JPH0637083A - Dryer for semiconductor wafer - Google Patents

Abstract

PURPOSE:To prevent natural drying of a semiconductor wafer which is finished for cleaning during a period until drying is started. CONSTITUTION:A holder 14 to be rotated through a spindle 16 is provided in a fixed chamber 2, and a tank 20 is so mounted at the holder 14 as to be rotated substantially at 90 degrees within a vertical plane at a rotary shaft 26 as a center. A wafer cassette in which a semiconductor wafer is contained is contained in the tank 20. An injection tube 28 for externally pouring water in the tank 20 is provided in the chamber 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying device used in a semiconductor manufacturing process for drying a semiconductor wafer after cleaning.

[0002]

2. Description of the Related Art A semiconductor wafer drying apparatus is provided with a fixed chamber having an openable / closable lid and a holder for rotating the semiconductor wafer in a horizontal plane to dry the semiconductor wafer. There is a commercially available rotary drying device that stores a wafer cassette in a holding unit and rotates the wafer cassette in a chamber to dry the wafer cassette.

[0003]

A semiconductor wafer is not immediately dried after being cleaned, but a waiting time exists between the cleaning and drying of the wafer, and the semiconductor wafer is left in the atmosphere during standby. Further, since a rotary dryer is usually capable of holding a plurality of wafer cassettes, the cassettes which have been cleaned have to wait in the atmosphere until a plurality of wafer cassettes are prepared. .
When the wafer after cleaning is left in the atmosphere, the water droplets attached during the cleaning step are naturally dried on the surface of the wafer, leaving a trace of drying as a stain, which adversely affects the characteristics of semiconductor elements formed thereafter. SUMMARY OF THE INVENTION It is an object of the present invention to provide a drying apparatus in which a semiconductor wafer that has been cleaned is prevented from naturally generating stains by preventing it from being naturally dried before the drying process is started. Is.

[0004]

A drying apparatus of the present invention comprises a fixed chamber having an openable / closable lid, a holder for rotating a semiconductor wafer in a horizontal plane in the chamber to dry a semiconductor wafer, and the holder. The wafer cassette, which is attached to the semiconductor wafer and stores the semiconductor wafers, is stored, and a tank having a drainage port that can be opened and closed and a water injection pipe for injecting water into the tank are provided. In a preferred aspect, the tank is provided with an ultrasonic transducer. The drying apparatus of the present invention also includes a steam supply mechanism that supplies steam into the chamber instead of pouring water into the tank, and an exhaust mechanism that exhausts the inside of the chamber.

[0005]

By providing the tank capable of injecting water, the semiconductor wafer is soaked in water in the tank after the cleaning is completed and before the drying process is started, whereby natural drying is prevented. If the tank is provided with an ultrasonic vibrator, ultrasonic waves can be applied to the semiconductor wafer in a standby state, and dust is unlikely to adhere to the wafer surface. By filling the inside of the chamber with water vapor or steam instead of immersing the semiconductor wafer in water during standby, the wafer will not naturally dry during standby.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical cross-sectional view of an essential part of one embodiment. Two
Is a fixed chamber, and is provided with a lid 4 which is opened when the wafer is taken in and out and closed when the wafer is dried. A filter (not shown) is provided in the center of the lid 4 for filtering air taken in from the outside. Although not shown in the figure, the lid 4 is provided with a mechanism for opening and closing the lid 4 and for opening and closing and locking the lid 4 when the lid 2 closes the chamber 2. A holding unit 14 that rotates in a horizontal plane to dry the semiconductor wafer in the chamber 2
Is provided and a spindle 16 fixed to the bottom of the holding part 14 projects downward from the bottom surface of the chamber 2 to rotate the holding part 14.
A spindle motor 18 is provided to drive the holder 14 to rotate via the motor 6. A gear meshes between the spindle motor 18 and the spindle 16.

A wafer cassette containing semiconductor wafers is housed in the holding unit 14, and a tank 20 having a water injection port that can be opened and closed is attached. In order to position the holder 14 when mounting or removing the wafer cassette in or from the tank 20 and when pouring water into the tank 20, a holder positioning motor 22 is provided below the chamber 2.
Is provided, and the motor 22 and the spindle 16 are connected by a belt. Although not shown in the figure, a lock mechanism for locking the positioned holding portion 14 and a cassette confirmation sensor for confirming that the wafer cassette is present in the chamber 2 are also provided.

FIG. 2 is a sectional view showing the inside of the chamber 2. A holding unit 14 that rotates via a spindle 16 is provided in the fixed chamber 2, and a tank 20 is attached to the holding unit 14 so that it can rotate 90 degrees in a vertical plane about a rotation shaft 26. . The chamber 2 is provided with a water injection pipe 28 for injecting water into the tank 20 from the outside.

As shown in FIG. 3, the tank 20 is provided with shutters 30 that can be opened and closed on its side surface and bottom surface.
The water injected from the water injection pipe 28 can be stored in the tank 20 by closing the shutter 30, and the water in the tank 20 is drained by opening the shutter 30 before drying.

FIG. 4 shows a mechanism for rotating the tank 20 in the vertical plane by about 90 degrees. The tank 20 is rotatably attached to the holding unit 14 about a shaft 26. A mechanism 36 for converting the rotation of the motor into the vertical rotation of the push-up rod 34 is provided at the bottom of the tank 20.
4 is moved upward to hold the tank 20 in a state where water can be poured with the opening upward, and the push-up bar 34 is moved downward to move the tank 20 to approximately 90 degrees in a vertical plane.
It can be rotated once to orient the opening laterally so that it is ready for the drying process. A wafer cassette 31 (FIG. 3) containing wafers is stored in the tank 20.

FIG. 5 shows the drain shutter 30 of the tank 20. The solid line position of the shutter 30 represents a closed state, and the broken line position represents an opened state for drainage.

Next, the operation of the embodiment shown in FIGS. 1 to 5 will be described. The wafer cassette 31, which stores the wafers that have undergone the cleaning process, is stored in the tank 20 with the opening thereof facing upward, and pure water is poured into the tank 20 from the water injection pipe 28. Soak in water to keep it from drying out. The lid 4 is opened when the wafer cassette 31 is taken in and out, and otherwise closed. When transferring to the drying process, the shutter 30 of the tank 20 is opened to open the tank 2.
0, and then the push-up bar 34 is lowered to rotate the tank 20 in the vertical plane by about 90 degrees, and then the tank 20 is rotated.
The bottom surface of the is adhered to the holding portion 14. Then, the holding unit 14 is rotated by the spin motor 18 to dry the semiconductor wafer.

In the above embodiment, the ultrasonic vibrator can be attached to the bottom surface or the side surface of the tank 20. This ultrasonic vibrator applies ultrasonic waves to a semiconductor wafer in a standby state which is housed in the tank 20 and immersed in water, and thereby prevents dust from adhering to the wafer surface.

FIG. 6 shows the main part of another embodiment. A holding portion 14 a that is rotated by a spindle 16 is provided in the chamber 2. The wafer cassette 31 containing the semiconductor wafer is directly held by the holding portion 14a. Steam is supplied to the chamber 2 from an external steam generator 40 through a three-way valve 42 and a steam pipe 44. An exhaust pump 46 is connected to the steam pipe 44 via a three-way valve 42.

In the embodiment shown in FIG. 6, the wafer cassette 31 containing the cleaned semiconductor wafer is held by the holding portion 14a, and the lid 4 is held in the closed state. Then, in the chamber 2, the three-way valve 42 is switched to connect the steam pipe 44 and the steam generator 40, and the steam 43 causes an organic solvent such as alcohol or water vapor 43 into the chamber.
Is supplied, the inside of the chamber 2 is oversaturated, and natural drying of the wafer is prevented. When a predetermined number of wafer cassettes are held in the chamber 2 and then the drying process is performed, the three-way valve 42 is switched to connect the exhaust pipe 44 and the pump 46, and the chamber 46 is exhausted by the pump 46. After that, the holding portion 14a rotates in the horizontal plane via the spindle 16 to perform drying. The present invention is not limited to the embodiments and can be variously modified without departing from the scope of the claims.

[0016]

According to the first aspect of the present invention, since the semiconductor wafer after cleaning is soaked in water while waiting for the drying process, natural drying does not occur and stains are generated to adversely affect the semiconductor element. Will disappear. By applying ultrasonic vibration while being immersed in water, dust in the water can be prevented from adhering to the wafer. According to the third aspect of the present invention, the semiconductor wafer is prevented from naturally drying by filling the chamber with steam during the standby from the cleaning process to the drying process.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an essential part showing an embodiment.

FIG. 2 is a vertical cross-sectional view showing the inside of the chamber of the same embodiment.

FIG. 3 is a perspective view showing a holding portion and a tank portion in the embodiment.

FIG. 4 is a side view showing a rotation mechanism of the tank in the embodiment.

FIG. 5 is a vertical sectional view showing the shutter of the tank in the embodiment.

FIG. 6 is a vertical sectional view of an essential part showing another embodiment.

[Explanation of symbols]

 2 Chambers 14 and 14a Holding part 16 Spindle 18 Spindle motor 20 Tank 28 Water injection pipe 30 Shutter 31 Wafer cassette 40 Steam generator 46 Pump

Claims (3)

[Claims] 1. A fixed chamber having an openable / closable lid, a holder for rotating a semiconductor wafer in a horizontal plane to dry the semiconductor wafer, and a wafer cassette attached to the holder and containing a semiconductor wafer. An apparatus for drying a semiconductor wafer, comprising: a tank having a drainage port that can be opened and closed and a water injection pipe that injects water into the tank. 2. The apparatus for drying a semiconductor wafer according to claim 1, wherein the tank is provided with an ultrasonic transducer. 3. A fixed chamber having an openable / closable lid, a holding unit for holding a wafer cassette containing a semiconductor wafer and rotating the wafer cassette in a horizontal plane to dry the semiconductor wafer, and inside the chamber. An apparatus for drying a semiconductor wafer, comprising: a vapor supply mechanism for supplying vapor into the chamber; and an exhaust mechanism for exhausting the inside of the chamber.