KR101058835B1 - Wafer drying apparatus and wafer drying method using the same - Google Patents

Abstract

An object of the present invention is to provide a wafer drying apparatus and a wafer drying method using the same that can reduce damage to the wafer and reduce the amount of gas used.

The present invention comprises a chamber in which a first rotating shaft is fixed to a side surface and a second rotating shaft is formed on the upper side thereof, and a first drain hole is formed at a lower side thereof; A tilt arm fixed to the first rotational shaft and the second rotational shaft and fixed to a cassette for mounting a wafer at an end thereof; A first nozzle for supplying an IPA / nitrogen gas to the cassette; A screw to move the second axis of rotation in a first direction or a second direction; And relates to a wafer dryer including a drive motor for rotating the screw and a wafer drying method using the same.

Description

Wafer Drying Apparatus and Wafer Drying Method Using The Same {WAFER DRYER AND METHOD FOR WAFER DRY METHOD USING THE SAME}

The present invention relates to a wafer drying apparatus and a wafer drying method using the same, and more particularly, to a wafer drying apparatus capable of reducing damage to a wafer and reducing the amount of gas used, and a wafer drying method using the same.

There are many types of wafers, but wafers used for manufacturing semiconductors, light emitting diodes (LEDs), solar cells, and the like have a thickness of 700 μm or less. As a wafer drying method, a method of evaporating moisture by using high temperature nitrogen was generally used. However, when using this method, dry nitrogen must be supplied for a long time, and the wafer is shaken by the dry nitrogen, which may cause damage to the wafer.

Looking at the operation of the conventional wafer dryer in more detail as follows. First, in the first step, a cassette containing a wafer is placed in a bath containing ultrapure water, isopropyl alcohol (IPA) / nitrogen mixed gas is injected, and dried using marangoni force. Then, it is dried by supplying nitrogen gas of 300 to 400lpm in the second step.

At this time, the wafer adheres to the cassette inclined surface in the first step, but only when very strong nitrogen gas is supplied in the second step. If it does not fall off, it will not dry, resulting in watermarks and particles.

In addition, since the wafer is very thin, the warpage of the wafer occurs, which causes the wafers to contact each other. When the wafers come into contact, they are stuck and difficult to drop again. In order to solve this problem, it is necessary to widen the wafer-to-wafer distance to prevent the wafers from contacting each other. For this reason, the number of wafers processed in a single process is reduced.

An object of the present invention is to provide a wafer drying apparatus and a wafer drying method using the same that can reduce damage to the wafer and reduce the amount of gas used.

In order to achieve the object of the present invention, a first aspect of the present invention includes: a chamber in which a first rotating shaft is fixed to a side and a second rotating shaft is formed to be movable at an upper side thereof, and a first drain hole is formed at a lower side thereof; A tilt arm fixed to the first rotational shaft and the second rotational shaft and fixed to a cassette for mounting a wafer at an end thereof; A first nozzle for supplying an IPA / nitrogen gas to the cassette; A screw to move the second axis of rotation in a first direction or a second direction; And to provide a wafer dryer comprising a drive motor for rotating the screw.

Additionally, it is to provide a wafer dryer in which a second nozzle for injecting pure water is formed on the upper side of the chamber and a second drain hole is formed on the opposite side.

In order to achieve the object of the present invention, a second aspect of the present invention includes a chamber in which a tilt arm is inclined by moving a screw in a first direction or a second direction to fix a cassette on which the wafer is mounted on the tilt arm. A first step of causing the screw to move in the first direction so that the cassette is inclined with the interface of pure water; A second step of cleaning the wafer with pure water in the chamber; Injecting pure water into the chamber to discharge foreign substances floating on the pure interface to the outside; A fourth step of drying the wafer by injecting IPA / nitrogen gas into the cassette and draining pure water in the chamber through a drain hole; Moving the screw in the second direction to inject the IPA / nitrogen gas into the cassette to dry the wafer; And a sixth step of drying the wafer by injecting IPA / nitrogen gas into the cassette by moving the screw in the first direction.

Additionally, after the sixth step, the screw is moved in the first direction and the second direction to supply the IPA / nitrogen gas to the cassette to dry the wafer, but the fifth step and the sixth step. It is to provide a wafer drying method using a wafer dryer further comprising a seventh step of moving shorter than the moving distance of the step.

Additionally, the IPA / nitrogen gas in the fourth to sixth steps provides a wafer drying method using a wafer dryer supplied at 150 to 260 lpm.

 In addition, the IPA / nitrogen gas in the seventh step is to provide a wafer drying method using a wafer dryer supplied at 80 to 140 lpm.

According to the wafer dryer and the wafer drying method using the same according to the present invention, it is possible to effectively spray the IPA / nitrogen mixed gas can reduce the amount of use of the gas and to prevent the wafer damage by reducing the contact between the wafers.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1A and 1B are side views illustrating a wafer dryer according to the present invention. 2A and 2B are views showing a nozzle and a cassette employed in a wafer dryer. Referring to FIGS. 1A, 1B, 2A, and 2B, the wafer dryer includes a chamber, a first rotating shaft 102, a second rotating shaft 106, a nozzle 104, a tilt arm 101, and a screw 105. ).

The first rotating shaft 102 is attached to the side of the chamber and the second rotating shaft 106 is formed on the upper side of the chamber. Then, the first drain port 107 is formed in the lower portion. Then, second nozzles and second drains are formed on both sides of the upper part of the chamber. In the chamber, a drying process may be performed by a cleaning process using a cleaning liquid and a mixed gas of IPA and nitrogen.

The tilt arm 101 is connected to the first rotating shaft 102 and the second rotating shaft 106, and the stage is positioned at the lower end of the tilt arm 101, and the cassette 103 is fixed on the stage.

The screw 105 rotates and converts the rotary motion into a linear motion to move back and forth. Therefore, the second rotary shaft 106 connected to the screw 105 allows linear movement. The screw 105 is rotated in a clockwise or counterclockwise direction by the drive motor 100.

The nozzle 104 has a supply part 104b through which nitrogen is supplied and first nozzles 104a through which nitrogen is discharged, and has an H shape as shown in FIG. 2. Nitrogen supplied from the nozzle 104 is to prevent the slot 103 of the wafer 103a and the cassette 103 from adhering to each other, and is formed in the H-shaped column of the nozzle 104 to form the wafer 103a and the cassette 103. ) Is formed close to the contact portion of the slot can be effectively injected nitrogen into the space between the wafer 103a and the slot of the cassette 103. Thus, the amount of nitrogen used can be reduced.

The tilt arm 101 is positioned in the chamber by the first rotary shaft 102 and the second rotary shaft 106. In addition, a stage is formed at the end of the tilt arm 101 and the cassette 103 containing the wafer 103a is mounted on the stage. At this time, the cassette 103 is tilted by the tilt arm 101. Referring to the operation of the tilt arm 101 in more detail, the first rotary shaft 102 is fixed to the chamber and the second rotary shaft 106 is the right as shown in Figure 1a by the movement of the screw 105 in the upper portion of the chamber To the left or to the left as shown in FIG. Then, the inclination angle of the tilt arm 101 is adjusted according to the moving distance of the second rotation shaft 106. In addition, since the cassette 103 is fixed to the end of the tilt arm 101, when the tilt arm 101 is tilted, the cassette 103 is also tilted. The cassette 103 has a plurality of slots formed therein, and the wafer 103a is positioned in the slot so that the wafer 103a is fixed in the cassette 103.

3 is a flowchart illustrating a method of drying a wafer using a wafer drying apparatus according to the present invention. Referring to Figure 3,

First Step (ST 100): The cassette 103 is placed on the stage of the tilt arm 101.

Second Step ST 110: The screw 105 is rotated to move the tilt arm 101 and the second rotation axis 106 of the screw 105 in the first direction. At this time, the first direction is the right direction of the chamber. When the second rotation axis 106 moves in the first direction, the tilt arm 101 is tilted. When the tilt arm 101 is tilted, the wafer comes into contact with the slot of the cassette only by gravity and the opposite side is dropped.

Third Step (ST 120): Pure water is supplied into the chamber of the wafer dryer to clean the wafer 103a with pure water. In the method of cleaning the wafer 103a, the cassette 103 is positioned in the chamber in a state where pure water is contained in the chamber in advance so that the wafer 103a is positioned in the chamber. At this time, foreign matter on the surface of the wafer 103a floats at the interface of pure water. At this time, the pure water is discharged from the second nozzle formed on the upper left side of the chamber and the pure water is discharged from the second drain formed on the upper right side of the chamber. In this case, foreign matter floating at the interface of pure water flows out through the second drain with the pure water.

Fourth Step (ST 130): Lock the second nozzle and the second drain. Then, the IPA / nitrogen mixed gas is discharged through the first nozzles 104a formed in the nozzle 104. In addition, the first drain port 107 is opened to discharge the pure water in the chamber through the first drain port 107. The marangoni phenomenon occurs by the IPA and the nitrogen mixed gas, and the wafer 103a is dried. At this time, the cassette 103 is tilted by the tilt arm 101 so that the wafer 103a is not perpendicular to the water surface. If the pure water is drained through the first drain hole 107 in a state where the wafer 103a is positioned perpendicular to the surface of the pure water, a pressure difference between the pure water wafer and the wafer is generated and the wafer 103a is caused by the pressure. Is bent to attach adjacent wafers. If the wafers 103a are attached to each other, they do not fall off, and damage may occur to the wafers 103a even if they fall. Therefore, the interval between the respective wafers 103a becomes wider, thereby reducing the number of wafers 103a processed in one process. However, when pure water is drained through the first drain 107 in a state where the wafer 103a is inclined and not perpendicular to the surface of pure water, the wafer 103a does not adhere to the adjacent wafer 103a. Therefore, damage to the wafer 103a can be reduced, and the number of wafers 103a processed in one process will be more than if the angle was not tilted. In addition, the wafer 103a is separated from the slot of the cassette 103 by the IPA / nitrogen mixed gas. Therefore, the pure water which existed on the surface which the slot of the wafer 103a and the cassette 103 contact | connects is discharged | emitted.

Fifth Step (ST 140): The rotation of the screw 105 in the opposite direction allows the second rotation shaft 106 to move in the second direction. The second direction is the left direction of the chamber. In this state, the I nozzle 104 is sprayed with IPA / N2 so that the other side of the wafer 103a is separated from the slot, and the pure water existing at the surface where the slot 103 is in contact with the slot of the cassette 103 is discharged. do.

Sixth Step (ST 150): The rotational direction of the screw 105 is alternately rotated clockwise counterclockwise to allow the second rotation 106 axis to alternately move in the first and second directions. . Thus, the IPA / nitrogen mixed gas is continuously discharged so that pure water can be reliably discharged between the wafer 103a and the slot of the cassette 103.

Seventh Step (ST 160): The rotational direction of the screw 105 is rotated alternately clockwise and counterclockwise to allow the second rotation axis 106 to move alternately in the first and second directions, In addition, the rotation speed of the screw 105 is reduced to reduce the distance that the second rotation shaft 106 moves in the first direction and the second direction. When the distance that the second rotation axis moves in the first direction and the second direction is reduced, the angle at which the tilt arm 101 is inclined is reduced, and as a result, the angle at which the wafer 103a is inclined is reduced. Even if the angle of inclination of the wafer 103a is reduced, the wafer 103a is dried by the IPA / nitrogen mixed gas, and thus the pure water remaining in the slot of the wafer 103a or the cassette 103 is reduced. It can be easily dropped from the slot. In addition, the injection amount of the IPA / nitrogen mixed gas can be reduced.

Eighth Step (ST 170): Nitrogen in the chamber is removed.

Ninth Step ST 180: The cassette 103 is lowered from the stand to finish the drying process of the wafer 103a.

While preferred embodiments of the present invention have been described using specific terms, such descriptions are for illustrative purposes only and it is understood that various changes and modifications may be made without departing from the spirit and scope of the following claims. You must lose.

1A and 1B are side views illustrating a wafer dryer according to the present invention.

2A and 2B are views showing a nozzle and a cassette employed in a wafer dryer.

3 is a flowchart illustrating a method of drying a wafer using a wafer drying apparatus according to the present invention.

Claims (6)

A chamber having a first rotating shaft fixed to a side thereof, a second rotating shaft movable at an upper portion thereof, and a first drain hole formed at a lower portion thereof; A tilt arm fixed to the first rotational shaft and the second rotational shaft and fixed to a cassette for mounting a wafer at an end thereof; A first nozzle for supplying an IPA / nitrogen gas to the cassette; A screw to move the second axis of rotation in a first direction or a second direction; And A wafer dryer comprising a drive motor to rotate the screw. The method of claim 1, And a second nozzle for injecting pure water on the upper side of the chamber and a second drain on the opposite side. A chamber in which the tilt arm is inclined by moving the screw in the first direction or the second direction to fix the cassette on which the wafer is mounted on the tilt arm, and then the screw moves in the first direction so that the cassette A first step of inclining the interface; A second step of cleaning the wafer with pure water in the chamber; Injecting pure water into the chamber to discharge foreign substances floating on the pure interface to the outside; A fourth step of drying the wafer by injecting IPA / nitrogen gas into the cassette and draining pure water in the chamber through a drain hole; Moving the screw in the second direction to inject the IPA / nitrogen gas into the cassette to dry the wafer; And And a sixth step of drying the wafer by injecting IPA / nitrogen gas into the cassette by moving the screw in the first direction. The method of claim 3, wherein After the sixth step, the screw is moved in the first direction and the second direction to supply the IPA / nitrogen gas to the cassette to dry the wafer, but the moving distance between the fifth and sixth steps A wafer drying method using a wafer dryer further comprising a seventh step of moving shorter. The method of claim 3, wherein IPA / nitrogen gas in the fourth to sixth step, the wafer drying method using a wafer dryer is supplied at 150 ~ 260lpm. The method of claim 4, wherein IPA / nitrogen gas in the seventh step, a wafer drying method using a wafer dryer is supplied at 80 ~ 140lpm.

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