JPH05198551A - Wafer drying equipment - Google Patents

Abstract

PURPOSE:To prevent dust discharged from the surface of a cleaned wafer from building up on the inner wall of a cleaning chamber and protect the surface of the wafer from contamination produced by the dust which builds on the cleaned surface of the wafer once again by installing a wall surface cleaning means which forces a wall surface cleaning soluton to flow down on the entire inner wall surface of the cleaning chamber. CONSTITUTION:A wall surface cleaning means 5 which supplies a cleaning solution 6 in such a fashion that the cleaning solution may flow down on the entire inner wall surface 2, comprises a pipeline formed in the shape of a ring. The pipeline is provided with a large number of liquid spray nozzles directed downward on the slant. The cleaning solution 6 is supplied so as to clean the inner wall surface 2 during the operation of a wafer drying equipment. The cleaning solution 6 is supplied in such a fshion that the solution may flow along the inner wall surface from the top to the bottom and no cleaning solution may be splashed on the inner wall surface 2. This construction makes it possible to clean without splash and eliminate the troubles that no dust from the wafer is deposited on the inner wall surface of the cleanin chamber, thereby minimizing the contamination of wafers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer drying apparatus, and more particularly, to inject a cleaning liquid into a cleaning chamber having a wafer mounting portion for mounting a wafer to clean the wafer mounted on the wafer mounting portion, The present invention relates to a wafer drying device that rotates a wafer by centrifugal force to dry the wafer.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, it is often necessary to clean a semiconductor wafer before finishing one treatment and then drying it. For cleaning and drying such a semiconductor wafer, a cleaning liquid is injected into a cleaning chamber having a wafer mounting portion for mounting the wafer to clean the wafer mounted on the wafer mounting portion, and the wafer mounting portion is rotated. Therefore, a wafer drying device for drying the wafer by centrifugal force is used.

FIG. 4 shows one conventional example of such a wafer drying apparatus, and FIG. 5 shows another conventional example. In the drawing, a is a wafer mounting portion rotatably provided in the cleaning chamber b, c is a lid, and d is a shower (only in the apparatus of FIG. 5) for ejecting the cleaning liquid to the inner wall surface e of the cleaning chamber b. . The wafer drying apparatus shown in FIG. 4 supplies the cleaning liquid for cleaning the semiconductor wafer into the cleaning chamber b from above to clean the semiconductor wafer mounted on the wafer mounting portion a, and then rotates the wafer mounting portion a. The cleaning liquid is removed by centrifugal force to dry the semiconductor wafer. In addition, the wafer drying apparatus shown in FIG. 5 is generally a wafer drying apparatus in which a shower d for spraying a cleaning liquid is added to the inner wall surface e of the cleaning chamber B in the cleaning chamber b so that dirt and other impurities attached to the inner wall surface e. Is designed to be removed.

[0004]

By the way, according to the conventional wafer drying apparatus shown in FIG. 4, when the wafer mounting portion a is rotated and dried after the injection of the cleaning liquid into the cleaning chamber b is completed. In addition, the dust on the semiconductor wafer itself and the wafer mounting portion is scattered by the centrifugal force and adheres to the inner wall surface e of the cleaning chamber b, and the cleaning liquid for cleaning the semiconductor wafer itself is also scattered on the inner wall surface e by the centrifugal force and splashes there. Since it returns to the semiconductor wafer again, the dust on the inner wall surface e of the cleaning chamber b mixes with the cleaning liquid or rises up inside the cleaning chamber b when it rebounds, so that the dust reattaches to the surface of the semiconductor wafer. was there.

The amount of dust adhering to the inner wall surface e of the cleaning chamber b increases as cleaning and drying are repeated by the wafer dryer. Therefore, unless the inner wall surface e of the cleaning chamber b is frequently cleaned, the degree of contamination of the semiconductor wafer cannot be reduced, and thus the quality and reliability of the semiconductor device cannot be improved. However, frequent cleaning of the inside of the wafer drying device causes an increase in maintenance cost, which is a factor that hinders cost reduction of the semiconductor device and is not preferable. Therefore, the problem cannot be overlooked.

Therefore, as in the wafer drying apparatus shown in FIG. 5, a shower d for ejecting a wall surface cleaning liquid (for example, ice) may be provided on the inner wall surface e of the cleaning chamber b to clean the inner wall surface e. It is being said. However, even this has not been able to fundamentally solve this problem. This is because the wafer and wafer mounting part a are attached to the piping part of the shower d.
A new problem arises that dust from the surface of the cleaning chamber b adheres, accumulates, and becomes a pollution source that contaminates the surface of the semiconductor wafer.
This is because it bounces back to the semiconductor wafer side, and as a result, the dust on the inner wall surface e rises up in the cleaning chamber b by the wall surface cleaning liquid or mixes with the wall surface cleaning liquid and directly adheres to the semiconductor wafer.

The present invention has been made to solve such a problem, and prevents dust from the surface of the wafer to be cleaned from adhering to the inner wall surface of the cleaning chamber and again adhering to the surface of the wafer and contaminating it. The purpose is to

[0008]

According to a first aspect of the present invention, there is provided a wafer drying device characterized in that wall cleaning means for causing a wall cleaning liquid to flow down is provided on the entire inner wall surface of a cleaning chamber. According to another aspect of the wafer drying apparatus of the present invention, a liquid curtain forming means for forming a liquid curtain is provided between the wafer mounting portion and the inner wall surface of the cleaning chamber.

[0009]

According to the wafer drying apparatus of the first aspect, since the wall surface cleaning liquid is made to flow down on the entire inner wall surface of the cleaning chamber, the entire wall surface of the cleaning chamber can be cleaned without splashing. Therefore, there is no fear that dust from the wafer will be accumulated on the inner wall surface of the cleaning chamber, the contamination of the wafer can be reduced, and a special operation for cleaning the inner wall surface of the cleaning chamber is not required, so that the maintenance cost is reduced.

According to the wafer drying device of the second aspect, since the liquid curtain is formed around the wafer mounting portion, dust scattered around the wafer when the wafer mounting portion is rotated is captured by the liquid curtain, and the liquid curtain is also provided. Even if there is dust that has passed through the cleaning chamber and has reached the wall surface of the cleaning chamber, the liquid curtain can prevent the dust from bouncing back on the wall surface of the cleaning chamber and returning to the wafer mounting portion. Therefore, the contamination degree of the wafer can be reduced as in the wafer drying apparatus according to claim 1.
Maintenance work is reduced because no special work is required to wash the inner wall of the washing room.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The wafer drying apparatus of the present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 is a sectional view showing one embodiment of the wafer drying apparatus of the present invention. In the drawings, 1 is a cleaning chamber, 2 is an inner wall surface of the cleaning chamber 1, and 3 is a wafer mounting portion rotatably provided inside the cleaning chamber 1. A semiconductor wafer (not shown) is mounted on the wafer mounting portion 3. .. 4 is a lid.

Reference numeral 5 is a wall surface cleaning means for supplying the cleaning liquid 6 so as to flow down the entire inner wall surface 2 of the cleaning chamber 1. The wall cleaning means 5 is composed of a pipe formed in an annular shape, and the pipe is a liquid jet port directed obliquely downward and outward. Have many. The wall surface cleaning means 5 supplies the cleaning liquid 6 to clean the inner wall surface 2 at all times during use of the wafer drying apparatus or only at a specific time such as drying or standby. It is necessary that the cleaning liquid 6 is supplied by the wall surface cleaning means 5 so as to flow downward along the inner wall surface 2 from a substantially upper end so that the cleaning liquid 6 does not splash on the inner wall surface 2.

In this way, even if the cleaning liquid 7 for cleaning the semiconductor wafer is scattered by the centrifugal force due to the rotation of the wafer mounting portion 3 and the dust therein adheres to the inner wall surface 2 of the cleaning chamber 1, the dust remains. It can be washed away by the cleaning liquid 6 supplied by the wall surface cleaning means 5. Therefore, there is no fear that dust from the wafer will be accumulated on the inner wall surface of the cleaning chamber, the contamination of the wafer can be reduced, and a special operation for cleaning the inner wall surface of the cleaning chamber is not required, so that the maintenance cost is reduced. It should be noted that pure water as a cleaning liquid, to which an activator is added, is supplied as the wall surface cleaning liquid 6 for the purpose of enhancing the cleaning effect on the inner wall surface 2.

Further, since the inner wall surface 2 of the cleaning chamber 1 is made of a material having wettability with the wall surface cleaning liquid such as pure water, the effect of preventing contamination of the semiconductor wafer can be enhanced. This is because if the wettability is good, it will be easy to seal (cover) the wall surface cleaning liquid without omission. It is preferable to improve the wettability so as to prevent the dust from splashing even if the seal of the wall surface cleaning liquid leaks even if only a small amount. Then, specifically, when an activator or a hydrophilic solvent (alcohol, etc.) is added to the cleaning liquid composed of pure water, the wettability of the cleaning liquid on the inner wall surface 2 is improved.

2 (A) and 2 (B) show different modifications of the wafer drying apparatus of FIG. In the wafer drying apparatus shown in FIG. 2 (A), a large number of holes 8 that open to the inner wall surface 2 are provided in the upper portion of the inner wall surface 2, and the wall surface cleaning liquid 6 that flows down the inner wall surface 2 of the cleaning chamber 1 is supplied through the holes 8. It is the one.

A ring-shaped groove may be provided in the upper portion of the inner wall surface 2 and a large number of holes opening at the bottom surface of the groove may be provided to supply the wall surface cleaning liquid 6 from the holes. In this case, the groove plays the role of spreading the cleaning liquid in the horizontal direction, and allows the flowing liquid to flow down the inner wall surface 2 without leaking. In order to enhance such an effect, it may be considered that the holes are oriented in a tangential direction of the inner wall surface 2 having a circular cross section or a direction close thereto.

In the wafer drying apparatus shown in FIG. 2B, the diameter of the inner wall surface 2 is reduced as it goes downward so that the cleaning liquid 6 can more reliably flow the dust on the surface of the inner wall surface 2. It is a slanted one. The technique of inclining the surface of the inner wall surface 2 as described above can be applied to both a wafer drying device that supplies a cleaning liquid as shown in FIG. 1 and a wafer drying device that supplies a cleaning liquid as shown in FIG. .

FIG. 3 is a sectional view showing another embodiment of the wafer drying apparatus of the present invention. In this embodiment, a liquid curtain forming means 10 for forming a liquid curtain 9 made of a liquid such as water is provided between the wafer mounting portion 3 and the inner wall surface 2 in the cleaning chamber 1. The liquid curtain 9 is formed in a tubular shape so as to block the space between the wafer mounting portion 3 and the inner wall surface 2, but may be a waterfall-like curtain or a spray-like curtain. May be.

According to such a wafer drying apparatus, since the liquid curtain 9 is formed around the wafer mounting portion 3, dust scattered around the wafer when the wafer mounting portion 3 rotates is captured by the liquid curtain. Even if there is dust that has passed through the liquid curtain 9 and reached the inner wall surface 2 of the cleaning chamber 1, the liquid curtain 9 can prevent the dust from bouncing back on the inner wall surface 2 of the cleaning chamber 1 and returning to the wafer mounting portion 3. Therefore, similar to the wafer drying apparatus of FIGS. 1, 2A, and 2B, the degree of contamination of the wafer can be reduced, and a special operation for cleaning the inner wall surface of the cleaning chamber is not required, so that the maintenance cost can be reduced. Is reduced. As shown in FIGS. 1 and 2, the inner wall surface 2
Both the cleaning of the wafer and the formation of the liquid curtain as shown in FIG. 3 may be performed in one wafer dryer.

By the way, the supply of the wall surface cleaning liquid and the formation of the liquid curtain may be always carried out or may be carried out only at a specific time.
This is more preferable because it has the effect of preventing the charging (charging due to the rotation of the wafer mounting portion) and the like, and the effect of preventing the adhesion due to the charging of dust is further enhanced.

[0021]

According to the first aspect of the present invention, there is provided the wafer drying apparatus having wall surface cleaning means for flowing down the wall surface cleaning liquid over the entire inner wall surface of the cleaning chamber. Therefore, according to the wafer drying apparatus of the first aspect, since the wall surface cleaning liquid is made to flow down on the entire inner wall surface of the cleaning chamber, the entire wall surface of the cleaning chamber can be cleaned without splashing. As a result, there is no risk of dust from the wafers accumulating on the inner wall surface of the cleaning chamber, the contamination of the wafer can be reduced, and a special operation for cleaning the inner wall surface of the cleaning chamber is not required, which reduces maintenance costs. ..

According to a second aspect of the present invention, there is provided a wafer drying device characterized in that it has liquid curtain forming means for forming a liquid curtain between the wafer mounting portion and the inner wall surface of the cleaning chamber. Therefore, according to the wafer drying device of the second aspect, since the liquid curtain is formed around the wafer mounting portion, the dust scattered around the wafer during the rotation of the wafer mounting portion is captured by the liquid curtain, and the liquid curtain. Even if there is dust that has passed through the cleaning chamber and has reached the wall surface of the cleaning chamber, the liquid curtain can also prevent the dust from bouncing back on the wall surface of the cleaning chamber and returning to the wafer mounting portion. Therefore, similarly to the wafer drying apparatus according to the first aspect, the degree of contamination of the wafer can be reduced, and a special operation for cleaning the inner wall surface of the cleaning chamber is unnecessary, so that the maintenance cost is reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a wafer drying apparatus of the present invention.

2A and 2B are cross-sectional views showing another modification of the wafer drying apparatus shown in FIG.

FIG. 3 is a sectional view showing another embodiment of the wafer drying apparatus of the present invention.

FIG. 4 is a cross-sectional view showing one conventional example of a wafer drying device.

FIG. 5 is a cross-sectional view showing another conventional example of a wafer drying device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning chamber 2 Inner wall surface 3 Wafer mounting part 5 Wall surface cleaning means 6 Wall surface cleaning liquid 7 Wafer cleaning liquid 8 Wall surface cleaning means provided on the inner wall surface 9 Liquid curtain 10 Liquid curtain forming means

Claims (2)

[Claims] 1. A cleaning liquid is injected into a cleaning chamber having a wafer mounting portion for mounting a wafer to clean the wafer mounted on the wafer mounting portion, and the wafer mounting portion is rotated to centrifugally move the wafer. A wafer drying apparatus for drying includes a wall surface cleaning means for flowing down a wall surface cleaning liquid over the entire inner wall surface of the cleaning chamber. 2. A cleaning liquid is injected into a cleaning chamber having a wafer mounting portion for mounting a wafer to clean the wafer mounted on the wafer mounting portion, and the wafer mounting portion is rotated to centrifugally actuate the wafer. A wafer drying device for drying, comprising a liquid curtain forming means for forming a liquid curtain between the wafer mounting part and the inner wall surface of the cleaning chamber.