JP2001015574A - Wafer transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer transfer apparatus having a simple structure at low costs. SOLUTION: This wafer transfer apparatus includes: a movable transfer device having thrust-up pins 12 upwardly or downwardly movable while supporting at least a wafer 1, induction field receiving means 10, and driving means 11 for driving the pins with an induction field; a guide rail 8 for regulating a moving path of the device 2; and induction field generating means 9 for applying the induction field to the means 10 of the device 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer transfer apparatus, and more particularly to a wafer transfer apparatus for transferring a wafer between a plurality of semiconductor manufacturing apparatuses in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor integrated circuit,
In order to process various wafers, wafers must be transported between various semiconductor manufacturing apparatuses. As one of such wafer transfer apparatuses, there is a magnetic levitation type wafer transfer apparatus using a linear motor. This is used, for example, in a case where a single wafer is transported and processed between apparatuses such as a stepper, a coater, and a developer in a photolithography process.

The magnetic levitation type wafer transfer device has a feature that the transfer device on which the wafers are loaded floats and is not in contact with the surroundings, thereby preventing generation of dust. Therefore, the wafer is transferred to the magnetic levitation type wafer transfer device. Loading must be performed in a floating state. As such a wafer transfer device, there is, for example, a device described in JP-A-4-132238. The conventional wafer transfer device will be described below with reference to the drawings.

FIG. 3 is a sectional view of a conventional wafer transfer device, in which a wafer 1 is transferred in a direction perpendicular to the plane of the drawing. In the figure, reference numeral 1 denotes a wafer, and 2 denotes a magnetic levitation type transfer device for loading and transferring the wafer 1, and an aluminum plate 3 and a rare earth permanent magnet 4 are embedded therein. 5 is a magnetic levitation magnetic coil, 6 is a lateral guiding magnetic coil, 8 is a guide rail, 12 is a push-up pin, and 16 is a push-up pin passage hole. Here, the push-up pins 12 are mechanically driven by a wafer loading device provided outside, and the drive unit is installed on the guide rail side.
It is configured to lift the pin upward. In addition,
FIG. 3 shows that the transfer device 2 is stopped and the wafer 1 is
2 indicates that it is in a state of being lifted up.

The operation will be described below. First, to the magnetic levitation magnetic force coil 5 and the lateral direction magnetic force coil 6 installed on the guide rail 8, a magnetic field having the same polarity as that of the repulsive force acting on the permanent magnet 4 mounted on the transfer device 2, that is, the same polarity is applied. By causing the transfer device 2
And the guide rail can be stably floated by about 1 to 5 mm. A thrust based on Lorentz force is generated by a magnetic field generated by passing an alternating current through the thrust generating coil 7 and an eddy current generated on the surface of the aluminum plate 3, and the wafer 1 is loaded on the transfer device 2. Conveyed by. At the time of attaching and detaching the wafer 1, four positions are set on the transfer device 2 (only two positions are visible in FIG. 3). The wafer 1 can be lifted up or down. The lifted-up wafer is moved from the transfer device 2 by a wafer transfer arm (not shown).

[0006]

However, in such a configuration, a portion where movement of the wafer 1 from the transfer device 2 or loading of the wafer 1 onto the transfer device 2 is required, that is, a semiconductor manufacturing apparatus is installed. It is necessary to incorporate the push-up pin 12 and its driving device on the guide rail side where it is located. For this reason, as the number of locations where the wafer is transferred to and from the wafer transfer device 2 increases, the same number of push-up pins 12 and their driving devices must be provided, which complicates the structure and increases the cost of the device. was there.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a low-cost and simple wafer transfer apparatus.

[0008]

According to the present invention, there is provided a wafer transfer apparatus comprising: a push-up pin capable of moving at least upward or downward while supporting a wafer; an induced magnetic field receiving means; and a drive for driving the push-up pin by the induced magnetic field. And a guide rail for defining a moving path of the transfer device, and a guide magnetic field generating means for applying a guide magnetic field to the guide magnetic field receiving means of the transfer device.

According to the present invention, the means for lifting up the wafer is provided in the wafer transfer apparatus itself. Therefore, even if the number of wafer transfer destinations increases, the number of facilities hardly increases as in the prior art, resulting in a large cost. Down becomes possible.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are used for the same parts as those of the related art.

FIG. 1 is a sectional view showing a configuration of an embodiment of a wafer transfer apparatus according to the present invention. FIG. 1 (a) shows a loaded state of a wafer, and FIG. 1 (b) shows a transferred state of a wafer. I have. In the figure, reference numeral 1 denotes a wafer, and 2 denotes a magnetic levitation type transfer device for transferring and stacking the wafer 1, and an aluminum plate 3 and a rare earth permanent magnet 4 are embedded therein. 5 is a magnetic levitation magnetic coil, 6 is a lateral guiding magnetic coil, 7 is a propulsion generating coil of the transfer device 2, 8 is a guide rail, 9
Is an induction magnetic field generating coil, 10 is an induction magnetic field receiving coil, 1
Reference numeral 1 denotes a structure in which a push-up pin driving coil is fixed to the transfer device 2 to generate a magnetic force, and is embedded in the transfer device 2. 12 is a push-up pin, 13 is a cover for covering the push-up pin, 14 is a rectifier circuit, and 15 is a push-up pin cylinder. The wafer 1 shown in FIG. 1 is moved by the transfer device 2 in a direction perpendicular to the plane of the paper, and the wafer 1 is in a lift-up state supported by the push-up pins 12.

The operation of the thus configured wafer transfer device will be described below. First, the transport device 2
Is lifted about 5 mm from the guide side by the repulsive action of the rare earth permanent magnet 4 and the magnetic levitation magnetic coil 5, and the gap of about 5 mm from the guide rail 8 by the repulsion of the rare earth permanent magnet 4 and the lateral guide magnetic coil 6. Is kept stable.

The lift-up by the push-up pins 12 in one transfer of the wafer in the transfer device 2 is performed in a floating state of the transfer device 2, and is performed by a wafer stacking device (not shown) provided on the guide rail 8 side. Controlled. More specifically, the wafer loading apparatus transmits an AC current to the induction magnetic field generating coil 9 so that power is transmitted to the induction magnetic field receiving coil 10 in a non-contact manner. As a result, a repulsive force is generated between the push-up pin driving coil 11 and another rare-earth permanent magnet 4 attached to the lowermost part of the push-up pin 12 as a substantially DC magnetic field, and the push-up pin is pushed up by about 5 mm, and the wafer 1 is measured from the surface of the transfer device 2 and lifted upward by about 4 mm. The time required for lifting is typically about 0.5 to 1 second, but this speed can be freely and easily compared to the conventional mechanical drive system by changing the power supplied to the induction magnetic field generating coil 9. Can be changed to The driving speed may be set according to the required time reduction of the processing step.

By arranging four push-up pins 12 on the side of the transfer device 2, the wafer 1 can be lifted up stably. The lifted-up wafer 1 can be easily transferred from the transfer device 2 by a wafer transfer arm or the like.

As shown in FIG. 1B, the wafer 1 loaded on the transfer device 2 is not lifted up as shown in FIG. There is no induction magnetic field generating coil 9 for driving the pin 12. In the steady state during the transfer without lifting the wafer 1, the wafer 1 is provided at the end of the transfer device 2.
It is fixed by a step of about 5 mm, and has an effect of suppressing generation of dust due to friction between the front surface of the transfer device 2 and the back surface of the wafer 1 due to wafer movement when the transfer device 2 is accelerated or decelerated.

In the present embodiment, a step is provided at a portion corresponding to the outer peripheral portion of the wafer of the transfer device 2 so that the wafer 1 does not move when the push-up pins are lowered. The wafer 1 may be fixed by providing three or more projections on the surface of the transfer device 2 corresponding to the outer peripheral portion of the wafer.

FIG. 2 is a cross-sectional view of a push-up pin used in the transfer device shown in FIG. It has a structure and suppresses the generation of dust from the push-up pins 12 during the actual drive of the push-up pins. The drive portion of the push-up pin, that is, the portion composed of the rare-earth permanent magnet 4 and the push-up pin cylinder 15 is configured to be inserted into the transfer device 2 as can be seen from FIG. . Therefore, cleaning of the transport device 2 and the push-up pins 12 is easy, and dust attached to the pins can be easily removed.

The transfer device 2 is not in contact with the guide rails 8 and the like, but is in contact with the wafer 1 to be loaded on the back surface. Although it is conceivable that particles such as particles adhere, cleaning can be facilitated by inserting the portion composed of the rare earth permanent magnet 4 and the push-up pin cylinder 15 in this manner.

As described above, according to the present embodiment, since the push-up pin driving device is mounted on the transfer device side except for the induction magnetic field generating coil, most of the drive devices move while mounted on the transfer device. That is, even if the number of semiconductor manufacturing apparatuses to which the wafers are transported increases, only the induction magnetic field generating coils increase, and the number of driving devices does not increase. On the other hand, in the conventional wafer transfer device, a wafer loading device having drive devices for the push-up pins 12 is required for the number of semiconductor manufacturing devices. Therefore, the more semiconductor manufacturing devices, the more disadvantageous.

Further, the increase in the number of drive units not only increases the number of drive units, but also complicates a control system for controlling many drive units, leading to an increase in cost and a decrease in reliability. However, in the wafer transfer device according to the present embodiment, since there is only one driving device, an extremely simple control system is sufficient, and the cost of the wafer loading device can be greatly reduced.

[0021]

As described above, according to the present invention, the means for lifting up a wafer is provided in the wafer transfer apparatus itself, so that even if the number of semiconductor manufacturing apparatuses to which the wafer is transferred is increased, the cost is reduced. An advantageous effect that a wafer can be moved can be obtained by a wafer transfer device having a simple structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a wafer transfer device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a push-up pin used in the wafer transfer device shown in FIG. 1;

FIG. 3 is a cross-sectional view of a conventional wafer transfer device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wafer 2 transfer device 3 aluminum plate 4 rare earth magnet 5 magnetic levitation magnetic coil 6 magnetic coil for lateral guide 7 propulsion force generation coil 8 guide rail 9 induction magnetic field generation coil 10 induction magnetic field reception coil 11 push-up pin drive coil 12 protrusion Raising pin 13 Raising pin cover 14 Rectifier circuit 15 Raising pin cylinder 16 Raising pin passage hole

Claims (5)

[Claims] 1. A movable transfer device having at least a push-up pin that can move upward or downward while supporting a wafer, an induced magnetic field receiving unit, and a drive unit that drives the push-up pin with the induced magnetic field, and the transfer device. And a guide rail for defining a moving path of the wafer and an induced magnetic field generating means for applying an induced magnetic field to an induced magnetic field receiving means of the transfer device. 2. The wafer transfer device according to claim 1, wherein the transfer device is a magnetic levitation type transfer device. 3. The wafer transfer apparatus according to claim 1, wherein the induction magnetic field generating means is provided near a processing apparatus for processing the wafer. 4. The driving means includes means for converting an induction magnetic field received by the induction magnetic field reception means into a substantially DC magnetic field, and a magnet attached to an end of the push-up pin and responsive to the substantially DC magnetic field. The wafer transfer device according to any one of claims 1 to 3, comprising: 5. The wafer transfer device according to claim 1, wherein a cover is provided around the push-up pin.