JPH0713995B2 - Substrate transfer device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a transfer device for a photomask, a wafer or the like in a manufacturing process of a semiconductor device.

[Background of the Invention]

With the growth of the semiconductor industry in recent years, there has been a demand for more efficient work of photorepeaters for manufacturing photomasks and inspection devices for manufactured masks. In particular, most of the mask supply (loading) and mask unloading (unloading) to the mask holder in the photo repeater and the mask inspection device have been performed manually in the past, and the work efficiency is extremely low. There is. Even when the mask loading and unloading work is automated, the target mask size is limited to one type, and masks outside the target size can be loaded and unloaded manually as usual. Depending on the mask size, it is necessary to prepare manually by changing the mask suction pipe of the mask carrier or changing the position of the positioning member of the mask cassette that stores the mask. However, the work efficiency is low. Further, in the case of manual work, there is also a disadvantage that the manufactured mask is defective due to dust generated by the worker. This applies not only to the mask but also to the transfer of a semiconductor wafer or the like.

[Object of the Invention]

The present invention solves the above-mentioned drawbacks, and is a substrate transfer device that allows convenient and automatic loading and unloading of masks, wafers, etc. of a plurality of sizes onto a substrate holder of a photorepeater (exposure device) or an inspection device. Is intended to provide.

[Outline of Invention]

INDUSTRIAL APPLICABILITY The present invention is an apparatus for transferring a substrate such as a mask or a wafer,
Each of the plurality of loading and unloading cassette mounting bases is provided with a cassette size detecting means, and the signals emitted from the respective detecting means are compared, and if the signals match, the sequence of the carrying device is started. The technical point is that it is configured to stop when there is a mismatch.

Example of Invention

FIG. 1 is a perspective view of a mask transfer apparatus attached to a mask exposure apparatus showing an embodiment of the present invention, FIG. 2 is a detailed view of a cassette on a cassette installation table, and FIG. 3 is an explanation of a cassette size detection apparatus. 4 and FIG. 4 are explanatory views of alignment, FIG. 5 is a perspective view of a loader, and FIG. 6 is a control block diagram of a transfer device.

As shown in FIG. 1, the mask transfer device is roughly divided into three parts. The first part is a loading and unloading cassette mounting base 1a, 1b for mounting mask cassettes 2a, 2b containing unexposed masks and exposed masks.
The second part is a pre-alignment part (20, 21, 22) for positioning the mask when supplying the mask to the mask holder, and the third part is to take out the exposed mask from the mask holder. , The part of the loader part (30, 31, 32, 40, 41) that stores in the unloading cassette, then conveys the unexposed mask from the loading cassette, performs pre-alignment, and then supplies it to the mask holder Is.

The structure of each part will be described below from the first part, which is the loading and unloading cassette base.

In FIG. 2, when the handle (3a) of the clamp lever (3) attached to the cassette setting table (1) is rotated around the fulcrum (3b) in the direction of the arrow (4), the clamp lever (3) is rotated. The abutment member (3c) presses the loading or unloading mask cassette (2) placed on the cassette installation table (1), and the cassette (2) is pressed to position the positioning member (5) and Contact (6). Positioning member (5),
(6) shows different contact portions (5a), (5b), (5c) and (6) depending on the cassette size (for example, 5 ″, 6 ″ and 7 ″).
Since a), (6b), and (6c) are provided, the cassette (2) is positioned by abutting against any abutting portion according to the size of the cassette. Further, as shown in FIG. 3, three cassette-size detecting projections (7), (8), and (9) are mounted on the cassette setting table (1), and each detecting projection has a hole ( The springs (7b), (8b), and (9b) are inserted in 10), (11), and (12) so as to be vertically movable. The cassette (2) on the cassette installation table (1)
Since the position is fixed by the positioning members (5) and (6) according to the size thereof, the detection protrusions (7), (8),
(9) Either of them is pressed, and as a result, the above-mentioned protrusion is pressed by the light-shielding blades (7a), (8).
Use either a) or (9a) for the photo sensor (13), (1
The photo sensor which is inserted in 4) and (15) and shielded from light emits a signal. This makes it possible to know the size of the cassette on the cassette installation table (1). In the above detection device, the springs (7b), (8b) and (9b) urge the protrusions (7), (8) and (9) upward, but the urging force is greater than the weight of the cassette. It is set small.
In addition, the cassette has a detection protrusion (7),
Only one of (8) and (9) is configured to be pressed, and two or more detection projections do not interfere with and be pressed against one cassette.

In order to determine the position of the cassette (2) when the mask in the cassette (2) is carried in and out of the loader part, as shown in FIG. 2, the cassette mounting table elevating device (16) is installed at the bottom of the cassette mounting table (1). ) Is provided, and further the cassette (2)
A proximity sensor (not shown) for detecting and detecting the lowermost mask is also provided.

For loading and unloading of masks in the cassette (2), in the case of the loading cassette, the masks stored in the lowermost stage are carried out in order, and in the case of the unloading cassette, the masks are stored in the cassette. The mask is configured to be sequentially carried into the empty groove below from the empty storage groove below the lowermost one of the masks.

Next, the structure of the pre-alignment portion of the second portion will be described. In FIG. 4, a positioning member (21) and a pressing member (22) are provided on the pre-alignment base (20) so as to be slidable only in the A and B directions, and the positioning member (21) and the pressing member (22 ) Are locating pins (21a), (21b), (21c), (22a), (22) for masks of 5 ″, 6 ″ and 7 ″, respectively.
b) and (22c) are fixed with different heights. The positioning member (21) by the pre-alignment start signal
The pressing member (22) is retracted to a predetermined position by a retracting mechanism (not shown), and a retracting completion signal is transmitted by a detecting means (not shown). The arm (41) on which the mask (25) to be transported is placed moves up and down in the vertical direction by the retract completion signal, and stops at a predetermined position in the vertical direction according to the size of the mask (25). That is, the positioning pins (21a), (21b), (21c) corresponding to the size of the mask (25) to be transported.
And (22a), (22b), and (22c), the mask is stopped at a position where it can abut. The vertical stop position is set by the vertical drive mechanism (3
3 photo sensors (35), (3
6) and (37).

When the loader positions the mask (25) on the arm (41) at a predetermined position and then deactivates the retracting mechanism (not shown) of the positioning member (21), the positioning member (21) causes the spring (21) to move.
It moves in the direction B by b) and comes into contact with the stopper (23) and stops. When it is detected that the positioning member (21) is in contact with the stopper (23), the retracting mechanism of the pressing member (22) is deactivated. As a result, the pressing member (22) slides in the A direction by the spring (22d), and the both ends (25a) and (25b) of the mask (25) are brought into contact with the positioning pins corresponding to the size of the mask (25). Stop. In FIG. 4, since it is a 6 ″ mask, both ends (25a) and (25b) of the mask (25) are shown.
Are in contact with the positioning pins (21b) and (22b).

As a result, the mask (25) will be A, B on the arm (41).
Directional positioning is complete. When the completion of the positioning of the mask (25) is detected, the arm (41) vacuum-sucks the mask (25), and the positioning member (21) and the pressing member (22) move in the A direction and the B direction respectively by the retracting mechanism. It stops at a predetermined retracted position, and pre-alignment in the A and B directions is completed. A, B
Pre-alignment of the mask (25) is completed by performing pre-alignment in the same manner in the C and D directions (see FIG. 1) orthogonal to the directions.

Next, the configuration of the loader section will be described with reference to FIG. The slider (40) integrated with the arm (41) that conveys the mask (25) slides on the rail (30) by a slider drive mechanism (not shown). Each arm (41) has 1 stair
A pair of mask mounting surfaces (42), (43) and (44) are formed so that they can be mounted according to the sizes 5 ″, 6 ″ and 7 ″ of the mask (25). Each mounting surface (42), (43),
(44) has a pair of suction grooves (42a) for mask suction,
(43a), (44a) are provided, and either of the suction grooves is a solenoid valve (not shown) depending on the size of the transfer mask.
Is connected to a vacuum source so that the loaded mask can be vacuum-sucked. The rail (30) is rotatably attached to the rotary drive mechanism (31), and its tip can be directed to the load cassette side, the exposure machine body side, and the unload cassette side. Furthermore, the rotary drive mechanism (31) is vertically movably attached to the vertical drive mechanism (32), and the rail (30) and the rotary drive mechanism (31) can be moved in the vertical direction. Positioning of the rail (30) in this vertical movement is performed by the photo sensors (33), (34), (35), (3
6) and (37) are shielded by the light shielding blade (38) fixed to the rotary drive mechanism (31). The reason why the mask (25) is moved to the above-mentioned pre-alignment portion and the vertical positioning is performed according to the size of the mask is due to the relationship between the photosensors (33) to (37) and the light shielding blade (38). As described above, the loader unit includes the slider (40), the arm (41) and the rail (30) that constitute the arm extension / contraction mechanism, the rotation drive mechanism (31) for rotating the arm extension / contraction mechanism, and the arm extension / contraction mechanism and rotation drive. The vertical drive mechanism (32) for vertically moving the mechanism (31) and the vertical drive mechanism (32) are configured to perform a so-called cylindrical coordinate system motion.

Now, FIG. 6 is a circuit block diagram of a control system for integrally controlling the mechanism shown in FIG. 1 to FIG. Main control circuit MC
Is the load side cassette setting unit LC and the unload side cassette setting unit ULC as shown in FIG. 2, the loader unit LD shown in FIG. 5, and the pre-alignment mechanism unit PAL shown in FIG.
Etc. is controlled comprehensively. Each of the loading side cassette installation unit LC and the unload side cassette installation unit ULC has sensors 13, 14, 15 for detecting the cassette size and a sensor 17, which detects the limit position for vertical movement of the installation table, as described above. 18, a proximity sensor PS, and a pulse motor PM for moving the installation table up and down. Further, the pre-alignment mechanism portion PAL is provided with a retracting operation between the positioning member 21 and the pressing member 22 and a drive mechanism (retracting mechanism) ACT for performing the pressing operation. An evacuation detection sensor SS that outputs an evacuation completion signal when both 22 and 22 come to the evacuation position is provided. On the other hand, as shown in FIG. 5, the loader unit LD includes a slider 40 for driving the arm 41 and an arm 40.
The rotation drive mechanism 31 for rotating 41 in the horizontal plane and the arm 41
A vertical drive mechanism 32 for moving the whole up and down is provided. Further, two sensors 33 and 34 for detecting the height position of the arm 40 in two steps are provided when the substrate is transferred to the main body device 50 such as an exposure device or an inspection device, and the arm 41 is used during pre-alignment. Three sensors 35,36,37 for detecting the height position of the board in three steps according to the size of the board
And are provided. In addition, the arm 41 of the loader unit LD is
As shown in FIG. 5, three suction grooves 42a corresponding to the board size, 43a, 44a but are formed, each of the suction grooves of the common through the electromagnetic valve B _1, B _2, B ₃ respectively Connected to vacuum source VS. The solenoid valves B ₁ , B ₂ , B ₃ are selectively selected by the main control unit MC. For example, LC on the loading cassette
In the state where the sensor 13 inside outputs the detection signal and the sensor 13 inside the unload side cassette installation unit ULC also outputs the detection signal, the main control unit MC has the same size for both the loading side and unloading side cassettes. (Here for 5 inches)
Solenoid valve B ₃
Choose to use. Of course, if the cassette size is different, or if an empty cassette is not installed on the unload side, the main control unit MC determines that the cassette size detection signals do not match, and issues an alarm to the operator at that time. Put the entire device in standby mode.

Next, the operation of the mask transfer device according to the present invention will be described. As an example, a case where a 6 ″ mask (25) is exposed by the exposure apparatus (50) is set, and this will be described in time series.

In Fig. 1, the operator first places the 6 "mask cassettes (2a) and (2b) on the loading cassette setting table (1a) and the unloading cassette setting table (1b). The installation bases (1a), (1b) are positioned at the highest point. By placing the 6 ″ cassettes (2a), (2b), the detection on the cassette installation bases (1a), (1b) When the projection (8) is pressed, the photo sensor (14) transmits a size determination signal. Compare the size determination signals of the loading and unloading cassettes, and set both cassette installation bases (1
If the signals from a) and (1b) are different, an alarm is issued and the process is stopped. If the signals match, the process moves to the next step. That is, both cassette setting bases (1a) and (1b) start descending, the mask stored in the lowermost one of the masks stored in the cassette is searched, and the 6 "mask mounting surface (43) of the loader is searched. ) A vacuum source is connected to the upper vacuum suction groove (43a) by a solenoid valve, and a sensor (36) for 6 ″ out of the three photosensors (35), (36) and (37) is attached to the light shielding blade ( The control circuit is switched so that the vertical drive mechanism (32) stops only when the light is blocked by 38).

In FIG. 2, when the cassette installation base (1) is lowered and the light shielding blade (17) fixed to the installation base (1) shields the upper origin photo sensor (18) from light, the pulse in the cassette base elevating part (16) A pulse encoder provided in a motor (not shown) starts pulse counting. The cassette setting table (1) is further lowered, and the storage mask at the bottom is a proximity sensor (not shown).
When it reaches within the detection distance, the signal is emitted from the sensor, which detects the number of steps from the lower surface of the cassette of the storage groove of the lowermost storage mask from the pulse count number at that time. For the unloading cassette, the groove (that is, the lowermost storage mask) is moved to the mask transfer position of the loader unit, the empty storage groove immediately below the storage groove. The dimension from the cassette mounting bottom surface to each storage groove position is guaranteed to be accurate enough to operate this mechanism.Therefore, it is possible to detect the number of steps from the bottom surface of the cassette in the lowermost mask storage groove. For example, the target mask or the storage groove can be moved to the transfer position with the loader by moving the cassette by the pulse count value corresponding to the size of the storage groove. Since the mask position detection accuracy of the proximity sensor may be set within one pitch of the cassette housing groove of the cassette, it is not necessary to use a sensor with such high accuracy. In the unloading cassette, if no mask is stored in the cassette, the cassette installation base (1) continues to descend, and at the time when the lower origin photo sensor (19) is shielded by the light-shielding blade (17). The cassette installation base (1) turns upward. At this time, the pulse count number is reset to 0 once, and from this point, the pulse is re-counted and the uppermost mask storage groove is moved to the mask transfer position with the loader. In this way, the resetting of the pulse count number to 0 is due to the error of the movement amount of the cassette installation table (1) caused by the accumulated error of the pulse cycle of the pulse whose counting is started by the upper origin photo sensor (18). This is because it is not added to the movement amount. With this configuration, it is only necessary to set the mechanical dimension positions of the upper origin photo sensor (18) and the lower origin photo sensor (19), and the loader section of each mask storage groove. The accuracy of movement to the delivery position is improved.

When the mask (25) is placed on the mask holder (51) on the main body of the exposure apparatus (50), both cassette installation bases (1
While a) and (1b) are descending, the loader directs the tip of the rail (30) to the exposure machine side, and the vertical drive mechanism (32) adjusts the rail height to the mask holder (51) entry height Z ₀ ( (Refer to FIG. 1), then the slider (40) moves on the rail (30), enters the mask holder (51), stops at a predetermined position, and operates the vertical drive mechanism (32). Arm (4
1) to a fixed position Z ₁ (see Fig. 1), and while raising the mask (25), move the mask (25) to the mask placement surface (43) of the arm (41).
Place on top and vacuum adsorb. Next, the slider (40) retreats on the rail (30) to carry out the mask (25), and the rotary drive mechanism (31) is operated to direct the tip of the rail (30) toward the unloading cassette. When the search for the lowermost storage mask of both cassettes is completed and the target mask or target groove is moved to the mask transfer position with the loader, the loader holds the mask (25) on the arm (41) and unloads it. Enter into the cassette (2b), insert the mask (25) into the mask storage groove, and proceed to a fixed position to stop. In this position, the mask (25) is completely stored in the cassette storage groove. Then, vacuum suction of the mask mounting surface (43) is stopped, and the arm (41) is moved to the fixed position Z ₀ by the vertical drive mechanism (32).
The mask (25) is stored in the cassette storage groove while descending to and while descending.

With the above, the mask unloading process is completed, and the process then proceeds to the supplying process. Operate the rotation drive mechanism (31) of the loader to direct the rail (30) toward the loading cassette, and slide the slider (40).
Moves forward on the rail (30) to load the cassette (2a)
Insert the arm (41) under the lowermost storage mask of and stop at the fixed position. Then, the vertical drive mechanism (32) is activated to raise the arm (41) to a predetermined position, and the mask (2
Place 5) on the placing surface (43) and vacuum suction. After that, the slider (40) retreats to a fixed position on the rail (30), and when the mask (25) is completely carried out from the cassette, the rotary drive mechanism (31) operates and the rail (30) moves to the exposure apparatus main body (50). Turn toward. After that, move to the pre-alignment process, and lower the rail (30) by the vertical drive mechanism (32),
When the light shielding blade (38) shields the photo sensor (36) from light, the descent is stopped, and the arm (41) stops vacuum suction of the mask (25) and stands by. At this time, as described above, the positioning member (21) and the pressing member (22) of the pre-alignment portion are retracted to the predetermined positions. When pre-alignment is completed, the arm (4
1) again vacuum-adsorbs the mask (25) and ascends to the fixed position Z _{1 and} then stops, and the arm (41) advances the mask onto the mask holder (51) and stops at the fixed position. ), The arm (41) starts descending,
During the descent, the mask (25) is placed on the mask holder (51). When the arm (41) descends to the fixed position, the rail (30) retracts and stops at the fixed position, and the mask supply process is completed.

The mask (25) mounted on the mask holder (51) is vacuum-adsorbed and enters the exposure step, and when the exposure is completed, the carrying device which receives the exposure end signal repeats the same mask unloading and supply steps as described above.

If all the mask blanks inside the load cassette have been supplied, or if the masks are stored in all the mask storage grooves inside the unload cassette, the loading or unloading cassette installation bases (1a), (1b) Raises to the highest position, issues an alarm and asks the operator to replace the cassette.

Since the operation of each part of the mask transporting apparatus described above is controlled by the control circuit mainly composed of the main controller MC as shown in FIG. 6, all the operations are performed automatically and with high work efficiency.

Although the above embodiment is an example of the mask exposure process, it can be used for the mask inspection process and can be used not only for the mask but also for the reticle. Further, it can be used in the same manner for automatic transfer of semiconductor wafers.

Further, in this embodiment, the mask is taken out from the load cassette and the processed mask is conveyed to another unload cassette. However, in the case of an inspection device, for example, a defective mask (or wafer) and a normal mask are A transport system in which the mask and the mask are separated may be considered.

Specifically, it is possible to carry out a sequence in which a mask which is found to be defective as a result of the inspection is conveyed to the unload cassette, and a normal mask is returned to the unload cassette again.

By the way, of the suction grooves 42a, 43a, and 44a corresponding to the mask size of the arm (41) shown in FIG. 5, it is necessary to determine which suction groove is to be used from one of the cassette setting tables. Size detection signal (photo sensor 13,14,15
Output signal from the solenoid valve shown in Fig. 6
B _1, B _2, may be selected one of B _3.

〔The invention's effect〕

The present invention relates to a substrate transporter for transporting substrates of a plurality of sizes, wherein a loading cassette and an unloading cassette installation table are provided with a detection means for discriminating the cassette size (substrate size) and mounted on both cassette installation tables. It is configured to send the size discrimination signal of the board by the placed cassette, compare the size discrimination signals of both cassette installation bases, and execute the next sequence, so that the following excellent effects can be obtained. I was able to.

(1) If the cassettes on both cassettes have different sizes, the device does not operate, and therefore troubles due to malfunction can be prevented.

(2) Since the substrate suction groove is connected to the vacuum source and the stop position is set in the pre-alignment section by the size discrimination signal, the operator simply places the cassette on the cassette setting table, and the subsequent steps are performed. All of them are automated and work efficiency has been dramatically improved.

In particular, with the progress of automation in today's factories, if an automatic transportation robot transports a substrate storage cassette in the factory, the transport device operates just by the robot placing the cassette on the cassette storage base. Is also advantageous in terms of labor saving and complete automation.

[Brief description of drawings]

FIG. 1 is a perspective view of a mask transfer device showing an embodiment of the present invention, FIG. 2 is a perspective view of a cassette installation table, FIG. 3 is an explanatory view of a size determination device of the cassette installation table, and FIG. FIG. 5 is an explanatory view of alignment, FIG. 5 is a perspective view of the loader, and FIG. 6 is a control block diagram. In the figure, (1) is a cassette installation table, (2) is a mask cassette, (30) is a rail, (31) is a rotary drive mechanism, (32) is a vertical drive mechanism, (40) is a slider mechanism, and (41) is An arm, (50) is an exposure device, and (51) is a mask holder.

Front page continuation (72) Inventor Akio Nishikata 1-6-3 Nishioi, Shinagawa-ku, Tokyo Inside Oi Manufacturing Co., Ltd. of Japan Optical Industry Co., Ltd. (72) Yasuhisa Matsumoto 1-3-6 Nishi-oi, Shinagawa-ku, Tokyo Japan Optical Oi Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A substrate transfer device having a plurality of cassette installation bases capable of mounting a plurality of types of cassettes having different sizes according to the size of the substrates to be stored, the substrate installation device being provided on each of the cassette installation bases. The cassette size detection means for detecting the size of the cassette placed on the table and outputting a cassette size detection signal corresponding to the cassette size is compared with the cassette size detection signals output from the respective cassette detection means, and the comparison is made. A substrate transfer apparatus comprising: a control unit that controls a transfer operation based on a result. 2. A substrate transfer device having a plurality of cassette installation bases capable of mounting a plurality of types of cassettes having different sizes according to the size of the substrates to be stored, the substrate installation device being provided on each of the cassette installation bases. The cassette size detection means for detecting the size of the cassette placed on the table and outputting a cassette size detection signal corresponding to the cassette size is compared with the cassette size detection signals output from the respective cassette detection means, and the comparison is made. A control unit that controls the transfer operation based on the result, and a transfer unit that has a suction unit that is different for each substrate size to be transferred, and that transfers the substrate between the plurality of cassettes while adsorbing the substrate to the suction unit. A vacuum source connected to the suction part of the transfer means, and a cassette size output from each of the cassette size detection means. When the match signal is matched, the substrate transfer apparatus characterized by comprising connecting means for connecting the suction part of the conveying means and the vacuum source which corresponds to the size of the substrates stored in the cassette, the.