JPH0963939A - Substrate carrier system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut down the replacement times of substrates by a method wherein carrier arms are driven in parallel with a stage shifting surface while a substrate holding part formed of recession trenches capable of inserting the carrier arm on the contact surface with the substrate on the stage either one out of the carrier arm or the substrate holding part is driven on the stage shifting surface in the orthogonal direction. SOLUTION: Carrier arms 24, 26 where base ends are respectively connected to the arm driving mechanism 38 comprising an arm driving device 36 in a cantilever state so that the carrier arms 24, 26 may be independently driven in the horizontal surface and in the upper and lower directions by this arm driving mechanism 38. Besides, a wafer holder 56 is mounted on an XY stage 40 as a substrate holder holding wafers W. On this wafer holder 56, a pair of circular recession trenches 58, 60 capable of inserting a pair of pawl parts 32 of a rotary wafer unloading rotary carrier arm 26 are formed. Furthermore, rotary carrier arms 24, 26 are composed to be vertically movable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer apparatus, and more particularly to a substrate transfer apparatus suitable for transferring a wafer as a substrate onto a wafer stage of an exposure apparatus.

[0002]

2. Description of the Related Art Conventionally, in a photolithography process for manufacturing a semiconductor element such as an IC (semiconductor integrated circuit), a projection exposure apparatus that exposes a mask or reticle pattern onto a wafer via a projection optical system has been used. Has been.

FIG. 6 shows an example of a wafer transfer system in this type of apparatus. Here, the flow of the wafer transfer process will be briefly described with reference to FIG. 6. In-line coater / developer (Coater-Developer: a device for coating a photoresist on a wafer or developing an exposed wafer) The wafer W sent from another semiconductor manufacturing apparatus such as the above is transferred to the robot arm 64, and sucked and held by the suction unit 68 on the robot arm 64.
After that, the robot arm 64 is driven in the direction of arrow A along the guide 67 by the arm driving device 66, and the wafer W is carried to the front of the pre-alignment device 70 by the robot arm 64. Robot arm 6 at this position
4 is extended and the rotary shaft 7 on the pre-alignment device 70 is extended.
The wafer W is transferred onto the wafer 2.

Here, the control device 74 rotationally drives the rotary shaft 72 via a drive mechanism (not shown) which constitutes the pre-alignment device 70. As a result, the wafer W starts rotating. During the rotation of the wafer W, the controller 74 monitors the output of the notch detection sensor (not shown) and
It waits until the notch (V-shaped notch) provided in the peripheral edge of the is detected. When the notch detection sensor detects the notch, the control device 74 stops the rotation of the rotary shaft 72 via the drive device. Next, in the control device 74, positioning pins 76, 78, 80 are passed through a pin driving mechanism (not shown).
Are simultaneously driven toward the rotary shaft 72. As a result, rough positioning (pre-alignment) of the wafer W in the rotation direction and the XY two-dimensional directions is completed. After completion of this pre-alignment, the control device 74 causes the positioning pins 76, 78,
Return 80 to its original position.

Next, the control device 74 drives the arm drive mechanism 84 which constitutes the rotary transfer arm drive device 82, and the wafer transfer rotary transfer arm 86 is prealigned with the hook portion at the tip of the rotary transfer arm 86. The apparatus 70 is turned to a position where it engages with the rotary shaft 72 and stopped, and the vacuum of the suction unit 88 provided on the rotary transfer arm 86 is turned ON. This causes the wafer W to rotate
6 is held by adsorption. In this state, the rotary transfer arm 86
Will wait. During this waiting, the exposure of the wafer W mounted on the XY stage 90 is completed, and the XY stage 90 moves to the position shown in FIG.
When the loading position shown in is reached, the wafer W is exchanged by the following procedure.

(1) In the main controller (not shown), the vacuum of the wafer holder 92 is turned off.

(2) Next, in the main controller, the three vertical moving pins (center up) 94, 96, 98 provided on the XY stage 90 are driven to rise, and the wafer W is removed from the wafer holder 92. .

(3) The controller 74 controls the arm drive mechanism 84 in response to an instruction from the main controller to center the wafer transfer unloading rotary transfer arm 100.
The wafer W is held under the wafers 4, 96, 98.

(4) Center up 9 in main controller
4, 96, and 98 are driven to descend, and the wafer W is transferred to the rotary transfer arm 100.

(5) The controller 74 vacuums the wafer W by the suction portion 102 of the rotary transfer arm 100.

(6) In the controller 74, the rotary transfer arm 100 is swung to retract the wafer W from the loading position, the wafer W is held, and the standby rotary transfer arm 86 is swung to lift the wafer W above the holder 92. Transport to.

(7) Center up 9 in main controller
4, 96, 98 are driven to move upward, and the wafer W is transferred from the rotary transfer arm 86 to the center-up 94, 96, 98.

(8) The controller 74 retracts the rotary transfer arm 86 from below the wafer W.

(9) Center up 9 in the main controller
The wafers W are mounted on the wafer holder 92 by lowering 4, 96 and 98.

(10) Turn on the vacuum of the holder 92.

[0016]

However, in the above-mentioned conventional example, in order to replace the wafer, the above (1) to
Since it is necessary to go through the procedure described in (10), there is a disadvantage that the replacement work takes a long time. Further, since it is necessary to mount a vertical drive mechanism such as a center-up mechanism on the wafer stage (XY stage), the weight becomes heavier and the settling time of the stage becomes longer, which deteriorates controllability. there were. Further, since the rotary transfer arm has a certain thickness, a space for inserting the rotary transfer arm is required between the wafer holder 90 and the wafer W. Particularly, the rotary transfer arm for loading and the rotary transfer arm for unloading are required. When the wafer is exchanged while intersecting the arms in the middle, it is necessary to widen the distance (working distance) between the projection lens PL and the wafer stage. Therefore, between the projection lens PL and the XY stage 90. There are various inconveniences such as easy occurrence of air fluctuations in the optical path of the optical system, and design restrictions that increase costs.

The present invention has been made in view of the disadvantages of the conventional example, and a first object thereof is to provide a substrate transfer apparatus capable of shortening the time for exchanging a substrate such as a wafer.

A second object of the present invention is to provide a substrate transfer device which can shorten the time for exchanging substrates such as wafers and can reduce the working distance when used in an exposure apparatus. To do.

A third object of the present invention is to provide a substrate transfer apparatus capable of improving the controllability by shortening the settling time by reducing the weight of the substrate stage.

[0020]

According to a first aspect of the present invention, there is provided a substrate transfer device for transferring a substrate onto a stage movable in a two-dimensional direction, the transfer arm holding the substrate; A horizontal drive mechanism for driving the arm in parallel with the stage moving surface; a concave groove formed on the stage, into which the transfer arm can be inserted while holding the substrate, is formed on the contact surface side with the substrate. A substrate holding member; and a vertical drive mechanism that drives at least one of the transfer arm and the substrate holding member in a direction orthogonal to the stage moving surface.

According to this, in a state where the substrate is held on the substrate holding member, the transfer arm is driven by the horizontal drive mechanism, the transfer arm is inserted into the concave groove of the substrate holding member, and the transfer arm is moved by the vertical drive mechanism. The substrate is transferred and held on the transfer arm only by slightly moving the arm upward relative to the substrate holding member. Then, when the transfer arm holding the substrate is retracted from the substrate holding member, the unloading ends. On the other hand, the transfer arm is driven by the horizontal drive mechanism to insert the transfer arm into the groove of the substrate holding member, and the transfer arm is driven slightly downward relative to the substrate holding member by the vertical drive mechanism. The substrate is transferred onto the substrate holding member. Then, after the substrate is transferred, the loading arm of the substrate is completed by passing through the transfer arm through the concave groove. Thus, the loading and unloading of the substrate can be performed by a very simple process of inserting the transfer arm into the groove and moving the transfer arm up and down relative to the substrate holding member. In addition, the replacement time of the substrate is shortened as compared with the case where the center-up is raised and lowered each time the substrate is loaded and unloaded.

According to a second aspect of the present invention, in the substrate transfer apparatus according to the first aspect, one transfer arm is provided for loading a substrate and one transfer arm is provided for unloading the substrate. According to this, if the loading transfer arm that holds the substrate at the same time as the unloading transfer arm is moved to just above the substrate on the holder, as described above, the substrate is unloaded from the groove for unloading. Immediately after the carrier arm for use is pulled out (the carrier arm holding the substrate is retracted from the substrate holding member), if the substrate holding member is raised by a predetermined amount, the substrate is transferred onto the substrate holding member, Substrate replacement is completed in an even shorter time. Further, in this case, in the case of the exposure apparatus, between the substrate and the projection lens,
It suffices that there is an interval for one loading transfer arm, and the working distance can be reduced.

In this case, the vertical movement mechanism may be constituted by the vertical movement mechanism of the substrate table on which the substrate holding member is mounted, as in the invention of claim 3, and the invention of claim 4 As described above, an arm up-and-down drive mechanism that drives the transfer arm in a direction orthogonal to the stage moving surface may be used. In the latter case, the transfer arm can be moved up and down by the arm up-and-down drive mechanism even when the substrate holding member side is stationary when the substrate is exchanged. The mechanism can also be omitted.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. This embodiment is an example in which the substrate transfer apparatus according to the present invention is applied to a wafer transfer system of an exposure apparatus.

FIG. 1 shows a schematic structure of a wafer transfer system 10 including a substrate transfer apparatus according to one embodiment. The wafer transfer system 10 includes a robot arm 64, a pre-alignment device 12, transfer arms 24 and 26, an XY stage 40 as a stage, and the like.

The robot arm 64 is guided by a drive mechanism 66 controlled by a main controller (not shown).
Is driven in the X-axis direction (left-right direction in FIG. 1). The robot arm 64 is driven by the drive mechanism 66 in the Y-axis direction (vertical direction in FIG. 1).
It can be expanded and contracted along with and can be moved up and down in the Z-axis direction orthogonal to the paper surface of FIG. A pair of suction units 68 are provided at both ends of the robot arm 64. When a vacuum source such as a vacuum pump (not shown) is turned on, the vacuum is started and the wafer W serving as a substrate.
Can be adsorbed.

The pre-alignment apparatus 12 includes a rotary shaft 14 driven by a rotary drive mechanism (not shown), and a notch detection sensor (not shown) for detecting a notch on the outer peripheral portion of the wafer W held on the rotary shaft 14. , Three positioning pins 16, 18 driven by a pin driving mechanism (not shown),
20 and 20 are provided. The rotation drive mechanism and the pin drive mechanism are controlled by the control device 22. Further, the output of the notch detection sensor is adapted to be monitored by the control device 22.

In this embodiment, the two rotary transfer arms described above as the transfer arms, that is, the rotary transfer arm 24 for wafer loading and the rotary transfer arm 2 for wafer unloading.
6 are provided. As shown in FIG. 1, the wafer transfer rotary transfer arm 24 has its tip bent in an arc shape, and a pair of arc-shaped claw portions 28 are provided at the bent portions, and the pair of claw portions 28 are provided. One suction unit 30 is provided. The suction unit 30 is connected to a vacuum source (not shown) such as a vacuum pump through a pipe (not shown) so that the wafer W can be vacuum-sucked and held. ON / OFF of the vacuum of the suction unit 30 is also controlled by the control device 22. The rotary unloading arm 26 for wafer unloading is also configured in the same manner and includes a pair of arcuate claw portions 32 and a pair of suction portions 34.

The transfer arms 24 and 26 are connected to an arm drive mechanism 38, which constitutes an arm drive device 36, with their base ends being cantilevered and supported by the arm drive mechanism 38 in a horizontal plane (parallel to the plane of the drawing). It is designed to be driven independently in the plane) and in the vertical direction (direction orthogonal to the plane of the drawing). That is, in this embodiment, the arm drive mechanism 38
The horizontal drive mechanism and the arm up-and-down drive mechanism are constituted by this. This arm drive device 36 (arm drive mechanism 3
8) is also controlled by the control device 22.

Next, the XY stage 40 will be described. The XY stage 40 is mounted on a surface plate 6 via a magnetic preload type air bearing (or vacuum preload type air bearing) (not shown).
2 is supported above and floats up through a predetermined space. A linear motor (for example, moving magnet type) mover 42 is provided at both ends of the XY stage 40 in the X direction.
44 is provided, and the movers 42 and 44 of these linear motors are driven along the linear motor stators (Y linear guides) 46 and 48 extending in the Y direction, whereby the XY stage 40 is moved. It can be moved to any position in the Y direction. In addition, the Y linear guide 46,
The positional relationship of the linear guides 48 is kept constant by a connecting member (not shown).
A mover of a linear motor (not shown) provided at both ends in the Y direction is integrally driven along a pair of X linear guides 50 (however, one is not shown in FIG. 1). That is, these Y linear guides 46,
The XY stage 40 can move in the X direction integrally with the unit 48.

A movable mirror 52Y extends in the X-axis direction at one end in the Y-direction of the XY stage 40, and a movable mirror 52X extends in the Y-axis direction at one end in the X-direction. Then, the position of the XY stage 40 is monitored by the X-axis laser interferometer 54X and the Y-axis laser interferometer (not shown) via these movable mirrors 52X and 52Y, and the step operation in the XY directions is not shown. It is monitored by the controller. The optical path of the laser light from the X-axis laser interferometer 54X and the optical path of the laser light from the Y-axis laser interferometer is the projection lens P.
It is designed to meet at the center O of L. In other words, X
The two-dimensional coordinate position of the XY stage 40 is measured with the center O of the projection lens PL as the origin by the axis laser interferometer 54X and the Y axis laser interferometer.

Further, the wafer W is placed on the XY stage 40.
Wafer holder 5 as a substrate holding member for holding
6 is mounted. This wafer holder 56 is shown in FIG.
A plan view (as it applies to so-called scan exposure) is shown. The wafer holder 56 includes a pair of claws 28 of the wafer transfer rotary transfer arm 24 and a pair of claws 3 of the wafer unload rotary transfer arm 26.
A pair of arcuate concave grooves 58 and 60 into which 2 can be inserted are formed. On the upper surface (contact surface with the wafer W) of the wafer holder 56, in a region other than the region in which the concave grooves 58 and 60 are formed, a convex portion 64 in which the suction portion 62 is formed is spread over almost the entire region. Is formed, and the remaining portion is the recess 6
It is supposed to be 6. That is, this wafer holder 56 is
Only the convex portion 64 contacts the wafer W, and has a shape devised so that the contact area is reduced. The depths of the grooves 58 and 60 are set such that the claw portions 28 or 32 can be inserted from the side surface while holding the wafer W.

Next, the wafer transfer operation by the wafer transfer system 10 of the present embodiment configured as described above will be described.

The wafer W sent from another semiconductor manufacturing apparatus such as a coater / developer via the in-line is transferred to the robot arm 64, and sucked and held by the suction unit 68 on the robot arm 64. Next, a main controller (not shown) drives the arm driving device 66, whereby the robot arm 64 starts moving in the direction of arrow A along the guide 67 while holding the wafer W. When the robot arm 64 reaches the front of the pre-alignment device 12, the main controller stops the arm driving device 66, and the robot arm 64 stops at that position. Next, in the main controller, the robot arm 64 is extended via the arm driving device 66 to convey the wafer W above the rotating shaft 14 on the pre-alignment device 12, and the robot arm 64 is driven downward by a predetermined amount to move the wafer W. It is mounted on the rotary shaft 14. At the same time, the main controller turns off the vacuum of the suction unit 68, and then retracts the robot arm 64 from the pre-unalignment device 12. As a result, the wafer W is transferred from the robot arm 64 onto the rotating shaft 14.

Here, the control device 22 drives a rotation drive mechanism (not shown) which constitutes the pre-alignment device 12. As a result, the rotary shaft 14 is rotationally driven, and the wafer W
Starts rotating. During the rotation of the wafer W, the control device 2
In 2, monitor the output of the notch detection sensor (not shown),
It waits until the notch provided in the peripheral portion of the wafer W is detected. When the notch is detected by the notch detection sensor,
The control device 22 stops the rotation of the rotary shaft 14 via the rotation drive device. Next, the control device 22 simultaneously drives the positioning pins 16, 18, and 20 toward the rotary shaft 14 via a pin driving mechanism (not shown). As a result, rough positioning (pre-alignment) of the wafer W in the rotation direction and the XY two-dimensional directions is completed. After the completion of this pre-alignment, the control device 22 returns the positioning pins 16, 18, and 20 to their original positions.

Next, the control device 22 drives the arm drive mechanism 38 which constitutes the rotary transfer arm drive device 36, and the rotary transfer arm 24 for wafer loading has a pair of claws 28 at the tip thereof for pre-alignment device 12. The wafer W is rotated to a position shown in FIG. 1 below the upper wafer W and stopped. Next, in the controller 22, the rotary transfer arm 24 is driven upward through the arm drive mechanism 38 to lift the wafer W from below by the pawl portion 28 to separate it from the rotary shaft 14, and the vacuum pump switch (not shown) is turned on. Then, the wafer W is sucked by the suction unit 30. In this state, the controller 22 causes the rotary transfer arm 24 to stand by until the exposure of the wafer W held on the wafer holder 56 mounted on the XY stage 40 is completed.

When the exposure of the wafer W held on the wafer holder 56 mounted on the XY stage 40 is completed and the XY stage 40 moves to the loading position of FIG. 1, the replacement work of the wafer W is started. .

The wafer exchanging operation will now be described with reference to FIGS. 4 to 5 along with the flowchart of FIG. 2 showing the control algorithm of the CPU in the control device 22.

In step 200, the rotary transfer arm 26 is swung via the arm drive mechanism 38 to rotate the rotary transfer arm 26.
The pair of claw portions 32 of the concave groove 58, 60 of the wafer holder 56.
To insert. The state at this time is shown in FIGS. When the claw portion 32 is completely inserted, the vacuum of the wafer holder 56 is turned off by the main controller (not shown).
FF is performed.

In the next step 202, the arm drive mechanism 38
The rotary transfer arm 26 is driven to rise through the wafer holder 56 to separate the wafer W from the wafer holder 56, and at the same time, the wafer W is vacuumed by the suction portion 34 (step 20).
4). The state at this time is shown in FIGS.

In the next step 206, the arm drive mechanism 3
The rotary transfer arm 26 is swung via 8 to retract the wafer W from the loading position and the rotary transfer arm 24 is swung to transfer the wafer W above the holder 56 at the loading position. The state at this time is shown in FIG. 4 (D) and FIG. 5 (A). FIG.
As is apparent from (A), in the present embodiment, the rotary transfer arm 26 and the rotary transfer arm 24 are driven to rotate in the opposite directions without interfering with each other.

When the wafer W is completely retracted by the rotary transfer arm 26, the rotary transfer arm 24 is driven downward through the arm drive mechanism 38 in step 208 to turn off the vacuum of the suction unit 30 and onto the wafer holder 56. The wafer 55 is delivered. The situation at this time is shown in FIG.
(B)-(C).

In the next step 210, the claw portion 28 is rotated by rotating the rotary transfer arm 24 via the drive mechanism 38.
Are retracted from the grooves 58 and 60. At this time, the groove 5
When the claws 28 are completely removed from the wafers 8, 60, the vacuum of the wafer holder 56 is turned on by the main controller (not shown). This completes the wafer exchange.

As described above, according to this embodiment, the wafer holder 56 is provided with the concave grooves 58 and 60, and the pair of claw portions 28 and 32 which can be inserted into the concave grooves 58 and 60 are provided to the rotary transfer arms 24 and 26. Since the rotary transfer arms 24 and 26 are respectively provided at the tips of the rotary transfer arms 24 and 26 and are vertically movable, the claw portions 28 (or 32) of the rotary transfer arm 24 (or 26) are formed in the concave grooves 58 and 60. By inserting and driving the rotary transfer arm 24 (or 26) up or down, the loading and unloading of the wafer W can be easily performed. Therefore, it is not necessary to raise the center, the weight can be reduced accordingly, the structure can be simplified, and the controllability can be improved by shortening the settling time. Further, the procedure for loading and unloading is remarkably simplified as compared with the conventional method using center-up, so that improvement of throughput can be expected by shortening the replacement time. In the above embodiment, the rotary transfer arms 24 and 26 are provided for wafer loading and unloading, respectively.
As is clear from the above, when the wafer loading arm 24 and the unloading arm 26 are driven simultaneously, the unloading arm 26 can be positioned in the space below the surface of the wafer holder 56, so the wafer loading arm It suffices that there is a space in which only 24 can be inserted between the projection lens PL and the holder, and the working distance can be reduced. In this case, when a single arm is used as both the wafer loading arm and the unloading arm, or when the two arms are not used at one time, the wafer is placed between the projection lens PL and the wafer holder. It suffices if there is a space having a size somewhat larger than the thickness, and the working distance can be further reduced.

Further, in this embodiment, since the widths of the concave grooves 58 and 60 are designed to be approximately the same as the width of the concave portion 66 on the wafer holder 56, the problem that the wafer W is distorted hardly occurs.

In the above embodiment, the case where two rotary transfer arms are used is illustrated, but the present invention is not limited to this, and the wafer loading and unloading arms are formed by a single arm. You can also use it.

Further, in the above-mentioned embodiment, the case where the transfer arm is movable in the vertical direction in addition to the rotation is exemplified, but the present invention is not limited to this, and for example, an XY such as a Z stage or a Z tilt stage. In the case of an exposure apparatus having a table that can be driven in a direction (vertical direction) orthogonal to the moving surface of the stage, this constitutes a vertical drive mechanism for vertically moving the wafer holder relative to the transfer arm. Is also good. Further, when the driving speed of the transfer arm is increased, the claw portion needs to be thicker, which may be larger than the thickness of the wafer holder. In this case, the XY stage may also be provided with a concave groove.

Furthermore, in the above embodiment, the case where the rotary transfer arms 24 and 26 are used as the transfer arms is illustrated, but it goes without saying that a transfer arm that moves in the X direction or the Y direction may be used. In this case, it is possible to match the moving direction of the arm and the direction of the concave groove, and there is also an advantage that the holder can be easily machined as compared with the case where the concave groove having an arc shape is provided as in the above embodiment. .

[0049]

As described above, according to the present invention, the substrate exchange time can be shortened as compared with the conventional case where the center-up is raised and lowered at every loading and unloading of the substrate. It has an excellent effect that is not possible in the past.

In particular, according to the second aspect of the invention, in addition to the effect of the first aspect of the invention, when used in the exposure apparatus, the load carrying arm 1 is provided between the substrate and the projection lens. It suffices if there is an interval for this, and there is also an effect that the working distance can be reduced.

Further, according to the invention described in claim 4, not only the center-up but also the vertical movement mechanism of the other substrate holding members can be omitted. Therefore, the settling time can be shortened by reducing the weight of the stage, and the control can be performed. There is an effect that the property can be improved.

[0052]

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of a wafer transfer system including a substrate transfer apparatus according to an embodiment.

FIG. 2 is a flowchart showing a main control algorithm of a CPU in the control device of FIG.

3 is an enlarged plan view showing the wafer holder of FIG. 1. FIG.

FIG. 4 is a diagram showing a state of wafer unloading by a substrate transfer apparatus according to an embodiment.

FIG. 5 is a diagram showing how wafers are loaded by a substrate transfer apparatus according to an embodiment.

FIG. 6 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

24 Rotation Transfer Arm for Wafer Loading (Transfer Arm) 26 Rotation Transfer Arm for Wafer Unloading (Transfer Arm) 38 Arm Drive Mechanism (Horizontal Drive Mechanism, Vertical Drive Mechanism,
Arm up / down drive mechanism) 40 XY stage (stage) 56 Wafer holder (substrate holding member) 58, 60 Recessed groove W Wafer (substrate)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/30 502J

Claims (4)

[Claims] 1. A substrate transfer device for transferring a substrate onto a stage movable in a two-dimensional direction, the transfer arm holding the substrate; and a horizontal drive for driving the transfer arm parallel to the stage moving surface. A mechanism; a substrate holding member provided on the stage, in which a concave groove into which the transfer arm can be inserted while holding the substrate is formed on the contact surface side with the substrate; the transfer arm and the substrate holding A substrate transfer device having a vertical drive mechanism that drives at least one of the members in a direction orthogonal to the stage moving surface. 2. The substrate transfer apparatus according to claim 1, wherein each of the transfer arms is provided for loading and unloading a substrate. 3. The substrate transfer apparatus according to claim 1, wherein the vertical drive mechanism is a vertical movement mechanism of a substrate table on which the substrate holding member is mounted. 4. The substrate transfer apparatus according to claim 1, wherein the vertical drive mechanism is an arm vertical drive mechanism that drives the transfer arm in a direction orthogonal to the stage moving surface.