JP3000997B1 - Semiconductor cleaning apparatus and semiconductor device cleaning method - Google Patents

Abstract

An object of the present invention is to provide a semiconductor cleaning apparatus and a semiconductor device cleaning method capable of removing impurities such as metals and organic substances brought into a liquid tank of a wet processing apparatus and keeping the liquid tank clean. A processing tank (7 in FIG. 1) installed in a cleaning processing chamber (11 in FIG. 1), a line (1a in FIG. 1) for supplying pure water to the processing tank, and a chemical solution in the processing tank Line (3 in FIG. 1), a line for supplying a cleaning liquid containing ozone to the processing tank (2 in FIG. 1), a wafer support unit (8 in FIG. 1) for supporting the wafer, and the wafer in the processing tank. And a transfer unit having a transfer unit (9 in FIG. 1) for transferring the semiconductor wafer. The method for cleaning a semiconductor device includes using a semiconductor cleaning apparatus including at least a wafer transfer unit (9 in FIG. 1). Before the cleaning, a cleaning liquid containing ozone is injected into the processing tank from the lower part of the tank, and overflows from the upper part of the tank to wash the processing tank and the wafer supporting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor cleaning apparatus and a semiconductor cleaning method, and more particularly to a wet processing apparatus for cleaning in a liquid tank and a method for cleaning a semiconductor device using the wet processing apparatus.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of semiconductor devices, improvement in yield in wet processing such as etching and cleaning has become an important issue. A conventionally used wet processing apparatus includes a processing tank for processing a wafer,
The basic configuration includes a mechanism for supplying pure water and a chemical solution to a processing tank and discharging a waste liquid, a transport mechanism for transferring a wafer into and out of the processing tank, and a drying mechanism for drying a wafer. The wafer is carried into the processing tank, (b) a chemical solution is injected into the processing tank to process the wafer, (c) pure water is injected into the processing tank to wash the wafer, and (d) the wafer is processed into the processing tank. A plurality of wafers have been processed by repeating the steps of carrying out and drying the wafers, and (e) discharging pure water from the processing tank.

[0003] Such a conventional cleaning method targets particles as impurities and aims at removing impurities adhering to an object to be cleaned such as a wafer. Therefore, in order to simply remove particles, circulating filtering of a chemical solution or the like is required. It was possible to deal with this by performing chemical exchange.

[0004]

However, in such a conventional wet processing, impurities such as metals and organic substances brought from the product may accumulate in the processing tank of the wet processing apparatus. In the semiconductor manufacturing process of (1), the requirements for contamination are even more severe, and it is necessary to reduce defects such as watermarking, and it is particularly necessary to sufficiently consider the influence of impurities such as metals and organic substances.
Therefore, there is a problem that it is difficult to remove these impurities accumulated in the processing tank only by pure water rinsing performed at the time of circulation filtering or chemical solution exchange as in the related art.

The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to remove impurities such as metals and organic substances brought into a liquid tank of a wet processing apparatus and to clean the liquid tank. An object of the present invention is to provide a semiconductor cleaning apparatus and a semiconductor device cleaning method that can be kept clean.

[0006]

According to the present invention, there is provided a semiconductor cleaning apparatus comprising: a cleaning processing chamber; a processing tank provided in the chamber; and means for supplying pure water and a chemical solution to the processing tank. A transfer unit having a wafer support unit that supports a wafer and a wafer transfer unit that transfers the wafer to the processing bath; and a wafer mounted on the processing bath and lifting the wafer from the processing bath. A semiconductor cleaning apparatus having at least a means for drying the wafer and a means connected to the chamber for discharging waste liquid discharged from the processing tank , after processing the wafer,
Before processing, the cleaning liquid containing ozone is supplied to the processing tank from the lower part of the processing tank, and the cleaning liquid overflows from the upper part of the processing tank , whereby the processing is performed.
A means for cleaning the tank and the wafer support .

According to a semiconductor device cleaning method of the present invention, there is provided a processing tank installed in a cleaning processing chamber, means for supplying pure water and a chemical solution to the processing tank, and a cleaning liquid containing ozone in the processing tank. A method for cleaning a semiconductor device using a semiconductor cleaning apparatus including at least a supply unit and a transfer unit having a wafer support unit that supports a wafer and a wafer transfer unit that transfers the wafer to the processing bath. After processing the wafer, before processing the next wafer, by injecting a cleaning liquid containing ozone from the lower part of the processing tank into the processing tank, overflowing the cleaning liquid from the upper part of the processing tank, The processing tank and the wafer support are cleaned.

Further, the method for cleaning a semiconductor device according to the present invention comprises:
A chamber for cleaning processing, a processing tank installed in the chamber, means for supplying pure water and a chemical solution to the processing tank, means for supplying a cleaning liquid containing ozone to the processing tank, and a wafer supported. Transfer means having a wafer support unit and a wafer transfer unit for transferring the wafer to the processing tank,
A unit mounted on the processing tank and drying the wafer when lifting the wafer from the processing tank; and a unit connected to the chamber and configured to discharge waste liquid discharged from the processing tank. (A) transporting the wafer to the processing tank by the wafer transporting means using the semiconductor cleaning apparatus, and (b) injecting a chemical solution into the processing tank to process the wafer. c) a step of injecting pure water into the processing tank to wash the wafer;
(D) at the time of unloading the wafer from the processing tank by the wafer transfer means, at least including a step of drying the wafer by the drying means; and (e) a step of discharging pure water from the processing tank. A method of cleaning a semiconductor device, wherein a semiconductor wafer is processed by repeating the steps (a) to (e), wherein after the step (e) and before the step (a), The wafer support is returned, and a cleaning liquid containing ozone is injected into the processing tank from a lower part of the processing tank, and the cleaning liquid overflows from an upper part of the processing tank, thereby cleaning the processing tank and the wafer supporting part. It is also possible to adopt a configuration in which

In the present invention, the wafer supporting portion is made of a comb-shaped fluororesin-based member, the ozone-containing cleaning solution has an ozone concentration in a range of 5 ppm to 30 ppm, and the drying means is a reduced pressure IPA (isopropyl). It is preferable to use a drying means using (alcohol).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor cleaning apparatus according to the present invention
In a preferred embodiment, a processing tank (7 in FIG. 1) installed in a cleaning processing chamber (11 in FIG. 1).
And a line (1a in FIG. 1) for supplying pure water to the processing tank;
A line for supplying a chemical solution to the processing tank (3 in FIG. 1) and a line for supplying a cleaning liquid containing ozone to the processing tank (2 in FIG. 1)
A semiconductor cleaning apparatus including at least a wafer support unit (8 in FIG. 1) for supporting a wafer and a transfer unit having a wafer transfer unit (9 in FIG. 1) for transferring a wafer to a processing bath. A method of cleaning an apparatus, wherein after processing a wafer, before processing the next wafer, a cleaning liquid containing ozone is injected into the processing tank from the lower part of the tank, and overflows from the upper part of the processing tank. And cleaning the wafer support.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 is a side view schematically illustrating a configuration of a one-bath wet processing apparatus according to an embodiment of the present invention. FIGS. 2 and 3 are semiconductor cleaning methods using the one-bath wet processing apparatus. FIG. 4 is a side view for explaining the steps in order.

Referring to FIG. 1, the configuration of a one-bath wet processing apparatus according to an embodiment of the present invention will be described.
The one-bath wet processing apparatus of the present embodiment accommodates a processing tank 7 for performing etching, cleaning, and the like of a wafer, a wafer handler 8 for supporting the wafer in the processing tank 7, and a wafer driving unit 9 for taking in and out the wafer. The pure water supply line 1, the chemical solution supply line 3, and the IP
The A supply line 4 and the waste liquid line 5 are connected to the ozone water supply line 2 which is a feature of this embodiment.

Ozone water is produced by converting pure water supplied from a pure water supply line 1b into ozone by an ozone water production device 10, and is introduced into a treatment tank 7 via an ozone water supply line 2. You. The concentration of ozone water is
Generally, about 5 ppm to 30 ppm having a cleaning effect is also effective for cleaning the inside of the tank, and the ozone water having this concentration is also used in the present embodiment.

Next, a cleaning processing sequence of the one-bath wet processing apparatus according to the present embodiment will be described with reference to FIGS. FIG. 2A shows a step of cleaning the inside of the tank by overflowing ozone water, FIG. 2B shows a preparation step before performing a process such as etching, and FIG.
FIG. 3D shows a process of etching or the like, and FIG.
4A shows a wafer drying process by A.

First, referring to FIG. 2A, the treatment tank 7
To clean the water, the waste liquid valve 15 and the pure water valve 13
And the chemical liquid valve 14 are closed, the ozone water valve 12 is opened, and a certain concentration of ozone water is introduced into the processing tank 7 and overflowed, so that the wafer handler in the processing tank 7 and the fluororesin-based comb teeth are formed. 8 can be kept clean.

Next, as shown in FIG. 2B, the ozone water valve 12 is closed, the waste liquid valve 15 is opened, the ozone water in the treatment tank 7 is drained, and the waste liquid valve 15 is closed. Then, the pure water valve 13 is opened, and the replacement of the pure water in the processing tank 7 is performed several times.

Next, as shown in FIG. 3C, the wafer 1 is placed in a wafer handler 8 in a processing tank 7 kept in a clean state.
After erecting 6, the chemical solution valve 14 is opened, a chemical solution is charged into the processing tank 7, and wet etching is performed. Then, using a large amount of pure water of about 20 to 50 l / min,
Perform wafer pure water rinsing. The pure water rinsing time is maintained until the specific resistance value of the pure water in the tank recovers to about 15 MΩ · cm and the specific resistance value becomes stable.

Finally, as shown in FIG. 3D, the wafer 16 is pulled out of the processing tank 7 filled with pure water and dried. In the one-bath wet processing apparatus of the present embodiment,
It is desirable to use a reduced pressure IPA (isopropyl alcohol) drying method. Note that the reduced pressure IPA drying method means that after the pure water rinsing of the processing wafer 16 is completed, IPA vapor is discharged to the upper surface layer of the pure water charged into the processing tank 7 to form a thin IPA layer at the gas-liquid interface. After that, the wafer 16 is moved at a low speed (several mm /
The water on the wafer 16 is extracted by IP
This is a method of removing water on the wafer 16 by substituting A and then drying the wafer under reduced pressure.

As described above, in the wet etching process performed as a pre-process of the film formation process that is sensitive to contamination in the semiconductor manufacturing process, the impurities accumulated in the processing tank 7 of the wet processing apparatus and the etching generation are performed. There is a concern about the effect of reattachment of impurities such as substances, but in this example,
The inside of the processing tank 7 of the wet processing apparatus is preliminarily cleaned before the wet processing using ozone water having an extremely strong oxidizing power. As a result, impurities brought into and accumulated in the processing tank 7 of the wet processing apparatus from the processing wafer or the like are removed.
Impurities such as etching products adhering to the wafer handler 8 installed therein can be completely removed. Further, after the ozone water is introduced into the treatment tank 7, the inside of the wet treatment apparatus is circulated and filtered for a certain period of time, so that the circulation piping line can be washed together.

In this embodiment, the one-bath wet processing apparatus is described. However, the present invention is not limited to the one-bath wet processing apparatus, but may be applied to a general wet processing apparatus having a large number of processing tanks. Cleaning in the tank using ozone water for removing impurities can be used.

In the case of a normal wet processing apparatus, the chemical in the chemical processing tank is used while being filtered for a certain period of time without performing chemical exchange for each product processing as in a one-bath wet processing apparatus. In addition, a large amount of impurities such as metals and organic substances brought from the product may accumulate in the chemical solution tank. However, by performing cleaning in the tank using the ozone water of the present invention at the time of liquid exchange, it becomes possible to remove impurities such as metals and organic substances accumulated in the tank, and cleanliness in the wet processing apparatus tank is reduced. Can be maintained.

[0022]

As described above, according to the present invention,
In the wet etching process, impurities and etching products accumulated in the tank of the wet processing device can be removed, and particles and water mark defects adhering to the product can be reduced to reduce contamination. Even in a sensitive film forming process, there is an effect that a film forming process can be favorably performed without generating an abnormality such as a protrusion or a crystal defect.

The reason is that, in the present invention, in order to remove impurities accumulated in the processing tank, ozone water is supplied from below the processing tank and overflows constantly during standby other than during processing. This makes it possible to always keep the wafer handler permanently installed in the processing tank and in the tank in a clean state, and to remove impurities, etching products, and the like accumulated in the tank of the wet processing apparatus. It is.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of a one-bath wet processing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view for explaining a semiconductor cleaning method using a one-bath wet processing apparatus according to one embodiment of the present invention in the order of steps.

FIG. 3 is a side view for explaining a semiconductor cleaning method using a one-bath wet processing apparatus according to one embodiment of the present invention in the order of steps.

[Explanation of symbols]

 1a, 1b Pure water supply line 2 Ozone water supply line 3 Chemical liquid supply line 4 IPA supply line 5 Waste liquid line 6 IPA discharge unit 7 Processing tank 8 Wafer handler 9 Wafer driving unit 10 Ozone water production device 11 Wet treatment chamber 12 Ozone water Valve 13 Pure water valve 14 Chemical liquid valve 15 Waste liquid valve 16 Wafer

Continuation of the front page (51) Int.Cl. ⁷ identification code FI H01L 21/306 H01L 21/306 JB (58) Investigated field (Int.Cl. ⁷ , DB name) H01L 21/304

Claims (6)

(57) [Claims] A cleaning chamber, a processing tank installed in the chamber, a means for supplying pure water and a chemical solution to the processing tank, a wafer support for supporting a wafer, and a processing tank. A transfer unit having a wafer transfer unit for transferring the wafer, a unit mounted on the upper part of the processing tank, and drying the wafer when lifting the wafer from the processing tank; and Means for discharging the waste liquid discharged from the processing tank, and at least , after processing the wafer, before processing the next wafer,
The processing tank and the wafer are supplied to the processing tank by supplying a cleaning liquid containing ozone from a lower part of the processing tank and overflowing the cleaning liquid from an upper part of the processing tank.
A semiconductor cleaning apparatus, comprising: means for cleaning a support portion . 2. The semiconductor cleaning device according to claim 1, wherein the wafer support portion is made of a comb-shaped fluororesin-based member, and the ozone-containing cleaning liquid has an ozone concentration of 5 ppm or more and 30 ppm or less. apparatus. 3. A processing tank installed in a cleaning processing chamber, means for supplying pure water and a chemical solution to the processing tank, means for supplying a cleaning liquid containing ozone to the processing tank, and a wafer supporter. And a transfer unit having a wafer transfer unit that transfers the wafer to the processing tank, and a method of cleaning a semiconductor device using a semiconductor cleaning apparatus including at least the wafer cleaning unit, and after processing the wafer, Before processing the next wafer, a cleaning liquid containing ozone is injected into the processing tank from the lower part of the processing tank, and the cleaning liquid overflows from the upper part of the processing tank, whereby the processing tank and the wafer support part are filled. Cleaning a semiconductor device. 4. A chamber for cleaning processing, a processing tank installed in the chamber, means for supplying pure water and a chemical solution to the processing tank, and means for supplying a cleaning liquid containing ozone to the processing tank. A transfer unit having a wafer support unit that supports a wafer and a wafer transfer unit that transfers the wafer to the processing tank; and a wafer mounted on the processing tank and used for lifting the wafer from the processing tank. Using a semiconductor cleaning apparatus having at least a unit for drying the wafer and a unit connected to the chamber and for discharging waste liquid discharged from the processing tank. (A) The wafer is processed by the wafer transfer unit. (B) injecting a chemical solution into the processing tank and processing the wafer;
(C) a step of injecting pure water into the processing tank to wash the wafer; and (d) drying the wafer by the drying means when the wafer is carried out of the processing tank by the wafer transfer means. And (e) discharging pure water from the processing tank. The method for cleaning a semiconductor device, comprising: repeating the steps (a) to (e) to process a semiconductor wafer. After the step (e) and before the step (a), the wafer support portion is returned to the processing tank, and a cleaning liquid containing ozone is injected into the processing tank from a lower portion of the processing tank, and the processing is performed. A method for cleaning a semiconductor device, comprising: cleaning the processing tank and the wafer support by overflowing the cleaning liquid from an upper part of the tank. 5. The wafer supporting portion is made of a comb-shaped fluororesin-based member, and the ozone-containing cleaning liquid has an ozone concentration in a range of 5 ppm or more and 30 ppm or less. Cleaning method for semiconductor devices. 6. The method for cleaning a semiconductor device according to claim 4, wherein said drying means is a drying means using reduced-pressure IPA (isopropyl alcohol).