JP2887219B2 - Transfer device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer apparatus for transferring a semiconductor wafer, for example, and a method therefor .

[0002]

2. Description of the Related Art When transferring a wafer in a semiconductor wafer manufacturing process, there is a special circumstance that generation of particles must be avoided as much as possible. In addition, since there are many wafer processing processes, the wafer transfer speed has a great effect on throughput. In addition, various methods have been devised for the structure of the transport mechanism, the method of delivery, and the like. For example, when a wafer is transferred between a processing station for forming a resist film on a wafer and a carrier (container for storing a wafer) station, a transfer mechanism including tweezers that can move forward and backward for mounting and holding the wafer. Then, the tweezers are made to face the front of the carrier on the mounting table of the carrier station, and then enter the carrier.Then, the wafer is scooped, then retracted and taken out of the carrier. While being transferred to the transfer arm, the tweezers receive the processed wafer from the other main transfer arm via the alignment table, return to the position facing the front of the carrier, and store the wafer in the carrier in the reverse method of removal. I am trying to do it. Then, for example, the carrier mounting table is moved up and down by an elevating mechanism, and the next wafer to be processed is removed from the carrier by tweezers, or the next wafer after processing is stored in the carrier, and the carrier station and the processing station The wafer is transferred between the two.

[0003]

However, since the wafers are accommodated in the carrier with play back and forth, left and right, the plane positions of the wafers vary, and furthermore, depending on the orientation of the wafer orientation flat (orientation flat) or the carrier. The wafer may be tilted due to its own distortion, or the wafer may be shifted from a predetermined position and protrude from the carrier. On the other hand, when the tweezers stop position and the extension stroke of the transfer mechanism are constant, when the tweezers scoop up the wafer, the wafer may be held displaced to the tip side from the expected position on the tweezers, and Since the clearance between them is very small, for example, about 6 mm, if the inclination of the wafer is large, the tweezers may hit the wafer and damage or drop the wafer. If the wafer is held on the tweezers at a position deviated from the expected position as described above, the wafer may drop during the subsequent transfer, and if the wafer falls in the carrier, the tweezers may be used next. When the wafer enters, the wafer may be damaged.

In order to prevent such a problem, a method of incorporating a vacuum mechanism or the like into the tweezers to suction the wafer is conceivable. In this case, however, the wafer is pressed against the holding surface of the tweezers with a strong force, so that the tweezers cannot be used. Particles tend to adhere to the wafer.

Further, when the wafer is stored in the carrier, the tweezers may pull the wafer out of the carrier while holding the wafer in the carrier due to the distortion of the carrier or the position of the orientation flat.
In this case, inconvenience such as another wafer being delivered on the wafer after that occurs.

The present invention has been made under such circumstances, and it is an object of the present invention to determine whether or not a transferred object has been reliably transferred between a transfer mechanism and a transferred object storage unit. The problem is to avoid trouble at the time of transporting the transported object.

[0007]

According to the first aspect of the present invention, there is provided a computer system comprising:
Each of the plate-like objects to be conveyed is approximately horizontal,
Housed in Oite sequence, and the transported object storage portion front is open, in a transfer apparatus for transferring the transported object between the forward and backward freely transport holding member for holding the conveying object, the The transfer holding member enters the transferred object storage section
A detecting unit that detects the presence or absence of a transported object at a preset position on the transport holding member when the transported object is taken out , the transporting holding member, and a tip of the holding member.
Steps protruding from the mounting surface of the transferred object at
An alignment member provided on the rear side of the object loading area is provided.
And the transport mechanism is provided.
When it is determined that
The notch and the positioning member contact each other before and after the transferred object
The position of the transferred object is adjusted on the transfer holding member .

According to a second aspect of the present invention, a plurality of plate-like transferred objects are provided.
Are arranged almost vertically and spaced apart vertically.
Is paid, and the transported object storage portion front is open, in a transfer apparatus for transferring the transported object between the forward and backward freely transport holding member for holding the conveying object, the holding said conveyor
Transmission or reflection through the optical path in the area where the transferred object is placed on the member
An optical path portion formed so as to emit light, and the transported object storage portion
Provided so that the optical path axis is formed vertically at the position facing the
And detecting the presence or absence of light reception from the optical path from the optical path,
Light emission that detects the presence or absence of a transported object on the optical path
And a detecting section comprising a light receiving section and the light path section.
Moves the transfer holding member from the front into the transferred object storage section.
Pull slightly forward from the maximum stroke position when entering
The position is set at a position crossing the optical axis of the detection unit when the detection is performed.

According to a third aspect of the present invention, there is provided a transfer apparatus for transferring a transferred object between a transferred object storage unit and a movable holding member for holding the transferred object. A light-emitting unit that arranges the conveyed goods storage units one above the other, forms a common optical path along the up-down direction at a position facing each storage unit front arranged vertically, and a light-receiving unit disposed on the optical path. It is determined whether or not the transferred object is being transferred for each transferred object storage unit, and the presence or absence of the transferred object is determined based on whether or not the light receiving unit receives light for the transferred object storage unit that is not being transferred. The vertical positional relationship data of each transported object storage unit is stored in advance, and based on this data, when another transported object storage unit in the vertical positional relationship with the transported object storage unit is being transferred, the data is stored. Protrude output for one conveyed object storage section Characterized by providing a control unit for prohibiting. According to a fourth aspect of the present invention, there are provided a plurality of plate-like transferred objects.
Are arranged almost vertically and spaced apart vertically.
The transported object storage section, which is
Transported to and from the transportable holding member
In the transfer method for transferring an object, the transfer holding
Move the member into the object storage area to remove the object
Lifting and holding, and then holding for transport
Retract the member a little and set it on the transfer holding member.
Detecting the presence or absence of the transferred object at the position
Holder for transport when it is determined that there is an object to be transported in the process
The material is further retracted, and the mounting surface is
Provided on the rear side of the step area protruding from
With the positioning members
Contacting and positioning the transferred object.
It is characterized by the following .

[0010]

According to the first, second and fourth aspects of the present invention, for example, when storing a transported object in the storage section, the transport holding member of the transport mechanism enters the transported object storage section and rises slightly by a predetermined distance. Drawn out. Here, if the transferred object is placed on the normal position of the holding member, the light from the light emitting unit of the detection unit is blocked by the transferred object when the holding member is pulled out, for example, to a preset position. It is determined that it is normal. On the other hand, when the transported object is too close to the leading end of the holding member, the light is transmitted or reflected, so that it is determined that the delivery is abnormal.

Further, according to the third aspect of the present invention, the presence / absence of transfer of the transferred object and the presence / absence of the protrusion are controlled for each of the plurality of transferred object storage sections arranged vertically, so that one transferred object storage section is provided. When a unit is transferring a transferred object, the light of the other transferred object storage unit is blocked, and it is judged that it is "overhanging" as it is, but the vertical position relationship of the transferred object storage unit is grasped. Therefore, the output of the "protruding" is not erroneously issued because the delivery of the related storage unit is considered.

[0012]

FIG. 1 is a perspective view showing a main part of an embodiment of the present invention.
FIG. 2 is a perspective view showing the overall configuration of the embodiment of the present invention.
In this embodiment, a carrier mounting table 1 provided with a carrier guide section 11 is installed facing a processing station S for forming a resist film, for example, so that four wafer carriers C can be arranged side by side. Between the mounting table 1 and the processing station S, a transport base 2 movable in the lateral direction (the direction in which the carriers C are arranged) and a transport holding member movable in and out along the transport base 2 are formed. A transport mechanism 4 having tweezers 3 is provided. In this embodiment, the carrier C corresponds to the storage section of the present invention, and the wafer W corresponds to the transferred object.

As shown in FIG. 3, the tweezers 3 are formed with stepped portions 31 and 32 protruding from a mounting surface to regulate the position of the peripheral edge of the wafer at the front end and the base end (front side), respectively. At the same time, the wafer W
A hole 33, which is an optical path for transmitting light from a detection unit described later, is formed at a position closer to the front end of a few millimeters corresponding to the limit position of the mounting allowable area. The light-emitting portions 51 are provided above and below the position immediately in front of the carrier so as to form an optical path immediately in front of the carrier normally mounted on the mounting table 1.
The light receiving section 52 is supported by a support member (not shown). Regarding the specific positions of the light emitting section 51 and the light receiving section 52, the optical path P is set so that the through hole 33 is located when the tweezers 3 is pulled out, for example, by 10 mm from the maximum stroke position (the position where the tweezers extend most in the carrier). Positioned to cross.

The light receiving section 52 is electrically connected to a control section 6 for monitoring the entire processing system. The control section 6 receives signals from the carrier C based on the detection result from the light receiving section 52. Mode of taking out wafer W and carrier C
Has a function of determining the status of transfer of a wafer according to the storage mode of the wafer W to the wafer and issuing an alarm when an abnormality occurs. For example, in the take-out mode of the wafer W, if no light is received when the tweezers 3 enter, or if light is received when the tweezers are retracted, it is determined that there is an abnormality. In this embodiment, as shown in FIG.
At the front end, a mapping sensor 21 (wafer detection sensor) composed of a light-emitting unit and a light-receiving unit disposed on the left and right sides is provided so as to be able to advance and retreat, and at the rear end, the peripheral edge of the wafer W together with the step 31 when the tweezers 3 retreat. Positioning member 2 for centering (positioning the center) of the wafer W in contact with the wafer W
2 is fixed to the left and right. Further, the processing station S is provided with a main transfer arm 7 for transferring a wafer to and from the transfer mechanism 4.

Next, the operation of the above embodiment will be described. First, a carrier C containing, for example, 25 wafers W before processing is placed at a predetermined position determined by the guide member 11 on the carrier mounting table 1, and the transport base 2 is moved to a position facing the front of the carrier C. . Next, the mapping sensor 21 is inserted into the carrier C and the mounting table 1 is intermittently moved up and down, for example, so that the mapping, that is, the presence / absence of wafers at each stage is detected, and then the tweezers 3 are advanced into the carrier C and slightly raised. After the wafer W is scooped up, it is retracted.

Here, in this example, when the tweezers 3 are retracted by 10 mm from the maximum stroke position, the through holes 33 of the tweezers 3 are located on the optical path of the detection unit including the light emitting unit 51 and the light receiving unit 52. However, as shown in FIG. 4A, the periphery of the wafer W
If it is located closer to the tweezers 3 than the tweezers 3, the light from the light emitting unit 51 is blocked by the wafer W, so that no light detection signal is output from the light receiving unit 52.
Determines that the delivery is normal. On the other hand, if the peripheral edge of the wafer W is located closer to the tip end of the tweezers 3 than the through hole 33 as shown in FIG. 4B, the light from the light emitting unit 51 passes through the through hole 33 and the light receiving unit 52 Control unit 6
Determines that the delivery is abnormal due to the input of the light detection signal, issues an alarm output command, and stops, for example, the transport process.

Therefore, it is possible to detect that the wafer W is not held by the tweezers 3 when the tweezers 3 are retracted slightly in this example by 10 mm in this example, or that the wafer W is shifted to the leading end side. Therefore, the wafer W to be transferred is not left in the carrier C, and the wafer W is not dropped from the tweezers 3 after the wafer W is taken out in an abnormal state. When the delivery is performed normally, the tweezers 3 are retracted, and the stepped portion 31 of the tweezers 3 and the positioning member 32 abut on the periphery of the wafer W at the same time as the retraction, and the centering of the wafer W is performed. Subsequently, after the transfer base 2 moves to the center position, the wafer W is transferred from the tweezers 3 to the main transfer arm 7 and transferred into the processing station S, for example, where a resist film forming process is performed.

Here, in the take-out mode of the wafer W, when the tweezers 3 goes to take out the wafer W, the detection unit detects the tweezers 3 at a position immediately before the maximum stroke, that is, at a position where the tweezers 3 is slightly returned from the maximum stroke position.
Since the presence / absence of the upper wafer W is detected, it is possible to prevent the removal operation of the wafer W while the wafer W remains in the carrier C due to a removal error.
In the storage mode (1), when the wafer W is to be set, it is detected whether or not the wafer W is placed at a normal position on the tweezers 3, and after the wafer is set, the tweezers 3 is pulled out from the carrier C. Sometimes the presence or absence of the wafer W on the tweezers 3 can be detected, so the wafer W is dropped in the carrier C when the wafer W is stored, or the wafer W is placed without being transferred to the carrier C due to distortion of the carrier C or the like. In this state, it is possible to prevent the next operation.

In the above description, as the detecting section, the light emitting section 51 and the light receiving section 52 are respectively arranged on one surface side of the tweezers 3, while a reflecting surface forming an optical path section is formed on the tweezers 3 instead of the through hole 33. Even if the light from the light emitting unit 51 is reflected by the reflecting surface and is received by the light receiving unit 52, the same operation and effect can be obtained. Then, a plurality of optical path portions may be formed in the length direction of the tweezers and the detection operation may be performed a plurality of times. In this case, the degree of the positional shift of the wafer on the tweezers can be detected.

Further, as in the above-described embodiment, the light emitting section 51 and the light receiving section 5 are so formed as to form an optical path immediately before the front of the carrier C.
Arrangement 2 is preferable because the protrusion of the wafer W from the carrier C can be simultaneously detected.

An example of the case where the protrusion of the wafer W is detected by the light emitting unit and the light receiving unit will be described.
For example, as shown in FIG. 5, a plurality of carrier mounting tables 1 are provided (in FIG. 5, two stages are provided for convenience), the carriers are mounted on each carrier mounting table 1 so as to overlap in the vertical direction, and in the column direction ( The light emitting unit 51 and the light receiving unit 52 are arranged above and below each carrier row so that a common optical path is formed along the vertical direction at a position facing the front of the carrier for each carrier row arranged in the (up and down direction).

The control unit 6 determines whether or not a wafer is being delivered (accessed) for each mounting area of the mounting table 1, that is, for each carrier (indicating the carrier when placed on the mounting table 1). If the transfer is not being performed, the presence or absence of the protrusion of the wafer from the carrier is detected based on the presence or absence of the light reception in the corresponding light receiving unit 52, that is, the light receiving unit 52 on the lower side of the carrier. For example, a function of monitoring the normal / abnormal of the above-mentioned delivery is provided. Further, the memory in the control section 6 stores data on the vertical position of each carrier. For example, in the example of FIG.
It is stored that C2 is at the upper and lower positions, and that Cn and C (n + 1) are at the upper and lower positions.
When another carrier in a vertical positional relationship with one carrier is being transferred with reference to the data, a function of protruding the one carrier and prohibiting output is provided. In such an embodiment, as shown in FIG. 6, the tweezers 3 is accessing the carrier C1 (during transfer of the wafer W).
If so, the control unit 6 monitors the normal / abnormality of the wafer transfer based on the signal from the light receiving unit 52 as described above, and determines that the wafer has protruded from the carrier C2 below the carrier C1. I do. In the carrier C2, the tweezers 3 are not being accessed, and the light from the light emitting unit 51 is blocked by the access operation on the upper side thereof. Therefore, if the tweezers 3 are left as they are, it is determined that the wafer is outside the signal, and a signal indicating that the wafer is outside the signal, for example, an alarm Is issued,
Since the positional relationship between the carriers C1 and C2 is stored in the memory, the carrier C which is in a vertical positional relationship with the carrier C2 is stored.
1 can be read out, and since the carrier C1 is being accessed, an overflow output, for example, an alarm output is prohibited for the carrier C2, and an erroneous alarm is output.
Does not emit noise. Therefore, if the protruding portion of the wafer is detected in this manner, a plurality of carriers in a vertical relationship can be shared by a common light-emitting portion and a light-receiving portion, and the normal delivery of the wafer can be performed for each carrier (each mounting area). Even if a program for managing each unit, such as monitoring abnormalities or protrusions, is adopted, it is possible to avoid the inconvenience that an alarm is issued even though the wafer W does not protrude from the carrier.

Further, when monitoring the normal or abnormal transfer of the wafer in the present invention, instead of providing the light emitting section 51 and the light receiving section 52, for example, the position of the tweezers 3 where the through hole 33 is formed is provided. Provide a capacitance switch unit, a mechanical switch unit, and a reflection type optical switch unit
It may be determined whether or not the wafer W is placed at a normal position.

In the present invention, not only the wafer W but also the LCD
The present invention is also applicable to a case where a plate-like body such as a substrate is transferred, or a case where a thick transported object is transferred between the storage unit and the transfer mechanism without being limited to the plate-like body.

Here, the control of the entire photoresist processing chamber including the station for transferring the wafer W shown in FIG. 2 (hereinafter referred to as "transfer station") and the coating station for forming the resist film. An example of the method will be described with reference to FIG. A1 to A in FIG.
n is a photolithography apparatus, in which a transfer station 81 and a coating station 8 are provided.
2. A stepper station 83 for performing exposure and a developer station 84 for performing development are provided. In this control system, each of the stations 81 to 84 is controlled by the block controller BC via the remote controller RC.
C is configured to be controlled by the host computer HC. The block controller BC issues a control command to each of the stations 81 to 84, receives information from each of the stations 81 to 84, and controls the entire photolithography apparatus. , The control commands from the block controller BC are translated to each station 81.
To 84, while translating the information from each of the stations 81 to 84 and giving it to the block controller BC.

Here, since the protocol of the block controller BC may differ from factory to factory, if the remote controller RC is interposed as described above, the translation for each protocol scheduled by the block controller BC is included in the remote controller RC. By providing the program, the unit consisting of the remote controller RC and each of the stations 81 to 84 is generalized, which is very convenient for assembling the system. On the other hand, if the remote controller RC is not provided, each station must be reassembled every time the block controller BC changes, which is inconvenient. Note that such a control method is not limited to the case of the photolithography process.

In order to manage wafers flowing between the stations, there is a method of managing wafers in lot units and carrier units. However, it is desirable to manage wafer units, that is, single wafers. Information such as which carrier belongs to which lot, or which process has progressed, so that wafers from the same carrier or the same lot can be processed differently. This is very advantageous in manufacturing a wide variety of wafers.

In the system shown in FIG. 7, when the detection unit detects an abnormality in the transfer between the transport mechanism 4 and the carrier C shown in FIG. 2, an alarm command is issued from the block controller BC and, for example, the transfer stage is started. An instruction to stop the delivery operation is issued to the application.

[0029]

According to the first aspect of the present invention, it is detected whether or not an object is present at a preset position on the holding member for conveyance. It is possible to confirm whether or not the transfer of the transported object has been performed normally between the devices, and it is possible to avoid troubles due to the transfer abnormality.

According to the second aspect of the present invention, since the optical path is provided on the holding member, and whether or not the transfer of the conveyed object is normal is checked by the presence or absence of the transmitted light or the reflected light from the optical path, the holding is performed. It can be easily checked without being affected by the structure of the members, and by changing the position of the optical path, it is possible to determine the timing of detection, for example, how long the holding member is pulled out of the storage unit when the detection is performed. , Very convenient.

Further, according to the third aspect of the present invention, it is possible to collectively determine the presence or absence of a conveyed object from a plurality of conveyed object storage units arranged vertically, and a "protruded" abnormality signal is erroneously detected. Output.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an example in which the embodiment of the present invention is applied to a transfer device between a carrier and a processing station.

FIG. 3 is a side view showing a holding member used in the embodiment.

FIG. 4 is an operation explanatory view of the embodiment.

FIG. 5 is a schematic perspective view showing a main part of another embodiment of the present invention.

FIG. 6 is a diagram illustrating a state of detection of protrusion of a wafer.

FIG. 7 is a block diagram illustrating an example of a control method of a wafer processing station.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mounting table 2 transfer base 3 tweezers 4 transfer mechanism 51 light emitting unit 52 light receiving unit 6 control unit C carrier W wafer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65G 1/00-1/20 B65G 49/07 H01L 21/68

Claims (4)

(57) [Claims] A plurality of plate-like objects to be conveyed are each substantially horizontal.
It is stored in an array with an interval up and down, and the front is open.
In a transfer device that transfers a transferred object between a transferred object storage unit that is open and a movable transfer holding member that holds the transferred object, the transfer holding member is disposed inside the transferred object storage unit. To enter
Detecting section for detecting the presence or absence of a transferred object at a preset position on the transfer holding member when removing the transferred object
And the carrying holding member, and
Steps protruding from the loading surface of the consignment, and placing of conveyed objects
Transport with alignment member provided on the rear side of the area
A transport mechanism when the detection unit determines that there is an object to be transported.
By retreating the feeding holding member, the step and the positioning member
Contact each other before and after the object to be transferred, and
A transfer device for performing alignment of a transferred object. 2. A method according to claim 1, wherein each of the plurality of plate-like objects is substantially horizontal.
It is stored in an array with an interval up and down, and the front is open.
In a transfer device for transferring a transferred object between a transferred object storage unit that is opened and a transferable holding member that holds the transferred object, a transfer device that transfers the transferred object on the transfer holding member. Light path in the mounting area
An optical path axis formed vertically or vertically at a position facing the transported object storage section and an optical path section formed to transmit or reflect.
Is provided to detect the presence or absence of light reception of the optical path from the optical path unit, to detect the presence or absence of an object to be conveyed on the optical path unit, a detection unit consisting of a light emitting unit and a light receiving unit,
The optical path section includes a transport holding member from the front surface of the transport holding member.
A little from the maximum stroke position when entering the storage
Set to a position that crosses the optical axis of the detector when pulled toward you.
Conveying apparatus characterized by that. 3. A transfer device for transferring a transferred object between a transferred object storage section and a transferable holding member for holding the transferred object, wherein a plurality of transferred object storage sections are provided. A light-emitting unit that is arranged vertically above and below, and that forms a common optical path along the up-down direction at a position facing the front of each transported object storage unit that is arranged vertically above and below, a light-receiving unit arranged on the optical path, It is determined whether or not the transported object is being delivered for each transported object storage unit, and the presence or absence of the transported object is determined based on whether or not the light receiving unit receives light for the transported object storage unit that is not being transferred. The data on the vertical position of the transported object storage section is stored in advance, and based on this data, when another transported object storage section having a vertical positional relationship with the transported object storage section is being transferred, the data is stored. Protrude output for one conveyed object storage section Conveying apparatus characterized by comprising a control unit for prohibiting. 4. A plurality of plate-like objects to be conveyed are each substantially horizontal.
It is stored in an array with an interval up and down, and the front is open.
Entry and exit storage section and forward / backward holding the transported object
Transfers the transferred object to and from the flexible holding member
In the transport method, The transport holding member is caused to enter the transported object storage portion,
A step of performing an operation of picking up and holding the transferred object, Next, the transfer holding member is slightly retracted, and the transfer holding portion is moved.
Detects the presence or absence of a transferred object at a preset position on the material
The process of When it is determined in this step that there is an object to be transported,
The holding member is further retracted and placed at the tip of the transfer holding member.
Steps protruding from the loading surface and behind the loading area of the load
With the positioning member provided, each of them is in front of the transported object.
Abutting the rear to align the transferred object.
A transport method characterized in that: