JPH0342697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a device for transporting a mask or reticle substrate, and more particularly to a device for conveniently transporting a mask or reticle in a semiconductor exposure apparatus.

[Conventional technology]

One of the issues that must be solved in the manufacture of semiconductors such as ICs, LSIs, and VLSIs is the problem of dust adhesion to masks or reticles. When transferring ultra-fine circuit patterns formed on a mask onto a wafer, if there is dust attached to the mask, the circuit pattern transferred onto the wafer may be damaged, resulting in damage to semiconductors such as LSIs that are manufactured into products through post-processing. This not only degrades the performance of the device, but in the worst case, impairs the entire functionality of the semiconductor device.

However, in conventional semiconductor manufacturing equipment, a worker must manually load a mask or reticle into a mask holder, so there is a high possibility that dust from the human body will adhere to the mask or reticle. Furthermore, as masks have become larger in diameter in recent years, they have become difficult to handle by hand, and there is a risk of scratches or damage to the masks due to carelessness on the part of workers.

Conventionally, when setting a mask, in the exposure area, the mask is set so that the alignment mark for aligning the wafer with respect to the mask provided on the mask is in the center of the field of view of the observation microscope. Alignment is performed by a worker, but this type of work is something that should be omitted in a clean room where human intervention is extremely discouraged.

By the way, several such automatic conveyance devices for masks or reticle have already been developed and used (Japanese Patent Application Laid-open No. 57-64930, Japanese Patent Application Laid-Open No. 55-62729,
JP-A-52-143771, etc.).

However, in these automatic transport devices, when the mask or reticle is loaded into the device, even if the mask or reticle is naked or loaded in a container of some kind, the mask or reticle may be loaded during transport. A system is in place to remove the mask or reticle from the container and transport it. However, since the mask or reticle is completely exposed after it is loaded or during transportation, it is easily contaminated with dust and is easily damaged when some kind of disturbance occurs. Therefore, because masks or reticles are very expensive and have very high precision, it goes without saying that they cannot be loaded into an automatic transport device while being stored in some kind of container, or even on the transport path inside the device. It is desirable to transport the product while it is protected in a container as much as possible.

[Purpose of the invention]

The present invention solves the problems of the conventional type described above, and by adding this device to an exposure device, it is possible to operate the exposure device without any human intervention. The purpose is to provide equipment.

[Structure of the invention]

In order to achieve the above object, a mask or reticle substrate transport device according to the present invention includes a lower lid on which a mask or reticle substrate is placed, and an upper lid that is formed to be detachably attached to the lower lid. a cassette carrier loaded with a plurality of dust-proof cassettes for storing the substrates in a substantially hermetically sealed state; a fork unit having a fork for taking out the substrate together with the lower cover of the dust-proof cassette from the cassette carrier; and after taking out the lower cover of the dust-proof cassette by the fork;
an elevator unit that moves the fork unit relative to the cassette carrier in a direction in which the plurality of dustproof cassettes are stacked in the cassette carrier; and an elevator unit that moves the fork unit to the cassette carrier by the elevator unit. a hand unit having a hand for sucking and holding the substrate in the lower lid of the dust-proof cassette and taking out the substrate from the lower lid of the dust-proof cassette after the substrate has been moved to a predetermined positional relationship with respect to the dust-proof cassette; The photoelectric detection system includes a substrate stage on which the taken out substrate is placed and holds the substrate by suction, and a photoelectric detection system that photoelectrically detects marks on the substrate suctioned and held by the substrate stage. a positioning unit that controls the movement of the substrate stage according to the detection result of the mark using the positioning unit, and positions the substrate at a predetermined position; and after the positioning of the substrate by the positioning unit is completed; The present invention is characterized by comprising a conveying unit that conveys the substrate to a substrate setting position.

[Explanation of Examples]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, particularly taking as an example a case in which a circular mask is automatically transported in a semiconductor device.

FIG. 1 is a perspective view showing the general configuration of an automatic mask conveyance device according to an embodiment of the present invention, and FIG.
The figure is a conceptual diagram of a path in which a mask is transported from a state in which it is stored in a dust-proof cassette to an exposure stage in this transport device.

In Fig. 1, the dustproof cassette 1 is stacked on a cassette carrier 2, and the main body 10 extracts the dustproof cassette 1 from the cassette carrier 2, and only the lower cover on which the mask is placed, and finally exposes the mask. A mechanism for transporting to a stage (not shown) is provided.

The general flow of the mask and the operation of each mechanism will be described with reference to FIGS. 1 and 2.

Initially, the mask is placed in the dust-proof cassette 1, which is composed of a lower lid and an upper lid, and loaded into the cassette carrier 2 at the mask position 9a. In this state, the operator specifies the slot number in which the dustproof cassette containing the desired mask is accommodated. Then, the fork 3 supported by the vertically moving elevator unit 4 moves up and down to the dustproof cassette position, and then the lower cover is pulled out with the mask placed thereon. Do not remove the top cover of the cassette.

The vertical position of the fork unit 3 is determined by a fixed index plate 5 and a photo switch 6 provided in the elevator unit 4 as shown in FIG.
As shown in B, it is precisely determined photoelectrically, and the locking or unlocking of the upper cover and the lower cover by the vertical movement of the fork unit 3, which will be described later, is stabilized.

The mask position in this state is shown by 9b (FIG. 2). Next, the fork 3 continues to rise, and the mask is transferred to the mask positioning stage 8. Here, the mask 9c is positioned by the mask positioning optical system 11, and then transported to the exposure stage position 9e via the mask hand 7 and the position 9d on the mask loader 12. In this way, the mask is transferred from the dustproof cassette to the main body 10 and the mask loader 12.
is automatically transported to the exposure stage via.

The above is the flow of masks inside the automatic mask transport apparatus of this embodiment.

The details of each part of this device will be described below in order.

FIG. 4 is a perspective view of the dustproof cassette 1 used in this embodiment, and FIG. 5 is a schematic diagram of the lower lid of the dustproof cassette. In FIG. 4, the central part 22a of the front wall 22 of the upper lid 21 protrudes compared to both ends 22b, and each of the retracted ends 22b is integrated with a flexible inverted L-shaped locking member 23. is installed. This inverted L-shaped locking member 2
The holes 23b of No. 3 are the locking protrusions 15 formed at corresponding positions on both ends of the front wall of the lower lid 13 in FIG.
It fits perfectly.

Further, there are guide pins 16 on both sides of the lower lid 13, which loosely fit into guide grooves provided at corresponding positions on the side wall portion 24b of the upper lid 1. This guide pin 1
6 is fitted into the guide groove of the upper lid, the hole 23b of the locking member 23 fits into the locking protrusion 15, so that the upper lid 21 and the lower lid 13 are sufficiently sealed.

Next, a protruding piece 26 provided at the lower end of the side wall portion 24b of the upper lid 21 serves as a carrier 2 for storing the cassettes 1 in multiple stages, as shown in FIG.
The guide pin 16 is held by a holding member 44, and is swingable about the position when the guide pin 16 is located at the innermost part of the guide groove.

As a result, when the locking members 15 and 23 are released, the upper cover 21 is rotated around the position 16a (FIG. 7) when the guide pin 16 is located at the innermost part of the guide groove as a fulcrum, and rotates through a predetermined rotation angle. The rotation is stopped by a stopper provided at the position, and the slanted state is established.

Furthermore, protruding pieces 14 are provided on both sides of the lower lid, and the lower surface of these protruding pieces is placed by a fork portion in the case of automatic conveyance, which will be described later.

Furthermore, explaining the inside of the lower lid with reference to FIG. 5, an annular portion 18 standing upright from the bottom portion is arranged near the center of the interior of the lower lid 13 on which a mask or a reticle is placed. Three or more protrusions 20 are arranged at equal intervals on the upper end surface of the annular portion 18, and the mask 17 is placed on the protrusions 20 with its pattern surface facing downward. At this time, there is no problem even if a pellicle membrane is attached to the lower surface of the mask.

Positioning pins 19 stand concentrically around the annular portion 18 . This positioning pin 19 is used when placing the mask 17 on the annular portion 18.
This is useful for determining the position of 7 at approximately the center inside the lower lid 13. Therefore, the height of the pin 19 is
Conveniently, it is set equal to or higher than the upper surface position of the mask 17 placed on the surface.

Next, a procedure for automatically taking out only the lower lid 13 on which a mask is placed from the dustproof cassette 1 will be explained. As mentioned above, the dustproof cassettes 1 are stacked on the cassette carrier 2, and only the lower lids 13 are automatically transported by the fork unit 3.

FIG. 6 is a diagram showing the appearance of the fork unit 3. The forks 3a and 3b have a slightly larger interval than both side walls of the lower lid 13, and the protruding piece 1 of the lower lid 13
Place the bottom surface of 4.

FIGS. 7 to 10 show how the fork unit 3 is used to automatically convey a mask.

FIG. 7 shows a state in which the fork unit 3 is moved horizontally so as to approach a predetermined dustproof cassette.

At this time, regarding the dustproof cassette, the protruding piece 26 of the upper lid 1 is held by the holding member 44 of the carrier, and the upper lid 21 and the lower lid 13 are held by the locking members 15, 2.
3, the dustproof cassette is integrally supported and fixed by the carrier.

Note that the protruding piece 14 of the lower lid is held by a guide bearing 43 of the carrier.

Next, in FIG. 8, the fork unit 3 is shifted upward by several mm by the elevator unit 4 (the fork unit 3 supports the lower surface of the protruding piece 14 of the lower cover 13, and the bearing 4 in the fork unit 3
6 shows the state in which the locking members 15 and 23 are released.

The upper lid 21 is moved to the fulcrum 16 by the urging force of the spring 45.
It rotates clockwise around point a, and its position in the rotational direction is regulated by a stopper (not shown), and it stops in a diagonally raised state as shown in the figure.

Note that the fulcrum 16a is the position when the guide pin 16 is at the innermost part of the guide groove.

FIG. 9 shows a state in which the fork unit 3 places the lower cover 13 and moves backward in the horizontal direction, that is, the lower cover 13 is pulled out. The vertical position of the fork unit 3 in FIG. 9 is the same as in FIG. 8. Furthermore, the position of the lower lid 13 in the transport direction is regulated on the fork unit 3.

FIG. 10 shows a state in which the fork unit 3 has reached the retracted position.

Thereafter, the lower lid 13 is carried to the uppermost position by the elevator unit 4, and the mask reaches under the mask hand unit 7.

The above is the order in which the mask is removed by the automatic transport system, but when inserting the mask into the dustproof cassette, the flow described above is reversed. That is, the mask is placed on the lower lid 13 and the fork unit 3
The guide pin 16 of the lower cover 13 reaches the innermost part of the guide groove of the upper cover 21.

Then, when the fork unit 3 is shifted downward, the claw portion 47 of the fork unit 3 engages the locking member 2.
3, the upper lid 21 rotates counterclockwise around the fulcrum 16a, and the locking member 23 of the upper lid 21
engages with the protrusion 15 of the lower lid 13, and the upper lid 21 and the lower lid 13 are integrated.

The fork unit 3 then retreats horizontally from the downwardly shifted position.

Detection of the vertical position of the fork by the index plate 5 and photo switch 6 is shown in FIGS. 3A and 3B.

For a fixed index plate 5, four photo switches 6a to 6d are provided in the elevator unit 4.

In Fig. 3A, photo switches 6a' to 6d' are upper cover 1.
The positions of the four photo switches are shown when the fork unit 3 is shifted downward by Δ to close the photo switch.

FIG. 3B is a view of FIG. 3A viewed from above, and shows a light emitting unit 6 such as a photo switch 6c, for example.
This shows a state in which the light from P is blocked by the index plate 5 and does not reach the light receiving section 6q, resulting in no output.

Lower vertical position of fork unit 3 (7th
(see figure) are detected by photo switches 6b' and 6c'. On the other hand, the high position of the fork unit 3 in the vertical direction (see FIGS. 8 to 10) is detected by the photo switches 6a and 6d.

In the figure, l ₁ and l ₂ are the light shielding parts of each index plate 5,
The lengths of the openings have different absolute values, and (l ₁ +l ₂ ) corresponds to the intervals between the cassette storage positions of the cassette carrier 2.

Through the above operations, the mask 17 that has been automatically transported together with the lower lid 13 by the fork unit 3 from the cassette carrier 2 is transported to the top position of the elevator 4, where it is once transferred to the hand unit 7.
The upper surface of the mask is sucked by the mask positioning stage 8, and the mask is transported to the θ stage 39 of the mask positioning stage 8. less than,
Mask positioning will be explained in detail.

FIG. 11 is a conceptual diagram of the mask positioning stage 8 and the mask positioning optical system 11.

In FIG. 11, the circular mask 17 is conveyed onto the θ stage 39. The θ stage 39 is
Full rotation of over 360° is possible.

When the mask 17 is carried onto the θ stage 39, the mask 17 is moved by four pressing rollers 34a to 34d (34c not shown) to the X and Y positions based on the external shape.
It is substantially fixedly positioned in the direction. And mask 17
After being fixed to the θ stage 39 by vacuum suction, the pressing rollers 34a to 34d are separated from the mask.

Now, on this mask positioning stage 8, an optical system 11 for detecting the mask position is arranged.
That is, 51 is a light source, 52a, 52b are CCD cameras, 53a, 53b are prisms, 54 is a half mirror, 55a, 55b are reflective mirrors, 56a,
Reference numeral 56b denotes an objective lens, which is used to detect the position of the mask, which will be described later.

After centering the mask in the X and Y directions, the θ stage 39 starts coarse rotation and at the same time, the CCD camera having a CCD line sensor starts operating.
When the image of the mask positioning pattern shown in FIG. A overlaps the CCD line sensor as shown in FIG. 12B, and the mask positioning pattern reaches a position where it can be electrically detected, rotation is stopped. Then, the θ stage 39 rotates in the opposite direction by a certain angle, and once the positioning pattern disappears from the field of view of the objective lens, it rotates in the normal direction again. At this time, the θ stage is
The θ stage is sent at a slow speed and stops when the mask positioning pattern is detected at a position (to be aligned in a predetermined position) within the field of view of the objective lens. To reverse rotation once, switch to fine movement, and then rotate forward again is as follows:
This is because the scanning speed of the CCD line sensor is slower than the movement speed of the θ stage during coarse movement, and if positioning is attempted with coarse movement, overrun may occur and positioning accuracy may deteriorate. In FIG. 11, 33a and 33b are cylinders, 30 is a pulse motor for driving in the θ direction, and 31 and 32 are gears.

Next, the principle of position detection using the CCD line sensor will be explained.

In FIG. 13, 50 is a CCD camera, 58
12 is a CCD image sensor shown as a model, 61 is a projection optical system, and 57 is a triangular positioning pattern as shown in FIG. CCD image sensor 5
No. 8 has the largest number of elements, 2048 elements, among those currently on the market. The light reflected by the mask positioning pattern is magnified by, for example, 10 times by the projection optical system 61 and reaches the CCD image sensor 58 . When the output signal at this time is expressed in correspondence with the length of the element, it becomes the output signal 59 in FIG. 13B. When this output signal 59 is cut at a certain arbitrary threshold level (threshold value) 60, the edges 57a and 57b of the position cutting pattern
The CCD image pickup devices 58a and 58b corresponding to the above are uniquely determined.

Therefore, as shown in FIG. 12B, this element 58
By checking the absolute positions of the CCD imaging elements 58a', 58b' corresponding to the edges of the positioning pattern 57', the positional deviation of the positioning pattern can be accurately detected.

Incidentally, when there is a deviation in the θ direction in FIG. 12B, the midpoint position of elements 58a and 58b is on the minus side, whereas the midpoint position of elements 58a' and 58b' is on the plus side.

Furthermore, when there is a shift in the x direction, the elements 58a,
This causes an imbalance between the spacing between the elements 58b and the spacing between the elements 58a' and 58b'.

Furthermore, when there is a shift in the y direction, the element 58a,
58b and elements 58a' and 58b' are both on the plus side or the minus side.

When the alignment is performed in this way, the element 5
The midpoint positions of 8a and 58b and the midpoint positions of elements 58a' and 58b' are at the O position in FIG. 12B, and the absolute positions of elements 58a, 58b, 58a', and 58b' are at predetermined positions.

The CCD image sensor used in the present invention is 1
Since the size of each element is 14 μm and a 10x projection optical system is used, the resolution of edge detection is approximately 1.4 μm, but in reality, the resolution of the edge detection is approximately 1.4 μm. Because the slope of the rise of the CCD image sensor output signal from O level to 1 level varies due to factors such as uneven illumination, the actual resolution is 4 to 6 μm, which is 3 to 5 times the ideal resolution. It is estimated that the

At the same time as determining the θ position through the above process,
The amount of deviation in the x and y directions is also measured, and according to this value,
After transporting the mask or reticle to the exposure position, the x, y stage at the exposure position
By correcting the amount of directional deviation, it becomes possible to position the mask with very high precision.

Here, the X and Y positioning method using the four pressing rollers after the mask 17 is carried onto the θ stage 39 will be described in more detail.

In FIG. 14, 36a to 36d support the pressing arms 35a to 35d movably in the radial direction from the rotation center O of the θ stage 39, and 33a to 33d support the pressing arms 35a to 35d.
This is an air cylinder for driving each of d. The support stands 36a to 36d are connected to the substrate 40 (11th
), and the air cylinders 33a~
33d is held as shown. Support stand 36
pins 38a, 38b for regulating the amount of movement of the rollers 34c, 34d supported by the pressing arms 35c, 35d in the direction of the rotation center O;
is fixed. The rollers 34c and 34d regulated by the pins 38a and 38b are connected to the mask 1.
This is the standard when centering 7. roller 3
4b presses the mask 17 in the X direction, that is, the direction in which the mask 17 is brought into contact with the roller 34d, and the roller 3
4a presses the mask 17 in the Y direction, that is, the direction in which the mask 17 is brought into contact with the roller 34c. Pressing arms 35a, 3 supporting rollers 34a, 34b
5b, the cylinders 33a and 33b are connected to the arm 35.
When moving a and 35b in the direction of the rotation center O,
Springs 37a and 37b are provided that generate biasing forces that resist the pressing forces of the cylinders 33a and 33b. Thereby, the mask pressing force of the rollers 34a, 34b when centering the mask 17 is weaker than the mask pressing force of the rollers 34c, 34d. This is because when the pressing forces of the four rollers 34a to 34d are equal, the arm 3
The pressing force on the mask 17 is balanced before the pins 5c and 35d come into contact with the pins 38a and 38b,
This is to prevent centering of the mask 17 from becoming inaccurate.

60a and 60b are control valves for controlling air from the air supply source 61, and the control valve 60a is connected to the rollers 34c and 34d via cylinders 33c and 33d.
The control valve 60b simultaneously controls the movement of the rollers 34a and 34b via the cylinders 33a and 33b. The control valves 60a and 60b are provided with rollers 34c and 34d that serve as references when centering the mask 17, and rollers 34a and 34a that bring the peripheral edge of the mask 17 into contact with the reference rollers 34c and 34d.
34b is provided to enable independent control. During centering, the control valve 60a moves the rollers 34c and 34d from the position shown in FIG. 15a to the position shown in FIG.
The rollers 34a, 34b are moved from the position of FIG. 15a to the position of FIG. 15c by the control valve 60b. In this way, all the rollers 34a to 34d
Compared to the case where the rollers are driven at the same time, unnecessary movement of the mask 17 due to pushing and pulling until the balance of each roller can be prevented, so the accuracy and reproducibility of centering of the mask 17 can be improved.

The operation after aligning the center of the mask 17 with the center of rotation of the holder 39 is as described above.

The mask 17 thus positioned on the mask pre-alignment stage is transported by the mask hand unit 7 shown in FIG. 2 to the mask chuck position 9d placed on the mask loader 12.

FIG. 16A shows a mask being vacuum-suctioned and conveyed by a mask hand. hand 7
1, three or more vacuum suction pads 75 are provided at equal intervals to suction the upper surface of the mask 17. However, since the mask 17 is attracted to the top surface, if the vacuum path is cut off for some reason, the mask 17 will fall. In order to prevent this, a mask dropping claw 73 is attached to the hand 71 so as to wrap around the underside of the mask 17 in case of an emergency. This claw 73
rotates around an axis 74. The rotation is performed by cylinder 72. FIG. 16B shows the state in which the claw 73 is rotated by the cylinder 72 when the mask 17 is placed on the mask chuck.

In addition, a vacuum switch (not shown) is provided in the middle of the suction vacuum path, and this switch can determine whether a mask is present or not.
Furthermore, a reflective optical sensor 76 is embedded in the hand 71 in order to increase the reliability of mask presence detection and to confirm that the mask 17 is present even if the mask falls and rests on the claw 73. It's included.

Although the above embodiment has been described using a circular mask as an example, there is no problem even if the mask is a rectangular mask or a reticle, and the performance completely equivalent to that of a circular mask can be obtained. However, in this case, some mechanisms will have to be changed. In FIG. 15, there is one reference roller 34c, 34d each, but by increasing the number to two each as shown in FIG. 17, accurate positioning of the θ component becomes possible.

In addition, the fork 3 is
As shown in Fig. 3, the position for raising and lowering is determined using four photo switches 6.
For example, a linear scale such as Magnescale may be used, or a potentiometer, rotary encoder, etc. may be used to read the rotation amount of the timing pulley shaft that drives the timing belt that transmits the vertical drive of the elevator. It is also possible by the method.

Furthermore, in FIG. 11, when measuring the amount of mask shift using a CCD line sensor, the mask positioning unit 11 was equipped with only the θ stage 39, but it is now equipped with X and Y stages, On this mask positioning stage, mask 1
After the mask 7 is completely positioned, a means for transporting the mask 17 by the mask hand 7 may be provided.

〔Effect of the invention〕

As explained above, according to the present invention, firstly, while the mask is being transported from the carrier to the mask positioning stage, the mask is transported while being placed on the cassette lower lid, thereby preventing dust from adhering to the pattern surface on the lower surface of the mask. It is possible to reduce the possibility of damage to the mask due to some kind of accident or the like.

By using an optical system equipped with a second CCD image sensor to detect and align the alignment pattern provided on the mask, it is possible to align the circular mask, and In positioning based on the mask periphery,
It is possible to overcome the problem that the positioning accuracy deteriorates when the position of the mask pattern from the periphery of the mask varies.

Furthermore, with such a high-precision positioning mechanism, conventionally, after a mask is placed in the exposure position, the operator can position the mask in a predetermined position while looking at a mask observation microscope. This eliminates the need for additional work.

As described above, by equipping a semiconductor exposure apparatus with the automatic mask or reticle transport device according to the present invention, there is no need for operator intervention, which leads to dust-free operation and a reduction in work errors.
It is expected that the yield rate for manufacturing integrated circuits such as LSI will greatly improve.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the automatic transport system, Figure 2 is the flow of a mask or reticle substrate by the automatic transport system, Figures 3A and B are illustrations of how to detect the vertical position of a fork using an index plate and a photo switch, and Figure 4 5 is a perspective view of the lower lid structure of the dust-proof cassette, FIG. 6 is a diagram showing the fork part of the automatic conveyance system, and FIGS. 7 to 10 are A diagram explaining the principle when separating the upper and lower lids of a dust-proof cassette and transporting a mask or reticle substrate placed on the lower lid. Figure 11 is an example of a system for detecting the position of a mask in this embodiment. FIG. 12A is a diagram showing an example of positioning marks used for positioning the mask in this embodiment, FIG. 12B is a diagram illustrating alignment using the marks, and FIGS. 13A and B are CDDs. 14 is a diagram showing the driving system of the roller in this embodiment. FIGS. 15 a to 15 c are diagrams showing the flow of driving the roller in this embodiment. Figure 16A,
FIG. 17 is a diagram showing the arrangement of rollers when a square mask is used in this embodiment. 1: Dustproof cassette, 2: Cassette carrier,
3: fork unit, 4: elevator unit, 5: index board, 6: photo switch,
7: Hand unit, 8: Mask positioning stage, 10: Main body, 11: Mask positioning optical system, 13: Lower lid, 17: Mask, 21: Upper lid, 3
4: Roller, 39: θ stage, 52: CCD camera, 57: Positioning mark, 71: Hand,
73: Fall prevention claw, 75: Suction pad.

Claims (1)

[Scope of Claims] 1. A dust-proof cassette that has a lower lid on which a mask or reticle substrate is placed, and an upper lid that is detachably attached to the lower lid, and stores the substrate in a substantially hermetically sealed state. a cassette carrier in which a plurality of cassettes are loaded; a cassette carrier that is movable forward and backward with respect to the cassette carrier, and with the top cover of the dustproof cassette remaining in the cassette carrier, the substrate is placed in the cassette together with the bottom cover of the dustproof cassette; a fork unit having a fork to be taken out from the carrier; after the lower cover of the dustproof cassette is taken out by the fork, the fork unit is moved into the cassette carrier in a direction in which a plurality of the dustproof cassettes are stacked in the cassette carrier; an elevator unit that moves relative to the dust-proof cassette; and after the fork unit is moved to a predetermined positional relationship with respect to the cassette carrier by the elevator unit, the substrate in the lower lid of the dust-proof cassette is sucked. a hand unit having a hand for holding the substrate and taking out the substrate from the lower lid of the dust-proof cassette; a substrate stage on which the substrate taken out by the hand is placed and holding the substrate by suction; a photoelectric detection system that photoelectrically detects marks on the substrate held by suction;
a positioning unit that controls the movement of the substrate stage according to the detection result of the mark using the photoelectric detection system and aligns the substrate at a predetermined position; and a positioning unit that aligns the substrate at a predetermined position. A transfer device for a mask or reticle substrate, comprising: a transfer unit that transfers the substrate to a substrate setting position after completion of the transfer. 2. The mask or reticle substrate transport device according to claim 1, wherein the mask or reticle substrate is placed on the lower lid with its patterned surface facing downward. 3. Claim 1, wherein the photoelectric detection system of the alignment unit includes an optical system that receives light reflected by the mark on the substrate, and a photoelectric detection element that detects an image of the mark by the optical system. Alternatively, the mask or reticle substrate transport device according to item 2.