JPH0657564B2 - Reticle carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor manufacturing apparatus, and more particularly, to an apparatus for automatically exchanging a thin plate-like object (hereinafter referred to as a substrate) such as a reticle (including a mask). The present invention relates to a substrate transfer device such as a reticle used.

Such a substrate transfer apparatus is, for example, an automatic substrate exchange apparatus equipped with a cassette library that stores a plurality of cassettes that individually store exposure reticle (mask) substrates. Suitable as a device that carries in the substrate taken out from the cassette and sends the substrate taken out from the cassette to the exposure position, stores unnecessary substrates in the cassette when replacing the substrate, and returns the cassette to the original library Used for.

[Prior Art] Conventionally, in this type of apparatus, desired substrates are taken out from a plurality of cassettes stored in a cassette library fixed to the apparatus main body in the library, and exposure is performed in the main body apparatus by tracing a long transfer path. Configured to feed to a position,
The substrate transfer route was the same for both the forward and return routes.

[Problems to be Solved by the Invention] Therefore, when exchanging a substrate, the next substrate cannot be sent until the unused substrate is removed from the path, that is, until the storing step is completed, and the substrate exchanging time It takes a lot of time, and there is an inconvenience that the substrate waiting state of the apparatus becomes long.

Generally, semiconductor manufacturing lines include a low-mix / high-volume production type line and a high-mix / low-volume production type line. In the latter line, board replacement is frequently performed, The long waiting time of the substrate in the device has a problem of significantly reducing productivity.

In addition, since the transfer path is long, the probability of dust adhesion to the substrate being transferred is high. Especially, in a device such as a stepper that reduces a pattern of one reticle and winds it around a large number of wafers, It had the major drawback of increasing the rate of defective products due to chip dust.

INDUSTRIAL APPLICABILITY The present invention eliminates the drawbacks in the above-mentioned conventional example, and is particularly applied to an exposure apparatus for manufacturing a semiconductor, makes it possible to replace a reticle (mask) at high speed, and to remove dust on the reticle during transportation. It is an object of the present invention to provide a reticle transport device that can reduce the probability of adhesion of the reticle.

[Means and Actions for Solving Problems] In order to achieve the above-mentioned object, the present invention provides a reticle set position (exposure position P ₇ ) of an exposure apparatus that exposes and transfers a reticle pattern onto a wafer, and a plurality of reticle cassettes. In a reticle transport device that transports a reticle between reticle cassette libraries (cassette library 2) that store a stack of layers, the reticle is provided in a transport path between the reticle set position of the exposure device and the reticle cassette library. A plurality of reticle cassette storage shelves (holder holders 71, 7) for storing a plurality of reticle cassettes less than the number of storage cassettes in the reticle cassette library.
2), a first transfer means (elevator mechanism / elevator position P ₂ ) for transferring the reticle together with the reticle cassette storing the reticle in the transfer path of the reticle cassette library and the reticle cassette storage shelf, and the exposure. Second conveying means (reticle ejecting fork 30 or / and) for conveying the reticle in the conveying path between the reticle set position of the apparatus and the reticle cassette storage shelf while the reticle is taken out from the reticle cassette stored in the reticle cassette storage shelf. It is characterized by having a reticle storage fork 90).

In one aspect of the present invention, the exposure apparatus has an apparatus main body and an air conditioning chamber that covers the apparatus main body, the reticle cassette storage shelf is provided inside the air conditioning chamber, or the reticle cassette library. May be separated from the exposure device, or the reticle cassette may be opened after being stored in the reticle cassette storage shelf.

[Embodiment] FIG. 1 is an overall external view of a reduction projection exposure apparatus (stepper) according to an embodiment of the present invention. In the figure, 1 is an entire air conditioning chamber, and 2 is a mobile reticle cassette library.

FIG. 2 is a perspective view of a part of the entire air conditioning chamber 1 of FIG. In the figure, 10 is the stepper body, 11 and 12
Is an image forming lens and an illuminating device which respectively constitute the stepper body 10, and 13 is an exposed object such as a semiconductor wafer on which the pattern of the reticle 6 is printed by the stepper body 10.

FIG. 3 is an explanatory diagram of the reticle transport system. In the figure, 4 is the reticle cassette (substrate storage container) presented in Japanese Patent Application No. 60-214591, Japanese Patent Application No. 60-214592 and Japanese Patent Application No. 60-293630, and 5 is the above Japanese Patent Application No. 60-293630. The presented cassette holder, 6 is a reticle, and 7 is a barcode reader / pattern position detection device. P ₁ is the first cassette storage position, which corresponds to the position of the library 2. P ₂ is an elevator position for raising and lowering the cassette holder 5 taken out from the cassette storage position P ₁ to a predetermined position, and P ₃ is a reticle extraction position for taking out the reticle 6 from the cassette 4 fed together with the cassette holder 5 from the elevator position P ₂ ( (Second cassette storage position), P ₄ is a transfer position (first transfer position) with a mechanism for feeding the reticle 6 upward, P ₅ is a reticle foreign matter inspection position, and P ₆ is a mechanism for carrying the reticle in and out to the exposure position. Transfer position with (2nd
Delivery position), P ₇ is the exposure position, P ₈ is empty cassette standby position for accommodating the reticle 6 having been subjected to the exposure process in the cassette 4.

In the above configuration, the reticle cassettes 4 arranged in the reticle cassette library 2 (first cassette storage position P ₁ ) in a stacked manner have the elevator mechanism come to the cassette storage position P in response to a command from the console of the exposure apparatus main body. _The holder 5 is moved together with the holder 5 to the elevator position P _2, and is moved up and down to a predetermined height here, and is further sent to and stored in the reticle extraction position P ₃ (second cassette storage position). When the reticle cassette 4 and the cassette holder 5 are stored in the second cassette storage position P ₃ , the cassette opening / closing drive source (not shown) at this position P ₃ is activated to open the cassette 4 and the internal reticle. 6 is ready for extraction. Due to the shapes of the upper lid and the lower lid of the cassette 4, in this open state, it is possible to detect the presence or absence of the reticle 6 inside the cassette 4 from the lateral direction.

Then, the reticle extraction mechanism (not shown) operates to open the cassette 4 at the reticle extraction position P ₃ .
Remove the reticle 6 from. The extracted reticle 6 passes through the first transfer position P ₄ and enters the reticle foreign substance inspection position P ₅ , where it is scanned under the foreign substance inspection light by the extraction mechanism, and whether there is a foreign substance on the reticle 6 or not. The location is confirmed. At this stage, the reticle 6 determined to be unusable in the process is returned to the original reticle cassette library 2 by the operation reverse to that described above.

Reticle 6 determined to be usable in the process as a result of foreign matter inspection
Is sent to the first transfer position P ₄ , is transferred to the vertical transport mechanism that is on standby at the lower side at this position, and rises to the second transfer position P ₆ .

Passing the mechanism for feeding feed the reticle 6 to the inside exposure device in this position, but it is to carry to the exposure position P _7, the reticle bar code reader pattern position detection unit 7, during this conveyance, scans the reticle 6 fed The pattern position of the reticle 6 is detected by how much the reticle is manufactured with respect to the end face. At the same time, the reticle-related exposure process conditions are read by the bar code pattern written on the reticle, data is sent to the console of the exposure apparatus main body, and the reticle 6 is transported to the exposure position P ₇ until the exposure process-related machine is reached. I am trying to finish the general setting.

On the other hand, at the above-mentioned second cassette storage position P ₃ , the reticle 6
The cassette 4 that has been taken out is closed by the opening / closing mechanism, is sent to the reticle storage position P ₈ during the vertical transport of the reticle 6 and the feeding operation to the exposure position P ₇ , and is returned by the end of the exposure process. Is waiting at this position.

The reticle 6 that has completed the exposure process is transported to the second delivery position P ₆ by the above-mentioned feeding mechanism, and is delivered to the reticle storage mechanism waiting at this position. Then, the cassette opening and closing mechanism drive source in a stored position P ₈ acts, cassette 4 waiting is opened in a retracted position P _8.
In this state, the reticle 6 is stored in the cassette 4 by the reticle storage mechanism, and the opening / closing mechanism works again to close the cassette 4.

The cassette 4 containing the reticle 6 is returned to the reticle extraction position P ₃ by the cassette exchange mechanism,
The original reticle cassette library 2 is passed through the elevator position P ₂ by the elevator mechanism waiting at this position.
It is returned to the inside storage position P ₁ .

Two cassettes can be stored in the above-mentioned cassette exchange mechanism. Therefore, if the reticle for the next process is instructed in advance, the reticle for the next process is finished up to the foreign substance inspection before the reticle for which the process is finished is returned, and the second delivery position is set at the second delivery position P ₄ . The reticle of the previous process was ejected from P ₆ (reticle storage position P
_The next reticle can be sent immediately after it is stored in the cassette waiting in step ₇ ).

By the way, in the conventional automatic reticle exchange apparatus, the reticle is taken out from the cassette in the library and reciprocated along a long path to the exposure position. For this reason, the probability of dust adhesion to the reticle during transportation increases, and particularly in a device such as a stepper that repeatedly prints the pattern of the reticle onto a large number of places on one wafer, each shot or each shot There was a major drawback in that the rate of defective products increased due to dust on each chip. In this embodiment, as described above, the reticle 6 and the cassette 4 are placed between the library 2 (cassette storage position P ₁ ) and the cassette extraction position P ₂ (or cassette standby position P ₈ ) of the air conditioning chamber 1.
By transporting the entire product, the above major drawbacks are eliminated.

FIG. 4 is an external view of the movable cassette library 2 of FIG. 1 viewed from the back side, that is, an external view of the side where the reticle cassette 4 to be sent into the exposure apparatus by the automatic exchange is carried out together with the cassette holder 5. . In the figure, the library main body 2 is provided with a storage means 21 including a readable / writable storage element that stores the name of the cassette housed in the library 2, parameters indicating the characteristics of the reticle, and the like. Reference numeral 22 is a door for the cassette storage portion of the library, which is formed on the front surface and the back surface of the library main body 2.

The arrow A in the drawing indicates the direction in which the reticle cassette 4 is pulled out by the automatic exchange.

This mobile cassette library is used for the entire air conditioning chamber 1
Or, it can be combined with and separated from the stepper body, and
The compatibility between the libraries and other reticle-related devices is improved, and the library 2 containing a predetermined number of cassettes is of a movable type so that the libraries 2 can be sequentially replaced according to the process or manufacturing type.

For this reason, it is possible to exchange each cassette library that stores various types of substrates to support a high-mix low-volume production line online, etc., and when changing the reticle cassette sent into the exposure apparatus main body, the exposure apparatus is controlled by the temperature control chamber. It is possible to prevent a situation in which the temperature inside the temperature control chamber and the temperature of the exposure apparatus fluctuate when the temperature control chamber is opened and the window of the temperature control chamber is opened to perform the replacement work manually.

Further, according to the above configuration, as shown in FIG. 11, maintenance inspection around the reticle such as the pattern generator 1a, the stand-alone type dust inspection machine 1b, the reticle cleaning device 1c, or the pellicle laminating device (not shown) is performed. It is easy to connect to the machine and does not require human intervention for reticle replacement, maintenance and inspection, and redundancy for a dust-free environment can be increased.

In FIG. 4, the storage means 21 records parameters necessary for the operation of the apparatus, such as the name and storage position of the reticle in the reticle cassette stored in the library 2 and initial setting items around the reticle in the stepper. A writable and erasable memory element is configured and is in a positional relationship capable of being joined with the reading means provided in the entire air conditioning chamber 1 or the stepper body, and the parameter is sent to the stepper body console 3 in a joined state. Is possible.

FIG. 5 shows the storage state of the cassette holder 5 in the library 2 and the operation at the time of manual loading / unloading (arrow B in the drawing) and loading / unloading by an automatic machine (arrow A in the drawing). In the figure, 4 is the reticle cassette described above, and 5 is a cassette holder. 23 and 25 are rolling columns, 24
Is a movable roller row frame, and 26 is a library housing and guide rail. Reference numeral 27 denotes a stopper mechanism formed on the roller row frame 24 so that the cassette holder 5 is prevented from rattling within the library. 28 is a roller, and 29 is a stopper for holding the holder 5 between the roller row frames 24 and 24. The left and right stages of the cassette library 2 are similarly configured.

The movement direction and stroke of the cassette holder 5 in the library 2 correspond to the length of the holder 5 in the front side direction of the library 2 in order to correspond to the cassette setting of the arrow B by the human hand and the loading / unloading operation of the arrow A by the automatic carrier. A stroke that allows the holder 5 to be inserted and removed is required in the rear surface direction. Further, since the library 2 is in a relationship of being joined to and separated from the entire air conditioning chamber 1 or the stepper body, there is no actuator serving as a driving source for movement in the library 2, and the holder 5 is taken in and out by a human. It is carried out by the power transmitted from the hands of the robot or an automatic machine.

The second stage of FIG. 5 shows a state in which the cassette holder 5 is extracted from the library 2. That is, the cassette holder 5 desired by the elevator mechanism (not shown) of the automatic carrier.
When facing the position of, the actuator of the elevator mechanism catches the stopper 29, pulls out the roller row frame 24 to the position shown in the drawing, and further releases the stopper 29. continue,
An extraction hook formed in the elevator mechanism catches the claw 5a attached to the cassette holder 5 and extracts the cassette holder 5 to the zushi position. As a result, the cassette holder 5 comes out of the library 2.

Further, when the holder 5 shown in the second stage is pulled out, the stopper mechanism 27 is supported by the rail 26 as shown in the figure, so that it serves as a stopper for the returned holder 5. However, the cassette holder 5 can always be stored in a fixed position with respect to the roller row frame 24.

The third row in FIG. 5 shows a state when the cassette is replaced by a human hand. In this state, the stopper mechanism 27 is disengaged from the supporting rail 26 and is in a released state, and the cassette holder 5 is stopped by the claw 5a coming into contact with the stopper member 24a fixed to the roller separate frame 24, so that the arrow B
It becomes easy to replace the cassette from the direction.

FIG. 6 is an explanatory diagram of the exposure apparatus of FIG. 2 viewed from the right side.

In the figure, the reticle cassette library 2 is in contact with the exposure apparatus chamber (entire air conditioning chamber) 1, and in this state, the lock member 15 configured on the exposure apparatus chamber side and the catch roller 2a configured on the cassette library 2 side. Coupling occurs and the relative positions of chamber 1 and library 2 are fixed. Then, the data stored in the storage unit 21 included in the reticle cassette library 2 is read by the reading unit 16 included in the exposure apparatus chamber 1, and the storage stage position of each reticle stored in the library 2, Also, data such as parameters of various processes including the reticle is sent to the main body and pooled in the storage means of the main body.

The reticle extracted by the designation on the main body side rides on the elevator mechanism at the elevator position P ₂ and is sent to the second cassette storage position P ₃ . This position is located in the middle part of the reticle cassette library 2 and minimizes the difference in conveyance time due to the height difference between the cassette positions in the reticle cassette library 2. Also, if so'll put reticle extracted cassette at a position P ₃ when installing the cassette with without the reticle cassette library 2 Manual, reticle withdrawn position P _3, the floor has been installed in the exposure apparatus Since the height from above is about 1 m 20 cm, it is easy to manually set the positional relationship.

The main aim of the mechanism and each function of the present embodiment is how to prevent dust from adhering to the reticle being transported and to feed it, and especially from the outside when the reticle alone is being transported. In order to prevent the adherence of suspended dust, the foreign matter inspection unit 8 and the transport area for the reticle that has come out of the cassette must be clean boxes.
This is realized by the heavy boxes 8a and 8b, the door 8c, and the air conditioner. That is, since the dust generated from the cassette replacement mechanism and the cassette opening / closing mechanism and the suspended dust are not allowed to enter the reticle transport area, the atmospheric pressure of each part is the highest in the foreign substance inspection unit 8 (in the box 8a), and then the reticle transport area (in the box 8a). 8b), the chamber 1 (outside the box 8b), and the chamber are lifted in this order. In FIG. 6, reference numeral 8c is a door that blocks the inflow of floating dust from the reticle transport area into the reticle foreign matter inspection unit 8. Further, 101 is an air conditioning unit, 102 is a cooler, 103 is a blower, 104 is a heater, 105 is a filter,
106 is a temperature sensor. 21b is a sealing material.

FIG. 7 is an external view of implementation of each operation mechanism from the reticle extraction position P ₃ fixed to the exposure apparatus to the reticle storage position P _{8 in} the basic configuration shown in FIG.

In FIG. 7, the cassette 4 extracted together with the holder 5 from the cassette library 2 is sent to the reticle extraction position (second cassette storage position) P ₃ and is fixedly mounted on the vertically movable holder support base 71. At this position P ₃ ,
A cassette opening / closing mechanism that separates the upper lid and the lower lid that configures the cassette 4 is configured, and a vertically movable holder support base.
After the time when it is confirmed that the holder 5 has been sent to the 71 and fixed, the cassette opening / closing mechanism operates, the upper lid of the cassette 4 is opened, and the reticle 6 inside can be taken out from the outside of the cassette 4. When in this state, the reticle extraction fork 30 extracts the reticle 6 in the cassette 4 and sends it at a constant speed into the reticle foreign matter inspection unit 8 (FIG. 6) which is an extension of the reticle. On the other hand, when it is confirmed that the reticle 6 has come out of the cassette 4, the cassette opening / closing mechanism operates and the cassette 4 is closed.

Two holder support bases at the reticle extraction position P ₃ are provided above and below the vertically movable holder support base 71 and the posture-maintaining holder support base 72, and are closed after it is confirmed that the cassette 4 is empty. The vertical movement type holder support base 71 at the lower position and the posture holding type holder support base 72 at the upper position can exchange the vertical position. As a result, the empty cassette 4 is sent to the upper position (reticle storage position P ₈ ), and at this position P ₈ , the exposure position P
_It waits until the reticle conveyed to the No. ₇ is returned by the end of the exposure process and carried into the reticle storage position P ₈ .

Referring to FIG. 6, reticle 6 extracted from cassette 4 is normally fed into reticle foreign matter inspection unit 8 as it is. However, when the reticle 6 is provided with the reticle dustproof film, due to the structure of the reticle foreign matter inspection unit at present, due to the frame of the reticle dustproof film, an uninspectable area (reticle 6 and pellicle dustproof film inside the frame of the reticle 6 is present. There is a joint corner of the frame). In order to inspect this portion, the reticle inspection unit 8 inspects the area again after the reticle 6 is rotated by 180 ° in plane. The θZ mechanism 40 at the delivery position P ₄ having this plane rotation mechanism.

Returning to FIG. 7, when the reticle 6 completes the foreign matter inspection by the reticle foreign matter inspection unit and returns to the delivery position P ₄ , the θZ mechanism 40 forks the reticle 4 from below the reticle extracting fork 30. It is taken out from 30, rotated by θ according to the reticle setting direction of the exposure apparatus, and sent to the delivery position P ₆ by the ascending operation by the Z mechanism.

At the position P ₆ , the reticle hands 52 and 53 having the opening / closing operation configured in the reticle transport mechanism 50 stand by in an open state, and the reticle 6 is supported by the positioning lower side and received at that position. The reticle transport hand 51 received at the delivery position P ₆ of the reticle 6 supports the lower surface of the reticle 6 in the abutting state with the two perpendicular end faces of the reticle 6 supported on the lower surface, and the exposure position P ₇ in the exposure apparatus
Transport straight to. A bar code reader / pattern position detection unit 7 is formed at one place during this straight line conveyance, and confirms a designated reticle while the reticle 6 is being conveyed at a constant speed, reads parameters related to the reticle of the exposure apparatus, and The deviation of the pattern of the reticle 6 currently being gripped from the center of the exposure apparatus is detected, and the setting of the exposure apparatus is completed by the end of conveyance.

The reticle transport hand 51 that has reached the exposure position P ₇ opens the reticle hands 52 and 53, releases the reticle 6 at that position, and places the reticle 6 on a pedestal (not shown) of the exposure apparatus. After that, the reticle transport hand 51 is changed to the reticle hand.
The exposure process is awaited with 52 and 53 left open.

The reticle 6 that has completed the exposure process is transferred to the reticle transport hand 51.
Is conveyed from the exposure position P ₇ to the delivery position P ₆ . At the delivery position P ₆ , the θZ mechanism 40 is lowered and retracted to the lower initial position, and the reticle storage fork 90 completes the reticle delivery preparation.

When the reticle transport hand 51 places the reticle 6 on the reticle storage fork 90 at the transfer position P ₆ , the reticle hands 52 and 53 are in the open state. This allows the mechanism (51 and 9
0) Reticle storage fork 90 without mutual interference
Can store the reticle in an empty reticle cassette waiting at the reticle storage position P ₈ .

Also in the reticle storage position P ₈ , the reticle extraction position P
There is an opening / closing mechanism drive source similar to that of No. ₃ , and by its operation the cassette 4 waiting at position P ₈ is opened, and after confirming that there is no reticle in the cassette 4, the reticle storage fork 90 is operated to operate the reticle. 6 is stored in the cassette 4. When the reticle storage fork 90 comes out of the cassette 4 after the storage, the cassette opening / closing mechanism drive source operates to close the cassette 4.

After that, the holder support base is again moved up and down to move the cassette 4 to the lower position (reticle extraction position) P ₃
To wait. The cassette 4 is returned to the reticle library by the cassette unloading mechanism.

For these series of operations, the operation of the cassette transport mechanism,
Reticle extraction operation, reticle foreign matter inspection, θZ operation,
When the reticle transport operation, reticle storage operation, cassette up / down replacement operation, cassette storage in the library, and supply operation are performed in series, the reticle replacement time for each process is about 3 to 4 minutes. On the other hand, in the present embodiment, the two holder support bases 71,
72 is provided, and the cassette 4 carried out from the library 2 is
At the reticle extraction position P _{3, the} reticle extraction operation is performed by the reticle extraction fork 30 and the reticle is emptied, then the upper lid is closed and the cassette is moved up and down to the reticle storage position P ₈ and, instead, the attitude-maintaining holder support base is used. The reticle 72 is moved to the reticle extraction position P ₃ so that the reticle cassette required in the next step can be transferred and placed on the attitude holding type holder support 72. Therefore, in the present embodiment, the replacement time is calculated based on the time when the exposure apparatus finishes the current process or the processing time of the number of wafers to be exposed in advance, and the cassette transfer time,
If each transport operation of the reticle of the next process is started in anticipation of the time required for machine operation such as reticle foreign matter inspection time,
The reticle of the next process can be made to stand by on the θZ mechanism 40, and when the reticle of the previous process finishes the exposure process and is sent to the reticle storage position P ₈ , the reticle of the next process is mounted θ.
The exchange time can be reduced to 30 seconds or less by adding a sequence program such that the Z mechanism 40 moves up to reach the delivery position P ₆ .

FIG. 8 is an operation explanatory view of the cassette changing mechanism 70 of FIG.

Next, the cassette changing mechanism 70 will be described with reference to FIGS. 7 and 8. In the figure, 71 and 72 are holder supports, 73 and 73 are pulleys fixed to the holder supports 71 and 72,
74 is an arm that rotatably supports the shafts of the pulleys 73, 73 at a prescribed interval. Arm 74 is at the midpoint between pulleys 73, 73
It is rotatably supported by the horizontal motion slider 76 at 75 and the upper and lower pulleys.
73 are connected by a belt 77. Therefore, the support arm
The 74 is rotatable with respect to the rotation center 75, but the holder support bases 71 and 72 can be moved up and down with respect to the rotation operation without changing the parallel posture. Vertically movable holder support 71
Is constrained by the upper and lower guides 79 and the three rollers 78 supporting the upper and lower guides 79 so as to be able to ascend and descend only in the Z direction in the horizontal posture. The horizontal movement slider 76 is a vertically movable holder support base.
As the arm 71 moves up and down, it can move in the horizontal direction while supporting the arm center 75, and supports the weight of the whole body at two positions at both ends of the shaft 80. 81 is an axis 80 that fixes the arm center 75
Is a rotary actuator that rotates the arm 74 with respect to the horizontal movement slider 76.

When a counterclockwise rotation input is applied to the arm 74 in the state shown in FIG. 7 when viewed from the front of the drawing, the vertically movable holder support base 71 rises in the Z direction while being horizontally supported. Further, since the attitude-holding type holder support base 72 has the horizontal attitude of the vertical-moving-type holder support base 71, the pulleys 73, 73 and the belt 77 operate to keep the horizontal posture of the operation in an arc motion about the shaft 80 as a rotation axis. To do. However, since the shaft 80 is supported by the horizontal movement slider 76, it moves horizontally to the left in the drawing as the holder support base 71 moves, and therefore the holder support base 72 moves as shown in FIG. It moves by drawing a locus that combines arcuate motion and horizontal motion. That is, in FIG. 8, when the arm 74 is rotated counterclockwise by 180 ° from the state similar to that of FIG. 7, the holder support base 71 vertically moves to the position 72 ′ through the position 71 ′, and at the same time, the holder support base 71 is supported. The table 72 rotates and moves to the position 71 via the position 72 '. This allows the holder supports 71 and 72
The positions of are switched. To return to the original state, the arm 74 can now be rotated 180 ° clockwise.

Since the attitude holding type holder support base 72 operates substantially horizontally at the end of the moving operation, it is possible to operate with a small impact by using a damper and a fixing mechanism as shown by 82 in FIG. The operation of the vertical movement type holder support 71 is a rotation operation around the rotation center of the shaft 80, so that a reduction mechanism is provided at the end of the operation. Further, while the arm 74 rotates about the rotation center of the shaft 80, the holder support bases 71 and 72 have a counterbalanced form about the shaft 80, so that the force required for the rotation is not so large. .

FIG. 9 is an explanatory view of the reticle feeding mechanism. FIG. 9 (a) shows a state in which the reticle is gripped and conveyed to the exposure position P _7, and FIG. 9 (b) shows the reticle opened at the second transfer position P _6. Shows the state.

In the figure, 52 is a hand with positioning XY reference rollers, 53 is a hand with Y reference rollers, 56 is an opening / closing operation actuator, 60 is a slider, 61 is a rotating shaft, 62 is a lever, 63 is a roller, 62a is a lever rotating shaft, and 62b is Is a spring, 65 is a flat belt, 66 is a slider stopper, 67 is an outer cover, 68 is a drive pulley, 69 is a driven pulley, and 70a is a slide rail.

The slider 60 fixes both ends of the flat belt 65, and the belt 65 has a lever rotating shaft 62a and a roller 63 supported by the lever 62 around the center.
And the lever 62 is tensioned by a spring 62b to remove the slack of the belt 65.
The spring 62b is formed on the left and right of the slider 60.
The belt 65 is stretched up to a drive pulley 68 via driven pulleys 69 on the left and right. As shown in FIG. 9 (a), the slider 60 which has reached the exposure position P ₇ hits the slider stopper 66 fixed on the slide rail 70a, which is its track, and rotates the drive pulley 68 a small amount from that state. When,
As shown in the figure, the tension T ₁ on the left side increases and the tension T ₂ on the right side increases.
Therefore, the difference T ₁ -T ₂ presses the slider 60 against the slider stopper 66. If this pressing force is stable, the reproducibility at this position is high.

This principle is the same for both left and right positions.

The flat belt 65 has a width corresponding to the thickness of the sliding portion of the reticle transport handle 51 in the height direction, and the outer cover 67 is all covered except for the sliding portion of the reticle transport hand 51 of the reticle feeding mechanism 51, The window of the above-mentioned slide portion substantially closes the opening. If the air is exhausted (not shown) at an arbitrary position in this space when configured in this way, the space will have a negative pressure, and the dust generated by the sliding action will not go out to the outside, and the dust will be generated by the transport mechanism. Dust will not adhere to the reticle being transported.

The reticle transport hand 51 that has come to the second transfer position P ₆ shown in FIG.
It is pressed against 66 to improve reproducibility at this position (stop position).

When the opening / closing operation actuator 59 is operated at these stop positions, its point of action moves the connecting shaft 58. The XY reference roller hand 52 and the Y reference roller hand 53 are levers having the left and right rotation shafts 61 formed on the slider 60 as fulcrums, and are connected to each other by the coupling shaft 58. The reticle can be opened and closed, and the reticle can be transferred to and from the θZ mechanism 40 and the reticle storage fork 90.

FIG. 10 is a view showing a state in which the reticle is being positioned and handled, and shows the principle of alignment of the reticle substrate while holding the reticle.

As described above, the hands 52 and 53 are in the closed state as shown by the operation of the opening / closing operation actuator.

54,55,56 are rollers, two for hand 52, one for hand 53
One is attached. Since the reticle generally has a square shape, if the outer circumferences of the rollers 55 and 56 and the end surface of the reticle come into contact with each other and the other end comes into contact with the outer circumference of the other roller 54, the outer shape of the reticle will be aligned. It will be possible.

Reference numerals 57 and 57 are eccentric rollers with a high friction coefficient on the outer circumference, which are obtained by decentering the center of rotation from the center of the circle, and have built-in springs so that the reverse forces F ₁ and F ₂ shown in the figure always work. When there is no reticle, it stops at the position 57a. When the reticle is sandwiched in the hand closed state, the XY reference roller hand 52 and the Y reference roller hand 53 move in the same direction as F in the figure, and give a force F to the reticle. An eccentric roller 57 formed on both hands 52 and 53 rotates like 57b. At this time, if a relationship of F >> F ₂ > F ₁ is established and the positions of both hands 52 and 53 in the closed state are fixed by the stroke regulation of the connecting shaft 58, the movement of the left and right eccentric rollers 57 and the outer periphery thereof and the reticle. Due to the friction coefficient with the end face and the force to return to 57a of the eccentric roller 57, the forces F ₁ and F ₂ are generated, and these component forces are the force to press the reticle against the outer circumference of the rollers 54, 55 and 56, f Forces _x , f _y1 and x _y2 are generated to align the reticle on the hand.

In this state, if the bar code reader / pattern position detector 7 is arranged in the path for transporting from the transfer position P ₆ to the exposure position P ₇ and the pattern position of the reticle being transported is measured, this pattern position will be the matching end surface of the reticle substrate. It is possible to know how far away from the reticle it is, and this can be used as the mechanical setting data of the main body device that copes with the manufacturing error of the reticle.

EFFECTS OF THE INVENTION As described above, according to the present invention, before the previous reticle is stored in the reticle cassette, the reticle to be conveyed to the reticle set position of the exposure apparatus next is stored in the reticle cassette. Since it can be transported in the transport path between the reticle cassette library and the reticle set position of the exposure apparatus as it is, and can be made to stand by at a position on the way, it is possible to shorten the time for reticle exchange with respect to the reticle set position of the exposure apparatus. In addition, it is possible to reduce the probability that dust such as floating dust adheres to the reticle being transported.

[Brief description of drawings]

1 and 2 are external views of a projection exposure apparatus according to an embodiment of the present invention, FIG. 3 is an explanatory view of a reticle transport system of the present invention, and FIG. 4 is a back surface of a movable cassette library. External view, FIG. 5 is an explanatory view of the inside of the library, FIG. 6 is an explanatory view seen from the right side of the apparatus, and FIG. 7 is an external view of the operation mechanism of the reticle extraction position or the reticle storage position in the apparatus. FIG. 8 is an operation explanatory view of a cassette replacement mechanism, FIG. 9 is an explanatory view of a reticle feeding mechanism, FIG. 10 is an explanatory view of a matching principle of a reticle handling mechanism, and FIG. 11 is a movable cassette library. It is explanatory drawing which joined and arranged with a peripheral device. 1: Overall air conditioning chamber of stepper 2: Mobile cassette library 4: Substrate storage container 5: Cassette holder 6: Reticle 7: Bar code reader / pattern position inspection device P ₁ : First cassette storage position P ₂ : Elevator position P ₃ : Second cassette storage position P ₄ : First transfer position P ₅ : Reticle foreign substance inspection position P ₆ : Second transfer position P ₇ : Exposure position P ₈ : Empty cassette standby position 15: Attached to chamber side Memory content reading means 21: Memory means 21b: Seal material 22: Library door 23: Roller 24: Roller row frame 25: Guide roller 26: Rail 27: Stopper 29: Stopper 30: Reticle extraction fork 40: θZ mechanism 50: Reticle Feeding mechanism 51: Reticle transfer hand 52: Hand with positioning XY reference roller 53: Hand with Y reference roller 54, 55, 56 Roller 57: Eccentric roll 58: Coupling shaft 59: Opening / closing actuator 60: Slider 61: Rotating shaft 62: Lever 62a: Lever rotating shaft 62b: Spring 63: Roller 64: Stopper 65: Flat belt 66: Slider stopper 67: Outer cover 68: Drive pulley 69: Driven pulley 70a: Slide rail 70: Cassette replacement mechanism 71: Vertical movement type holder holder 72: Posture holding holder holder 73: Pulley 74: Support arm 76: Horizontal movement slider 77: Belt 78: Roller 79: Guide 80: Axis 81: Rotary actuator 82: Damper 101: Air conditioning unit 102: Cooler 103: Blower 104: Individual heater 105: Filter 106: Temperature sensor.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP 59-186320 (JP, A) JP 57-64928 (JP, A) JP 60-5520 (JP, A) JP 62- 102524 (JP, A) JP 60-154241 (JP, A) JP 62-248233 (JP, A) JP 61-176129 (JP, A) JP-B-3-48097 (JP, B2) US Patent 4999671 (US, A)

Claims (4)

[Claims] 1. A reticle transport device for transporting a reticle between a reticle set position of an exposure device for exposing and transferring a reticle pattern onto a wafer and a reticle cassette library containing a plurality of reticle cassettes in a stacked form. A reticle cassette storage shelf that is provided in a transport path between the reticle set position of the exposure apparatus and the reticle cassette library, and stores a plurality of reticle cassettes, the number of which is less than the number of storage cassettes in the reticle cassette library, and the reticle cassette. A first transport unit for transporting the reticle together with the reticle cassette storing the reticle in a transport path between the library and the reticle cassette storage shelf; and a reticle set position of the exposure apparatus and the reticle cassette storage shelf. In front of the reticle in the transport path A second conveying means for conveying in a state taken out from the reticle cassette housed in the reticle cassette storage rack, the reticle-carrying device characterized in that it comprises. 2. The exposure apparatus has an apparatus main body and an air conditioning chamber for covering the apparatus main body, and the reticle cassette storage rack is provided inside the air conditioning chamber. The reticle transport device according to the item. 3. The reticle transport apparatus according to claim 1, wherein the reticle cassette library is separated from the exposure apparatus. 4. The reticle transfer device according to claim 1, wherein the reticle cassette is opened after being stored in the reticle cassette storage shelf.