JPS63300838A - Wafer replacing method for processor - Google Patents

Abstract

PURPOSE:To improve throughput as a whole by using one of the transfer feed arms taking out a processed wafer from a processor immediately thereafter the other transfer feed arm inserting its supporting unprocessed wafer into the processor. CONSTITUTION:After a transfer feed arm 30-1 takes out a processed wafer 10 from a processor 60, before the wafer 10 is carried to a predetermined storage part, the other transfer feed arm 30-2 inserts its supporting unprocessed wafer into the processor 60. Consequently, the processor 60 enables a process to be immediately started for this new inserted wafer 10. Accordingly, work for the next replacing operation, in which the transfer feed arm 30-1 once relocates its supporting processed wafer 10 to the storage part successively further supports the next expected unprocessed wafer, can be performed parallelly in time with the processing time by the processor 60.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to various process sequences generally required for forming semiconductor integrated circuits, in which a wafer, which is a base substrate on which the integrated circuit is constructed, is subjected to various treatments. The present invention relates to a method of exchanging wafers to a processing apparatus required when processing them individually in the apparatus, and particularly relates to an improvement for shortening the overall integrated circuit production time, that is, throughput.

<Prior art> In general, in semiconductor circuit fabrication technology, materials such as silicon-based or gallium arsenide-based materials are used as the starting material or base substrate for constructing integrated circuits, although they vary depending on the purpose, except for a part of the periphery. A semiconductor wafer with a constant radius and circular contour is used in the process.

As is well known, these semiconductor wafers are cut out into individual chips after many chips of integrated circuits are formed on them, so during the construction of such integrated circuits, photolithography equipment and CVD equipment Alternatively, at or near the final process, a trimming device that trims the resistive parts formed at various places on the wafer, etc., takes out the processed wafer and inserts a new unprocessed wafer into various processing equipment. A replacement operation of inserting the wafers is required, but unless the wafers are continuously processed using a belt conveyor method, this replacement operation involves handling the wafers one by one.

Here, a specific example of such a conventional replacement operation will be described, albeit briefly.

61. Each figure shows a processing device 60 such as a laser trimming device that trims the resistance value of each part on the wafer, for example.
A cassette 20 is shown in which a plurality of wafers 10 to be processed one by one by this processing apparatus 60 can be stored in a stacked manner for waiting and for temporary storage after processing.

Inside the cassette 20, there are a plurality of storage stages 22. at appropriate intervals in the height direction. ...... is provided,
Actually, this storage stage 22. . . . are each often constructed as a groove cut in the side wall of the cassette, and each wafer 10 is made of a suitable material. . . . , whose diametrically opposing edges are the grooves 22 . ...It is supported and stored within the cassette by entering it to an appropriate depth.

Also shown outside of FIG. 6 is a transfer arm 30 capable of supporting and transferring wafers 10 one by one using a wafer support portion 31 at its tip. Mechanisms for supporting and releasing wafers on the wafer support section 31 have conventionally generally been classified into mechanical chuck systems and vacuum suction systems, but here, compared to the mechanical chuck system, The risk of physically damaging the wafer is extremely low, and it is easy to grip the wafer.
It is best to consider a vacuum suction method, which is advantageous in that there are no parts that must be moved mechanically for release.

That is, in FIG. 6, although not shown, an opening for vacuum suction is formed on the surface of the wafer support portion 31, and this opening is also not shown, but is connected to a passage passing through the arm main body. Furthermore, it is connected to the suction part of a vacuum suction machine such as a suitable compressor through an external tube, and therefore, when the vacuum suction machine is operated with the wafer IO mounted on the wafer support part 31, Arm 3
The wafer l can be stably moved without causing any relative deviation from zero.
O can be supported and fixed.

Furthermore, the transfer arm 30 is driven by a drive mechanism (not shown).
It is driven in the vertical direction shown by arrow UD and in the front-back direction shown by arrow FR. In some cases, it is possible to drive not only the front-rear FR direction and the up-down UD direction but also the left-right direction perpendicular to these directions. For convenience, in this book, the directions for up and down, front and back, etc. are assumed to follow the directions mentioned above.

Of course, if the suction operation by the vacuum suction machine is stopped after the wafer 10 is conveyed to the specified location by the transfer arm 30, the wafer 10 will simply rest on the wafer support part 31 under its own weight. As will be described later, the wafer 10 can be easily removed from the wafer support 31 by automatic release within the cassette due to its own weight or by using a suitable take-out device.

However, if we first look at Figure 6 (^), we see that the processing device 60
One wafer IO is inserted into the wafer 10, and is subjected to processing such as resistance value trimming.

On the other hand, if you look inside the cassette 20, for the sake of understanding here, one row is empty 22. Other than yelling,
All other stages are occupied by wafers IO.

This vacant facility 22. 6(A) is the stage where the wafer 10 currently being processed is stored after the processing is completed. And this stage 22. The wafers 1O that have already been processed are waiting in the upper stages, and the wafers 1O that are in the lower stages are wafers that will be processed by the processing device 60 from now on.

Therefore, if the wafer currently being processed in FIG. 6(A) is stored in the currently empty stage 221 after it has been processed, the wafer that is currently being processed in FIG.
−． Wafers stored in! 0 is retrieved and scheduled to be sent to the processing unit.

When the predetermined process for the wafer lO in the processing apparatus 60 in FIG. 6(A) is completed, the transfer arm 30, which has been waiting beside the processing apparatus 60, is moved as shown in FIG. 6(B). enters the processing apparatus 60 as shown by arrow F and is positioned below the processed wafer lO, and then is slightly lifted within the processing apparatus 60 as shown by arrow U, and moves the wafer lO to the wafer support 31. Place it on top.

Under this state, a vacuum suction machine (not shown) operates, and the wafer lO is suctioned and temporarily fixed onto the wafer support 31, and then the transfer arm 30 retreats as shown by arrow R, and the processed wafer lO is removed. It is pulled out to the outside of the processing device 60.

Next, the transfer arm 30 is driven to an appropriate height as shown by the arrow U in order to store the processed wafer 10 in the storage stage 22 which is currently vacant in the cassette toss 0. , as shown by the imaginary arrow F in the figure, preparations are made to insert the tip into the cassette.

From this state, as shown in FIG. 6(C), the transfer arm 30 is driven in the forward direction F so as to send the supported wafer 10 toward the scheduled storage stage in the cassette 20.
When the wafer reaches a position where it can be accommodated in the storage stage 22°, it is driven slightly downward so that both diametrically opposing edges of the wafer 10 face the upper surface of the storage stage.

At this time, the operation of the vacuum suction device is stopped, and therefore the wafer lO that was placed on the wafer support part 31 of the transfer arm 30 is moved to the corresponding stage 22. Its diametrically opposed edges are supported from below by the upper surface of the container, and the container settles into that position due to its own weight, completing storage in the corresponding step 22□.

Thereafter, the transfer arm 30 moves backward as shown by arrow R in the figure, and then moves to the next lower storage stage 22. - starts moving to take out the wafer 10 stored in and waiting.

In other words, after being lowered a little by one step from the state shown in Fig. 6(C), the forward direction F is lowered as shown in Fig. 6(D).
The tip wafer support 31 is inserted under the wafer 10 stored in the next stage 221-t, and the wafer 10 is driven upward U so as to be slightly lifted, and the wafer lO is placed on the wafer support 31. At the same time, the vacuum suction device also works to temporarily fix the wafer on the wafer support 31.

Next, the transfer arm 30 retreats in the direction of the arrow R in FIG. I am going to

From here, as shown by the group of imaginary line arrows in FIG. , is driven slightly downward, and at the same time,
The operation of the vacuum suction device is stopped, and the wafer 10 is placed at a predetermined position in the processing device 60 by its own weight.

Thereafter, when the transfer arm 30 is pulled out to the rear R, the state returns to the state shown in FIG. 6(A), and the same sequence as described above is repeated.

In addition, in FIG. 6(D), after pulling out a new wafer lO to be processed next from the cassette 20, the processing apparatus 6
In the middle of the transfer process of inserting into 0, a process of rotational angle position matching is also illustrated.

This is a process of rotating the wafer 1O by an appropriate angle in order to align the coordinate system of the wafer 10 to be processed with the coordinate system set in the processing apparatus 60 used, but since it is not essential to the present invention, it will be described later. This will only be briefly described in the preferred embodiments of the present invention, and will be put aside for the time being.

<Problems to be Solved by the Invention> However, if we look at the wafer exchange operation to the processing apparatus 60 in the conventional example described above in terms of time, it becomes as shown in FIG.

The first thing to say is that in these conventional methods,
When the transfer arm 30 is in operation, the processing device 60 is completely at rest, and conversely, when the processing device 60 is in operation, the transfer arm is completely at rest.

In other words, the processing time TA during which the processing device is operating is the arm standby time TA, and the wafer that has been processed is taken out and the next wafer to be processed is transferred to the processing device 60.
The replacement time Tp required for re-insertion into the memory becomes the standby time TP of the processing device.

Furthermore, the replacement time TP is in FIG. 7, and as shown by subdividing the time domain of the replacement operation, TI: time for taking out processed wafers from the processing apparatus 60.

T2: Time for transferring the processed wafer taken out to the side of the cassette 20.

T, storage time for storing the processed wafers in the second cassette 20;

T4: Time to take out the next unprocessed wafer from the cassette 20 while fixing it on the wafer support part 31 at the tip of the arm after storage.

T5: Time to transfer the unprocessed wafer taken out to the side of the insertion port of the processing device.

■8: And the time to insert this unprocessed wafer into the processing equipment.

Total sum (Tp=T++T2+T3+T4+Ts+Ta)
Therefore, it actually takes a considerable amount of time.

Furthermore, as shown by the imaginary line in FIG. 6(D), when it is essential to adjust the rotational angle position of the sea urchin during the transfer process from the cassette 20 side to the processing device 60 side, The time for this will also be added to the transfer time T.

On the other hand, the time TAi that the mechanical system must be inactive for the replacement operation, that is, the processing time T by the processing device 60
As for A, it is not uncommon for this to take quite a long time.

As is clear from the above, in the conventional replacement method in which the processing step by the processing device and the replacement step using the transfer arm are placed in a serial relationship in time, both the processing device 60 and the transfer arm 30 There are times TA and Tp during which the other party must be completely stopped because the other party is operating, and these TA and TP generally tend to be quite long, so it is difficult to improve productivity in the first place. It is difficult from this point of view, and at best we have no choice but to rely on other factors other than the system principle, such as the processing speed of the processing equipment itself or the drive speed of the transfer arm itself, and in reality, we have to accept this even if productivity is low. I was in an unavoidable situation.

The present invention has been made to alleviate the actual situation of the conventional example, and by making it possible to shorten the processing device standby time and the standby time of the mechanical system for replacement operation (arm standby time), the overall improvement is achieved. The object of the present invention is to provide a method for replacing wafers in a processing apparatus that can easily improve throughput.

<Means for Solving the Problems> In the conventional example described above, both the processing time and the replacement time were in a serial relationship in terms of time. This hindered productivity improvement.

Therefore, in order to achieve the above object, the present invention proposes a method for exchanging wafers to a processing apparatus having the following configuration so that the processing time and the exchanging time are at least partially parallel in time. .

A wafer exchange method for inserting a new unprocessed wafer after removing a processed wafer from a processing device, the method comprising: inserting an unprocessed wafer into the processing device by linearly moving in and out of the processing device, respectively; A pair of transfer arms are provided that can take out the processed wafer from the processing device: After one wafer has been processed in the processing device, one of the pair of transfer arms transfers the processed wafer. and taking out the processed wafer from the processing apparatus; and inserting the unprocessed wafer supported by the other transfer arm into the processing apparatus while the one transfer arm supports the processed wafer; A method for exchanging wafers to a processing apparatus, characterized by: restarting the above-mentioned processing on the unprocessed wafer.

<Operations and Effects> In the present invention, after one arm of the elbow-based transfer arm takes out a processed wafer from the processing apparatus, before transporting the processed wafer to, for example, a predetermined temporary storage location; , an unprocessed wafer supported by the other arm can be inserted into the processing device, so that the processing device can immediately begin processing the newly inserted wafer.

This means that from the transfer mechanism's point of view, if an unprocessed wafer is immediately inserted into the processing equipment as described above, it will be processed in the previous processing step, taken out of the processing equipment, and transferred to one side. Transferring processed wafers that are still supported by the transfer arms to a temporary storage location, and subsequently supporting unprocessed wafers that are to be processed in the next processing step on one of the transfer arms; Work to prepare for the next replacement operation can be performed in parallel with the processing time of the processing device.

Thus, in accordance with the present invention, as described in the summary above, a pair of transfer arms is used, and as soon as one arm removes a processed wafer from the processing apparatus, the other transfer arm supports the transfer arm. 5 Even if the time TA required for the processing and the time TP required for wafer replacement are exactly the same as in the conventional example described above, such processing At least part of the preparation process for the work and the replacement work is executed in parallel in time, so as mentioned earlier, the arm standby time TA and the processing equipment standby time D from the side of the standby side are , are both shorter.

If the processing time and the replacement preparation time are the same, the arm standby time TA will be zero, and the processing equipment standby time TP will be only until the processed wafer is taken out by the pair of arms and the unprocessed wafer is inserted. It will only last for an extremely short period of time.

The above exchange preparation time is the arm mechanism operating time excluding the time from when one arm takes out a processed wafer from the processing equipment to when the other arm inserts an unprocessed wafer. For example, it can be considered as the time to take out a new unprocessed wafer from the cassette after a processed wafer taken out of the processing apparatus is inserted into a predetermined temporary storage location such as a cassette.

Also, if the replacement preparation time by the arm is shorter than the processing time, the arm only needs to wait for that short amount of time.
At this time as well, the waiting time Tp for the processing equipment is only the time for exchanging old and new wafers for the processing equipment as described above, and conversely, if the processing time is shorter than the replacement preparation time on the arm mechanism side, the waiting time Tp for the processing equipment is The waiting time of the apparatus is simply the short time added to the above-mentioned time for exchanging old and new wafers, and there is no waiting time for the arm.

In this manner, according to the present invention, productivity can be dramatically increased in this type of semiconductor integrated circuit fabrication technology in which wafers are transferred to a processing apparatus one by one.

Embodiment FIG. 1 shows a preferred embodiment according to the replacement method of the present invention.

The present invention uses a processing device 60 that takes out a processed wafer one by one and inserts a new unprocessed wafer.
If so, it can be applied to any type of device, including, for example, a laser trimming device that trims resistors formed at various locations on a wafer to a predetermined value.

Similarly, although the device itself for temporarily storing processed and unprocessed wafers is not limited, the illustrated embodiment assumes a cassette 20 capable of storing a plurality of wafers in a stacked manner. Such a cassette 20 may be similar to that already described in connection with the prior art.

In the present invention, wafer! A pair of transfer arms are used that can take out and insert 0 one by one while supporting them, and these two transfer arms are: ]L, , 3L.
, the specific individual structure of the wafer, the means for selectively fixing and supporting the wafer to the arm, the means for releasing the wafer from the arm, etc. are not limited, but it is necessary to have at least a so-called linear skating mechanism. Therefore, it is required to be able to enter and exit the processing device 60 in a straight line.

This is due to the problem of inertia, and in reality, there is currently no other suitable mechanism that can allow fairly high-speed movement when feeding a supported wafer into a predetermined position. A linear skating mechanism is optimal in this respect, and one employing a linear motor is particularly desirable.

Further, as for the mechanism for selectively supporting and releasing the wafer, it is preferable to use a vacuum suction system rather than a mechanical chuck system, although the present invention is not limited to this.

The present invention will now be explained through this example.
As shown in the figure (^), one wafer 10. is being processed, the pair of transfer arms 3
0-, , 3 (In L2, one arm, for example, the transfer arm 30-2, is on standby to take out the wafer 10° that is currently being processed after it has been processed, and the other transfer arm 30- On the wafer support part 31 of I, an unprocessed wafer 10.- is scheduled to be processed next.

is already supported and waiting.

Therefore, unlike the conventional example, at this time, at least two wafers I are stored in the cassette 20 as a temporary storage device.
01.10+-+ at least two empty spaces 22, . 2
2. ,, there is. For understanding, all other stages have wafers l.
The wafers placed above the vacant space 22 are treated and placed as unprocessed wafers.

Each arm 3L, 3L2 is supported on a guideway 35 via a drive mechanism 34 so as to be capable of linear movement. For example, this linear skating mechanism is particularly preferably a linear motor. In case of mechanism,
The control magnetic field generating means embedded in the guide path 35 and the magnetic field generating means provided in the drive mechanism 34 interact with each other, allowing forward movement, backward movement, speed control, stopping, etc. However, such a mechanism system is not limited to the mechanism example used by the present applicant as illustrated later, and can be assembled extremely easily by a person skilled in the art.

In the processing apparatus 60, the wafer 10. When the processing is completed, the second transfer arm 30-2, which does not support the wafer, is driven in the forward direction F as shown in FIG. The processed wafer 10 is lifted upwardly U. is placed on the wafer support part 31, and at the same time, a vacuum suction mechanism (not shown) is operated to temporarily fix the processed wafer lθ5 on the wafer support part 31.

In addition, in this embodiment, as also shown in the reference mechanism example described later, the first and second transfer arms 30-, , :
]O-2 are configured to move together integrally.

However, in principle, if the necessary movements can be made in each process of the present invention at that time, these pair of arms 3
(L, 30-2 may be made to move individually.

The processed wafer 10 enters the processing apparatus 60. The second transfer arm 30-2 that has picked up the processed wafer 10. is taken out from inside the processing device 60. This state is shown in FIG. 1(C).

However, in the present invention, after the processed wafer is taken out from the processing apparatus 60, the unprocessed wafer 10. −.

is intended to be inserted into the processing device 60.

Therefore, the pair of transfer arms 3 (L, 30-2) are driven slightly downward, as shown in FIG.
After the unprocessed wafer 10 . ．． is sent to a predetermined processing position in the processing device 60.

At this time, the unprocessed wafer 10. -, are inserted slightly above the predetermined installation position, so the first
As shown in FIG. By stopping the operation of the mechanism, the unprocessed wafer IO= is placed with its white stone at a predetermined installation position in the processing apparatus.

Thereafter, when the first transfer arm 30-3 is pulled back to the rear R, from this point on, the processing apparatus 60 immediately receives the newly inserted unprocessed wafer 10. −, processing becomes possible.

On the other hand, the previously processed wafer 10. which is still placed on the second transfer arm 30-2 at this point. By using the processing time by the processing device 60, the empty space 22. on the predetermined stage in the cassette 20, on this platform.
can be stored in.

That is, the pair of transfer arm mechanisms can independently move upward U without waiting even after the processing by the processing device 60 starts, and after positioning the second transfer arm at a predetermined height with respect to the cassette 20, As shown in FIG. 1(F), by driving forward F, the processed wafer 1
0. Blank 22. can be sent to.

Therefore, using the same procedure as the conventional mechanism for releasing the wafer from the transfer arm, as shown in FIG. 1(G), while driving the second transfer arm 30-2 slightly downward, the vacuum suction mechanism The operation of the processed wafer 10. is stopped and the processed wafer 10. The diametrically opposed edges of the corresponding storage stage 22. After that, by pulling out the second transfer arm 30-2 backward R, the target processed wafer 10. The unprocessed wafers 10. to be processed next time are then placed on the wafer support section 31 of the first transfer arm, which is now empty. -2 can now be temporarily fixed.

That is, as shown in FIG. 1(H), after positioning the first transfer arm 30-7 at an appropriate height relative to the cassette 20, the first transfer arm 30-7 is driven forward F to transfer its wafer support 3.
1 to below the target unprocessed wafer 10.2, lift it up slightly, and while placing the unprocessed wafer 10,-2 on the wafer support 3I, operate a vacuum suction mechanism (not shown), and place the unprocessed wafer 10.2 on the wafer support 3I. The first transfer arm 30-1 may be pulled back to the rear R while the unprocessed wafer IO is temporarily fixed.

Thereafter, as shown by the imaginary line in FIG. 1 (11), if necessary, the rotational angle position of the unprocessed wafer 1O1-2 that has been pulled out is aligned, and then the pair of arm mechanisms are moved downward. The second transfer arm 3o-2, whose wafer support portion is currently vacant, transfers the wafer 10. which is currently being processed in the processing apparatus 60. -, placed at an appropriate height for removal after processing, it will be in exactly the same state as in Figure 1 (A), and after that, repeat the above steps up to Figure 1 (G). This makes it possible to efficiently process the unprocessed wafers stored in the cassette 20 and then re-storage them.

In particular, in the case of the present invention, the processed wafer 1 shown in FIG.
0. After the wafer is taken out, the replacement preparation work until wafers to be processed next time are prepared as shown in FIG. 1(G) can be performed in parallel with the processing work by the processing device 60. For this reason, the time relationship between the operations of the processing device side and the arm mechanism side is shown in FIG. 5 in contrast to FIG. 7 mentioned earlier in accordance with the conventional example.

When one wafer has been processed by the processing device 60, when the present invention is applied, the processed wafer is taken out by one of the transfer arms, and then as soon as possible,
The unprocessed wafer that has been waiting supported by the other transfer arm is inserted into the processing device 60, so that the processing device 60 can immediately thereafter, if desired, enter into processing operation for this newly inserted wafer. .

On the other hand, once a new wafer is placed in the processing device 6 in this way,
Once inserted into the cassette 20, while the processing device 60 is processing the wafer, the processed wafer taken out from the processing device 60 is transferred to the cassette 20.
After being stored, unprocessed wafers for next processing can be taken out from a predetermined stage within the cassette 20, transferred again, and placed on standby outside the processing apparatus.

Therefore, the time TP during which the processing device 60 has to stand by without operating is a small sum of the time T1 for taking out the processed wafer and the time T6 for inserting a new evaporator. The time T^ that the mechanism must stand by will also be the same as the processing time if the time required for the above-mentioned replacement preparation is shorter.

On the other hand, the replacement preparation time (T2 + 'r
3+ 7. + Ts) takes longer than the processing time, the arm's waiting time TA becomes practically a prison (
(always some sort of continuous movement), the waiting time T of the processing device becomes longer by the difference from the preparation time, but in any case, as is clear, the above parallel movement As a result, the standby time of both the processing device 60 and the transfer arm mechanism is significantly reduced compared to the case where the conventional example is limited to a serial sequence. Performance or throughput is significantly improved.

Although the present invention has been described above, the present invention can be applied to various semiconductor circuit manufacturing methods and devices as long as the gist of the present invention is not departed from. There is no problem if additional processing steps are added.

Even in such a case, at least if the rational wafer exchange operation according to the present invention is taken, it is possible to allow the processing device and the transfer arm mechanism to operate simultaneously, but each according to a separate purpose. The time overlap certainly provides time savings compared to conventional serial sequences.

As already mentioned several times, in addition to the cassette 20 in the above embodiments, any arm mechanism may be used as long as it allows movement according to the process of the present invention. Further, the wafer rotational angle position matching device shown by imaginary lines in the drawings and slightly explained can be selected as required.

However, in order to assist in understanding the present invention, the present applicant has provided an example of the configuration around the cassette and the configuration around the arm used in a laser resistance trimming device configured by applying the present invention, as well as an example of the rotation angle position of the sea urchin. Examples of the configuration of the alignment device are illustrated in FIGS. 2 to 4 in a schematic but easy-to-see form.

First, the cassette 20 will be briefly described with reference to FIG. 2. The cassette 20 has a pair of side walls 21, 21,
The upper ends are connected to each other by a top plate 24 as necessary, and the opposing inner surfaces of the side walls 21, 21 are each provided with a plurality of grooves 22. ...... are cut out, and the whole is a resin injection molded product.

The cassette 20 is removably placed on a suitable support surface 23, and grooves 22. ····teeth,
Each of them constitutes the wafer storage shelf of each stage described above, and therefore, the wafers 10 made of a suitable material are inserted into this groove to a suitable depth with their diametrically opposing edges.
stored in a cassette.

The cassette 20 is also detected by a wafer presence/absence detection device 50.
It is monitored whether wafers are stored in each internal stage. This wafer presence/absence detection device 50 is constructed using a support stand or a housing 5 that supports various mechanisms and parts as a whole.
1, and a reflective photo-interrupter 52 (indicated by a phantom line) is housed in this housing.

As is well known, the photo-interrupter 52 is widely used as an optical non-contact object detection device in various modules on the market, and also in a discrete configuration. When an object exists in the optical path of a light beam such as a laser beam emitted from a projector,
With respect to a predetermined angle of incidence regarding the point of incidence on this object, reflected light that is reflected along a path with the same reflection angle enters a light receiver, thereby detecting the presence of the object in a non-contact manner.

Of course, conversely, if the object 10 is not present, the reflection mechanism described above will not occur and no converted electrical output will occur at the output of the receiver, so this can be used to detect the absence of an object.

Of course, the object IO is a wafer here, and the geometrical relative positions of a light projector and a light receiver (not shown) with respect to the wafer are initialized fairly accurately, except for certain tolerances.

In the mechanical system illustrated here, the wafer presence/absence detecting device 50 as well as the transfer arm mechanism can scan in the vertical direction indicated by the arrow UD mentioned above.

As a result of such scanning, when the illustrated wafer 1° is detected, a drive mechanism system (not illustrated) is used to remove the wafer 10 from the cassette and transport it to a predetermined location for the next process. , after the height of the arm 30 is first adjusted along the direction of the arrow U-D, the arm 30 enters into the cassette to capture the wafer, and vice versa, according to the mechanism already described for the explanation of the present invention. When storing the item in a predetermined stage, it is first detected whether or not the relevant stage is empty, and then the above-mentioned storing operation occurs.

In FIG. 2, only a tree is shown among the transfer arms 3L, 30-2 used in the pair of the present invention, but this is because the pair of arms may have the same configuration, so one piece is used as a representative. This is to avoid complicating the drawings. Therefore, the suffix "-8, -2" is omitted, and the transfer arm 30
It is shown as.

This arm 30 has a wafer support part 31 which is cut out at the tip and has a horseshoe shape, on which a wafer lO can be placed. An opening 33 for vacuum suction is provided at a position (near the base of the horseshoe-shaped support portion 31 relative to the arm main body portion 32 extending rearward in a rod-like shape in the illustrated case).

When only this arm portion is taken out and shown as a pair according to the present invention, it is as shown in FIG. 3.

That is, the above-mentioned vacuum suction opening 33 is connected to a vacuum suction machine (not shown) such as a suitable compressor through a passage (not shown) passing through the arm main body 32 and further via external tubes 36, 36. Therefore, when the vacuum suction machine is operated with the wafer 10 mounted on the wafer support part 31, there is no relative displacement with respect to the arm 30. The wafer 10 can be stably supported and fixed, and in this state, the arm 30 can be driven vertically along the screw shaft 37 by a drive mechanism (not shown).

This screw shaft 37 also has a manual handle 38,
This is, of course, for manually moving the arm mechanism in the height direction.

The first and second transfer arms:] O-, 30-2 are arranged quite close to each other in the height direction as shown in the figure, and are shown schematically in FIG. It has the illustrated guideways 35, 35 and also has individual drives 34, 34 for linear skating movement therebetween, which are necessary for realizing the method of the invention already described. Individual forward and backward movements are possible.

The wafer presence/absence detecting device 50 shown in the second figure is fixed to a suitable part of the pair of transfer arm mechanisms so as to dynamically move together with the pair of transfer arm mechanisms.

By the way, as shown particularly well in FIG. 2, the outer diameter contour of the wafer 10 normally used does not remain circular over the entire circumference, but a portion of the periphery is cut off in a straight line or has a notched shape. Notches are added to form a non-circular contour portion 11.

These linear cuts or notches are necessary to ensure that the portion to be processed on the wafer is correctly positioned relative to the processing coordinate system set in the processing equipment when the wafer is inserted into each processing equipment, especially using automated equipment. This is for displaying the rotational angle position for matching.

This is because, if there is no such non-circular contour portion 11 for indicating the rotation angle position and the wafer maintains a circular contour with a substantially constant diameter over its entire circumference, it will be difficult to determine which direction the wafer is inserted into the processing equipment. This is because an automatic insertion device such as a transfer arm has no way of knowing whether the direction is correct or not.

In other words, this non-circular contour portion 11 is a mark for coordinate system alignment or orientation, and the non-circular contour portion 11 is detected by an automatic rotation angle alignment device generally called a flat finder or notch finder. Then, the wafer is rotated so that it reaches a predetermined rotational angle position to achieve a predetermined coordinate system alignment, and then the coordinate-aligned wafer is processed by an automatic insertion device such as the transfer arm mechanism described here. Used to be inserted into a device.

For example, in the case of a flat finder, a configuration as shown in FIG. 4 is adopted.

A support edge 4 on which the periphery of the target wafer 10 is placed on the upper surface
! A rotary shaft 42 is provided at the center, and the upper end can vacuum-adsorb the wafer.

The arm supporting the wafer 10, for example, the first transfer arm 30-1 in the illustrated case, is driven in the direction of the arrow in the figure, and then driven in the F direction to move the illustrated flat finder 4.
After positioning the wafer on the support edge 41 of 0, releasing the vacuum suction as described above, and releasing the wafer, when the wafer is moved back, the rotating shaft 4 that vacuum suctioned the wafer replaces the wafer.
2 rotates, and at the same time, a transmission type photo-interrupter 43 consisting of a light projector and a light receiver is activated.

This photo-interrupter 43 has a part of the support edge 41 cut out, and a light beam is passed through this cutout from the emitter side to the receiver side.
When the wafer placed on 1 is rotated, this photo-
Only when the non-circular contour portion 11 passes under the interrupter, the light beam can be captured on the receiver side,
This makes it possible to know the rotational angular position of the wafer.

Generally, this light beam is a pulsed beam with a known frequency, and therefore the rotational angular position of the wafer can be detected with considerable accuracy by counting the number of pulses detected by the receiver per revolution of the wafer. Can be done.

Therefore, if the cassette 20 shown in FIG.
Initially, when a plurality of wafers are manually stored in the wafer, even if the wafers are oriented at an appropriate rotation angle, they can be inserted into the processing device 60 by passing through the flat finder 40. can all be made to coincide with a predetermined rotation angle direction.

Above, each component used by the present applicant in the device to which the present invention has been applied has been explained, albeit briefly, to aid in understanding the present invention. However, as filed separately from the present application, improvements have been made to eliminate the causes of false detection in the wafer presence/absence detection device 50, improvements in positioning with respect to the flat finder 40, etc., but they are not directly related to the present invention. The present invention is equally and effectively applicable not only to such an improved manufacturing system but also to a semiconductor circuit manufacturing system in which conventionally used peripheral mechanisms are used as they are.

Note that the linear skating regarding the transfer arm is a concept that includes linear stepping of digital operation.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of a preferred embodiment of the method for exchanging wafers to processing equipment according to the present invention, and FIG. 2 is a schematic configuration of an example of a cassette as a wafer storage device used in an equipment system to which the method of the present invention can be applied. 3 are schematic configuration diagrams of an example of a pair of transfer arm mechanisms used to realize the method of the present invention,
FIG. 4 is a schematic configuration diagram of a flat finder configuration example as a rotation angle position alignment device that may be used during the wafer transfer process, and FIG. 5 is the operational relationship between the processing device and transfer arm mechanism when the present invention is applied. FIG. 6 is an explanatory diagram of a conventional wafer exchange method, and FIG. 7 shows that in the conventional example, the processing device and the transfer arm mechanism operate only in a temporally serial relationship. FIG. In the figure, 10, 10+, to, -, 101-2 are wafers, 20 is a cassette as a storage device, 22, 22
+, 22+-+ are wafer storage stages, 30, 30-+
, 30-2 is a transfer arm that can move linearly, 31 is a wafer support, and 60 is a processing device. one! Figure 4 1-0 Kuehawafu 7/・Fine type Higenkyu Narrow

Claims (1)

[Scope of Claim] A wafer exchange method that inserts a new unprocessed wafer after taking out a processed wafer from a processing device; A pair of transfer arms are prepared into which unprocessed wafers can be inserted and processed wafers can be taken out from the processing equipment; On the other hand, the processed wafer is taken out of the processing apparatus, and while the processed wafer is supported by the one transfer arm, the unprocessed wafer supported by the other transfer arm is inserted into the processing apparatus. A method for exchanging wafers to a processing apparatus, comprising: causing the processing apparatus to restart the above-mentioned processing on the unprocessed wafer.