JPH06283493A - Substrate cooling device - Google Patents

Abstract

PURPOSE:To cool a substrate treated at a high temperature accurately at a target temperature at high speed while improving the uniformity of in-plane temperature distribution after the cooling of the substrate. CONSTITUTION:Peltier elements 14... are mounted between a substrate base plate 10, in which a substrate is placed on a top face, and a coolant flowing type heat-exchanging means flowing a coolant so that one heat-exchanging surface is brought into contact with the substrate base plate 10 and the other heat-exchanging surface is brought into contact with the coolant flowing type heat-exchanging means. The driving of the Peltier elements 14... is controlled, the substrate is quenched at a cooling pre-stage while quenching is stopped at a cooling post-stage, and the substrate is cooled accurately at a target temperature to be cooled.

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,
A substrate cooling device for cooling a substrate such as a substrate for an optical disk to a target temperature near room temperature, which has been heated to a high temperature before and after a photoresist solution coating or developing process in a photolithography process, In order to cool the substrate with good in-plane uniformity, the substrate is placed on or close to the upper surface of the substrate placement plate for heat diffusion conduction, and the substrate is cooled through the substrate placement plate. Regarding a cooling device.

[0002]

2. Description of the Related Art The following is a conventional substrate cooling device. A. First Conventional Example As disclosed in Japanese Patent Laid-Open No. 59-48925, a substrate is placed on a cooling plate in which a pipe for passing a cooling liquid having a temperature lower than a desired cooling temperature is embedded, and the cooling plate is thermally diffused. The substrate is cooled as a substrate mounting plate for conduction. B. Second Conventional Example As disclosed in Japanese Utility Model Laid-Open No. 63-46840, the temperature is substantially the same as the desired cooling temperature on the lower surface of the substrate mounting plate on which the substrate is mounted and along the lower surface of the substrate mounting plate. The substrate is cooled by providing a discharge tank for discharging the constant temperature liquid.

[0003]

By the way, in the substrate cooling device, the heated substrates are received one after another and the cooling process is repeated. In the cooling process for each one of the substrates,
Immediately after mounting the substrate, the substrate mounting plate receives the heat from the high temperature substrate and is rapidly heated. After that, when the amount of heat absorbed by the cooling liquid becomes larger than the amount of heat from the substrate and the action of the heat absorption by the cooling liquid begins to overcome, the temperature starts to fall and finally the target cooling temperature is reached. Repeat the temperature cycle.

In order to improve the cooling processing speed under such a circumstance, the cycle of the temperature raising / lowering cycle is shortened, that is, the substrate is placed at the first stage of the temperature raising / lowering cycle immediately after placing the substrate. It is desirable to reduce the temperature rise of the substrate mounting plate by rapidly cooling the mounting plate. This is because when the temperature of the substrate mounting plate rises, the temperature difference between the substrate mounting plate and the substrate becomes small and the cooling rate of the substrate decreases.

Further, in order to improve the yield, in-plane uniformity of the substrate and uniformity of the processing temperature of each substrate are strictly required in the cooling process, and as a result, the target cooling temperature is not reached at the final stage of the temperature raising / lowering cycle. It is desired that the substrate be cooled accurately without excess and deficiency.

However, in any of the above-mentioned first and second conventional examples, it was difficult to cool the substrate rapidly and accurately.

That is, in the first conventional example, one substrate
Each time a wafer is received, the first stage of the heating / cooling cycle causes a large amount of refrigerant to flow rapidly, while the final stage of the heating / cooling cycle does not cool the substrate below the target cooling temperature. The flow rate of the refrigerant must be adjusted very quickly every time the cooling process is performed on each of the substrates, such as by suddenly stopping or narrowing down the flow rate, which necessitates extremely difficult flow rate control. Further, even if the flow rate control as described above can be performed, at the time when the flow of the refrigerant is stopped,
Due to the endothermic action of the refrigerant staying in the pipe embedded in the substrate mounting plate, the temperature lowering action of the substrate cannot be stopped instantaneously, and it was difficult to accurately cool the substrate to the target cooling temperature. .

On the other hand, in the second conventional example, it is possible to cool rapidly by increasing the circulation flow rate of the constant temperature liquid, but the temperature of the circulating constant temperature liquid is equal to or slightly lower than the cooling target temperature. It is the temperature, and it is only the first stage of the temperature raising / lowering cycle where the temperature difference is large that strong cooling can be achieved by circulating a large amount of constant temperature liquid, and at the final stage when the temperature of the substrate drops to near the cooling target temperature, Since the temperature difference between the substrate and the liquid becomes small, the cooling rate becomes slow, and it takes time to accurately cool the substrate to the target cooling temperature.

The present invention has been made in view of the above circumstances, and cools a high-temperature-processed substrate to a target temperature at high speed and accurately, and the in-plane temperature distribution after cooling and each substrate. It is an object of the present invention to improve the uniformity of processing temperature for each.

[0010]

In order to achieve the above-mentioned object, the present invention provides a substrate cooling apparatus for cooling a substrate by placing it on the upper surface or by closely placing it on the upper surface. A substrate mounting plate to be mounted closely, a cooling liquid flow type heat exchange means for circulating a cooling liquid, one heat exchange surface is in contact with the substrate mounting plate, and the other heat exchange surface is a cooling liquid flow type heat exchange means. It is composed of a Peltier device in contact with.

[0011]

According to the structure of the substrate cooling apparatus of the present invention, the temperature on the side in contact with the substrate mounting plate can be made lower than the temperature of the cooling liquid as the Peltier element is driven, and the heat of the conventional cooling liquid can be reduced. Compared to the case of absorbing heat from the substrate to cool it only by exchanging it, the substrate can be cooled more rapidly, and when the target temperature is approached, the drive of the Peltier element is controlled to freely control the degree of heat absorption from the substrate. By doing so, the temperature on the side in contact with the substrate mounting plate on which the substrate is mounted can be rapidly and accurately changed to the target temperature.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall vertical sectional view showing an embodiment of a substrate cooling device according to the present invention. A substrate cooling device 3 is provided in a lower part of a housing 2 and a substrate heating device 4 is provided above it.
Is provided.

The substrate cooling device 3 is provided with a cooling plate 6 in the processing chamber 5 and a substrate supporting pin 8 which can be moved up and down through a through hole 7 formed in the cooling plate 6. By loading and unloading the substrate W by the substrate transport robot (not shown) in the raised state, and by lowering the substrate support pin 8,
The substrate W can be placed and supported on the cooling plate 6. Although not shown, an air cylinder is interlocked with a support member 9 that integrally holds the substrate support pins 8 ...
The substrate support pins 8 are moved up and down by the expansion and contraction of the air cylinder.

As shown in the plan view of FIG. 2, the cooling plate 6 is a substrate mounting plate 10 made of aluminum on which the substrate W is mounted.
Cooling liquid circulation type heat exchange means configured to connect a first water supply pipe 11 and a first drain pipe 12 to a water cooling plate 13 of aluminum water cooling type, and a substrate mounting plate Between the water cooling plate 10 and the water cooling plate 13, one heat exchange surface
And a Peltier element 14 for rapid cooling interposed so that the other heat exchange surface is in contact with the water cooling plate 13. In the figure, reference numeral 15 indicates a temperature measuring resistance element which is embedded in the substrate mounting plate 10 and measures the temperature of the substrate mounting plate 10.

The Peltier elements 14 ... Are connected to a current controller 16 and the current controller 16 is connected to a microcomputer 17, and a temperature for outputting a temperature signal based on the temperature measured by the temperature measuring resistance element 15 is output. The detector body 18 is connected to the microcomputer 17.

In the microcomputer 17, after the substrate W is placed on the substrate placing plate 10, a rapid cooling signal is output until a high temperature is reached and a large current is passed through the Peltier elements 14 ... After the temperature is reached, a quenching stop signal is output to control so as to reduce the current flowing through the Peltier elements 14 ..., The substrate W is rapidly cooled in the first stage of cooling, and the target temperature is approached. At the final stage of cooling, the rapid cooling is stopped to accurately cool the substrate W to the target temperature, and control is performed so as not to cool the substrate W to a temperature lower than the target temperature. It is configured to be cooled to the target temperature.

A water-cooled aluminum sub-cooling plate 21 connected to the second water supply pipe 19 and the second drain pipe 20 is provided on the ceiling of the processing chamber 5, and the cooling plate 6 in the processing chamber 5 is provided. The temperature of the atmosphere inside the processing chamber 5 above the substrate W placed on it is cooled to the same temperature as the target temperature (for example, 20 ° C.) for cooling the substrate W by the cooling plate 6. Has been done.

The substrate heating device 4 comprises a heating plate 23 provided with a heating means such as a plate heater in the processing chamber 22. As in the substrate cooling device 3, the substrate support pins are moved up and down and transported. The substrate W is loaded and unloaded by a robot, and the loaded substrate W is placed on the heating plate 23 and heat-treated at a high temperature (for example, 150 ° C.).

In the above-described embodiment, when the sub-cooling plate 21 is provided on the ceiling side of the processing chamber 5, the substrate W which has been subjected to high temperature processing by the substrate heating device 4 is cooled by the substrate cooling device 3 to a target temperature such as room temperature. In addition, the ambient temperature in the processing chamber 5 is cooled to the target temperature by the sub-cooling plate 21, and while the substrate W is cooled to the target temperature by the cooling plate 6, a temperature gradient from the ambient temperature is not generated, and the substrate from the surroundings While cooling the substrate W at high speed without supplying heat to W,
Although it is configured to further improve the uniformity of the in-plane temperature distribution of the substrate W after the cooling, the present invention provides:
The sub-cooling plate 21 may not be provided.

In the above embodiment, the substrate W is placed directly on the cooling plate 6 to be supported, but for example, a plurality of bottomed holes having a predetermined depth are formed in the cooling plate 6, A ceramic ball having a diameter of several hundreds of microns, which is slightly larger than the depth of the hole, is fitted into this hole, so that the substrate W is placed on the ceramic ball and a predetermined minute gap is provided between the cooling plate 6 and the substrate W. The substrate W may be supported in a state of being closely mounted (not shown).

[0022]

As described above, according to the substrate cooling apparatus of the present invention, even if the substrate heated to a high temperature is frequently received and cooled by the drive control of the Peltier element, the cooling is not performed in the first stage of the cooling process. , It can be cooled to a lower temperature than the cooling liquid and can be cooled rapidly, and at the final stage of the cooling process, the substrate can be accurately cooled to the target temperature so that it does not exceed the target temperature and is cooled too much. The substrate can be cooled to the target temperature quickly and accurately, the processing speed is high, the processing temperature is uniform for each substrate, and the productivity can be improved.

In addition, since the substrate is not directly cooled by the Peltier device but is cooled through the substrate mounting plate, it is possible to improve the uniformity of the in-plane temperature distribution after cooling.

Further, since the heat radiation side of the Peltier element is cooled by the flow of the cooling liquid by the cooling liquid flow type heat exchange means, unlike the case of air cooling, the heat generated by the rotation of the air cooling fan accompanying the use of the air cooling device is generated. It is very useful for improving quality without generating dust and disturbing the surrounding air flow controlled to downflow in a clean room by an air-cooling fan.

[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 schematic plan view of a main part.

[Explanation of symbols]

 3 ... Substrate cooling device 10 ... Substrate mounting plate 11 ... First water supply pipe 12 ... Second drain pipe 13 ... Water cooling plate 14 ... Peltier element W ... Substrate

Claims (1)

[Claims] 1. A substrate cooling device for cooling a substrate by placing it on the upper surface or by closely placing it on a top surface, and a substrate mounting plate on which the substrate is placed on or by the proximity of a substrate, and a cooling liquid flower for circulating a cooling liquid. And a Peltier element having one heat exchange surface in contact with the substrate mounting plate and the other heat exchange surface in contact with the cooling liquid circulation type heat exchange means. apparatus.