JP2000331972A - Cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a semiconductor product by efficiently removing foreign materials adhering to an object to be cleaned, such as the belt, etc., and preventing the occurrence of the problem of foreign materials re-adhere to the cleaned object. SOLUTION: A cleaning device 20 is provided with a tank main body 21 which can contain a cleaning solution and a conveyance belt 1, an ultrasonic wave oscillating means 22 which gives vibrations to the belt 1, and supplying means 23 and 24 which supply the cleaning solution to the tank main body 21. The device 20 is also provided with a discharging means 25, which discharges the cleaning solution S in the tank main body 21, a soil detecting means 26 which detects the degree of soiling of the cleaning solution S, and a control means 27 which controls the oscillation of the oscillating means 22 and the supply of the cleaning solution S by means of the supplying means 23 and 24 based on the detected results of the soil detecting means 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technology of a cleaning apparatus using ultrasonic waves. More specifically, the present invention relates to a cleaning apparatus that is effective as a technique for cleaning a transport belt or the like that transports a semiconductor wafer in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor device, for example, in a process of forming a film, first, it is necessary to transfer a wafer on a transfer belt to a film forming section in a semiconductor device manufacturing apparatus for forming a film. .

In the process of transporting the wafer, foreign matters adhere to the transport belt due to various factors, and there is a problem that the foreign matters adhere to the wafer. Therefore, it is necessary to take measures to effectively remove the foreign substances.

As a method for removing the foreign matter, there is a technique described in, for example, JP-A-10-284571. This technology is used in a semiconductor manufacturing apparatus that places a semiconductor wafer on a circulating transport belt and transports the semiconductor wafer to a predetermined processing unit. Ultrasonic means for peeling off from the conveyor belt by sound waves, and magnet means for attracting and collecting a foreign matter which is separated and floats in the liquid or exists on the liquid surface by magnetic force are provided.

[0005]

However, in the case of the technology described in this publication, although the metallic foreign matter to be magnetized can be effectively removed, it is not very effective in removing other foreign matter. As a reason, even if the metallic foreign matter floating in the liquid or on the liquid surface is suctioned and removed by the magnet means, other foreign matter remains in the liquid or on the liquid surface,
There is a problem that the remaining foreign matter re-adheres to the transport belt.

As another foreign substance, when the semiconductor manufacturing apparatus is an apparatus for forming a film on a wafer, there is a generated film which adheres to the transport belt at the same time in the film forming process. The resulting film on the belt is also usually washed with an ultrasonic cleaning device.

[0007] However, this type of conventional ultrasonic cleaning apparatus has a constant cleaning capability and is in a low-capacity and poor circulation state. Therefore, it is transported again with the generated film attached, and foreign substances adhere to the wafer. There was a problem.

Further, when the film pressure of the formed film formed on the belt increases or when the use time becomes longer,
Corrosion occurs due to reattachment of the generated film and poor circulation in the tank containing the cleaning liquid, and problems have arisen in terms of ensuring the quality of semiconductor products.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and is configured so that an ultrasonic wave transmitting means and a cleaning liquid supply means of a cleaning apparatus can be automatically controlled in accordance with a cleaning result, thereby cleaning a belt or the like. It is an object of the present invention to provide a cleaning apparatus capable of improving the quality of a semiconductor product by removing foreign matter adhering to a body efficiently and eliminating the problem of reattachment after the removal.

[0010]

In order to achieve the above object, according to the present invention, there is provided a tank body capable of storing a cleaning liquid and an object to be cleaned, and an ultrasonic oscillator for applying vibration to the object to be cleaned in the tank body. Supply means for supplying the cleaning liquid into the tank body, discharging means for discharging the cleaning liquid in the tank body, dirt detection means for detecting the degree of dirt of the cleaning liquid, and based on the detection result of the dirt detection means, A control unit for controlling the oscillation number of the ultrasonic oscillation unit and controlling the supply of the cleaning liquid by the supply unit is provided.

According to this configuration, the ultrasonic wave transmitting means and the cleaning liquid supply means of the cleaning apparatus can be automatically controlled in accordance with the cleaning result by the dirt detecting means and the control device for detecting the degree of dirt of the cleaning liquid. Become. This makes it possible to obtain the number of ultrasonic oscillations and the supply amount of the cleaning liquid under optimum cleaning conditions according to the contamination of the cleaning liquid in the tank body. As a result, it is possible to efficiently remove foreign substances attached to the object to be cleaned such as a belt and eliminate the problem of reattachment after the removal, thereby improving the quality of semiconductor products.

In a preferred configuration example, the ultrasonic oscillation means may have a plurality of oscillation units, and the control means may have a function of changing the number of oscillation units to change the number of oscillations.

With this arrangement, a plurality of oscillating units are arranged over the entire area of the object to be cleaned, so that efficient cleaning can be performed. In addition, the number of oscillations and power can be easily adjusted. From this point, the cleaning efficiency can be improved.

In a further preferred configuration, the cleaning liquid discharging means is set so as to discharge when the cleaning liquid in the tank body exceeds a certain amount.

In this way, it is possible to suppress the waste of the cleaning liquid, and it is possible to greatly reduce the running cost.

In a further preferred configuration example, the object to be cleaned is a transport belt taking a circulation path, and passes through the cleaning liquid in the tank body in the middle of the circulation path.

With this configuration, since the transport belt passes through the cleaning liquid in the middle of the circulation path, the cleaning can be stably performed even during the operation of the apparatus, and the efficiency of the operation of the apparatus is greatly improved.

In a further preferred embodiment, the transport belt is a transport belt for a semiconductor wafer in a semiconductor manufacturing apparatus.

With this configuration, it is possible not only to efficiently clean the entire surface of the transport belt, but also to remove foreign substances adhering to the semiconductor wafer via the belt with high accuracy.

In a further preferred embodiment, the semiconductor manufacturing apparatus is a normal pressure CVD apparatus.

In the case of this configuration, since the configuration is a cleaning device in the atmosphere, no special measures are required, and the configuration can be made compact.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a schematic configuration of a normal pressure CVD apparatus, and FIG. 2 is a side view thereof. FIG. 3 is a side view showing a schematic configuration of the cleaning apparatus according to the present invention, and FIG. 4 is a flowchart showing a control system thereof.

First, with reference to FIG.
The VD device includes a transport belt 1 for transporting a semiconductor wafer 2.
The drive pulleys 3 and 4 form a substantially loop-shaped circulation path traveling in the direction of arrow 5. Further, a gas head 6 for injecting a gas for forming a generated film on the semiconductor wafer 2 is provided. A plurality of gas heads 6 are arranged to form a film forming unit 7. The film forming section 7 includes a heater block 1
There are nine.

Therefore, a formed film is formed on each semiconductor wafer 2 on the transport belt 1 by the film forming unit 7. Here, in addition to the target film formed on the semiconductor wafer 2, a generated film is also formed on the belt, so that the generated film becomes a foreign substance. An HF muffle unit (hydrofluoric acid cleaning device) 10 is arranged to remove the foreign matter.

The HF muffle unit 10 includes a box-shaped container body 11 that surrounds the middle of the traveling conveyor belt 1 and an HF supply device 12 that supplies HF in the form of bubbles together with N ₂ gas into the container body 11. Have. These constitute a bubbling system. The HF supply device 12 is configured such that bubble-like HF is supplied into the container body 11 by N ₂ gas supplied into the tank 15 via the regulator 13 and the valve 14. HF muffle unit 10
Is provided with an adjustment valve 16 on the HF supply side.

The conveyor belt 1 preliminarily cleaned by the HF muffle unit 10 is heated by a heater 17 to remove HF. Thereafter, cleaning is performed in the cleaning device 20 according to the present invention.

FIG. 2 shows the structure of the cleaning device 20. The cleaning device 20 includes a tank main body 21 capable of storing the cleaning liquid and the transport belt 1, an ultrasonic oscillator 22 that vibrates the transport belt 1 in the tank main body 21, and a supply that supplies the cleaning liquid into the tank main body 21. Means 23, 24 and tank body 21
Discharging means 25 for discharging the cleaning liquid S from the inside, dirt detecting means 26 for detecting the degree of dirt of the cleaning liquid S, and, based on the detection result of the dirt detecting means 26, controlling the oscillation frequency of the ultrasonic oscillating means 22 and supplying the same. A control unit 27 for controlling the supply of the cleaning liquid S by the units 23 and 24;

The tank body 21 is open at the top, and pure water is used as the cleaning liquid contained therein. The ultrasonic oscillating means 22 has a plurality of oscillating units, and the control means 27 includes a function of changing the number of oscillating units 22 to change the number of oscillations. Thus, the plurality of oscillation units 22 are arranged so as to cover the entire area of the transport belt 1 in the cleaning liquid so that efficient cleaning can be performed. Further, the number of oscillations and the power can be easily adjusted.

The cleaning liquid discharging means 25 comprises a discharging pipe,
The cleaning liquid S in the tank main body 21 is set to overflow when reaching a predetermined amount (water level). Thereby, care is taken to suppress the wasteful use of the cleaning liquid.

The transport belt 1 taking a circulation route is configured to pass through the cleaning liquid in the tank body 21 in the middle of the circulation route. The transport belt 1 in the tank body 21 is submerged in the cleaning liquid by the weight roller 30 and transported. Accordingly, the transport belt 1 passes through the cleaning liquid in the middle of the circulation path, so that the cleaning can be performed stably even during the operation of the apparatus, and the efficiency of the operation of the apparatus is greatly improved.

Each of the cleaning liquid supply means 23 and 24 comprises a water supply pipe. One supply means 23 is connected to the upper portion of the tank body 21 and the other is connected to the lower portion. This is because the cleaning liquid in the tank main body 1 is sufficiently stirred and foreign substances floating on the liquid surface are easily discharged directly from the drain pipe. Electromagnetic valves 231 and 241 are connected to these supply means 23 and 24, respectively. These electromagnetic valves are controlled to open / close or open by a control means (control device) 27.

The dirt detecting means 26 comprises, for example, an optical sensor or the like which converts the degree of dirt of the cleaning liquid into an electric signal and outputs it by detecting the amount of light transmitted according to the degree of dirt of the cleaning liquid.

As shown in the control flow chart of FIG. 4, the control device 27 sends an open / close or open signal to the electromagnetic valves 231 and 241 based on the detection value of the dirt detection means 26, controls the water amount, and simultaneously oscillates. It has a function of sending a signal for controlling the oscillation number of the means 22 and controlling the output.
Therefore, the control program is incorporated in the control device 27 so that the most suitable conditions for cleaning the transport belt are obtained. The data required to create this control program can be easily obtained from the experimental results.

According to the present embodiment, the following effects can be obtained.

(1) It is possible to obtain the oscillation number and the water amount under the optimum cleaning conditions according to the dirt in the tank main body 21. Thereby, adhesion of a film and damage to the tank main body 21 can be suppressed, and device management becomes easy.

(2) The running cost can be greatly reduced by suppressing waste of water.

(3) By controlling the number of oscillations,
You can also control the degree of dirt and standby time.

(4) Efficient cleaning can be performed over the entire area of the conveyor belt 1.

(5) Stable cleaning can be performed even during operation of the apparatus, and the operation of the apparatus is very efficient.

(6) Creation with a compact system is possible.

In the above embodiment, an example is shown in which the present invention is applied to a conveyor belt cleaning apparatus for conveying semiconductor wafers. However, another semiconductor manufacturing apparatus which requires cleaning of a belt or another apparatus similar thereto. It can also be applied to

[0043]

As described above, according to the present invention, the ultrasonic wave transmitting means and the cleaning liquid supply means of the cleaning apparatus are configured to be automatically controlled in accordance with the cleaning result, whereby the object to be cleaned such as a belt is provided. It is possible to provide a cleaning apparatus capable of improving the quality of a semiconductor product by eliminating the problem of efficient removal of foreign matter adhering to the semiconductor device and reattachment after the removal.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a semiconductor manufacturing apparatus incorporating a cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side view of a semiconductor manufacturing apparatus incorporating the cleaning apparatus according to the embodiment of the present invention.

FIG. 3 is a schematic side view of the cleaning device according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a control system of the cleaning apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1: conveyor belt, 2: wafer, 20: cleaning device, 2
1, tank body, 22: oscillation means, 23, 24: supply means,
231, 241: solenoid valves, 25: discharging means, 26: dirt detecting means, 27: control means.

Claims (6)

[Claims] 1. A tank body capable of storing a cleaning liquid and an object to be cleaned, ultrasonic oscillation means for applying vibration to the object to be cleaned in the tank body, supply means for supplying a cleaning liquid into the tank body, and a tank body Discharging means for discharging the cleaning liquid from the inside; dirt detecting means for detecting the degree of dirt of the cleaning liquid; and, based on the detection result of the dirt detecting means, controlling the oscillation frequency of the ultrasonic oscillation means and cleaning the cleaning liquid by the supply means. A cleaning device comprising: a control unit that performs supply control. 2. The apparatus according to claim 1, wherein said ultrasonic oscillation means has a plurality of oscillation units, and said control means has a function of changing the number of oscillation units to change the number of oscillations.
The cleaning device according to the above. 3. The cleaning apparatus according to claim 1, wherein the cleaning liquid discharging means is set so as to discharge when the cleaning liquid in the tank body exceeds a predetermined amount. 4. The cleaning apparatus according to claim 1, wherein the object to be cleaned is a transport belt that takes a circulation path, and passes through the cleaning liquid in the tank body in the middle of the circulation path. 5. The cleaning apparatus according to claim 4, wherein said transport belt is a transport belt for a semiconductor wafer in a semiconductor manufacturing apparatus. 6. The cleaning apparatus according to claim 5, wherein said semiconductor manufacturing apparatus is a normal pressure CVD apparatus.