JP3799193B2 - Wafer transfer device - 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

[0001]
BACKGROUND OF THE INVENTION
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]
[Prior art]
In the manufacturing process of a semiconductor integrated circuit, in order to process various wafers, the wafers must be transferred between various semiconductor manufacturing apparatuses. One such wafer transfer apparatus is a magnetic levitation type wafer transfer apparatus using a linear motor. For example, this is used in the case where a stepper, a coater, and a developer in a photolithography process are transported and processed in a single wafer mode.
[0003]
The magnetic levitation type wafer transfer device has the feature that the transfer device loaded with wafers floats so that it is not in contact with the surroundings and prevents the generation of dust. Need to be done in the state. As such a wafer transfer apparatus, there is an apparatus described in, for example, Japanese Patent Application Laid-Open No. 4-132238, and this conventional wafer transfer apparatus will be described below with reference to the drawings.
[0004]
FIG. 3 is a cross-sectional view of a conventional wafer transfer apparatus. In this apparatus, the wafer 1 is transferred in a direction perpendicular to the paper surface. 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, in which an aluminum plate 3 and a rare earth permanent magnet 4 are embedded. 5 is a magnetic levitation magnetic coil, 6 is a lateral guide 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 pin 12 is mechanically driven by a wafer stacking device provided outside, and the drive unit is installed on the guide rail side, and for example, lifts the pin upward several cm with an air cylinder. It is configured. FIG. 3 shows that the transfer device 2 is stopped and the wafer 1 is lifted up by the push-up pins 12.
[0005]
The operation will be described below. First, the magnetic levitation magnetic coil 5 and the lateral guide magnetic coil 6 installed on the guide rail 8 have a polarity in which a repulsive force acts on the rare earth permanent magnet 4 attached to the transport device 2, that is, a magnetic field having the same polarity. By generating this, the gap between the conveying device 2 and the guide rail can be stably levitated by about 1 to 5 mm. Thrust based on the Lorentz force is generated by a magnetic field generated by passing an alternating current through the propulsion force 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. It is conveyed by. At the time of detachment of the wafer 1, four places are installed on the transfer device 2 (only two places are visible in FIG. 3), and the four push-up pins 12 are actually installed on the guide rail 8 through the push-up pin passage holes 16. The wafer 1 can be lifted up or down. The lifted wafer is moved from the transfer device 2 by a wafer transfer arm (not shown).
[0006]
[Problems to be solved by the invention]
However, in such a configuration, the wafer 1 is moved from the transfer device 2 or pushed to the guide rail side where the wafer 1 is required to be loaded on the transfer device 2, that is, where the semiconductor manufacturing apparatus is installed. It is necessary to incorporate the pin 12 and its driving device. 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 drive devices must be provided, resulting in a complicated structure and higher cost as the device. was there.
[0007]
The present invention solves the above-described conventional problems, and an object thereof is to provide a wafer transfer apparatus having a simple structure at a low cost.
[0008]
[Means for Solving the Problems]
A wafer transfer apparatus of the present invention includes a moveable transfer apparatus having at least a push-up pin that can move upward or downward while supporting a wafer, an induced magnetic field receiving means, and a drive means that drives the push-up pin by the induced magnetic field, and A guide rail that defines a moving path of the transfer device; and an induction magnetic field generation unit that applies an induction magnetic field to the induction magnetic field reception unit of the transfer device , wherein the drive unit receives the induction magnetic field received by the induction magnetic field reception unit. It comprises means for converting to a substantially DC magnetic field and a magnet attached to the end of the push-up pin and sensitive to the substantially DC magnetic field .
[0009]
According to the present invention, the means for lifting the wafer is provided in the wafer transfer device itself, so even if the number of wafer transfer destinations increases, there is almost no increase in equipment as in the prior art, and a significant cost reduction is possible. It becomes.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol shall be used about the same part as the said conventional thing.
[0011]
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a wafer transfer apparatus according to the present invention. FIG. 1 (a) shows a wafer loading state and FIG. 1 (b) shows a wafer transfer state. In the figure, reference numeral 1 denotes a wafer, and 2 denotes a magnetic levitation type transfer device that transfers and transfers the wafer 1, in which an aluminum plate 3 and a rare earth permanent magnet 4 are embedded. 5 is a magnetic levitation magnetic coil, 6 is a lateral guide magnetic coil, 7 is a propulsion force generation coil of the transport device 2, 8 is a guide rail, 9 is an induction magnetic field generation coil, 10 is an induction magnetic field reception coil, and 11 is a push-up The pin driving coil is fixed to the transfer device 2 to generate a magnetic force, and is embedded in the transfer device 2. Reference numeral 12 denotes a push-up pin, 13 a cover for covering the push-up pin, 14 a rectifier circuit, and 15 a push-up pin cylinder. The wafer 1 shown in FIG. 1 is moved in a direction perpendicular to the paper surface by the transfer device 2, and the wafer 1 is in a lift-up state supported by push-up pins 12.
[0012]
The operation of the wafer transfer apparatus configured as described above will be described below. First, the conveying device 2 floats 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 guide rail 8 by the repulsion of the rare earth permanent magnet 4 and the lateral guiding magnetic coil 6. And a gap of about 5 mm is stably maintained.
[0013]
In this transfer device 2, the lift-up by the push-up pins 12 at the time of one wafer transfer is performed in the floating state of the transfer device 2, and is controlled by a wafer stacking device (not shown) provided on the guide rail 8 side. . More specifically, this wafer loading device causes an alternating current to flow through the induction magnetic field generating coil 9 to transmit electric power to the induction magnetic field receiving coil 10 in a non-contact manner. The transmitted alternating current passes through the rectifier circuit 14 and is substantially a direct current. As a result, a repulsive force is generated between the thrust pin driving coil 11 and another rare earth permanent magnet 4 attached to the lowermost portion of the thrust pin 12 as a substantially DC magnetic field. 1 is measured from the surface of the conveying device 2 and lifted upward by about 4 mm. The standard time required for lifting is about 0.5 to 1 second, but this speed can be freely and easily compared with the conventional mechanical drive system by changing the electric power supplied to the induction magnetic field generating coil 9. Can be changed. The driving speed may be set according to the time reduction required for the processing step.
[0014]
By disposing four push-up pins 12 on the transfer device 2 side, the wafer 1 can be lifted up stably. The lifted wafer 1 can be easily transferred from the transfer device 2 by a wafer transfer arm or the like.
[0015]
As shown in FIG. 1B, the wafer 1 loaded on the transfer device 2 is in the middle of transfer as shown in FIG. 1B. The wafer 1 is not lifted up, and the push-up pins 12 displayed in FIG. There is no induction magnetic field generating coil 9 for driving. In a steady state during transfer without lifting the wafer 1, the wafer 1 is fixed by a step of about 0.5 mm provided at the end of the transfer device 2, and the wafer moves during acceleration / deceleration of the transfer device 2. Thus, there is an effect of suppressing the generation of dust by rubbing the front surface of the transfer device 2 and the back surface of the wafer 1.
[0016]
In this embodiment, a step is provided in a portion corresponding to the wafer outer peripheral portion of the transfer device 2 so that the wafer 1 does not move when the push-up pin is lowered. The wafer 1 may be fixed by providing three or more protrusions on the surface of the transfer device 2 corresponding to the above.
[0017]
FIG. 2 is a cross-sectional view of the push-up pin used in the conveying device shown in FIG. When the push pin is actually driven, the generation of dust from the push pin 12 itself is suppressed. The drive portion of the push pin, that is, the portion composed of the rare earth permanent magnet 4 and the push pin cylinder 15 is configured to be inserted into the transfer device 2 as is apparent from FIG. . For this reason, the transport device 2 and the push-up pin 12 can be easily cleaned, and dust attached to the pin can be easily removed.
[0018]
The transport device 2 is not in contact with the guide rail 8 or the like, but is in contact with the wafer 1 to be loaded on the back surface. For example, by loading a resist-coated wafer or the like, particles such as resist are loaded on the transport device 2. However, if the portion composed of the rare earth permanent magnet 4 and the push-up pin cylinder 15 is inserted, the cleaning becomes easy.
[0019]
As described above, according to the present embodiment, since the push-up pin drive device is attached to the transport device side except for the induction magnetic field generating coil, most of the drive devices are moved while mounted on the transport device. Thus, even if the number of semiconductor manufacturing apparatuses that are wafer transfer destinations increases, only the induction magnetic field generating coils increase, and the number of driving apparatuses does not increase. On the other hand, the conventional wafer transfer device requires a wafer stacking device having driving devices for the push-up pins 12 as many as the number of semiconductor manufacturing devices. Therefore, the more semiconductor manufacturing devices are disadvantageous.
[0020]
In addition, the increase in the number of drive devices is not only an increase in the number of drives, but it also complicates the control system for controlling many drive devices, leading to increased costs and reduced reliability. Since the wafer transfer apparatus according to the embodiment has only one drive device, an extremely simple control system is sufficient, and the cost of the wafer stacking device can be greatly reduced.
[0021]
【The invention's effect】
As described above, according to the present invention, since the means for lifting the wafer is provided in the wafer transfer apparatus itself, even if the number of semiconductor manufacturing apparatuses that are the transfer destination of the wafer is increased, the wafer transfer can be performed at a low cost with a simple structure. The apparatus provides the advantageous effect that the wafer can be moved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a wafer transfer apparatus according to the present invention. FIG. 2 is a cross-sectional view of a push-up pin used in the wafer transfer apparatus shown in FIG. Sectional view [Explanation of symbols]
1 wafer 2 conveyance device 3 an aluminum plate 4 rare earth permanent magnets 5 a magnetic levitation force coil 6 lateral guide force coil 7 propulsion generating coil 8 the guide rail 9 induces the magnetic field generating coil 10 induced magnetic field receiving coil 11 butt-out raised pin drive coil 12 butt-out raised pins 13 butt-out raised pin cover 14 rectifier circuit 15 thrust pins cylinder 16 thrust pins passing hole

Claims (4)

A movable transfer device having at least a push-up pin that can move upward or downward while supporting a wafer, an induction magnetic field receiving unit, and a drive unit that drives the push-up pin by the induction magnetic field, and a movement path of the transfer device are defined. Means for applying an induction magnetic field to the guide rail and the induction magnetic field reception means of the transport device , wherein the driving means converts the induction magnetic field received by the induction magnetic field reception means into a substantially DC magnetic field. And a magnet that is attached to an end of the push-up pin and that is sensitive to the substantially DC magnetic field . The wafer transfer apparatus according to claim 1, wherein the transfer apparatus is a magnetic levitation transfer apparatus. The wafer transfer apparatus according to claim 1, wherein the induction magnetic field generation unit is installed in the vicinity of a processing apparatus that processes a wafer. The wafer transfer apparatus according to any one of claims 1 to 3, characterized in that the covering is provided around the front Symbol thrust pins.

Images