JPH11191582A - Cassette conveying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cassette conveying system, capable of preventing reduction in yield rate by chemical fume/mist and foreign material and reducing the air-conditioner operating cost of a clean room. SOLUTION: Over almost an entire surface of the underfloor part of a working area 99 (class 1,000-10,000) wherein a semiconductor manufacturing device 12 is provided, a cassette conveying area with high cleanliness (class 1-10), wherein an orbit 21 comprising a plurality of loop-shaped rails and direct line rails arranged at the regularity is arranged, is provided. Thus, high-cleanliness space can be reduced greatly in comparison with the conventional clean room. The reduction in the air-conditioner working cost of the clean room can be achieved greatly. Furthermore, since the cassette conveying area 16 is separated from the semiconductor manufacturing device 12, workers and the like, the contamination of the wafer in conveyance by chemical fume/mist and foreign material can be prevented, and the yield rate is improved. Also since a plurality of running routes to the destination can be selected, the cassette can be moved quickly between the devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette transfer system for moving a cassette for storing wafers between semiconductor manufacturing apparatuses in a semiconductor manufacturing line.

[0002]

2. Description of the Related Art In the manufacture of semiconductors, since fine processing in the order of microns is performed on a wafer, foreign matter, for example, dust particles, chemical fumes, mist, etc., on the wafer directly causes a reduction in product yield. . For this reason, the semiconductor manufacturing line has conventionally been provided in a clean room, which is a highly clean environment in which foreign substances are strictly controlled to a low level. FIG. 15 is a diagram illustrating a conventional general clean room air conditioner. In the figure, 1 is an external conditioner that takes in outside air and controls temperature and humidity, 2 is a utility zone in which power supply equipment, environmental protection equipment, and the like are arranged, 3
Is a silencer, 4 is a dry coil, 5 is a circulation fan, 6 is a ceiling chamber in which a ceiling filter 7 is installed, 8 is a partition wall that separates areas having different cleanliness levels, and 9 is a loader / unloader section of a semiconductor manufacturing apparatus. And a work area in which cassette transport devices and the like are arranged, 10 is a maintenance area for performing device maintenance, 11 is provided on the entire floor of the work area 9, and a grating that allows air to pass through the utility zone 2, and 12 includes an inspection device and the like. Reference numeral 13 denotes a semiconductor manufacturing apparatus, 13 denotes an operator wearing a dust-free garment, 18 denotes a cassette for storing wafers, 19 denotes a carriage for transporting the cassette 18, and 35 denotes a track as a traveling route of the carriage 19. Note that, in the drawing, arrows indicate the flow of air.

In a conventional clean room, outside air is taken in by an external air conditioner 1, temperature and humidity are controlled, and air in which dust particles are controlled to a predetermined cleanliness level is supplied to a utility zone 2. Thereafter, the temperature of the air is further controlled through the silencer 3, the dry coil 4, and the circulation fan 5, and the air is introduced into the ceiling chamber 6. Subsequently, air is filtered by a ceiling filter 7 installed in the ceiling chamber 6, for example, HEPA or ULPA, to remove dust particles, and to a prescribed cleanliness level in the work area 9 and the maintenance area 10 divided by the partition wall 8. Air, for example
Work area 9 is class 1-10, maintenance area 1
For 0, air in the class of about 1,000 to 10,000 is supplied. The air introduced into the work area 9 and the maintenance area 10 passes through the grating 11 on the floor, and is circulated again to the ceiling chamber 6 by the circulation fan 5. Further, the clean room is in a more positive pressure state than the outside air in order to prevent foreign substances from entering from the outside air.

[0004] There are several hundred types of semiconductor manufacturing apparatuses 12 including an inspection apparatus and the like installed in the clean room, and maintenance and chemical liquid exchange are frequently performed.
In order to prevent the diffusion of the chemical fumes / mist and foreign substances generated during the maintenance, the work area 9 and the maintenance area 10 are conventionally separated by a partition wall 8 or a separating curtain, and the work area 9 is cleaned higher than the maintenance area 10. Was on the level. Conventionally, the cassette 18 containing the wafers is transported by driving a linear induction motor to a track 35 provided in the work area 9, for example, a single loop-shaped rail provided in a space above the semiconductor manufacturing apparatus 12. The trolley 19, which is the source, is run, and the cassette is moved between the respective manufacturing processes. At this time, the cassette 18 is transferred from the stop position of the cart 19 to the stocker 9a for temporarily storing the cassette and temporarily stored, and the cassette 18 stored in the stocker 9a is mainly transferred to each semiconductor manufacturing apparatus 12 by the worker 1
3 had been conveyed.

[0005]

As described above, in the conventional clean room, in order to maintain the work area 9 for directly handling wafers at a high cleanliness level, the maintenance of the semiconductor manufacturing apparatus 12 is performed more cleanly than the work area 9. The maintenance is performed in the maintenance area 10 having a low level.
However, it is difficult to perform maintenance on all the semiconductor manufacturing apparatuses 12 in the maintenance area 10 due to the arrangement of the apparatuses. In practice, the maintenance may be performed in the work area 9. In this case, there is a problem that the cleanliness level of the work area 9 is reduced due to the diffusion of the chemical fume / mist and foreign matter generated during the maintenance. In recent years, with the miniaturization and high integration of LSIs, the cause of a decrease in yield has been the problem of chemical (chemical) contamination from particle contamination. Chemical pollution includes, for example, acids, alkali gases, volatile boron, phosphorus, organic gases, etc.
These sources include, for example, workers 13, members, interior materials, and intrusions from the outside. Acid gas, especially H
F promotes the volatilization of boron from the filter medium, and the alkali gas is an obstacle to the resolution of the resist.
Boron and phosphorus cause malfunctions of LSI products, and organic gases cause troubles such as a decrease in withstand voltage of insulating films and clouding of lenses, and both are important issues.

Further, the conventional work area 9 has a very large volume, and requires a large amount of power to keep it at a high cleanliness level. Approximately 40% of the electricity used in conventional semiconductor manufacturing plants is required for air-conditioning operation in a clean room, and reduction in air-conditioning costs has been desired. In addition, in the conventional cassette transport method, since the carriage 19 travels on a single loop-shaped track 35 provided in the work area 9, there is no choice in the traveling course, and the flow of the carriage 19, ie, the flow of the cassette 18, is reduced. There was a stagnation. Further, since wafers to be products are stored in the cassette 18, it is not preferable that the worker 13 serving as a dust source directly transports the cassette 18.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and in a semiconductor manufacturing line, it is possible to prevent a decrease in yield due to chemical fumes / mist and foreign matters, and to reduce the operating cost of air conditioning in a clean room. It is still another object of the present invention to provide a cassette transport system in which a cassette for accommodating wafers can be quickly moved without stagnation between semiconductor manufacturing apparatuses.

[0008]

A cassette transport system according to the present invention is provided in a work area in which a plurality of semiconductor manufacturing apparatuses are installed, a lower part of the work area, and a track corresponding to an installation position of the semiconductor manufacturing apparatuses. Is provided,
A cassette transport area maintained at a higher degree of cleanliness than the work area, a cart for mounting a cassette for storing wafers, traveling on the above-mentioned track, and moving the cassette between semiconductor manufacturing apparatuses, its driving means, and cassette transport. The area is connected to the loader / unloader section of each semiconductor manufacturing equipment, and the cassette elevating / lowering area maintained at the same high cleanliness level as the cassette transport area, the cassette handling robot and the cassette provided respectively in the loader / unloader section of the semiconductor manufacturing equipment. It is provided with a cassette elevating means provided in the elevating area for transferring cassettes between the cassette handling robot and the carriage. Further, the height of the cassette transfer area is set to such an extent that the carriage on which the cassette is mounted can travel, for example, about 1 m. Further, the cassette transport area, the cassette elevating area, and the loader / unloader section of the semiconductor manufacturing apparatus are filled with chemical free air or high-purity dry air.

In addition, a track having a plurality of loop-shaped rails and linear rails arranged between a plurality of semiconductor manufacturing apparatuses with regularity, and a cassette for accommodating wafers are placed and run on the track, A trolley for moving the cassette between the semiconductor manufacturing apparatuses and its driving means, and a semiconductor manufacturing apparatus for the next process to which the cassette mounted on the trolley is to be moved, and a traveling route of the trolley to the semiconductor manufacturing apparatus is determined. Control means. Further, the loop-shaped rail is provided so as to be inscribed in the straight rails arranged in a lattice shape, and the loop-shaped rail and the straight rail share a portion in contact with each other. Furthermore, the loop-shaped rail and the straight rail have a partition plate that switches the running direction in one of left, right, and straight directions at a location where the common rail is separated from the common rail to a single rail.

The track is provided with a sensor for detecting the presence or absence of a bogie on the rail. Further, the control means, while searching for the shortest running route to the semiconductor manufacturing apparatus of the next process, which is the destination of the cassette mounted on the truck, detects the presence or absence of another bogie on the shortest running route by a sensor, When another bogie is detected on the shortest running route, the other bogies are searched and the presence or absence of other bogies on other running routes is detected.If no other bogie is detected, another bogie is detected. Is set as the traveling route of the bogie. Further, the control means predicts, for the shortest traveling route or another traveling route to the semiconductor manufacturing apparatus in the next process, which is the destination of the cassette mounted on the truck, whether or not there is interference with another truck during traveling. The route in which no other bogie is detected and there is no interference with other bogies during traveling is defined as the bogie traveling route. In addition, the track is laid in a cassette transfer area provided almost all over the lower floor of the work area where the semiconductor manufacturing equipment is installed, and the cassette transfer area is maintained at a higher degree of cleanliness than the work area. It is.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an air conditioner of a clean room employing the cassette transport system according to the first embodiment of the present invention. In the figure, 1
Is an air conditioner that takes in outside air and controls temperature and humidity, 2a, 2b
Is a utility zone in which power supply facilities and environmental protection facilities are arranged, 3 is a silencer, 4 is a dry coil, 5 is a circulation fan, 6 is a ceiling chamber in which a ceiling filter 7 is installed, and 12 includes an inspection device and the like. Semiconductor manufacturing equipment, 13
Is a worker wearing a dust-free garment, 14 is a chemical-free air generator that is supplied with air from the external conditioning machine 1 and supplies chemical-free air to the utility zone 2b, 9
Reference numeral 9 denotes a work area in which the semiconductor manufacturing apparatus 12 is arranged and work and maintenance are performed, and 16 denotes a work area 99.
A high-cleanness cassette transfer area provided on almost the entire lower surface of the floor 15, a filter 17 for removing dust particles,
Reference numeral 8 denotes a cassette for accommodating wafers, reference numeral 19 denotes a carriage for transporting the cassette 18, and reference numeral 20 denotes a loader / unloader section of the semiconductor manufacturing apparatus 12 maintained at the same high level of cleanliness as the cassette transport area 16. The loader / unloader unit 20 and the cassette transport area 16 are connected by a cassette elevating area (not shown). The cassette elevating area includes the loader / unloader unit 20 of the semiconductor manufacturing apparatus 12.
Cassette handling robot and trolley 19 provided in
Cassette elevating means for transferring the cassette 18 between the cassettes. In the drawings, arrows indicate the flow of air.

The clean room according to the present embodiment comprises:
The outside air is taken in by the outside conditioner 1, the temperature and humidity are controlled, and the air in which the dust particles are controlled to the first cleanliness level is supplied to the utility zone 2a. Thereafter, the temperature of the air is further controlled through the silencer 3, the dry coil 4, and the circulation fan 5, and the air is introduced into the ceiling chamber 6. Subsequently, the dust is removed from the air by a ceiling filter 7 installed in the ceiling chamber 6, for example, HEPA or ULPA, and a second cleanliness, for example, class 1000 to 10
000 air is supplied to the work area 99. At this time, the work area 99 is in a positive pressure state with respect to the outside of the clean room. On the other hand, the chemical-free air of the third cleanliness supplied to the utility zone 2 b from the external controller 1 via the chemical-free air generating device 14 passes through the silencer 3, the dry coil 4, and the circulation fan 5. Further, the temperature and the humidity are controlled, and the filter 17, for example, HEP
A, dust particles are removed by ULPA, the fourth cleanliness,
For example, it is controlled to a high degree of cleanliness of classes 1 to 10 and supplied to the cassette transport area 16. At this time, the air having the fourth cleanliness is supplied so that the cassette transfer area 16 is in a positive pressure state outside the clean room. The loader / unloader unit 20 of the semiconductor manufacturing apparatus 12 and the cassette transport area 16 are connected by a cassette lift area provided with a cassette lifting unit, and the loader / unloader unit 20 and the cassette lift area are the same as the cassette transport area 16. Is filled with air of a fourth cleanliness, which is chemical free air.

Next, a description will be given of a cassette elevating area connecting the cassette transport area 16 and the loader / unloader section 20 of the semiconductor manufacturing apparatus 12. FIG. 2 (a),
3B is a side view and a top view for explaining a method of taking the cassette 18 into the loader / unloader unit 20 of the semiconductor manufacturing apparatus 12. FIG. In the drawing, reference numeral 21 denotes a track on which a carriage 19 for carrying a cassette travels; 22, a drive source for a linear induction motor for driving the carriage; 23, a cassette elevating area;
Reference numeral 24 denotes a cassette handling unit for transferring the cassette 18 between the cart 19 and the cassette cassette 25 for temporary standby.
6 is a feed screw for raising and lowering the cassette handling unit 24, and 27 is a loader / unloader unit 20 of the semiconductor manufacturing apparatus.
2 shows a cassette handling robot provided in the cassette. In the drawings, the same or corresponding parts are denoted by the same reference numerals,
Description is omitted.

The operation of loading the cassette 18 conveyed by the cart 19 into the loader / unloader section 20 will be described below. The carriage 19 on which the cassette 18 is mounted is moved by the linear induction motor driving source 22 into the cassette transport area 1.
6 and stops at the transfer point A of the semiconductor manufacturing apparatus in the next process where the cassette 18 is moved. Next, the cassette 18 placed on the carriage 19 is picked up by the cassette handling unit 24 capable of driving the Y, Z axes and theta axes, and the posture of the cassette 18 is set to 90 degrees.
It is transferred to the temporary standby cassette table 25 (transfer point B) while being rotated by an angle. Next, the cassette 1 placed on the temporary standby cassette table 25 by the cassette handling robot 27 capable of driving the X, Z axes and theta axes provided in the loader / unloader section 20 of the semiconductor manufacturing apparatus.
8 is set at a prescribed position of the loader / unloader unit 20, for example, a transfer point C.

Next, the dispensing operation of the cassette 18 will be described. After the processing is completed, the cassette 18 set at the transfer point C or D of the loader / unloader section 20 is transferred to the temporary standby cassette table 25 (transfer point B) by the cassette handling robot 27. Thereafter, the cassette 18 is picked up by the cassette handling unit 24, and the bogie 1 is rotated while rotating the cassette posture by 90 degrees.
9 is set at transfer point A. By providing the above-described cassette elevating means, the cassette 18 is transferred between the cart 19 in the cassette transport area 16 and the loader / unloader unit 20 of the semiconductor manufacturing apparatus.

FIGS. 3A and 3B are a side view and a top view showing a cassette storage method according to the present embodiment. In the drawing, 28 is a cassette storage for temporarily storing cassettes, 29 is a cassette handling robot provided in the cassette storage 28, and 30 is a cassette storage shelf. In the drawings, the same or corresponding parts have the same reference characters allotted, and description thereof will not be repeated. The cassette storage 28 and the cassette transport area 16 are connected by a cassette elevating area 23, and the cassette elevating area 23 has a cassette 18 between a cassette handling robot 29 provided in the cassette storage 28 and a cart 19. Cassette raising / lowering means for transferring the cassette. The cassette storage 28 and the cassette elevating area 23 are filled with high-purity, chemical-free air, similarly to the cassette transport area 16.

Hereinafter, a method of transferring the cassette 18 between the carriage 19 and the cassette storage 28 in the cassette transfer area 16 according to the present embodiment will be described. First, trolley 1
The cassette 18 transported by the cassette 9 is stored in the cassette storage 28.
The operation of importing data to the storage device will be described. The carriage 19 on which the cassette 18 is mounted travels on a track 21 laid in the cassette transfer area 16 by a linear induction motor driving source 22 and moves to a transfer point A of a cassette storage 28 which is a temporary storage place of the cassette 18. Stop. Next, the cassette 18 placed on the carriage 19 is picked up by the cassette handling unit 24 capable of driving in the Y and Z axes, and is transferred to the cassette stand 25 (transfer point B) for temporary standby. Next, the cassette 1 placed on the cassette stand 25 for temporary standby is moved by the cassette handling robot 29 provided in the cassette storage 28 and capable of driving the X, Z and theta axes.
8 is placed at a designated position on the cassette storage shelf 30. Next, the payout operation of the cassette 18 will be described. Designated cassette 18 on cassette storage shelf 30
Is transferred to the cassette stand 25 for temporary standby (transfer point B) by the cassette handling robot 29. After that, the cassette 18 is
And set it at the transfer point A of the cart 19.

According to the present embodiment, the height of the cassette transport area 16 is sufficient to allow the carriage 19 on which the cassette 18 is mounted to travel, for example, about 1 m. The space with high cleanliness can be greatly reduced as compared with the conventional clean room, and furthermore, by separating the cassette transfer area 16 from the work area 99,
Work area 99 cleanliness class 1000-10000
Since it can be kept to a low level, it is possible to greatly reduce the operating cost of air conditioning for a clean room. Further, the cassette transport area 16 is provided with the semiconductor manufacturing apparatus 12 and the worker 1.
Since the wafer is completely separated from the third and the like, the wafer being transported in the cassette is not affected by the chemical fume / mist and foreign matter, and the production yield is improved.

Embodiment 2 FIG. 4 is a diagram showing an air conditioner of a clean room employing the cassette transport system according to the second embodiment of the present invention. In the figure, reference numeral 11 denotes a grating that is provided on the entire surface of the cassette transfer area 16 and allows air to pass through the utility zone 2b. In the drawings, the same or corresponding parts have the same reference characters allotted, and description thereof will not be repeated. In the present embodiment, the floor of the cassette transfer area 16 is the grating 11, and the track of the carriage 19 for transferring the cassette 18 is provided on the grating 11. Conventionally, in a clean room generally having a high cleanliness level of about class 1 to 10, a ceiling filter 7 is provided on the entire ceiling and a grating 11 is provided on the entire floor.
And a down flow method in which high-purity air supplied from the ceiling filter 7 passes through the grating 11 almost vertically is adopted. In the present embodiment, by adopting the entire downflow method, even if dust occurs due to some trouble in the cassette transfer area 16, it is possible to recover the cleanliness very efficiently and in a short time.

The clean room in the present embodiment is
The chemical-free air of the above-mentioned third cleanliness supplied from the external controller 1 to the utility zone 2 b via the chemical-free air generating device 14 passes through the silencer 3, the dry coil 4, and the circulation fan 5. Further, the temperature and humidity are controlled, and dust particles are removed by a ceiling filter 17 provided at the ceiling of the cassette transfer area 16, for example, HEPA or ULPA.
And is supplied to the cassette transport area 16. The air having the fourth cleanliness is supplied to the grating 11 provided on the floor of the cassette transfer area 16.
And returns to the utility zone 2b, and is circulated again to the cassette transport area 16 by the circulation fan 5.
In this embodiment, the loader / unloader unit 20 of the semiconductor manufacturing apparatus 12 and the cassette transfer area 16
Are connected by a cassette elevating area provided with a cassette elevating means. The method of loading the cassette 18 into the loader / unloader unit 20 of the semiconductor manufacturing apparatus 12 is the same as in the first embodiment, and a description thereof will be omitted.

In the first and second embodiments, the chemical-free air generator 14 is used to generate air having the fourth cleanliness. However, a high-purity dry air generator may be used. In this case, the cassette transport area 16, the cassette elevating area 23, and the loader / unloader unit 20 of the semiconductor manufacturing apparatus 12 are filled with high-purity dry air. Furthermore, in the first and second embodiments, the cassette transport area 16 is provided almost entirely under the floor 15 of the work area 99, but may be provided almost entirely over the ceiling of the work area 99, and the same effect is obtained. can get.

Embodiment 3 FIG. Embodiments 1 and 2 above
In the above, the high-cleanness cassette transfer area 16 provided on almost the entire lower surface of the floor 15 of the work area 99 has been described. In the present embodiment, a track 21 on which a carriage 19 that moves a cassette 18 for storing wafers between semiconductor manufacturing apparatuses 12 including an inspection apparatus travels in the cassette transfer area 16 will be described in detail. FIG. 5 is a perspective view illustrating an outline of the cassette transport system according to the present embodiment, and FIG. 6 is a plan view illustrating a track of the cassette transport system according to the present embodiment. In the figure, reference numeral 21 denotes a track formed by combining a plurality of loop-shaped rails and straight rails, and reference numeral 31 denotes an installation point of the semiconductor manufacturing apparatus 12, and the cassette elevating area 23 described in the first embodiment.
Is provided at the position where the carriage 19 stops. In the drawings, the same or corresponding parts have the same reference characters allotted, and description thereof will not be repeated. The track 21 according to the present embodiment is formed by combining a plurality of loop-shaped rails and linear rails arranged with regularity, and the loop-shaped rail is inscribed in the linear rails arranged in a grid. The loop-shaped rail and the straight rail are provided so as to share a portion in contact with each other (FIG. 6).

FIG. 7 is a plan view showing a structure of a track switching point in the present embodiment, and FIG. 8 is a side view showing a method of switching a track switching point. In the figure, 32,
Reference numerals 32a to 32e denote partition plates for switching the traveling direction of the cart 19, 33 denotes a cylinder for raising and lowering the partition plates 32a to 32e by pneumatic pressure, and 34 denotes a roller.
The track 21 in the present embodiment has a switching point
That is, at a portion where the common portion of the loop-shaped rail and the straight rail is separated into individual portions, there are five partition plates 32a to 32e that switch the running direction to one of left, right, and straight. These partition plates 32
a to 32e are individually separated and can be moved up and down by a cylinder 33. 8A shows a state in which the partition plate 32 is raised, and FIG.
2 indicates a lowered state. When switching the traveling of the carriage 19, the combination of the partition plates 32a to 32e and the switching of the linear induction motor which is the driving source of the carriage 19 arranged on the track 21 are performed.

The combination of the partition plates 32a to 32e and the traveling direction of the carriage 19 will be described below with reference to the drawings. FIG.
FIG. 11 to FIG. 11 are plan views showing the configurations of the partition plates 32a to 32e in the case of selecting the straight traveling, right and left directions, respectively. In the case of straight-ahead selection, as shown in FIG.
a, 32b and 32e are lowered to the lower part of the track 21, and the straight track 21 is constituted by the partition plates 32c and 32d. In the case of rightward selection, as shown in FIG. 10, the partition plates 32b and 32d are lowered to the lower part of the track 21, and the partition plate 3
The right turn trajectory 21 is constituted by 2a and 32e. Further, in the case of the leftward selection, as shown in FIG. 11, the partition plates 32a, 32c are lowered to the lower part of the track 21, and the partition plate 32b, 32e forms the left-turn track 21.
The traveling route of the bogie 19 is determined by the switching points using the partition plates 32a to 32e as described above.

FIG. 12 is a diagram showing an example of a traveling route of the carriage 19 by the cassette transport system according to the present embodiment, in which a, b, and c are switching points of the track 21, and 31a, 31b, and 31c are respectively. This is an installation point of the semiconductor manufacturing apparatuses A, B, and C. In FIG. 12, when the cart 19 moves to the device installation point 31a, the truck 19 passes the route A, that is, the switching points a and c, with a left turn and a left turn, respectively, to reach the destination. Similarly, when the trolley 19 moves to the device installation point 31b, the trolley 19 passes the route B, that is, the switching points a and c, with left and right turns, respectively, to reach the destination. When the cart 19 moves to the device installation point 31c, it passes straight through the route C, that is, the switching point a, and reaches the destination.

Next, control means for controlling the traveling of the carriage 19 will be described. FIG. 13 is a schematic diagram of a carriage traveling control block of the cassette transport system according to the present embodiment. The track 21 includes a sensor (not shown) for detecting the presence or absence of the cart 19 on the rail.
The semiconductor manufacturing apparatus 12 of the next process, which is the destination of the cassette 18 placed on the semiconductor manufacturing apparatus 9, is selected, and the optimum traveling route of the carriage 19 to the semiconductor manufacturing apparatus 12 is determined. At this time, it is confirmed that, as preconditions, the cassette 18 after the processing is completely set on the carriage 19 and that the selection of the semiconductor manufacturing apparatus 12 in the next process is completed. Then, dolly 19
In addition to searching for the shortest traveling route (first candidate) to the semiconductor manufacturing apparatus 12 in the next process, which is the destination of the cassette 18 placed in the shortest traveling route, the presence or absence of another carriage 19 on the shortest traveling route is detected by a sensor. , Another truck 1 on the shortest running route
9 is detected, the traveling routes of the second, third, and n-th candidates are gradually searched, and the presence or absence of another bogie 19 on those routes is detected. The route not performed is set as a traveling route candidate of the bogie 19. Further, the control means predicts the presence or absence of interference with the other bogies 19 during traveling on the shortest running route or the second, third, n-th candidate, etc., and other bogies 19 are detected. And a route determined to have no interference with other bogies 19 during running is determined as a running route. FIG.
It is a figure which shows the example of the section division which detects the presence or absence of the cart 19 on a loop-shaped rail. In this example, the loop rail
The vehicle is divided into four sections (b), (c), and (d), and the presence or absence and position of the cart 19 in each section are detected by sensors.

In this embodiment, the plurality of loop-shaped rails are all the same size, but various sizes of loop-shaped rails may be combined. Further, since the cassette transport area 16 has a high degree of cleanliness, the inside of the loop of the loop-shaped rail may be effectively used as a temporary storage place for the cassette 18. In this case, for example, several linear rails are provided in the loop-shaped rail, and the cassette 18 can be kept on standby while being mounted on the carriage 19.

[0028]

As described above, according to the cassette transport system of the present invention, almost all of the lower part of the work area where the semiconductor manufacturing apparatus including the inspection apparatus is installed has a higher cleanness than the work area. The cassette transfer area is kept at a fixed height, and the work area and the cassette transfer area are separated.
There is an effect that contamination by mist and foreign matter can be prevented, and the production yield is improved.

The height of the cassette transport area is such that a carriage on which the cassette is mounted can travel, for example, about 1 m.
Therefore, the high cleanliness space can be significantly reduced as compared with the related art, and the cleanliness level of the work area can be suppressed low, so that the air conditioning operation cost of the clean room can be reduced.

Further, according to the cassette transport system of the present invention, in a track formed by combining a plurality of loop-shaped rails and linear rails arranged with regularity, the loop-shaped rail and the linear rail are respectively separated from the common portion. Can be freely switched between left and right or in the straight traveling direction at the point where the cassette is separated into a single part, so that a plurality of traveling routes to the semiconductor manufacturing apparatus in the next process can be selected, and the cassette is stagnated. It is possible to move quickly.

[Brief description of the drawings]

FIG. 1 is a diagram showing an air conditioner of a clean room employing a cassette transport system according to a first embodiment of the present invention.

FIGS. 2A and 2B are a side view and a top view illustrating a method of loading a cassette into a loader / unloader unit of the semiconductor manufacturing apparatus according to the first embodiment of the present invention.

FIG. 3 is a side view and a top view illustrating a cassette storage method according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating an air conditioner of a clean room employing the cassette transport system according to the second embodiment of the present invention.

FIG. 5 is a perspective view illustrating an outline of a cassette transport system according to a third embodiment of the present invention.

FIG. 6 is a plan view showing a trajectory of a cassette transport system according to a third embodiment of the present invention.

FIG. 7 is a plan view showing a structure of a track switching point according to Embodiment 3 of the present invention.

FIG. 8 is a side view showing a method of switching a track switching point in Embodiment 3 of the present invention.

FIG. 9 is a plan view showing a configuration of a partition plate when a straight traveling direction is selected on a track according to Embodiment 3 of the present invention.

FIG. 10 is a plan view showing a configuration of a partition plate when a rightward direction is selected in the track according to the third embodiment of the present invention.

FIG. 11 is a plan view showing a configuration of a partition plate when a leftward direction is selected on the track according to the third embodiment of the present invention.

FIG. 12 is a diagram illustrating an example of a truck traveling route of the cassette transport system according to the third embodiment of the present invention.

FIG. 13 is a schematic diagram of a trolley traveling control block of the cassette transport system according to the third embodiment of the present invention.

FIG. 14 is a diagram showing an example of section division for detecting the presence or absence of a bogie on a loop-shaped rail according to Embodiment 3 of the present invention.

FIG. 15 is a diagram showing a conventional general clean room air conditioner.

[Explanation of symbols]

1 external controller, 2, 2a, 2b utility zone,
3 silencer, 4 dry coil, 5 circulation fan, 6
Ceiling chamber, 7 ceiling filter, 8 partition wall,
9,99 Work area, 10 Maintenance area, 1
1 grating, 12 semiconductor manufacturing equipment, 13 workers, 14 chemical-free air generator, 15 floors,
16 cassette transport area, 17 filters, 18 cassettes, 19 carts, 20 loader / unloader section, 2
1, 35 tracks, 22 linear induction motor drive source, 23
Cassette elevating area, 24 cassette handling section, 25 cassette stand for temporary standby, 26 feed screw, 2
7, 29 cassette handling robot, 28 cassette storage, 30 cassette storage shelf, 31, 31a, 3,
1b, 31c Device installation point, 32, 32a, 32
b, 32c, 32d, 32e Partition plate, 33 cylinder, 34 rollers.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuya Sakamoto 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Seiji Ishibashi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Rishi Electric Co., Ltd.

Claims (10)

[Claims] 1. A work area in which a plurality of semiconductor manufacturing apparatuses are installed. The work area is provided below a floor of the work area, a track is provided corresponding to an installation position of the semiconductor manufacturing apparatus, and a height higher than the work area is provided. A cassette transport area maintained at a clean level, a cart for placing a cassette for storing wafers, traveling on the track, and moving the cassette between the semiconductor manufacturing apparatuses, and a driving means therefor; A cassette lifting / lowering area connected to the loader / unloader section of each of the semiconductor manufacturing apparatuses, which is maintained at the same high cleanliness as the cassette transport area; a cassette handling robot provided at each of the loader / unloader sections of the semiconductor manufacturing apparatus; The cassette handling robot is provided in the cassette elevating area, and is provided between the cassette handling robot and the carriage. Cassette transport system comprising the cassette lifting means for performing bets delivery. 2. The cassette transport system according to claim 1, wherein the height of the cassette transport area is such that the carriage on which the cassette is mounted can travel, for example, about 1 m. 3. The cassette transport area, the cassette elevating area and the loader / unloader section of the semiconductor manufacturing apparatus are filled with chemical free air or high-purity dry air. Cassette transport system. 4. A track having a plurality of loop-shaped rails and linear rails arranged between a plurality of semiconductor manufacturing apparatuses with regularity, and a cassette for accommodating a wafer is placed on the track and travels on the track. A trolley for moving the cassette between the respective semiconductor manufacturing apparatuses and its driving means, selecting the semiconductor manufacturing apparatus in the next step which is a destination of the cassette mounted on the trolley, and A cassette transport system comprising control means for determining a traveling route of a cart. 5. The loop-shaped rail is provided so as to be inscribed in a linear rail arranged in a lattice pattern, and the loop-shaped rail and the linear rail share a portion in contact with each other. 5. The cassette transport system according to 4. 6. The loop rail and the straight rail each have a partition plate that switches a running direction to one of left, right, and straight ahead at a position where the common rail separates from the common rail. 5. The cassette transport system according to 5. 7. The cassette transport system according to claim 4, wherein the track is provided with a sensor for detecting the presence or absence of a bogie on a rail. 8. A control means for retrieving a shortest traveling route to a semiconductor manufacturing apparatus in a next process, which is a destination of a cassette mounted on a truck, and for detecting presence or absence of another truck on the shortest traveling route. If another bogie is detected on the shortest traveling route, another bogie is searched for, and the presence or absence of another bogie on the other traveling route is detected. 8. The cassette transport system according to claim 7, wherein when not performed, the other traveling route is set as a traveling route of the truck. 9. The control means determines whether or not there is interference with another bogie during running on a shortest running route or another running route to a semiconductor manufacturing apparatus in a next process, which is a destination of a cassette mounted on the bogie. And a route determined that no other bogie is detected and that there is no interference with other bogies during traveling is set as the traveling route of the bogie.
The cassette transport system described in the above. 10. The track is laid in a cassette transfer area provided substantially all over a lower floor of a work area in which a semiconductor manufacturing apparatus is installed, and the cassette transfer area has a higher degree of cleanliness than the work area. The cassette transport system according to claim 4, wherein the cassette transport system is maintained.