JP5612266B2 - Cooling system - Google Patents

Description

The present invention relates to the cooling equipment. More specifically, the present invention relates to a cooling device and a cooling method that can be suitably used for cooling a heated plate-shaped object.

  A silicon wafer as a raw material for a semiconductor device is obtained by thinly slicing a silicon single crystal rod. This silicon single crystal rod can be manufactured by a CZ (Czochralski) method in which a single crystal is grown from dissolved silicon in a quartz crucible, but when the silicon single crystal is pulled up, a slightly melted quartz crucible is obtained. Oxygen from is mixed into the dissolved silicon. This oxygen is mixed into the crystal as the single crystal silicon grows and remains as a thermal donor.

  When a silicon wafer doped with a thermal donor is used for manufacturing a semiconductor device, the quality of the semiconductor device is not constant, for example, the resistivity of the silicon wafer is not uniform.

  Therefore, in order to reduce thermal donors, a heat treatment is performed on the silicon wafer that has been subjected to an etching process (donor killer heat treatment). In this heat treatment, for example, a silicon wafer heated to about 550 to 800 ° C. is rapidly cooled to around 400 to 300 ° C. Under the present circumstances, both sides of the silicon wafer manually taken out from the heating furnace are used. Cooling by alternately applying the wind of the fan. Therefore, it is difficult to uniformly cool the silicon wafer, and a plurality of silicon wafers cannot be processed at the same time, so that work efficiency is poor.

  On the other hand, in the field of plate glass, the plate glass on the roller conveyor is cooled by blowing cooling air from a large number of outlets disposed above and below the roller conveyor (for example, Patent Documents). 1-2). In the apparatuses described in Patent Documents 1 and 2, the plate glass is swung in the in-plane direction in order to make the blowing of cooling air uniform.

Japanese Patent Publication No. 6-23069 Japanese Patent No. 2589975

  The apparatuses described in Patent Documents 1 and 2 can automatically cool a plate glass that is a plate-like object, but have a configuration in which cooling air is blown from a direction substantially perpendicular to the surface of the plate glass on the roller conveyor. Therefore, when simultaneously cooling a plurality of objects to be processed, it is necessary to lengthen the roller conveyor and dispose the cooling air jet outlet along the entire length of the roller conveyor. There is a problem that costs increase. Further, since the silicon wafer and the plate glass are different in strength in the heated state, cooling time, etc., the cooling method of the plate glass cannot be referred to.

The present invention has been made in view of such circumstances, and is capable of simultaneously cooling a plurality of plate-like objects to be processed and capable of cooling each object to be processed quickly and uniformly. It is an object of the present invention to provide the equipment.

A cooling device according to the present invention is a device that cools a heat-treated object by blowing cooling air,
A holder capable of holding at least one plate-like object to be processed standing;
An air supply means for supplying cooling air in a direction substantially parallel to the in-plane direction of the object to be processed held by the holder;
A swing mechanism that swings the holder so that an angle formed between an in-plane direction of the workpiece and a cooling air supply direction changes within a predetermined range and / or cooling air for the workpiece. A rotation mechanism for rotating the holder so that the supply direction of
The swing mechanism and / or the rotation mechanism includes a turntable on which the holder is placed and a motor for rotating or rotating the turntable in a heating chamber in which a workpiece is heated. , Further comprising a transport mechanism for transporting the workpiece to be cooled into the cooling chamber,
The cooling device is disposed adjacent to the heating chamber and outside thereof.
The cooling chamber in which the workpiece in the cooling device is cooled is communicated with the heating chamber, and the workpiece is transported between the cooling chamber and the heating chamber by a transport mechanism,
It said air supply means, said to supply cooling air from a direction intersecting the conveying direction and the horizontal direction the object to be treated is conveyed, on one side of the retainer, between the heating chamber and the cooling chamber It is arranged at a position spaced outside the opening ,
An opening / closing door for opening or closing the opening is provided, and the opening / closing door is closed when the object to be processed is heat-treated in a heating chamber and cooled in the cooling chamber .

In the cooling device according to the present onset bright, by swinging and / or rotate the holder can be held in a state of standing plate-shaped object to be processed, and the in-plane direction of the plate-shaped object to be processed The angle formed with the cooling air supply direction can be changed within a predetermined range. Therefore, the cooling air can be uniformly supplied to the plate-shaped workpiece, and as a result, the workpiece can be uniformly cooled. In addition, since the object to be processed is held in a standing state by the holder, it is possible to perform a cooling process on a plurality of objects to be processed at the same time. In this case, the holder can be swung and / or rotated. A plurality of objects to be processed held by the holder can be cooled quickly and uniformly.

The predetermined range may be a range of −45 ° to + 45 °. By changing the angle formed between the in-plane direction of the workpiece and the cooling air supply direction within a range of −45 ° to + 45 °, the cooling air is uniformly supplied to the entire workpiece. Thus, the workpiece can be cooled quickly and uniformly.

The swing mechanism or a rotation mechanism, a turntable the retainer is placed, that make up the turntable and motor for forward and / or reverse. Accordingly, by rotating the turntable forward and / or reverse with a motor, the object to be processed held by the holder placed on the turntable can be easily and reliably rocked and / or rotated. .

Prior Kihiya retirement unit, the holder of the heating chamber in which the processing object is heated, it Runode have a transport mechanism for transporting the cooling chamber in which the object to be treated is cooled, the object to be processed by hand And can be automatically moved from the heating chamber to the cooling chamber by the transfer mechanism.

The transport mechanism includes a rod;
The turntable is configured to be movable up and down,
At the tip of the rod is formed a locking portion that is open downward and can be locked to the holder, and
The lowering of the turntable that is organized as the engagement between the retainer and the rod end of the engagement portion on the turntable is released. Therefore , the engagement between the rod and the holder can be automatically released by lowering the turntable.

According to the cooling equipment of the present invention, it is possible to cool a plurality of plate-shaped object to be processed simultaneously, each object to be processed can be rapidly and uniformly cooled.

It is a plane explanatory view of one embodiment of the cooling device of the present invention. It is side surface explanatory drawing of the cooling device shown by FIG. It is a figure explaining the relationship between the flow of cooling air and a plate-shaped workpiece.

Hereinafter, with reference to the accompanying drawings, an embodiment of the cooling equipment of the present invention in detail.
FIG. 1 is an explanatory plan view of a cooling device C according to an embodiment of the present invention, and FIG. 2 is an explanatory side view of the cooling device C shown in FIG. The cooling device C is used for donor killer heat treatment for reducing thermal donors from a silicon wafer, and includes a holder 1 that holds a silicon wafer S, which is a plate-like object, and air that blows cooling air onto the silicon wafer S. The cooling fan 2 as supply means and the swing mechanism 3 that swings the holder 1 are mainly configured.

  The holder 1 has a structure in which a rectangular lower frame 13 and an upper frame 14 are fixed to column members 12 erected at four corners of a bottom plate 11, and between the long side frame members 14 facing the upper frame 14. A plurality of partition rods (not shown) that support the standing silicon wafer S and function as a partition material between the plurality of silicon wafers S are arranged at predetermined intervals. The holder 1 is made of quartz in consideration of heat resistance, cleanliness, thermal shock resistance, and the like, but can also be made of other materials such as high-purity thermal shock-resistant ceramics. Moreover, the holder 1 is not limited to the above-described one, and for example, a frame member provided with a groove or a protrusion may be used instead of the partition bar.

The cooling fan 2 includes a fan main body 21 and a motor 22 that rotates the fan main body 21, and the motor 22 is a mounting bar fixed to the side wall 4 a of the cooling chamber 4 in which the silicon wafer S is cooled. 23 is attached. The cooling fan 2 blows cooling air into the cooling chamber 4 in a substantially horizontal direction from an opening (not shown) formed in the side wall 4a. The wind speed is not particularly limited in the present invention, but is usually 3 to 15 m / sec. Further, the air volume can be appropriately selected in consideration of the volume of the cooling chamber 4 and the cooling rate, but is approximately 70 to 180 m ³ / min.

  The swing mechanism 3 includes a turntable 31 disposed in the cooling chamber 4 and a motor 32 disposed below the turntable 31 and rotating the turntable 31 forward and backward. The holder 1 is disposed on the turntable 31, and the silicon wafer S held by the holder 1 can be swung by alternately rotating and rotating the turntable 31 in this state.

  The elevating base 33 on which the turntable 31 and the motor 32 for rotationally driving the turntable 31 in the present embodiment are configured to be movable up and down by a drive mechanism 34 having a motor. By raising and lowering the turntable 31, as will be described later, the holder 1 disposed on the turntable 31 and a rod described later can be engaged, or the engagement can be released.

  A preliminary chamber 5 is provided adjacent to the cooling chamber 4 without being separated by a partition wall. The spare chamber 5 is provided with a fixed position 6 where the holder 1 can be placed. The holder 1 holding the cooled silicon wafer S is moved from above the turntable 31 by a transfer mechanism (not shown). It is pushed out onto the fixed position 6.

  The cooling chamber 4 is provided adjacent to a heating chamber 8 for heating the silicon wafer S to a predetermined temperature via an openable / closable door 7. The heating chamber 8 and the auxiliary chamber 5 are arranged at a position that forms an angle of 90 ° with the turntable 31 as the center. The heating chamber 8 is configured to be heated to about 100 to 1000 ° C. by an electric heater.

  A transport mechanism 40 for transporting the holder 1 is provided at a position opposite to the cooling chamber 4 across the heating chamber 8. The transport mechanism 40 is mainly composed of a rod 41 configured to freely advance and retract, and a drive mechanism 42 that moves the rod 41 forward or backward in the axial direction thereof. The drive mechanism 42 is separated from the rod 42 by a predetermined distance and is arranged in parallel below the rod 42, a ball screw nut 44 disposed on the outer periphery of the ball screw shaft 43, and the ball screw nut 44. The connecting member 45 is connected to the rod 42 and the motor 51 is connected to the ball screw shaft 43 via a speed reduction mechanism 50. The front end side end (the end opposite to the motor 51) and the rear end side end of the ball screw shaft 43 are rotatably supported by the bearing device 52, respectively. The ball screw nut 44 and the connecting member 45 connected thereto are configured to be movable along the axial direction of the ball screw shaft 43 by the rotation of the ball screw shaft 43. Therefore, by controlling the rotation of the motor 51, the rod 42 connected to the connecting member 45 can be advanced or retracted by a predetermined distance along the axial direction.

  At the tip of the rod 41, a locking portion 46 is formed which is made of a member having a substantially U-shaped cross-section with the lower part opened. The locking portion 46 is configured to be able to engage with an upper edge portion of the locking wall 47 erected from the end edge of the bottom plate 11 of the holder 1. The holder 1 can be moved along the axial direction of the rod 41 by advancing or retracting the rod 41 with the locking portion 46 and the locking wall 47 engaged.

Next, a method for cooling the silicon wafer S using the above-described cooling device C will be described.
First, the holder 1 on which a plurality of silicon wafers S are mounted is disposed at a predetermined position on the turntable 31 in the cooling chamber 4. At this time, the turntable 31 is in the lower position, and the open / close door 7 between the cooling chamber 4 and the heating chamber 8 slides upward so that the cooling chamber 4 and the heating chamber 8 are opened. Become.

  Next, the motor 51 is rotated to advance the rod 41 to a predetermined position. Thereafter, the turntable 31 is raised to engage the locking portion 46 at the tip of the rod 41 with the locking wall 47 of the holder 1. In the state where the turntable 31 is raised, the upper surface of the turntable 31 and the floor surface of the heating chamber 8 are substantially flush with each other. After the engagement, the motor 51 is reversed to retract the rod 41 to a predetermined position, whereby the holder 1 on the turntable 31 is pulled to the heating position in the heating chamber 8.

  Next, the opening / closing door 7 is slid downward to close the opening between the cooling chamber 4 and the heating chamber 8, and then the inside of the heating chamber 8 is heated by a heating means (not shown) so that the silicon wafer S has a predetermined temperature, For example, the temperature is raised to about 600 ° C., and heated and held at that temperature for a predetermined time, for example, 15 minutes to 2 hours. Thereafter, the motor 51 is rotated to advance the rod 41, the holder 1 is moved as close as possible to the opening / closing door 7, and then the opening / closing door 7 is slid upward to cool the cooling chamber 4 and the heating chamber 8. Open the opening between. Thereafter, the rod 41 is further advanced to a predetermined position, and the holder 1 holding the heated silicon wafer S is pushed out to a predetermined position on the turntable 31.

  In the above heating process, heating is performed in a state where the locking portion 46 at the tip of the rod 31 and the locking wall 47 of the holder 1 are engaged, so that the holder 1 after the heating is completed for the cooling operation. Moving to the turntable 31 can be performed in a short time. Further, since the holder 1 is moved onto the turntable 31 with the holder 1 being as close to the door 7 as possible, the temperature drop of the silicon wafer S that is the object to be processed is minimized. Can be suppressed.

  After the holder 1 is moved to a predetermined position on the turntable 31, the turntable 31 is lowered to engage the engaging portion 46 at the tip of the rod 41 with the engaging wall 47 of the holder 1. To release. Next, the motor 51 is reversed to retract the rod 41 to a predetermined position, and the opening / closing door 7 is slid downward to close the opening between the cooling chamber 4 and the heating chamber 8.

  Thereafter, the motor 22 of the cooling fan 2 is driven to rotate the fan main body 21, and the cooling air is sent into the cooling chamber 4. The holder 1 that holds the silicon wafer S is arranged on the turntable 31 so that the cooling air supply direction and the in-plane direction of the silicon wafer S that is the object to be processed substantially coincide with each other.

  At the time of cooling, the motor 32 is rotated forward and reverse at a predetermined cycle to swing the turntable 31 on which the holder 1 holding the silicon wafer S is placed. Thus, the angle formed by the in-plane direction of the silicon wafer S and the cooling air supply direction can be changed within a predetermined range. Therefore, the cooling air can be supplied uniformly to the silicon wafer S, and as a result, the silicon wafer S can be cooled quickly and uniformly.

  When cooling air is supplied in a direction parallel to the in-plane direction of the silicon wafer S, if the silicon wafer S is not moved, the upstream of the silicon wafer S as shown in FIG. The contact with the cooling air increases at the side end portions, and the cooling efficiency of the other portions deteriorates. In addition, the temperature difference in the surface becomes significant, and the silicon wafer S may break. On the other hand, as shown in FIG. 3B, when the silicon wafer S is swung, the cooling air can be uniformly supplied to the entire silicon wafer S. It can cool uniformly.

  The temperature of the silicon wafer S is measured by a radiation thermometer or the like, and after the temperature is lowered to a predetermined temperature within a predetermined time, for example, 3 minutes, the rotation of the motor 22 of the cooling fan 2 is stopped. Next, the cooling operation is completed by pushing the holder 1 holding the cooled silicon wafer S from the turntable 31 to a fixed position indicated by 6 in the preliminary chamber 5 by a transfer mechanism (not shown).

[Other variations]
The above-described embodiments are examples of the present invention and are not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims for patent, and further includes all modifications equivalent to the configuration of the scope of claims for patent.

For example, in the above-described embodiment, the holder for holding the silicon wafer S is swung in order to uniformly supply the cooling air to the silicon wafer S that is the object to be processed. In some cases, the cooling air can be uniformly supplied to the object to be processed by rotating the holder. Specifically, a processing object such as a box that is not as thin as the silicon wafer S can uniformly supply cooling air to the processing object by rotating the holder.
Moreover, as a mechanism for moving the rod 41 in the axial direction and a mechanism for moving the turntable 31 up and down, for example, a hydraulic device or the like can be used, and is not particularly limited in the present invention.

1 Holder 2 Cooling fan (air supply means)
DESCRIPTION OF SYMBOLS 3 Oscillation mechanism 4 Cooling chamber 5 Preliminary chamber 7 Opening / closing door 8 Heating chamber 21 Fan main body 22 Motor 31 Turntable 40 Transfer mechanism 41 Rod 42 Drive mechanism 43 Ball screw shaft 44 Ball screw nut 45 Connecting member 46 Locking portion 47 Locking wall 51 motor

Claims (4)

An apparatus for cooling a heat-treated object by blowing cooling air,
A holder capable of holding at least one plate-like object to be processed standing;
An air supply means for supplying cooling air in a direction substantially parallel to the in-plane direction of the object to be processed held by the holder;
A swing mechanism that swings the holder so that an angle formed between an in-plane direction of the workpiece and a cooling air supply direction changes within a predetermined range and / or cooling air for the workpiece. A rotation mechanism for rotating the holder so that the supply direction of
The swing mechanism and / or the rotation mechanism includes a turntable on which the holder is placed and a motor for rotating or rotating the turntable in a heating chamber in which a workpiece is heated. , Further comprising a transport mechanism for transporting the workpiece to be cooled into the cooling chamber,
The cooling device is disposed adjacent to the heating chamber and outside thereof.
The cooling chamber in which the workpiece in the cooling device is cooled is communicated with the heating chamber, and the workpiece is transported between the cooling chamber and the heating chamber by a transport mechanism,
It said air supply means, said to supply cooling air from a direction intersecting the conveying direction and the horizontal direction the object to be treated is conveyed, on one side of the retainer, between the heating chamber and the cooling chamber It is arranged at a position spaced outside the opening ,
An opening / closing door for opening or closing the opening is provided, and the opening / closing door is closed when the object to be processed is heated in the heating chamber and cooled in the cooling chamber . The cooling device according to claim 1 , wherein the open / close door moves in the vertical direction to open and close the opening .   The cooling device according to claim 1 or 2, wherein the predetermined range for swinging the holder is a range of -45 ° to + 45 °. The transport mechanism includes a rod;
The turntable is configured to be movable up and down,
At the tip of the rod is formed a locking portion that is open downward and can be locked to the holder, and
The cooling device according to any one of claims 1 to 3, wherein the cooling device is configured to be disengaged between the holder on the turntable and the locking portion at the tip of the rod when the turntable is lowered.

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