JPH0828416B2 - Wafer transfer robot - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot that operates in a decompressed room (vacuum chamber) or a clean room, and more specifically, in a semiconductor integrated circuit manufacturing facility, it moves a wafer to a desired position in the vacuum chamber. The present invention relates to a manipulator or a wafer transfer robot that can be used.

[0002]

2. Description of the Related Art For example, semiconductor chips or wafers are processed in a clean room because dust, oil mist, or the like attached at the manufacturing stage deteriorates the yield due to so-called particle contamination and deteriorates the productivity. Further, since the manufacturing process is often performed in a vacuum, the transfer of the wafer in the manufacturing apparatus is performed in a vacuum by a robot. Here, a conventional example of a wafer transfer robot is shown in FIG.

In FIG. 4, the wafer transfer robot is
The drive unit 50 is provided in the atmosphere A and the handling unit 60 is provided in the vacuum chamber V. The drive unit 50 is provided with a first motor M ₁ and a second motor M _2, and an output shaft 51 of the first motor M ₁ is connected to a vertical hollow drive shaft 62. On the other hand, the output shaft 52 of the second motor M ₂ is connected to the small drive shaft 63 provided in the hollow drive shaft 62. Therefore, when the motors M ₁ and M ₂ rotate, the drive shafts 62 and 63 are rotationally driven in a predetermined direction by a predetermined amount.

A first horizontal arm 64 is fixed to the upper end of the hollow drive shaft 62, and a second horizontal arm 65 is rotatably provided at the tip of the first horizontal arm 64. On the other hand, the small drive shaft 6
A pulley 66 is fixed to the upper end of the pulley 3,
A belt 67 is looped between the pulley and a pulley (not shown) provided at the pivotally attached portion of the second arm 65. Therefore, when the belt 67 is driven, the second
The arm 65 is rotationally driven with respect to the first arm 64.

When the motor M ₁ is rotated in a predetermined direction by a predetermined amount, the hollow drive shaft 62 is rotated, and the first arm 64 integrally fixed to the hollow drive shaft 62 is also in a horizontal plane as indicated by an arrow a. Rotate. Therefore, the second arm 65 also integrally rotates, and the wafer (not shown in FIG. 4) on the hand 68 attached to the tip of the second arm 65 is transferred to a predetermined angular position in the horizontal plane. On the other hand, when the motor M ₂ is driven, the small drive shaft 63 is driven, and the second arm 65 moves to the pulley 66,
The belt 67 causes the first arm 64 to move as indicated by the arrow b.
Is driven within a predetermined angle range in the horizontal plane. As a result, the wafer (not shown) on the hand 68 can be transferred by a predetermined amount inward or outward of the radius.

Here, when a relatively rotating member is mechanically supported, fine particles are generated from that portion and the wafer is contaminated. Therefore, in a conventional robot, a magnetic fluid seal is also provided on the bearing to prevent dust generation.
The motor and the vacuum chamber are sealed by an O-ring, and the drive shafts 62 and 63 penetrating the atmosphere side and the vacuum side are sealed by a magnetic fluid seal.

[0007]

However, in the magnetic fluid seal adopted in the above-mentioned conventional robot, gas is generated when a vacuum of, for example, about 10 ⁻⁶ Torr is generated and the wafer is contaminated by the generated gas. However, there is a problem that the yield deteriorates.

The magnetic fluid seal has an operating temperature of 0.
There is also a problem that the temperature is relatively low at about -80 ° C.

The present invention has been proposed in view of the above-described problems of the prior art, and it is possible to transfer a wafer in a clean room or a vacuum chamber, and to generate harmful dust, oil mist, etc. on the wafer. It is an object of the present invention to provide a wafer transfer robot that does not suffer from the above-mentioned problems and is not affected by the operating temperature or the degree of vacuum at the operating location.

[0010]

According to the present invention, in a wafer transfer robot for transferring a wafer in a vacuum chamber, the vacuum chamber is partitioned from an atmospheric pressure chamber by a partition, and the partition has a cylindrical side wall. A rotating body having a peripheral surface and an upper surface, which is supported in a non-contact state by a magnetic bearing in the vacuum chamber; and a horizontal direction which is supported in a non-contact state on the upper surface of the rotating body and in a horizontal direction. A wafer transfer arm that can move linearly is accommodated, and the rotating body is arranged so that its peripheral surface faces the cylindrical side wall.
At least two magnetic bearings for supporting the wafer transfer arm on the upper surface of the rotating body in a non-contact state are provided on the upper surface of the rotating body and the wafer transferring arm, which face each other. Includes a portion made of a magnetic material, and means for driving a magnet magnetically coupled to the magnetic material portion of the arm is provided outside the vacuum chamber.

In implementing the present invention, the magnet (external magnet) provided outside the vacuum chamber may be a permanent magnet or an electromagnet. The number and attachment position of the external magnets are not particularly limited, but it is preferable that the arm movement distance be as long as possible without interfering with the processing equipment adjacent to the wafer transfer robot.

Further, the portion (target) made of a magnetic material in the wafer transfer arm is preferably provided at a position corresponding to the external magnet.

Further, in carrying out the present invention, a motor for rotating and driving the rotating body is provided.

In addition to this, means for supplying electric power to the magnetic bearing for supporting the arm is provided. Here, as the means for supplying the electric power, a power supply cable from a stationary body is usually used, or a battery built in the rotating body and a means for supplying electric power in a non-contact manner like a transformer are used together. Is preferred. However, it is possible to use only one of them.

Further, it is preferable that the magnetic bearing for supporting the rotating body is provided with one supporting the rotating shaft direction of the rotating body and one supporting the rotating body in the radial direction. Then, both the axial support and the radial support may be configured by electromagnets, or either one may be configured by a permanent magnet.

[0016]

Since the present invention is constructed as described above,
By rotationally driving the rotating body, it rotates in a predetermined direction by a predetermined amount. As a result, the transfer direction of the wafer transfer arm is determined. Further, the transfer distance of the wafer transfer arm is determined by linearly moving the external magnet. Therefore, by appropriately setting the transfer direction and the transfer distance of the wafer transfer arm, it is possible to transfer the wafer on the hand attached to the arm, for example, to the desired position.

Here, in the present invention, since the magnetic bearings are supported in a non-contact manner, fine particles (dust) are not generated when the rotary body is driven to rotate or the external magnet and the arm are linearly moved. Further, since no magnetic fluid seal is used, the operating temperature range is widened, and no gas is generated even in an extremely high vacuum.

As a result, the wafer is prevented from being contaminated and the yield in manufacturing the semiconductor integrated circuit is improved.

In addition to this, according to the present invention, since the arm moves by linearly moving the external magnet, the electric power to be supplied to the rotating body can be reduced accordingly. That is, it is possible to reduce the load on a means for supplying electric power in a contactless manner such as a battery and a transformer built in the rotating body.

[0020]

Embodiments of the present invention will be described below with reference to FIGS.

As shown in these figures, the robot of the present invention comprises a rotating body 1 and a wafer transfer arm 10 provided on the rotating body, which are partitioned by a partition wall W. It is arranged in a vacuum chamber R in a non-contact manner. As shown in the figure, the partition wall W includes a top wall Wa and a cylindrical side wall W.
It is composed of b and the bottom wall Wc. The rotating body 1 is disposed in the vacuum chamber R such that the peripheral surface thereof faces the cylindrical side wall Wb, and the magnetic bearings 2 and 3 thereof are provided on the rotating body 1 and the partition wall W which face each other. Has been. That is, the radial magnetic bearing 2 is provided on the side wall Wb and the peripheral surface of the rotating body 1 in order to support the atmospheric pressure chamber A side outside the side wall Wb and the rotating body 1 side in a radial non-contact manner. ing. On the other hand, the magnetic bearing 3 is a bearing in the thrust direction (rotating shaft direction), and like the bearing 2, in order to support the atmospheric pressure chamber A side and the rotating body 1 side in the rotating shaft direction in a non-contact manner, the magnetic bearing 3 and the bottom wall Wc It is provided in the facing portion of the rotating body 1. The vacuum chamber R having the arm 10 provided on the upper portion of the rotating body 1 is wider than the portion surrounding the rotating body 1. A side wall Wd is formed in the vacuum chamber R so as to expand.

In order to drive the rotating body 1 around the axis C, the stator 4 of the motor is provided outside the bottom wall Wc, and the rotor 5 of the motor is provided on the rotating body. A battery 7 is mounted on the rotating body 1 to obtain necessary power, and a transformer 6 is provided as a means for supplying electric power in a contactless manner.

The upper surface 8 of the rotator 1 has an extension 9 which projects partially radially outward, as shown. The magnetic bearing column 20 is provided on the extension 9 and
A book is erected on the upper surface 8 of the rotating body 1 in a substantially linear shape.

A magnetic bearing 21 is formed at the upper end of the column 20. Although not shown accurately, the magnetic bearing 21 has a structure for linearly and non-contactably guiding the wafer transfer arm 10 as shown in FIG. Although three columns 20 are shown in the illustrated embodiment, the number of columns 20 is not particularly limited as long as it is two or more.

The wafer transfer arm 10 has a linear shape. The magnetic body 11 is attached to one of the ends. This magnetic body cooperates with a magnet for driving an arm, which will be described later, and is unnecessary if the entire arm is made of a magnetic body. A hand 13 is detachably attached to the other end of the wafer transfer arm 10 as shown in FIG.
The wafer 14 is accurately positioned and placed on this hand. However, it is also possible to employ a hand configured to hold the wafer.

A magnet 12 that magnetically couples or cooperates with the magnetic material 11 of the wafer transfer arm 10 to drive the arm 10 is provided on the atmospheric pressure chamber A side above the top wall Wa. Then, it is adapted to be driven in the direction indicated by the arrow X by an appropriate means (not shown).

Next, the operation of the above embodiment will be described.
The motor 4 is composed of a step motor or the like, and the control device controls the rotation direction and the rotation amount. When the motor 4 is energized, the rotating body 1 rotates, the wafer transfer arm 10 also rotates, and the direction of the arm 10 is determined.

Next, when the magnet 12 is driven by a predetermined amount, the magnetic body 11 which is magnetically coupled with the magnet 12 to cooperate with each other,
The wafer transfer arm 10 linearly moves in the horizontal direction by a predetermined amount. As a result, the wafer 14 is transferred to a predetermined position.

When the wafer is transferred to another chamber such as a process chamber, the gate valve 15 is provided on the expanded side wall Wd, and this valve is opened and closed to move the wafer transfer arm 10 as shown in FIG. To the outside of the side wall Wd.

Even if the external magnet is driven first and then the rotor is driven, or these are driven simultaneously,
Obviously, it works the same way.

Although not described in the illustrated embodiment, in carrying out the present invention, a counterweight in consideration of the number of magnetic bearings of the wafer transfer arm and the arm balance,
Various other modifications are possible, but these are not shown in the drawings. In other words, the illustrated embodiment is merely an example, and the technical content of the present invention is not limited to this.

[0032]

As described in detail above, according to the present invention,
The rotating body is supported and driven in a contactless manner by a magnetic bearing, and the arm is driven by an externally provided magnet. Since both the rotating body and the wafer transfer arm are driven in a non-contact manner, no dust or the like is generated by mechanical contact and the wafer is not contaminated.

Further, since a magnetic fluid seal is not required as in the conventional case, there is no gas leakage and it can be used in a high temperature environment and a high vacuum environment.

In addition to this, since the wafer transfer arm is moved by linearly moving the external magnet, the electric power to be supplied to the rotating body can be reduced accordingly. Further, it is mechanically simpler than the one in which the wafer transfer arm is linearly moved by a linear motor, can be provided at low cost, and consumes less power.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

FIG. 2 is a drawing of the embodiment shown in FIG.

FIG. 3 is a side view showing an operating state of the embodiment shown in FIG.

FIG. 4 is a perspective view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotating body 2, 3 ... Magnetic bearing 4, 5 ... Motor 10 ... Wafer carrying arm 11 ... Magnetic body 12 ... Magnet C ... Rotating shaft A ... Atmosphere chamber R ... Vacuum chamber W ... Partition wall

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location B65G 54/02 (72) Inventor Yukio Ikeda 11-1 Haneda-Asahicho, Ota-ku, Tokyo (56) References Japanese Patent Laid-Open No. 2-15993 (JP, A)

Claims (1)

[Claims] 1. A wafer transfer robot for transferring a wafer in a vacuum chamber, wherein the vacuum chamber is partitioned from an atmospheric pressure chamber by a partition wall, and the partition wall has a cylindrical side wall, and the vacuum chamber is provided in the vacuum chamber. A rotating body which is supported by a magnetic bearing in a non-contact state and has a peripheral surface and an upper surface, and a wafer transfer arm which is supported in a non-contact state on the upper surface of the rotating body and is linearly movable in a horizontal direction. The rotating body is arranged such that the peripheral surface thereof faces the cylindrical side wall, and the magnetic bearings that support the wafer transfer arm on the upper surface of the rotating body in a non-contact state are At least two wafer transfer arms are provided on the upper surface of the rotating body and the wafer transfer arm that face each other. The wafer transfer arm includes a portion made of a magnetic material, and is magnetically coupled to the magnetic material portion of the arm. A wafer transfer robot characterized in that means for driving a magnet to be coupled is provided outside the vacuum chamber.