JP2008028318A - Conveying device and conveying method of semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new semiconductor wafer conveying device using a Peltier element. <P>SOLUTION: A semiconductor wafer conveying device is characterized by being provided with: a Peltier element 12 that is formed in a ring shape of a flat plate; a ring-shaped holding plate 14 comprising an insulating plate that is fixed to the lower surface of the Peltier element 12; a tubular heat sink 16 comprising insulating material that is fixed to the upper surface of the Peltier element 12; a cover 18 closing the upper surface side of the heat sink 16; a suction device 29 removing the air in a chamber 20 that is closed by the cover 18; a heating medium circuit 30 that is formed in the heat sink 16; a liquid feeding part 37 feeding the heating medium to the heating medium circuit 30; an energizing device 15 energizing the Peltier element 12; and a mobile mechanism 38 cooperating with the cover 18 and moving the heat sink 12 or the like with the cover 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor wafer transfer apparatus and transfer method.

In the field of semiconductor wafer manufacturing, the polishing surface has been increased and non-contact handling is also required for handling during loading and unloading. There is a method of using a so-called Bernoulli chuck that is not in contact with the wafer (Japanese Patent Laid-Open No. 8-203984).
In the case of using this Bernoulli chuck, since it can be transferred to the wafer in a non-contact manner, it is effective for transferring a high-temperature wafer.

JP-A-8-203984

However, when the Bernoulli chuck is used, there are the following problems to be solved.
That is,
1. Since the negative pressure generated by the flow of nitrogen gas is used, the holding power is weak.
2. Pins and guides are necessary for positioning the wafer, and mechanical contact of the pins and guides with the wafer is inevitable.
3. Noise is generated due to the consumption of a large amount of nitrogen gas.
4). Mixing of particles into nitrogen gas is unavoidable, and particles adhere to the wafer surface, which hinders flat polishing of the wafer surface in a subsequent process, for example, a polishing process.
5. In a state where the wafer is housed in a carrier, such as a double-side polishing apparatus, the wafer cannot be taken out therefrom. Therefore, it could not be used for loading and unloading of wafers with a double-side polishing apparatus.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a new semiconductor wafer transfer apparatus and transfer method using Peltier elements.

  A semiconductor wafer transfer device according to the present invention includes a Peltier element formed in a flat ring shape, a ring-shaped holding plate made of an insulating plate that covers the lower surface of the Peltier element and is fixed to the lower surface, and the Peltier element. A cylindrical heat sink made of an insulating material that covers the upper surface of the element and is fixed to the upper surface; a lid that closes the upper surface of the heat sink; and a heat sink space (hereinafter referred to as a chamber) that is closed by the lid A suction device that excludes air, a heat medium circuit formed on the heat sink, a liquid feeding unit that supplies the heat medium to the heat medium circuit, an energization device that energizes the Peltier element, and the lid And a moving mechanism for moving the heat sink, the Peltier element, and the holding plate together with the lid.

The moving mechanism includes a heat sink, a Peltier element, a vertical movement mechanism for moving the holding plate up and down, and a horizontal movement mechanism for moving it horizontally along with the lid.
The holding plate and the heat sink may be formed of ceramics.

  A semiconductor wafer transfer method according to the present invention is a semiconductor wafer transfer method using any one of the above semiconductor wafer transfer devices, the step of supplying a liquid onto the surface of the wafer to be transferred, And a step of bringing the holding plate lower surface side of the transfer device into contact with the surface of the liquid supplied to the wafer surface, and supplying the heat medium to the heat medium circuit of the heat sink by the liquid feeding unit. The Peltier element is energized by an energizing device, the liquid is cooled and solidified, the wafer is fixed to a holding plate, and the air in the chamber is removed by the suction device to make the chamber space negative. And a step of moving the transfer device by the moving device to transfer the wafer to a desired location.

According to the present invention, the liquid (pure water) is frozen by the Peltier element and the wafer is fixed to the holding plate by the freezing force, and the space (chamber) in the heat sink that is the sealed space is made negative pressure, The wafer can be strongly held on the holding plate.
In addition, since the wafer is held by solidifying (freezing) the liquid, it is different from holding by completely non-contact, but when holding the wafer, the wafer does not move, so the conventional Bernoulli chuck There is no need to mechanically hold the wafer with pins or guides as in the case of. In addition, by using a pure liquid such as pure water as the liquid, there is no particle adhesion or contamination on the wafer. Therefore, it is suitable for wafer loading and unloading in a semiconductor wafer double-side polishing apparatus. Can be used.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory diagram showing an outline of the transport device 10.
In FIG. 1, reference numeral 12 denotes a Peltier element formed in a flat ring shape from a known material. The size of the Peltier element 12 is smaller than the wafer W to be transferred, and is formed on a donut-shaped perforated plate.

  A ring-shaped holding plate 14 made of an insulating plate such as ceramics is fixed to the lower surface of the Peltier element 12 so as to cover the lower surface side. An appropriate adhesive may be used for fixing the holding plate 14. An energizing device 15 energizes the Peltier element 12. The energization device 15 is provided with a control unit (not shown) that switches the direction of current.

  Further, a cylindrical heat sink 16 made of an insulating material such as ceramics is fixed so as to cover the upper surface of the Peltier element 12. The heat sink 16 is preferably the same size as the Peltier element 12. An appropriate adhesive is also used for fixing the heat sink 16. The upper surface side of the heat sink 16 is closed by a lid 18, thereby forming a chamber 20.

  A screw hole 22 is formed in the lid 18, a pipe joint 24 is screwed into the screw hole 22, a pipe 26 is connected to the pipe joint 24, and the pipe 26 is connected to a negative pressure source 28, whereby the chamber The inside of the space 20 can be made negative pressure by eliminating the air in the space 20. A suction device 29 is configured by the pipe joint 24, the pipe 26, the negative pressure source 28, and the like.

  A heat medium circuit 30 in which the heat medium is circulated is formed in the heat sink 16. A heat medium such as tap water is circulated in the heat medium circuit 30 by a circulation pipe 32 and a circulation pump 34. Reference numeral 36 denotes a tank. A liquid feeding part 37 is constituted by the circulation pipe 32, the circulation pump 34, and the like.

The transport apparatus 10 includes a moving mechanism 38 that is linked to the lid 18 and moves the heat sink 16, the Peltier element 12, and the holding plate 14 together with the lid 18.
Reference numeral 40 denotes a vertical movement mechanism that forms part of the moving mechanism 38. In the present embodiment, the vertical movement mechanism 40 uses a cylinder device. That is, the cylinder device 40 is fixed on the swing arm 42, and the vertical moving plate 45 is fixed to the lower end of the rod 44, and the vertical moving plate 45 is connected to the lid body 18 via the connecting rod 46.

Therefore, by moving the rod 44 up and down by the cylinder device 40, the heat sink 16, the Peltier element 12, and the holding plate 14 can be moved up and down together with the lid 18.
Further, as shown in FIG. 2, the swing arm 42 is configured to reciprocate in a horizontal plane around the rotation shaft 48. As a result, the wafer W is held at the X position (for example, the wafer W storage position) and transported to the Y position (for example, a polishing apparatus) and released, or the wafer is held at the Y position and transported to the X position and discharged. Can be.

  The swinging arm 42, the drive motor 50, etc. constitute a horizontal movement mechanism. The horizontal movement mechanism is not limited to the above. For example, the horizontal movement mechanism may be configured by a cylinder device to perform linear reciprocation.

Next, a method for transporting the wafer W by the transport apparatus 10 will be described.
First, at the holding position of the wafer W (for example, the storage position of the wafer W), a freezing liquid (for example, pure water) is supplied onto the surface of the wafer W from the nozzle 52 (FIG. 1). As a result, the liquid forms a thin film on the surface of the wafer W.

  Next, the horizontal movement mechanism and the vertical movement mechanism are driven to bring the transfer device 10 closer to the wafer W, and the lower surface of the holding plate 14 of the transfer device 10 is supplied to the surface of the wafer W to form a thin film surface. Abut.

  Next, the Peltier element 12 is energized by the energization device 15 while supplying the heat medium to the heat medium circuit 30 of the heat sink 16 by the liquid feeding unit 37, the liquid is cooled and solidified (freezing), and the wafer W is held on the holding plate 14. Secure to. The high temperature side of the Peltier element 12 is absorbed by the heat medium and radiated. As the liquid freezes, the chamber 20 in the heat sink 16 becomes a sealed space.

  Next, the air in the chamber 20 of the heat sink 16 is removed by the suction device 29, and the internal space of the heat sink 16 is set to a negative pressure. Thereby, the wafer W is completely held on the holding plate 14 side by the freezing force of the liquid and the negative pressure in the chamber 20. At this time, if freezing is insufficient or the distance from the wafer W is excessive, the negative pressure in the chamber does not increase. By measuring this, it can be determined whether icing and holding have been performed reliably.

Next, the vertical movement mechanism and the horizontal movement mechanism are driven to move the wafer W upward and horizontally, and move it to a predetermined position.
The controller of the energization device 15 switches the energization direction to invert the high temperature side and the low temperature side of the Peltier element 12. The Peltier element 12 absorbs heat from the heat medium, dissipates it to the frozen liquid, and dissolves it. At the same time, the holding of the wafer W can be released by setting the inside of the chamber 20 to a positive pressure.

  As described above, in the present embodiment, the liquid (pure water) is frozen by the Peltier element 12 to fix the wafer W to the holding plate 14 by the icing force, and the chamber 20 in the heat sink 16 that is a sealed space is negatively charged. By using the pressure, the wafer W can be strongly held on the holding plate 14.

  In this embodiment, since the wafer W is held by solidifying (freezing) the liquid, it is different from holding by complete non-contact, but the wafer W may move when holding the wafer W. Therefore, it is not necessary to mechanically hold the wafer W with pins and guides as in the case of the conventional Bernoulli chuck. In addition, by using a pure liquid such as pure water as the liquid, there is no particle adhesion or contamination on the wafer W. Therefore, it is suitable for wafer loading and unloading in a semiconductor wafer double-side polishing apparatus. Can be used.

It is explanatory drawing of the outline of the conveyance apparatus of a semiconductor wafer. It is explanatory drawing which shows rocking | fluctuation of the rocking | fluctuating arm of a conveying apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor wafer transfer device 12 Peltier element 14 Holding plate 15 Current supply device 16 Heat sink 18 Lid 20 Space 22 Screw hole 24 Pipe joint 26 Pipe 28 Negative pressure source 29 Suction device 30 Heat medium circuit 32 Circulation pipe 34 Circulation pump 36 Tank 37 Liquid feeding part 38 Moving mechanism 40 Vertical movement mechanism (cylinder device)
42 Oscillating arm 44 Rod 45 Vertical moving plate 46 Connecting rod 48 Rotating shaft 50 Drive motor 52 Nozzle

Claims (4)

A Peltier element formed in a flat ring shape;
A ring-shaped holding plate made of an insulating plate that covers the lower surface of the Peltier element and is fixed to the lower surface;
A cylindrical heat sink made of an insulating material that covers the upper surface of the Peltier element and is fixed to the upper surface;
A lid for closing the upper surface side of the heat sink;
A suction device for excluding air in the heat sink space closed by the lid;
A heat medium circuit formed on the heat sink;
A liquid feeding section for supplying a heat medium to the heat medium circuit;
An energizing device for energizing the Peltier element;
A semiconductor wafer transfer apparatus, comprising: a movement mechanism that is linked to the lid body and moves the heat sink, Peltier element, and holding plate together with the lid body.   2. The semiconductor wafer transfer apparatus according to claim 1, wherein the moving mechanism includes, together with the lid, a heat sink, a Peltier element, a vertical movement mechanism for moving the holding plate up and down, and a horizontal movement mechanism for moving it horizontally.   3. The semiconductor wafer transfer apparatus according to claim 1, wherein the holding plate and the heat sink are made of ceramics. A semiconductor wafer transfer method using the semiconductor wafer transfer apparatus according to claim 1,
Supplying liquid onto the surface of the wafer to be transferred;
Bringing the transfer device closer to the wafer and bringing the holding plate lower surface side of the transfer device into contact with the surface of the liquid supplied to the wafer surface;
Supplying the heat medium to the heat medium circuit of the heat sink by the liquid feeding unit, energizing the Peltier element by the energizing device, cooling and solidifying the liquid, and fixing the wafer to the holding plate;
Removing the air in the heat sink space by the suction device to make the heat sink space negative pressure;
A method of transporting a semiconductor wafer, comprising the step of transporting the wafer to a desired location by moving the transport device by the moving device.