JPH0724399A - Chemical treatment device - Google Patents

Abstract

PURPOSE:To feed chemical liquid by means of low energy and simultaneously cool drain liquid simply and securely by heat exchanging the chemical liquid to be fed into a chemical tank and the drain discharged out of the chemical tank in a device of immersing and treating a material to be treated in the chemical liquid in the chemical tank. CONSTITUTION:A pump 2 for feeding out chemical liquid and a liquid feeding- out tube 3 are disposed in a chemical tank 1 for storing the chemical liquid. On the other hand, a heat exchanger 8 is disposed in a wafer treatment device (chemical treatment device) 4 together with a chemical tank 5 for treating chemicals, a heater 6 and a drain tube 7. In the heat exchanger 8, heat exchange is carried out between the chemical liquid to be fed into the chemical tank 5 and the drain discharged out of the chemical tank 5. That is, the temperature of the chemical liquid to be fed into the chemical tank 5 is raised by the heat exchange with the chemicals, while the temperature of the drain is lowered simultaneously. The viscosity of chemical liquid is lowered by the arrangement and feeding of chemicals is carried out by means of low energy, and simultaneously drain is cooled simply and securely without the necessity of a special cooling device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical processing apparatus used for wafer processing in the manufacture of semiconductor devices.

In recent years, semiconductor devices have been highly integrated, but on the other hand, the price is remarkably reduced, and it is necessary to manufacture them at low cost. Moreover, energy saving is required not only for cost reduction but also for environmental protection.

[0003]

2. Description of the Related Art In a conventional chemical processing apparatus, the chemical solution to be used is stored in a chemical tank inside the apparatus, and when the wafer is heated by a heater to a constant temperature, the wafer is immersed in the chemical solution in the chemical tank for processing. Was going on. In this case, if the purity of the chemical liquid in the chemical tank deteriorates, the chemical liquid was discharged from the tank and a new chemical liquid was supplied.

However, since the chemical solution to be supplied is supplied at room temperature, the resistance in the pipe is large for the chemical solution having high viscosity, and it took a considerable time to store the required quantity of the chemical solution in the chemical tank. In addition, in order to discharge the chemical liquid with reduced purity,
Since the chemical liquid is at a high temperature, if it is discharged as it is, the drain pipe etc. may be deformed by heat, so it had to be discharged once via the cooling water tank.

[0005]

In the conventional chemical treatment equipment, a large-capacity pump is required to feed a highly viscous chemical liquid, and a cooling device for lowering the temperature of the chemical liquid to be discharged is provided. I had to attach it.

It is an object of the present invention to supply chemicals to a chemical treatment apparatus with low energy and at the same time cool the discharge of chemicals to reduce the required energy such as electric power.

[0007]

[Means for Solving the Problems] A solution to the above problems is a chemical treatment apparatus for dipping an object to be treated in a chemical solution filled in a chemical tank 5 to perform treatment. When,
This is achieved by a chemical treatment device having a heat exchanger 8 for exchanging heat with the waste liquid discharged from the chemical tank.

[0008]

In the present invention, the thermal energy of the high temperature discharged chemical liquid is applied to the supplied chemical liquid by the heat exchanger so that the thermal energy can be closed.

FIG. 1 illustrates the principle of the present invention. In the figure, 1 is a chemical tank for storing a chemical solution, 2 is a pump for delivering the chemical solution, 3 is a liquid supply pipe, 4 is a wafer processing apparatus (chemical processing apparatus), 5 is a chemical tank for chemical processing, 6 is a heater, 7 is a drain pipe, and 8 is a heat exchanger.

The temperature of the chemical liquid supplied to the chemical tank 5 is heated by heat exchange with the waste liquid by the heat exchanger 8, and at the same time, the temperature of the waste liquid is lowered. Therefore, equipment costs such as a cooling device for cooling the drainage and utility costs such as electric power can be reduced.

As a conventional example similar to the present invention, there is also an example ¹⁾ in which the gas supplied to the processing furnace is heated by the exhaust gas of the processing furnace to save energy, but in this case, the exhaust gas is cooled. In contrast to this, the present invention is intended for both the heating of the supply liquid and the cooling of the discharge liquid because the object of heat exchange is the liquid, and in particular, it was conventionally necessary to cool the discharge liquid. It has the effect of eliminating the need for a cooling device.

1) See Japanese Patent Laid-Open No. 04-44314

[0013]

FIG. 2 is a block diagram of an embodiment of the present invention. In this embodiment, a wafer processing apparatus will be described as an example of the chemical processing apparatus.

In the figure, a chemical tank in the wafer processing apparatus 4 is shown.
The chemical liquid is supplied from the chemical tank 1 to the liquid 5 through the liquid feed pipe 3 after being filtered by the filter 9. The level sensor 14 detects the amount of chemical liquid in the chemical tank 5, and if it reaches a certain amount, the controller
With 10, the pump 2 and solenoid valve 11a are controlled to stop the supply.

The chemical liquid stored in the chemical tank 5 is heated by the heater 6, the temperature is detected by the temperature sensor 12a, and the controller 10 controls the temperature to a constant temperature. The chemical solution after wafer processing is discharged through the drain pipe 7 by opening the solenoid valve 11c by the controller 10. At that time, the drainage temperature is lowered by passing through the heat exchanger 8 and at the same time, a new chemical tank 1 is added.
The chemical solution supplied from is heated.

When the heat exchanger 8 has some abnormality and the drainage is discharged at a high temperature, the temperature sensor 12b detects the drainage temperature, the solenoid valve 11b is opened, and the cooling water in the emergency cooling device 13 is opened. The temperature of the drainage is lowered by flowing the so that the temperature of the drainage at the drainage outlet does not affect the piping in the subsequent stage.

Next, a specific example of the heat exchanger 8 will be described. 3 (A) and 3 (B) are sectional views of the heat exchanger used in the examples. FIG. 3 (A) shows a system in which the heat of the drainage is jointly heated via a heat medium such as water. In this case, in order to increase the efficiency of heat exchange and to increase the heat transfer area of the passages for the supplied chemical liquid and the drainage liquid, a large number of thin tubes are connected in parallel.

FIG. 3B shows a structure for heating the supplied chemical liquid by using the waste liquid as a heat medium. Also in this case, the supply chemical solution passes through a path in which a large number of thin tubes are connected in parallel. The material of the above thin tube differs depending on the chemical solution, but for example, Teflon-based PFA tube is used.

[0019]

According to the present invention, by exchanging heat between the chemical liquid supplied to the chemical treatment apparatus and the waste liquid at a temperature higher than room temperature, the viscosity of the chemical liquid supplied can be lowered and the chemical liquid can be supplied with low energy. At the same time, it became possible to cool the drainage liquid that became hot, and the required energy such as electric power could be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the heat exchanger used in the example.

[Explanation of symbols]

 1 Chemical tank for storing chemical solution 2 Pump for discharging chemical solution 3 Liquid supply pipe 4 Wafer processing equipment (chemical processing equipment) 5 Chemical tank for chemical processing 6 Heater 7 Drain pipe 8 Heat exchanger 9 Filter 10 Controller 11a, 11b , 11c Solenoid valve 12ap 12b Temperature sensor 13 Emergency cooling device 14 Level sensor

Claims (1)

[Claims] 1. A chemical treatment apparatus for performing treatment by immersing an object to be treated in a chemical liquid filled in a chemical bath (5), the chemical liquid being supplied to the chemical bath (5), and the chemical bath. A chemical treatment apparatus having a heat exchanger (8) for exchanging heat with the discharged waste liquid.