JPH0969508A - Board processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the processing liquid at an appropriate temperature at low cost. SOLUTION: An ultrasonic oscillator 22 is driven to heat a processing liquid 40 with ultrasonic energy. When temperature sensor 18 detects the temperature of processing liquid higher than (a target temperature + an error range), an on/off valve 33 is opened to feed a large quantity of propagation water to a propagation water tank 20 through a second flow rate regulation valve 32 thus cooling the processing liquid 40. When the temperature of processing liquid 40 drops below the target level, the on/off valve 33 is closed to interrupt propagation water supply through the second flow rate regulation valve 32. The propagation water is fed only through a first to flow rate regulation valve 31 and the propagation water supply to the propagation water tank 20 is reduced. Consequently, the temperature of processing liquid 40 is regulated substantially to a target level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for performing processing such as cleaning using ultrasonic vibration on a substrate immersed in a processing solution in a processing bath.

[0002]

2. Description of the Related Art As a conventional substrate processing apparatus, there is known one in which a substrate is placed in a processing bath containing a processing liquid and the substrate is immersed in the processing bath.

Although there are various types of substrate processing apparatuses that perform various types of processing, a cleaning apparatus will be described below. In such a cleaning apparatus, the processing tank containing the processing liquid for cleaning the substrate is immersed in the propagation water storage tank filled with propagation water. An ultrasonic transducer is provided on the back surface of the bottom of the propagation water storage tank, and ultrasonic energy is applied to the substrate in the processing tank via the propagation water and the processing liquid. Thus, by applying ultrasonic energy to the substrate, the cleaning effect can be enhanced.

In such a cleaning apparatus, when ultrasonic energy is applied to the substrate by the ultrasonic vibrator, the ultrasonic energy acts on the processing liquid to heat the processing liquid. Since the temperature of the treatment liquid was set to a relatively high temperature (for example, 60 ° C. or higher), it was not necessary to consider the amount of heat given by the ultrasonic energy to the treatment liquid.

However, in recent years, in order to reduce the cost of the heat treatment of the cleaning device and to improve its safety, and when the substrate is processed at a high temperature, the surface of the substrate becomes rough and the quality of the substrate deteriorates. The need to turn it into When the treatment liquid is kept at a low temperature in this way, the amount of heat that ultrasonic energy gives to the treatment liquid cannot be ignored, so
It is necessary to cool the processing liquid.

FIG. 2 is a diagram for explaining a conventional cleaning device provided with a cooling device for the processing liquid. Processing tank 10
Is filled with a processing liquid 40 for performing a cleaning process on the substrate. This treatment tank 10 is immersed in a propagation water storage tank 20 filled with propagation water 50. A treatment liquid ultrasonic transducer 22 for applying ultrasonic energy to the substrate is provided on the bottom surface of the propagation water storage tank 20. Here, the treatment liquid 40 in the treatment tank 10 is once discharged to the outside of the treatment tank 10, and again passes through the pump 12, the electronic heating / cooling elements 13 and 13 formed of Peltier elements, and the filter 14 and again.
It is circulated by being introduced into 0. At this time, the processing liquid 4
Zero is cooled or heated by the electronic cooling elements 13 during the circulation. The electronic cooling / heating elements 13, 13 are controlled so that the processing liquid 40 reaches the target temperature based on the output of the temperature sensor 18 arranged in the processing tank 10.

[0007]

However, in the device as shown in FIG. 2, the electronic cooling / heating element 13 is generally expensive, which causes a rise in the device cost. In particular, in such an application, in order to cool the treatment liquid 40 heated by the ultrasonic transducer 22 to the target temperature, the cooling capacity of the single electronic cooling / heating element 13 is often insufficient. There were often times when I had no choice but to use it. Therefore, there is a problem in that the cooling device portion for the processing liquid 40 is very expensive.

Therefore, an object of the present invention is to provide a substrate processing apparatus capable of setting a processing liquid such as a processing liquid at an appropriate temperature at low cost.

[0009]

In order to solve the above problems, a substrate processing apparatus according to a first aspect of the present invention is in contact with a processing bath containing a processing liquid for performing a predetermined process on a substrate, and a part of the processing bath. A fluid storage means for containing a fluid, an ultrasonic transducer provided in the fluid storage means for applying ultrasonic waves to a substrate in the processing bath via the fluid, and a temperature detection means for detecting the temperature of the processing liquid in the processing bath , Controlling the fluid supply means based on the output of the temperature detecting means and the fluid supply means for supplying the fluid of the predetermined temperature to the fluid storage means, and controlling the flow rate of the fluid of the predetermined temperature supplied from the fluid supply means to the fluid storage means. And a control means for controlling.

In the substrate processing apparatus according to the second aspect of the present invention, the control means controls the flow rate of the fluid supplied from the fluid supply means to the fluid storage means in two stages.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram illustrating a substrate cleaning apparatus according to an embodiment of the present invention. The processing tank 10 made of quartz or the like is filled with a processing liquid 40 for cleaning a substrate such as a semiconductor wafer. In this processing tank 10,
A substrate support mechanism (not shown) is arranged, and this substrate support mechanism holds a plurality of substrates immersed in the processing bath 10 for cleaning in an organized state.
The processing liquid 40 overflowing from the partition wall 11 provided in the processing tank 10.
Is led out of the processing tank 10 and is a pump 12 that is a circulation system.
And is introduced again into the processing tank 10 via the filter 14,
It is uniformly discharged from the processing liquid discharger 16. A temperature sensor 18, which is a temperature detecting means, and a heater 19 are immersed in the processing tank 10, and a control circuit (not shown) connected to them is based on the output of the temperature sensor 18. When it is determined that the temperature of the treatment liquid 40 in the treatment tank 10 is lower than the target temperature range, the heater 19 is energized to heat the treatment liquid 40, and the temperature of the treatment liquid 40 is quickly raised to the target temperature range. . The heater 19 may be provided between the filter 14 and the pump 12. Here, the target temperature range refers to a temperature range in which an allowable error range with respect to the target temperature is adjusted.

The entire processing tank 10 is immersed in a propagation water storage tank 20 which is a fluid storage means filled with propagation water 50 which is a fluid for propagating ultrasonic vibrations. An ultrasonic transducer 22 is provided on the back surface of the bottom of the propagation water storage tank 20, and ultrasonic energy is applied to the substrate in the processing tank 10 via the propagation water 50 and the processing liquid 40.

In this propagation water storage tank 20, a temperature control device 30, a first flow rate control valve 31, and a second flow rate control valve 3 are provided.
2. Propagated water is supplied via the propagated water supply means including the open / close valve 33 and the like. A part of the propagating water storage tank 20 to which the propagating water is supplied is partitioned by a partition wall 24, and the propagating water 50 overflowing from the upper end of the partition wall 24 is drained to the outside of the propagating water storage tank 20. The propagation water 50 in the water storage tank 20 is kept at a constant water level.

The first flow rate control valve 31 constituting the propagating water supply means prevents the ultrasonic transducer 22 from being damaged by the heat generated by itself, and the treatment liquid 40 scattered from the treatment tank 10 is prevented. Ultrasonic transducer 2 mixed with propagating water 50
In order to prevent the corrosion of the water 2, a relatively small amount of the propagation water 50 is constantly circulated. Further, the second flow rate control valve 32 lowers the temperature of the propagation water 50 in the propagation water storage tank 20 when the temperature of the treatment liquid 40 in the treatment tank 10 exceeds the target temperature range, and the propagation water storage tank 20 In order to lower the temperature of the treatment liquid 40 to the target temperature range via the propagating water 50 inside,
This is for supplying a relatively large amount of the propagation water 50 into the propagation water storage tank 20. The opening / closing valve 33 arranged in series with the second flow rate adjusting valve 32 is an air valve and is opened / closed by a control circuit (not shown). Note that this control circuit monitors the output of the temperature sensor 18, and when it detects that the temperature of the processing liquid 40 in the processing tank 20 is higher than the target temperature range, it opens the open / close valve 33. Thus, the propagating water 50 is supplied into the propagating water storage tank 20 via the second flow rate adjusting valve 32 to lower the temperature of the propagating water 50 in the propagating water storage tank 20 to reduce the temperature of the treatment liquid 40 in the treatment tank 10. Reduce the temperature to the target value. On the other hand, when it is detected that the temperature of the treatment liquid 40 in the treatment tank 10 is lower than the target value, the opening / closing valve 33 is closed to supply the propagation water 50 through the second flow rate adjusting valve 32. Then, the cooling by the propagation water 50 in the propagation water storage tank 20 is stopped. At this time, the heater 19 can be operated to quickly raise the treatment liquid 40 to the target temperature.

The temperature control device 30 heats the propagating water 50 such as pure water supplied at a relatively low temperature to a predetermined temperature so that the propagating water 50 supplied to the propagating water storage tank 20 does not become extremely low temperature. To do. That is, the temperature of the propagating water 50 set by the temperature adjusting device 30 should not be higher than the target temperature range of the treatment liquid 40 in the treatment tank 10, but originally there is no particular lower limit. However, in the specific example, the temperature of the propagation water set by the temperature control device 30 is set to a temperature obtained by subtracting the error range from the target temperature of the processing liquid 40 in the processing tank 10. The target temperature and the error range are determined by the processing liquid and the processing method used.

For example, there is a process called SC-1 cleaning.
The SC-1 cleaning is performed by filling the treatment tank 10 with a mixed solution of an aqueous ammonia solution, hydrogen peroxide solution, and pure water (the treatment solution 40 composed of this mixture solution is referred to as ammonia-hydrogen peroxide mixture) at 20 to 40 ° C. In this process, the substrate is immersed in ammonia-hydrogen peroxide mixture in the treatment tank 10 to remove contaminants on the substrate surface.
When it is desired to keep the ammonia-hydrogen peroxide mixture, which is the treatment liquid 40, at the target temperature 30 ° C. error range ± 1 ° C. in this SC-1 cleaning,
For example, the temperature of the propagating water 50 set by the temperature control device 30 is set to 27 ° C., and the opening / closing valve 33 is opened / closed so that the propagating water 50 in the propagating water storage tank 20 falls within the range of 30 ° C. ± 1 ° C. Adjust. At this time, the first flow control valve 3
1 is adjusted in advance to a supply amount such that the propagated water 50 constantly supplied to the propagated water storage tank 20 does not become excessive and the treatment liquid 40 in the treatment tank 10 does not become a supercooled state. Also, the second
The flow rate of the flow rate adjusting valve 32 is adjusted to be higher than the flow rate of the first flow rate adjusting valve in order to quickly cool the processing liquid 40.

The operation of the apparatus shown in FIG. 1 will be described below. First, while the propagation water storage tank 20 is filled with the propagation water 50 having the target temperature, the treatment liquid 40 having a temperature such that the temperature reaches the target temperature when the treatment water 10 is introduced is introduced. And
Start processing the substrate. At this time, the opening / closing valve 33 is closed and a small amount of the propagation water 50 is supplied to the propagation water storage tank 20 through the first flow rate adjusting valve 31.

When the ultrasonic oscillator 22 is driven in accordance with the processing of the substrate, the ultrasonic wave energy heats the processing liquid 40. The control circuit not shown is the temperature sensor 1
When it is detected that the temperature of the treatment liquid 40 is higher than (target temperature + error range) based on the output of 8, the opening / closing valve 33 is opened and a large amount of the propagating water 50 is passed through the second flow rate adjusting valve 32. It is supplied to the propagation water storage tank 20. As a result, the treatment liquid 40 in the treatment tank 10 becomes the surrounding propagation water 5
It is cooled rapidly by radiating heat to zero.

On the other hand, when the processing liquid becomes lower than the temperature of (target temperature-error range) because the substrate is frequently taken in and out of the processing tank 10, the control circuit (not shown) causes the open / close valve 33 to be closed. Is closed, the supply of the propagation water 50 through the second flow rate adjusting valve 32 is stopped, and the propagation water 50 is supplied only from the first flow rate adjusting valve 31 to supply the propagation water 50 to the propagation water storage tank 20. Reduce the amount. As a result, the cooling of the treatment liquid 40 in the treatment tank 10 by the propagation water 50 is stopped. In this case, the heater 19
Is operated to rapidly heat the treatment liquid 40 until it reaches the target temperature. In this way, the temperature of the treatment liquid 40 is adjusted within the target temperature range. At this time, since the electronic cooling element is not used, the cooling device for cooling the processing liquid 40 can be made relatively inexpensive, and the processing liquid 40 can be cooled only by adjusting the flow rate of the second flow rate adjusting valve 32. The capacity can be adjusted to a desired value as appropriate.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. For example, an electronic cooling element using the Peltier effect may be arranged between the pump 12 and the filter 14. In this case, the relatively expensive electronic cooling element makes the cooling device for the processing liquid 40 relatively expensive,
Due to the synergistic effect of the second flow rate control valve 32, the opening / closing valve 33, etc., the temperature of the processing liquid 40 in the processing tank 10 can be adjusted more precisely.

[0022]

As is apparent from the above description, according to the substrate processing apparatus of the first aspect, the control means controls the fluid supply means on the basis of the output of the temperature detection means, so that the fluid supply means is controlled. Since the flow rate of the fluid having the predetermined temperature supplied to the fluid storage means is controlled, the temperature of the processing liquid in the processing tank can be adjusted easily and inexpensively.

Further, according to the substrate processing apparatus of the second aspect, the control means controls the flow rate of the fluid supplied from the fluid supply means to the fluid storage means in two steps, so that the temperature adjustment is easy. Become.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the structure of a substrate cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view illustrating the structure of a conventional substrate cleaning apparatus.

[Explanation of symbols]

 10 Treatment Tank 12 Pump 14 Filter 18 Temperature Sensor 19 Heater 20 Propagated Water Storage Tank 22 Ultrasonic Transducer 30 Temperature Control Device 33 Open / Close Valve 40 Treatment Liquid 50 Propagated Water

Claims (2)

[Claims] 1. A processing tank for containing a processing liquid for performing a predetermined process on a substrate, a fluid storage means for storing a fluid in contact with a part of the processing tank, and a fluid storage means provided in the fluid storage means for storing the fluid. An ultrasonic transducer that applies ultrasonic waves to the substrate in the processing tank via the temperature detecting means for detecting the temperature of the processing liquid in the processing tank, and a fluid supply for supplying a fluid of a predetermined temperature to the fluid storage means. And a control unit that controls the fluid supply unit based on the output of the temperature detection unit and controls the flow rate of the fluid at the predetermined temperature supplied from the fluid supply unit to the fluid storage unit. A substrate processing apparatus characterized by the above. 2. The substrate processing apparatus according to claim 1, wherein the control unit controls the flow rate of the fluid supplied from the fluid supply unit to the fluid storage unit in two stages.