JPH02126649A - Transfer apparatus - Google Patents

Abstract

PURPOSE:To execute a replacement operation without relying on an operator's memory or the like by installing a means to display the timing for replacement of an object to be treated for dummy use when the limited number of usable times, of the object to be treated for dummy use, which has been set in advance for each treatment content of a treatment container has been reached. CONSTITUTION:A control part 60 increases the number of used times whenever a batch treatment of a wafer 11 for treatment use mounted on a port 5 as a treatment container has been finished; after the treatment has been finished, the control part reads out the limited number of usable times which has been set in advance by a memory 64; the control part compares the current number of used times with the limited number of usable times. Only when both of the number of times coincide, a display, e.g., an alarm 68, is driven. Accordingly, it is possible to surely recognize the proper timing for replacement in such a way that an operator need not pay attention to anything about the timing for replacement which relied on the operator's experience and memory in a conventional method.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for loading a processing object and a dummy processing object into a processing container and batch processing the processing container together. The present invention relates to the transfer device used.

(Prior Art) An example of this type of transfer device is a wafer transfer device used in a heat treatment device that heat-treats semiconductor wafers.

This device was published in Japanese Patent Application Laid-Open No. 54-34774. Japanese Unexamined Patent Publication No. 61-22
4430. Unexamined Japanese Patent Publication No. 62-69633゜ Publication No. 61-27
640, etc., and is well known to those skilled in the art.

This transfer device also executes exchange of dummy wafers and monitor wafers. For example, as shown in FIG. 4, three monitor wafers 12 are mounted at the center and both ends of the processing wafer group 11. Depending on the process, the monitor wafer may be placed only in the center of the process wafer 11, or one monitor wafer may be placed at each end of the process wafer 11.
There are some that arrange sheets.

In this case, the wafers for processing 11 and the monitor wafers 12 are transferred to the boat 5 for each process.
The dummy wafer group 10 is not transferred each time, but is repeatedly used for a plurality of processes.

Here, the significance of mounting such a dummy wafer group 10 on the boat 5 is as follows. That is, such dummy wafer groups 10 are placed on both ends of the boat 5 in the longitudinal direction.
When this boat 5 is placed in a process tube, the dummy wafer group 10 will be placed on the process gas introduction side and discharge side of the process tube. When processing the processing wafer group 11, it is necessary to introduce a uniform flow rate of process gas between the opposing surfaces of the processing ware group 11. However, on the gas introduction side and the exhaust side of the process tube, it is not possible to introduce a uniform flow rate of gas between the urchins I\ due to the disturbance of the gas flow. In this case, if a film deposition process such as CVD is performed, thin films having different thicknesses will be formed between each wafer. Therefore, a buffer zone for securing a region where a uniform flow rate can be supplied between each sea urchin/% is formed by such a dummy λ group 10.

(Problems to be Solved by the Invention) By the way, by repeatedly using the dummy Uninow group 10 for a plurality of treatments, the following problems have arisen. That is, generally the group of wafers for processing 11
Regarding the treatment, many items are treated at high temperatures, but when the first group of dummy wear 10 is repeatedly exposed to high temperatures, it sometimes breaks due to thermal stress. In addition, reaction products will also adhere to such a dummy wafer group 11, but this reaction product will scatter in the process tube and adhere to the processing wafer group 11 as impurities, causing the processing There was a problem in that the yield of Ueno\Group 11 decreased.

Therefore, in the past, operators relied on their experience and memory, for example, by conducting a visual inspection of the dummy mm2 group 10, or by counting the number of times the dummy mm2 group 10 was processed. They were exchanging.

However, since the replacement timing of such dummy wires 1 group 10 depends on the operator's experience and memory, the replacement timing often varies. and,
If emphasis is placed on preventing the adverse effects on the processing wafer group 10, the number of replacements of the dummy Uninow group 10 increases more than necessary, which increases the workload of the operator. On the other hand, if the timing for replacing the dummy wafer group 10 is missed, there is a problem that the processing of the first processing ware group 11 is adversely affected as described above.

Therefore, an object of the present invention is to automatically detect when to replace a dummy processing object, which conventionally relied on the operator's experience and memory, thereby reducing the operator's work burden and achieving the above-mentioned requirements. It is an object of the present invention to provide a transfer device that can reliably prevent a decrease in the yield of objects to be processed due to missed replacement timing.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a method for loading and unloading objects to be processed using a device for transferring objects to be processed into a processing container in which a dummy object to be processed has been loaded in advance. The transfer device is equipped with a means for displaying that it is time to replace the dummy processing object when the number of uses of the dummy processing object reaches the limit set in advance for each processing content for the processing container. be.

(Function) The present invention is configured such that a limit number of times the dummy processing object can be used is set in advance for each processing content, and when this limit number of uses is reached, the operator is warned that it is time to replace the object. ing.

The limit number of times of use is such that even if the dummy object to be processed is used repeatedly within this number of times, it will not be damaged and the attached reaction products will be scattered as impurities onto the object to be processed. If the number of times is set to a value that does not occur, it is possible to utilize the dummy processing object to the maximum extent possible, and moreover, it is possible to reliably prevent an adverse effect on the processing object. Note that the above-mentioned limit on the number of uses may be set by an operator's input, or may be set automatically by the Bost CPU, etc. that manages the processing process of the processing container. It's okay.

(Example) Hereinafter, an example in which the present invention is applied to a wafer transfer apparatus used in a heat treatment apparatus for semiconductor wafers will be specifically described with reference to the drawings.

As shown in FIGS. 5 and 6, this wafer transfer device includes a head 40 that moves up and down in the figure, and a head 40 that moves up and down in the figure.
0 via an arm 42, and has a structure including a pair of chucks 44 and 44 that can be opened and closed in the left and right directions in the figure (Utility Model Publication No. 61-27640). The pair of chucks 44, 44 have chuck grooves (not shown) that can chuck wafers one by one.
．． By narrowing the distance between the opposing grooves 44, the wafer can be chucked in the groove. On the other hand, a wafer push-up device 50 is provided at a lower position facing the pair of chucks 44, 44, and allows a table 52 that can move up and down to come into contact with the lower end of the wafer and push it up. Then, the carrier cassette 30 or the first
．． The second dedicated monitor container 20.22 is connected to the table 52 of the wafer lifting device 50 and the pair of chucks 44.
By pushing up the table 52, the wafers in each container are pushed upward, and as shown in FIG. The trowel held at 44 makes it possible to take out the wafers from each of the containers. Thereafter, the chuck 44.44 that supported this wafer is moved to a position above the boat 5 on the boat transfer device 4 by the horizontal movement of the wafer transfer device 3, and the chuck 44. 44 and a wafer lifting device 50, it can be mounted on the boat 5.

Conversely, if the processed wafers on the boat 5 are to be returned to the respective containers, this can be done by performing the reverse process of the transfer operation described above.

Next, regarding the control system of the wafer transfer device 3, the first
This will be explained with reference to the figures.

First, a control section 60 is provided which controls the transfer operation of the wafer transfer device 3, and this control section 60 controls the transfer operation of the wafer transfer device 3 shown in FIGS. The drive control of the transfer drive unit 62 is performed to execute the transfer operation. As a characteristic configuration of the apparatus of this embodiment, the control section 60 includes a memory 64. An input section 66 and an alarm 68 are connected respectively.

The human power section 66 is used to set and input the limit number of times the dummy wafer group 10 can be used for the boat 5, which is a processing container.
In the case of a configuration having tiered furnaces, a dedicated boat 5 is provided for each tier of furnaces, so the human power department 66 has a dummy boat 5 for each of these four types of boats 5. A limit number of times the wafer 10 can be used can be set and input. The memory 64 includes an input section 66
The limit number of times of use for each boat 5, which has been manually inputted, is input via the control unit 60 and stored. Here, each boat 5 corresponds to each process tube of the multi-stage furnace 7 on a 1:1 basis, and in this embodiment, for convenience of explanation, it is assumed that one process tube always performs the same process. still,
All the process tubes of the multi-stage furnace 7 are not limited to those that perform the same process, for example, some can be used as a diffusion furnace,
Others can be used as CVD furnaces.

In this embodiment, the number of times the dummy wafer 10 is used is limited to a number depending on the processing content. For example, in the case of diffusion processing, the contamination of the dummy wafer group 10 is relatively small, so the usage limit is set to several thousand times; In this case, the limited number of times of use is set to several times.

In addition to controlling the drive of the transfer drive unit 62 described above, the control unit 60 also determines whether the limited number of times the dummy wafer 10 can be used has been reached. That is, this control unit 60 controls the processing wafers 11 mounted on the boat 5.
Each time batch processing is completed, the number of uses is incremented, and after the processing is completed, a preset usage limit is read from the memory 64, and the current number of uses is compared with the usage limit. That's what I do. Then, only when the two counts match, a display, for example an alarm 68, is activated. Of course, the information may be communicated verbally or by a light display. The number of used patterns may be counted at the time of loading or unloading after wafer transfer.

Next, the effect will be explained.

The transport operation of the carrier cassette and the boat 5, and the wafer transfer operation between these two are as described above, so the description will be omitted. This will be explained with reference to the flowchart shown in the figure.

First, a setting for the limited number of times NL of use of the dummy wafer 10 is inputted (step 1). The setting input for the limited number of times of use NL is performed using, for example, a numeric keypad on the input section 66.
This will be carried out for every 5 boats. Then, the limited number of uses NL manually inputted via this human input 66 is stored in a predetermined area of the memory 64 via the control unit 60. Thereafter, the control unit 60 sets the number of processing times N of each boat 5 to its initial value 0 (Step 2), and sets this to each boat 5 in the memory 6.
Store in 4.

After the initial operation as described above is completed, heat treatment of the processing wafers 10 in each carrier cassette is started. Here, in the case of the apparatus of this embodiment, one common wafer transfer device 3 is used for the multi-stage furnace 7 having four stages, so a dedicated boat 5 corresponding to each stage is used. The wafer transfer device 3 sequentially transfers wafers at different times, and the boat 5 transfers the wafers to each stage of process tubes.

The unloading operation of the boat 5 carrying the group of processed wafers 11 is also carried out at different times for each stage, so that even when the boat 5 is unloading, one boat 5 It will be set in the transport device 4.

In this way, the boat 5 carrying the processed wafer group 11 is set on the boat transport device 4, and
When the boat 5 is set at the wafer transfer position by driving the boat transport device 4, the controller 60 recognizes that the process has ended through detection by a sensor (not shown) (step 3).

When the control section 60 recognizes that the heat treatment has been completed for one boat 5, the control section 60 increments the number of processing times N set as an initial value and sets it to N-N+1 (step 4). Next, the control unit 60 reads the newly set number of processing times N and the limited number of times NL of use for this boat 5 stored in advance in the memory 64, and compares the two numbers of times (step 5)
.

At this time, since this is the first processing, the number of processing times for the boat 5 will not reach the usage limit number NL, so the process returns to before step 3 and waits for the next processing to end.

The above operation flow is performed for each boat 5 corresponding to each process tube of the multistage furnace 7, and it is determined whether or not the number of times of use N, which is preset for each boat 5, has been reached. .

By repeatedly processing the boat 5 carrying the same dummy wafer group 10 in the process tube, the nil limit number of times of use can be achieved, especially when the amount of reaction products is large, such as in CVD. Since the number of times is set relatively small, the state of NL-N is detected first in step 5. In this way, when the control unit 6,0 detects that the determination in step 5 has been established, the control unit 60 issues a warning to the operator by driving the alarm 68 ( Step 6).

This warning allows the operator to recognize that it is time to replace the dummy wafer group 10 mounted on the boat 5.
The dummy wafer group 10 is removed and a new dummy wafer group 10 is mounted. After the replacement process of the dummy wafer group 11 is completed, for example, by operating a reset switch provided in the input section 66, this operation input signal is manually inputted to the control section 6o, and this operation input signal is manually inputted to the control section 6o. In the result control unit 60, dummy wafer group 1
It is possible to detect that the 0 exchange operation has ended (
Step 7). After this, the process returns to step 2, and the number of processing times N for the boat 5 in which the dummy wafer group 10 was exchanged is initialized to its initial value of 0. From then on, in the same manner as described above, from step 3 Step 7
The operation will be repeated.

As explained above, according to this embodiment, the limited number of times of use for the eight dummy thread groups 10 mounted on the boat 5 is registered in advance, and each time the processing for this boat 5 is completed, The current number of times N of processing has been completed is compared with the limited number of times of use NL, and only when the two match, the operator can be warned that it is time to replace the dummy wafer group 10. Therefore, the operator can reliably recognize the appropriate replacement time without having to pay any attention to the recognition of the replacement time, which conventionally relies on the operator's experience and memory.

Next, another embodiment of the present invention, particularly an embodiment in which the usage limit NL is automatically set by the host CPU, will be described with reference to FIGS. 7 and 8.

First, host C, which controls each operation of the semiconductor manufacturing process,
A PU 70 is provided, and the host CPU 70 controls not only the heat treatment apparatus of the embodiment, but also all of the semiconductor manufacturing processes that are the pre-process and post-process. Therefore, this host CPU 70
Regarding the control of the heat treatment apparatus described above, the operator knows all processing lots for each boat 5 corresponding to each stage of process tubes. Therefore, in the embodiment described above, the limit number of uses NL was set by input from an operator who knows about the processing loft.
In this embodiment, regarding the setting of the usage limit number NL,
It can be executed by the host CPU 70.

This host CPU 70 is connected to a CPU 72 that controls the entire heat treatment apparatus that is the apparatus of this embodiment.
Based on input commands from the host CPU 70, this CPU 72 controls various operations such as carrying in and out of carrier cassettes from the stacker 2, driving the wafer transfer device 3, transporting the boat transporting device 4, and driving the elevator 6. It is supposed to be in charge.

On the other hand, as shown in FIG. 8, the control system within the heat treatment apparatus includes a control section 60, a transfer drive section 62. Memory 64. It has an input section 66 and an alarm 68. Here, the difference from the above embodiment is that the setting of the limited number of uses NL is not performed based on the operation input from the input unit 66, but a command from the host CPU 70 is input to the control unit 60 via the CPU 72. This is what we are doing. Therefore, the input section 66 shown in FIG. 8 does not require a function for manually operating the limited number of times NL of use, but only a reset switch operated after the exchange of the dummy wafer group 10 is completed, for example. What you have is fine.

Further, the present embodiment device differs from the control system of the above embodiment device in that a display section 69 connected to the control section 60
The point is that it has been established.

Next, the operation of this embodiment device will be explained.

The difference in the operation of the apparatus of this embodiment from that of the above-mentioned embodiments is that the limit number of uses NL is set in step 1 shown in FIG. 2 based on a command from the host CPU 70. That is, as mentioned above, the host CPU 70 knows all the processing lots of wafers loaded on each boat 5, and by knowing the processing contents in this way, it can set the usage limit number NL according to the processing contents. Settings are possible. After completing the setting of the usage limit N, based on the command from the host CPU 70, (
Step 1), by performing the operations from Step 2 to Step 7 similar to the above embodiment based on the operation of the control unit 60, the dummy wafer group 10 mounted on the boat 5 is It is possible to send out a warning that it is time for replacement. Moreover, compared to the case where the usage limit number NL is set by the operator's operation input as in the above embodiment, in the case of this embodiment, the usage limit number NL is set without requiring human intervention. It is possible to prevent human errors that tend to occur at this stage. Therefore, reliability regarding the timing of replacing the dummy wafer group 10 can be further improved.

Moreover, since the apparatus of this embodiment has a display unit 69 connected to the control unit 60, the display unit 69 displays the current number of processing completions for the dummy wafer group 10 mounted on the boat 5.
can be displayed.

As a result, the operator can check the number of times on the display 69 screen at any time. The advantage of being able to perform this type of confirmation operation is that the operator is not always in the vicinity of the transfer device 3, but must also monitor other parts of the equipment, and can immediately remove the dummy wafer after the alarm sounds. In order to perform the replacement operation of group 10, it is preferable to be able to recognize in advance when this alarm will sound. Therefore, as mentioned above, the number of times the dummy wafer group 10 is used is displayed on the display section 6.
9, it is possible to check whether or not it is almost time to replace the dummy wafer group 10. If the time for replacement is near, the dummy wafer group 10 is placed on standby near the wafer transfer device 3 in advance. This makes it possible to carry out the above-mentioned process quickly.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention.

For example, in the above embodiment, one wafer transfer device W3 is used in common for a plurality of heat treatment furnaces, but the same can be applied to a case where the wafer transfer device 3 and the heat treatment furnaces are in a 1:1 relationship. It is.

Further, in the above embodiment, the present invention is applied to a processing apparatus for heat-treating semiconductor wafers, but the object to be processed and the type of processing thereof are not limited thereto, and at least the object to be processed and the dummy object are It is possible to apply the present invention to various applications in which a processing body is mounted in a processing container and subjected to batch processing.

[Effects of the Invention] As explained above, according to the present invention, a limit on the number of times the dummy processing object can be used is set in advance regarding the time to replace the dummy processing object that is mounted in a processing container and used repeatedly. A warning is issued when the number of times the dummy object is processed reaches the usage limit, and this time is automatically detected, so the replacement operation described above can be performed without relying on the operator's memory. can be carried out appropriately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control system of a wafer transfer apparatus to which the present invention is applied, FIG. 2 is a flow chart showing the operation flow of the control system shown in FIG. 1, and FIG. FIG. 4 is a schematic explanatory diagram for explaining the overall configuration of the heat treatment apparatus including the transfer device, and FIG. 5 and 6 are respectively a front view and a side view of the wafer transfer device, and FIGS. 7 and 8 are detailed explanations of the present invention.
FIG. 8 is a block diagram showing the relationship between the PU and the heat treatment device, and FIG. 8 is a block diagram showing the control system within the wafer transfer device. 3... Processing object changing device, 5... Processing container (boat), 10... Dummy processing object, 11... Processing object, 6
0...Control section, 64...Memory, 66...Input section, 68...Alarm, 6...Display section, 70...
Host CPU, 72...CPU0 agent Patent attorney Inoue - (1 other person) Figure 1 6B Figure Cause Figure Figure

Claims (1)

[Claims] (1) In a transfer device that loads and removes objects to be processed by a processing object transfer device into a processing container in which a dummy object to be processed is loaded in advance, the processing container is set in advance for each processing content. 1. A transfer device comprising means for displaying that it is time to replace the dummy processing object when the number of times the dummy processing object has been used reaches the limit.