperature T _Pn the elevated peak temperature T _H at the time when the direction of T _{Pn + 1} from the T _Pn becomes lower.

Step 11: When the plate temperature T _P of the cooling plate 5 reaches the temperature rising peak, the controller 23
Is the temperature rise peak temperature T from the first table memory 30.
The second set temperature T _S2 associated with _H is determined and read.

The first table memory 30 is, for example, as shown in FIG.
As shown in (b), the temperature difference ΔTa between the temperature rising peak temperature T _H and the first set temperature (target temperature) T _S1 and the first set temperature T _S1 associated with this temperature difference ΔTa. The temperature difference ΔTb from the second set temperature T _S2 is stored and is experimentally obtained in advance. The temperature difference ΔTa is determined by the initial temperature of the substrate W or the substrate size, and the temperature difference ΔTb depends on the temperature difference ΔTa when the plate temperature T _P and the substrate temperature T _W are the target temperatures (first set temperature). It is determined empirically so that the point of convergence to T _S1 ) (end of cooling t ₂ ) is matched. The difference in cooling (converging) time based on the suitability of the temperature of the second set temperature T _S2 will be described later.

[0041] Step 12: plate temperature T _P is determined whether reaches the second set temperature T _S2, when the plate temperature T _P has reached the second set temperature T _S2, the temperature control unit 26, the first set temperature T _S1 is set as the target temperature for PID control. That is, as shown in FIG. 6B, at the time t _S when the second set temperature is reached, the temperature control unit 26 finishes the cooling by the normalized maximum cooling output started in step 8, and the cooling is performed. PI is adjusted so that the plate temperature T _P of the plate 5 becomes the first set temperature T _S1.
The driving of the Peltier element 15 is started by the D control function.

Here, the temperature change when the substrate is cooled will be described with reference to the time chart of FIG. 6 (b).

When the substrate W before the cooling process is placed on the cooling plate 5 at the time t ₁ of cooling start, the substrate temperature T _W of the substrate _W is in a high temperature state (for example, 100 ° C. or higher), so that it is shown in FIG. As described above, the substrate temperature T _W begins to drop sharply by being absorbed by the cooling plate 5. On the other hand, since the heat transfer amount of the substrate W absorbed by the cooling plate 5 is higher than the heat transfer amount of the cooling plate 5 cooled by the Peltier element 15, the plate temperature of the cooling plate 5 is increased. T _P is pulled by the substrate W and temporarily rises. At this time, from the start of cooling t ₁ to the second set temperature T
Until the time point t _S at which _S2 is reached, the Peltier element 15 is driven very strongly with the normalized maximum cooling output, so that the rise of the plate temperature T _P pulled by the substrate W is suppressed. Therefore, the plate temperature T _P is quickly recovered, and the substrate temperature T _W is also cooled at a high speed.

Next, the difference in substrate cooling time between when the maximum cooling output is normalized and when it is not normalized will be described with reference to FIG. FIG. 9A is a time chart when the cooling is performed with the normalized maximum cooling output, FIG. 9B is a time chart when the cooling output is increased without being normalized, and FIG. 9C is a normalized chart. It is a time chart when the cooling output is reduced without being performed. In addition,
Here, it is assumed that the second set temperature TS2 does not change even if the temperature rise peak temperature TH changes.

As shown in FIG. 9A, when the maximum cooling output is normalized, at the end of cooling t ₂ , the plate temperature T _P and the substrate temperature T _W are mutually equal to the target temperature (the first temperature). Since the points of convergence to the set temperature T _S1 ) coincide, the temperature difference between the plate temperature T _P and the substrate temperature T _W is large until the target temperature is converged, and the substrate W can be cooled efficiently.

As shown in FIG. 9 (b), when low-temperature cooling water is supplied and the cooling output rises, the plate temperature T _P does not rise too much and reaches the second set temperature T _S2 early. become. Therefore, after the time ts, cooling is performed by the PID control aiming at the first set temperature TS1. That is, since the cooling by the normalized maximum cooling output ends early, the effect of shortening the cooling time by the maximum cooling output is small, and after starting the PID control targeting the first set temperature TS1, Since the plate temperature T _P is controlled to the first set temperature T _S1 , the plate temperature T _P and the substrate temperature T _{W at the} end of cooling
And the temperature difference between the substrate temperature T _{W and} the target temperature takes time to converge, and as a result, the time until the substrate temperature T _W reaches the target temperature (substrate cooling time t _E ) becomes long.

Meanwhile, as shown in FIG. 9 (c), the high-temperature coolant cooling power is supplied is decreased, plate temperature T heating peak T _H of _P becomes high, and the second set temperature T _The time t _S to reach _S2 is also delayed. Since the substrate W is sufficiently cooled during this period, the substrate temperature T _W falls below the target temperature along with the plate temperature T _P. As a result, the time until the substrate temperature T _W reaches the target temperature (substrate cooling time t _E ) becomes long.

As described above, when the maximum cooling output is not normalized, the substrate cooling time t _E becomes long due to the temperature fluctuation of the cooling water, and the cooling history of the substrate temperature T _W varies.

Next, the difference in the substrate cooling time based on the suitability of the setting of the second set temperature T _S2 will be described with reference to FIG. FIG. 10A is a time chart when the initial temperature of the substrate W and an appropriate second set temperature T _S2 according to the substrate size are set, and FIGS. 10B and 10C are appropriate second settings. This is an example when the temperature T _S2 is not set, and FIG.
10B is a time chart when the substrate W having a low initial temperature (or a small substrate size) is supplied, FIG.
In (c), the initial temperature is high (or the substrate size is large) when the appropriate second set temperature T _S2 is not set.
7 is a time chart when the substrate W is supplied. 10A and 10B, the same second set temperature T S2 as in the case of FIG. 10A is set.

[0050] As shown _in FIG. 10 (a), a suitable second
_Setting when the constant temperature TS2 is _set is _have your cooling at the end t2, the time to converge _to match _the plate temperature TP and the substrate temperature TW and each other target temperature (first set temperature TS1) And the plate temperature T is reached until the target temperature is reached.
Since the temperature difference between P and the substrate temperature TW is large, the substrate W can be cooled efficiently.

As shown in FIG. 10B, the same second _{setting is used.}
When cold substrate W at a constant temperature TS2 is placed _{on the} cooling plate 5, the plate temperature TP second early without significant Atsushi Nobori
Will reach the set temperature TS2. Therefore, after that, the PID control is performed to cool the first set temperature TS1. That is, since the cooling by the normalized maximum cooling output ends early, the effect of shortening the cooling time by the maximum cooling output is small.
_And After the PID control starts with the first set temperature _T S1 and the target, it means that the plate temperature TP is controlled _{to the} first set temperature TS1, the plate temperature TP and the substrate temperature TW which definitive _cooling end temperature difference Ri _of small, will _have on the time to convergence to the target temperature of the substrate temperature TW is, as a result the time until the substrate temperature TW reaches the target temperature (substrate cooling time tE) becomes longer.

Meanwhile, FIG. 10 (c), the same as the second _set temperature TS2 at high _temperature of the substrate W Ru _placed on the cooling plate 5, the plate _temperature TP of heating peak TH Becomes higher, and the time _t S for reaching the second set temperature _T S2 is also delayed. Since the substrate W is sufficiently cooled _during this, even the cormorants _or to well below the target temperature until the substrate temperature TW in accompanied _Tsu the plate temperature TP. As a result, the time until the substrate temperature TW reaches the target temperature (substrate cooling time tE) becomes long.

Therefore, in this embodiment, FIG. 10 (b ₎ and FIG.
0 urchin _I shown in (c) by a two-dot chain line, when cold of the substrate W, the lower the temperature increase peak _T H, the second set _temperature T'S2
By _setting lower in cooling end t2, to match the time in which the plate temperature T'P and the substrate temperature T'W converges to _goal temperature to each _other. On the other hand, If the temperature of the substrate W, the higher the temperature increase peak _T H, the second set _temperature T "S2
By increasing _configure, in cooling end t2, to match the time when the plate temperature T "P and the substrate temperature T" W converges to the target temperature with each other. Therefore, when processing a plurality of substrates W having different initial temperatures, the cooling time of the substrates W is irrelevant regardless of the initial temperature (or the substrate size) of each substrate by matching the time points at which the substrates converge to the target temperature. It becomes almost constant.

[0054] _returns to FIG. 6 (b), the plate temperature TP and reaches a suitable second set temperature TS2 in accordance with the heating peak temperature TH (time ts), with temperature control unit 26, the Peltier element 15 the first _set as _targets temperature to be PID control
The constant temperature TS1 is set. As a result, the plate _temperature T
Since P is PID controlled first set _temperature TS1 as the target, the substrate temperature TW is Ru _{are precision} be cooled without chilled _over too be below _the first set temperature TS1. At this time, in tS point, the temperature difference between the plate temperature TP and the substrate temperature _T W delta
Since T _S2 (for example, 0.5 _{° C.} ) is larger than the conventional temperature difference ΔTS1 (for example, 0.3 ° C. ₎ between the target temperature (first set temperature TS1) and the substrate temperature TW _, heat moves quickly. As a result, the substrate temperature TW also changes to the first set temperature T
You will reach S1 faster. Therefore, the substrate W can be cooled to the target temperature accurately and at high speed. Also,
When processing a plurality of substrates W, the cooling history between the substrates W becomes substantially constant. Therefore, for example, when the photoresist liquid is applied to the substrates W, the characteristics such as the photosensitivity may be different between the substrates W. There is no inconvenience such as non-uniformity.

Returning to the flow charts of FIGS. 4 and 5. Steps _14, 15, 16: Next, the controller 23
The substrate cooling time tE _{set in} advance to determine whether or not the time is up. The substrate cooling time tE is _board W
Taking into account the variations in the initial temperature of the set to a _small tooth long. When the substrate cooling time tE is up, at the cooling end time t2, the controller 23 issues a pin raising command to the substrate raising / lowering drive unit 28 to extend the substrate support pins 7 by extending the air cylinder 10. As a result, the substrate W is lifted above the cooling plate 5 and the cooling is completed. Then, the process returns to step 3 until the _next substrate W is placed on the cooling _plates 5, holds the plate temperature TP of the cooling plate 5 to the first set temperature TS1. _Is this
By repeating these operations, the plurality of substrates W are cooled to the first set temperature TS1, for example, room temperature of 20 ° C., and then transferred to the next processing step.

With the above configuration, the substrates W can be cooled at a high speed, and a plurality of substrates W can be efficiently cooled in the same cooling time (cooling history). As a result, the throughput of the substrate cooling device is improved and the throughput of the entire device is improved.

In the above embodiment, the Peltier element 15 is an electronic cooling element, the cooling water is a refrigerant, the heat radiating plate 14 is a heat radiating means, the heat transfer plate 11 is a substrate mounting member, and the cooling water temperature sensor 18 is a refrigerant temperature detecting means. , Plate temperature sensor 1
6, the control unit 22 corresponds to a control unit, the temperature control unit 26 corresponds to a drive control unit, and the second table memory 31 corresponds to a storage unit. Further, in the controller 23, the duty ratio reading function corresponds to the reading unit, and the placement detecting function corresponds to the placement detecting unit.

In the above embodiment, the Peltier element 15
Although the drive control element amount for controlling the current is the duty ratio of the current flowing to the Peltier element 15, other values, for example, the magnitude of the current may be used as the drive control element amount.

[0059] In the _above SL embodiment, before the substrate W is placed on the cooling plate 5, but is _controlled such that the first set temperature TS1, the present invention is not limited to being _this However, for example, the plate temperature TP is the first set temperature T
The temperature may be lower than S1. That is,
The cooling plate 5, by you _to configure so as to lower predetermined _temperature than the target temperature to be cooled to the substrate W, in the cooling _start of the substrate W, the temperature difference between the substrate temperature TW and the plate temperature TP is Larger, the substrate temperature TW is cooled faster toward a predetermined temperature below the target temperature.

In the above embodiment, the Peltier device 15 is set to P before the cooling of the substrate W is started and after the second set temperature TS2 is reached.
While driving in ID control, the present invention is not limited thereto, for example, also _good it intended to control _on-off
In short, the cooling plate 5 is attached to the plate temperature T
It suffices that the control drive is performed with those set temperatures as targets so that P becomes the first set temperature TS1.

Further, in the above-mentioned embodiment, it is detected whether or not the substrate W is carried onto the cooling plate 5 by discriminating the substrate sending-out signal from the transport control section 21, but the present invention is not limited to this. Not, for example,
The plate temperature sensor 16 may be used to detect whether the substrate W has been loaded onto the cooling plate 5 by comparing it with a predetermined set temperature. That is, when the substrate W is loaded, the cooling plate 5 also rises in temperature to some extent, and thus the loading may be detected.

In the above embodiment, the substrate W is placed on each of the proximity balls 8 on the cooling plate 5 so as to be placed close to the cooling plate 5, but the present invention is not limited to this. However, the substrate W may be directly placed on the cooling plate 5 without providing the proximity ball 8.

[0063]

As is apparent from the above description, according to the first aspect of the invention, the electronic cooling element is provided so that the heat absorption amount per unit time of the cooling means becomes a predetermined constant value according to the refrigerant temperature. Since the drive is controlled, even if the temperature of the cooling water fluctuates,
The substrate can be cooled under the same temperature condition, and the processing quality of the substrate can be stabilized.

According to the invention of claim 2, the device of claim 1 can be easily realized by so-called electronic control.

According to the third aspect of the present invention, since the drive control element amount of the electronic cooling / heating element corresponding to each refrigerant temperature is predetermined, the control of the electronic cooling / heating element can be performed quickly and easily.

According to the invention of claim 4, it is possible to extremely easily control the electronic cooling element in order to obtain a desired heat absorption amount.

According to the substrate cooling device of the fifth aspect, the cooling means has a maximum heat absorption amount per unit time within a range in which a constant cooling condition is not impaired even if the coolant temperature fluctuates. Thus, the substrate placed on the substrate placing means is also cooled at a high speed under constant conditions, the cooling history of the substrate can be kept constant, and the throughput of the apparatus can be improved.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view showing an embodiment of a substrate cooling device according to the present invention.

FIG. 2 is a plan view of a main part of FIG.

FIG. 3 is a block diagram.

FIG. 4 is a flowchart of a control operation.

FIG. 5 is a flowchart of control operation.

FIG. 6 is a time chart.

FIG. 7 is a diagram illustrating a second table memory.

FIG. 8 is a diagram illustrating a duty ratio of a current value.

FIG. 9 is a diagram illustrating a difference in substrate cooling time between when the maximum cooling output is normalized and when it is not normalized.

FIG. 10 is a diagram illustrating a difference in substrate cooling time based on suitability of setting of a second set temperature.

FIG. 11 is a schematic vertical sectional view of a conventional device.

FIG. 12 is a time chart of a conventional device.

[Explanation of symbols]

 2 ... Substrate cooling device 4 ... Processing chamber 5 ... Cooling plate 7 ... Substrate support pin 11 ... Heat transfer plate (substrate mounting member) 13 ... Air cylinder 14 ... Radiating plate (radiating means) 15 ... Peltier element (electronic cooling element) 16 ... Plate temperature sensor 18 ... Cooling water temperature sensor (refrigerant temperature detecting means) 20 ... Input section 21 ... Transport control section 22 ... Control section (control means) 23 ... Controller 24 ... First set temperature storage section 26 ... Temperature control section 27 ... Cooling drive unit 28 ... Substrate lift drive unit 30 ... First table memory 31 ... Second table memory (storage means) W ... Substrate

Claims (5)

[Claims] 1. A substrate mounting member is cooled by a cooling means including an electronic cooling / heating element and a heat radiating means for radiating heat of the electronic cooling / heating element by circulating a refrigerant, and the substrate is brought into contact with the substrate mounting member. In a substrate cooling device that cools the substrate by placing it on or in close proximity to it, in accordance with the coolant temperature detecting means for detecting the temperature of the coolant flowing through the heat radiating means, and the coolant temperature detected by the coolant temperature detecting means, A substrate cooling device comprising: a control unit that drives and controls the electronic cooling / heating element such that an amount of heat absorbed by the cooling unit per unit time with respect to the substrate mounting member becomes a predetermined constant value. 2. The control means stores a drive control element amount of the electronic cooling element for keeping a heat absorption amount per unit time of the cooling means at a predetermined constant value in response to a change in refrigerant temperature. Means, a reading means for reading the corresponding drive control element amount based on the refrigerant temperature detected by the refrigerant temperature detecting means, and drive control of the electronic cooling / heating element based on the drive control element amount read by the reading means. The substrate cooling apparatus according to claim 1, further comprising a drive control unit. 3. The substrate according to claim 2, wherein the storage means is a table memory that stores a plurality of refrigerant temperatures and a drive control element amount of the electronic cooling / heating element corresponding to each refrigerant temperature. Cooling system. 4. The substrate cooling apparatus according to claim 2, wherein the drive control element amount of the electronic cooling / heating element is a duty ratio of a current supplied to the electronic cooling / heating element. 5. A substrate mounting member is cooled by a cooling means comprising an electronic cooling element and a heat radiating means for radiating heat of the electronic cooling element by circulating a refrigerant, and the substrate is brought into contact with the substrate mounting member. In a substrate cooling device that cools the substrate by placing it on or in close proximity to it, a placement detecting unit that detects placement of the substrate on the substrate placing member, and a temperature of a coolant that flows to the heat radiating unit is detected. And a cooling means in the case where a refrigerant having a predetermined upper limit temperature, which is circulated to the heat radiating means, circulates the amount of heat absorbed by the cooling means per unit time with respect to the fluctuation of the refrigerant temperature. Based on the refrigerant temperature detected by the refrigerant temperature detection means, storage means for storing the drive control element amount of the electronic cooling element for equalizing the maximum heat absorption amount per unit time with respect to the substrate mounting member of Reading means for reading the corresponding drive control element amount, and driving the electronic cooling / heating element based on the drive control element amount read by the reading means when the substrate is placed on the substrate placing member. A substrate cooling apparatus comprising: a drive control unit for controlling.