JPH03237717A - Washer for semiconductor substrate - Google Patents

Abstract

PURPOSE:To keep the resistivity value (water quality) of water in an inner water tank constant, and to hold the washing effect of a silicon substrate constant by installing a water-quantity controller with a resistivity meter and a water-quantity control circuit to a silicon-substrate washer. CONSTITUTION:The quantity of water is adjusted by a water-quantity controller 10 from a water supply piping 5, and an inner water tank 2 is supplied with water. Foreign matters on a silicon substrate 1 in the inner water tank are washed away by water. Since foreign matters are increased and a resistivity value (water quality) in the inner water tank is lowered when the water stays in the inner water tank, water is fed continuously and made to overflow from the inner water tank to an outer water tank 3, and drained through a drain piping 6. When the numeric value of a resistance detecting section 9 in the inner water tank 2 is varied at that time, a water quantity control circuit 11 transmits a signal over the water-quantity controller 10, and the feed of water into the inner water tank is adjusted. Accordingly, the resistivity value of water in the inner water tank 2, into which the silicon substrate 1 is introduced, is adjusted by the water-quantity controller 10 through the water-quantity control circuit 11, thus keeping water quality in the inner water tank constant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor substrate cleaning apparatus that controls water quality by controlling the amount of water in a semiconductor device manufacturing process, particularly in a silicon substrate cleaning process.

BACKGROUND OF THE INVENTION Conventionally, high-quality water has been used to clean silicon substrates in the manufacturing process of semiconductor devices.

The configuration of a conventional silicon substrate cleaning apparatus will be explained with reference to FIG.

1 is a silicon substrate, 2 is an inner water tank, 3 is an outer water tank, 4 is a resistivity meter, 5 is a water supply pipe, 6 is a drainage pipe, 7 is a valve, and 8 is a flow meter.

First, from the water supply pipe 5 to the inner water tank 2 containing the silicon substrate 1.
Water is supplied to the tank, overflows into the external water tank 3, and is discharged through the drainage pipe 6. By continuing this series of operations, foreign matter on the silicon substrate is washed away by the water stream. The water quality in the inner water tank 2 is managed by measuring its resistivity value with a resistivity meter 4 to prevent a decrease in cleaning effectiveness due to deterioration in water quality.

Note that 7 is a valve that adjusts the amount of water, 8 is a flow meter that indicates the water flow rate, and 9 is a resistivity measuring section.

Problems to be Solved by the Invention However, in the above conventional configuration, the specific resistance value of the inner water tank
Water quality> was only displayed, so even if the water quality fluctuated and decreased, there was a possibility that silicon substrates would continue to be cleaned, reducing the cleaning effect and reducing the yield rate of good semiconductor devices. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor substrate cleaning apparatus that can solve the above-mentioned conventional problems.

Means for Solving the Problems In order to achieve this object, the semiconductor substrate cleaning apparatus of the present invention includes a resistivity meter for measuring water quality and a water flow control device having a water flow control circuit.

Operation With this configuration, the value of the resistivity meter in the inner water tank is input to the water flow control circuit, and a control signal corresponding to the input value is output to the water flow control device so as to adjust the water supply amount.

If the specific resistance value (water quality) in the inner tank decreases, the water quality can be restored by increasing the amount of water supplied.

As a result, the specific resistance value (water quality) in the inner water tank is set to - constant,
To prevent fluctuations in the silicon substrate cleaning effect due to deterioration in water quality.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a semiconductor substrate cleaning apparatus according to an embodiment of the present invention.

In Fig. 1, 1 is a silicon substrate, 2 is an inner water tank, and 3 is a silicon substrate.
4 is a resistivity meter, 5 is a water supply pipe, 6 is a drainage pipe, 7 is a valve, 8 is a flow meter, 9 is a resistance detection section, 10 is a water flow control device, and 11 is a water flow control circuit.

Next, the operation of the silicon substrate cleaning apparatus of this embodiment will be explained.

First, the amount of water is adjusted by the water amount control device 10 from the water supply pipe 5 and then supplied to the inner water tank 2. Foreign matter on the silicon substrate 1 in the inner water tank is washed away by water. When that water stagnates in the inner tank, foreign matter increases, and the specific resistance value in the inner tank (
Since the water quality (water quality) decreases, water is continuously supplied to overflow from the inner water tank to the outer water tank 3, and is drained through the drainage pipe 6. At that time, when the value of the resistance detection section 9 in the inner water tank 2 changes, the water amount control circuit 11 sends a signal to the water amount adjustment device 10 to adjust the amount of water supplied to the inner water tank.

According to this embodiment, the specific resistance value of the water in the inner water tank 2 containing the silicon substrate 1 is adjusted by the water flow control device 10 via the water flow control circuit 11. The value (water quality) can be kept constant.

If the specific resistance value (water quality) in the inner water tank 2 decreases, the specific resistance value (water quality) can be restored by increasing the amount of water.

Effects of the Invention According to the present invention, by providing a silicon substrate cleaning apparatus with a resistivity meter and a water flow control device having a water flow control circuit,
It is possible to realize an excellent semiconductor substrate cleaning apparatus that can maintain a constant specific resistance value (water quality) of water in an internal water tank and can maintain a constant silicon substrate cleaning effect.

Specific resistance detection unit, 10...Water flow control device, 11.
...Water flow control circuit.

Claims (1)

[Claims] A semiconductor substrate cleaning device equipped with a resistivity meter for measuring water quality and a water flow rate control device with a water flow rate control circuit.