JPS6078680A - Washer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technique that is effective when applied to a cleaning device, particularly an overflow cleaning device.

[Background technology]

A wafer cleaning process is one of the essential processes when manufacturing semiconductor devices. A wafer cleaning step is always performed at the end of an acid treatment (eg, an etching step). In this process, one of the conditions for improving yield is to completely remove not only acid content and other substances from the wafer surface, but also foreign matter (small dust).

As shown in FIGS. 1 and 2, a general overflow cleaning device includes an inner tank (cleaning tank) 4 in which an object to be cleaned 1 (for example, a wafer 3 housed in a cartridge 2) is immersed, and an upper part of the inner tank 4. Cleaning liquid 5 (in this case, waste liquid 6) flowing outward from the edge
Also called. ). Inner tank 4
A supply port 8 for supplying the cleaning liquid 5 to the inner tank 4 is provided at the bottom of the tank 7, and a drain port 9 is provided at the bottom of the outer tank 7. When cleaning the object 1 to be cleaned, the object 1f is placed in an inner tank 4 containing cleaning liquid 5. Cleaning liquid 5 is in inner tank 4
Since it is sequentially supplied from the lower part of the tank, it rises and washes the object 1 while overflowing from the upper edge of the inner tank 4 and enters the outer tank 7.

At this time, among the contaminants on the object to be cleaned 1, insoluble contaminants 1
A part of the 0 floats to the surface of the cleaning liquid. Then, together with the floating contaminants 10 and the cleaning liquid 5 which exceeds the capacity of the inner tank 4, the cleaning liquid 5 becomes a waste liquid 6 and flows into the outer tank 7 to be eliminated.

However, the overflow cleaning device having such a structure has the following problems.

That is, in order to efficiently remove floating contaminants 1O, it is desirable that the waste liquid 6 overflows from the entire upper edge of the inner tank 4, but in reality, only a portion of it flows out, as shown in Figure 2. . Therefore, in order to cause the cleaning liquid 5 to overflow over the entire upper edge of the inner tank, it is conceivable that K should perform advanced horizontal adjustment of the inner tank 4 or use a large amount of the cleaning liquid 5. However, the former type of horizontal adjustment is difficult and time consuming, and is often inadequate. Moreover, in the latter method of using a large amount of cleaning liquid, the usage efficiency of the cleaning liquid is low. In particular, when the cleaning liquid is expensive, it is not preferable to use a large amount of the cleaning liquid because it increases the cleaning cost. As a result, there is currently a problem in that the contaminants 10 that are not removed from the inner tank 4 re-adhere to the objects to be cleaned IVc that are pulled up from the inner tank 4 after cleaning, causing poor cleaning. This has been made clear by the applicant.

[Object of the Invention] An object of the present invention is to provide an overflow cleaning device with high cleaning effect.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, in the present invention, an auxiliary tank is provided outside the inner tank, and the waste liquid that overflows from the upper edge of the auxiliary tank swells up on the upper edge of the inner tank to drain out the cleaning liquid that does not flow out due to surface tension. The cleaning liquid overflows all around the upper edge of the tank to improve the cleaning effect.

[Embodiment] FIG. 3 is a cross-sectional view showing a part of an oat 70-cleaning device according to an embodiment of the present invention.

This cleaning device has a cartridge 1. Wafer 3 accommodated in cage 2
An inner tank (washing tank) 4 in which the object to be cleaned 1 is placed, and an outer tank 41 in which the cleaning liquid 5 (in this case [i, is also referred to as waste liquid 6) flowing out from the upper part of the inner tank 4 is collected. J7 and outer tank 7
and an auxiliary tank 11 provided between the inner tank 4 and the inner tank 4. A supply port 8 for supplying the cleaning liquid 5 to the inner tank 4 is provided at the bottom of the inner tank 4 .

Further, a drain port 9 for discharging the waste liquid 6 is provided at the bottom of the outer tank 7. Further, a supply port 13 is provided at the bottom of the auxiliary tank 11 through which a portion of the waste liquid 6 discharged from the drain port 9 is pumped by the pump 12 into the auxiliary tank 11. The auxiliary tank 11 is narrow, and the upper edge of the auxiliary tank 11 is slightly lower than the upper edge of the inner tank 4.

When cleaning the object 1 with such a cleaning device, the object 1 is placed in the inner tank 4 to which the cleaning liquid 5 is sequentially supplied. Since the cleaning liquid 5 is sequentially fed into the inner tank 4 from the lower part of the inner tank 4, it cleans the object 1 to be cleaned and cleans the object 1 to be cleaned.
Contaminants 10 liberated from the inner tank 4 are caused to flow out from the upper edge of the inner tank 4 together with the cleaning liquid 5. At this time, even if the waste liquid 6 does not flow out from a part of the upper edge of the inner tank 4 due to the surface tension of the cleaning liquid 50, the waste liquid sent to the auxiliary W 11 by the pump 12 remains outside the inner tank 4. 6 rises at the upper edge of the inner tank and flows out from the auxiliary tank 11 toward the outside Wj7. The swollen portion of this waste liquid 7 comes into contact with the waste liquid 6 which has risen due to surface tension from the inside of the inner tank 4 to the upper edge at the upper edge of the inner tank 4, breaking the surface tension and causing the inner tank to The cleaning liquid 5 in the tank 4 flows out all around the upper edge of the inner tank.

〔effect〕

(1) In the present invention, since the cleaning liquid (waste liquid) is discharged from all parts of the inner tank to the outer tank, contaminants in the inner tank are effectively removed. As a result, it is possible to prevent contaminants from being deposited on the objects to be cleaned that have been taken up from the inner tank, so that effective cleaning can be carried out.

(2) In the waste liquid removal promotion mechanism consisting of an auxiliary tank etc. that promotes the efficient removal of cleaning liquid in the inner phase of the present invention, the waste liquid discharged from the outer tank is used, so the amount of cleaning liquid used is Less economical. Therefore, the present invention is economically more effective when using expensive cleaning fluids.

(3) From the above (1), the present invention has a high
It is easy to use and does not require horizontal adjustment of the inner tank.

(4) In the present invention, the upper edge of the auxiliary tank is lower than the upper edge of the inner tank, so even if the amount of cleaning liquid supplied to the inner tank is accidentally reduced too much or completely stopped, contamination may occur. Nothing will ever re-enter the inner tank.

(5) From the above (1) to (4), efficient cleaning can be achieved at low cost.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, as shown in FIG. 4, as a waste liquid removal promoting device, a nozzle 14 for spraying the waste liquid 6 is provided around the entire upper edge of the inner tank 4, and If the cleaning liquid 50, which accumulates on the upper edge of the cleaning liquid 50 due to surface tension, is structured to break the surface tension, the same effect as in the embodiment described above can be obtained. Note that the nozzle 14 needs to be set so that the waste liquid 6 is ejected in a direction that prevents the ejected waste liquid 6 from entering the inner tank 4 .

[Application field]

Although the invention has been described in terms of its application to wafer cleaning technology, which is its background, the present invention is not limited thereto, and can be widely used to clean various articles that require cleaning.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional overflow cleaning device, Fig. 2 is a perspective view thereof, Fig. 3 is a sectional view showing the main parts of an overflow cleaning device according to an embodiment of the present invention, and Fig. 4 is a similar one. FIG. ]...Object to be cleaned, 2...Cartridge, 3...Ueno 1.4...Inner tank (cleaning tank), 5...Cleaning liquid, 6
...Waste liquid, 7...Outer fence, 8...Supply port, 9...
Drain port, 10... Contaminants, 11... Auxiliary tank, 12.
... Pump, 13... Supply port, 14... Nozzle. Figure 3 Figure 4 Written amendment to the procedure (spontaneous) Indication of the case Patent application No. 186721 filed in 1986, Name of the invention Cleaning device Amendment person/II to i and 1 Tomo Patent applicant name Name f5101 Stock company t1 Hitachi Manufactured by TfE, (D subject area) Contents of amendment (1) Figure 2 of the drawing attached to the application is amended as attached.

Claims (1)

[Claims] 1. A cleaning device that cleans the objects to be cleaned in the cleaning tank by overflowing the cleaning liquid from the upper edge of the cleaning tank, which prevents the cleaning liquid in the cleaning tank from flowing out over the entire upper edge of the cleaning tank. A cleaning device characterized by being provided with a mechanism for promoting waste liquid removal.