JPH0590388A - Transferring apparatus - Google Patents

Abstract

PURPOSE:To improve the operability of a diffusion furnace by automatically delivering a cassette to an external conveyor by a cassette stage of a transferring apparatus, providing a stocker for containing a plurality of cassettes, and always obtaining a preparation of a cassette to be primarily processed before processing. CONSTITUTION:A cassette 1 on a cassette stage 8 is conveyed to a predetermined position of a stocker 9 by a first conveying robot 101. A cassette 1a to be primarily processed contained in a section A of the stocker 9 is conveyed to a section X of a transfer stage 11 by a second conveying robot 12, and a semiconductor wafer 2 is transferred from the cassette 1a to a heat treating board 4 by a transfer unit 13. In the meantime, a cassette 1a to be next primarily processed is similarly conveyed and transferred to the other section Y on the stage 11, and transferred. The similar operation is repeated to end the transfer of the wafers 2 contained in the cassette 1a to be primarily processed and an inspection cassette 1d to the board 4, and the wafers 2 are diffused in a diffusion furnace 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for automatically transferring and transferring semiconductor wafers from an external transfer device to a processing furnace for impurity diffusion and heat treatment.

[0002]

2. Description of the Related Art FIGS. 4 and 5 are a front view and a plan view showing the structure of a conventional transfer device of this kind, and FIG. 6 is a perspective view showing a cassette for storing semiconductor wafers. In the figure,
Reference numeral 1 is a cassette for storing semiconductor wafers 2, 3 is a stocker for storing a plurality of these cassettes 1, 4 is a heat treatment having holding grooves (not shown) for holding several tens of semiconductor wafers 2 at equal intervals in a horizontal state A boat 5 is an elevator for feeding the heat treatment boat 4 into the diffusion furnace 6, and 7 is a transfer machine for transferring the semiconductor wafers 2 in the cassette 1 housed in the stocker 3 to the heat treatment boat 4 by vacuum suction. The semiconductor wafers 2 are handled one by one by means such as the like, and as shown by the arrows in the figure, a traveling operation (arrow X), an ascending / descending operation (arrow Z), a forward / backward operation (arrows Y ₁ , Y ₂ ). , A transfer hand 7a capable of turning motion (arrow θ).

Next, the operation of the conventional transfer device configured as described above will be described. First, an operator inserts a production cassette in which a semiconductor wafer that can actually be a product is stored, into the stocker 3 at a predetermined position. In addition, as shown in the figure, six cassettes 1 are stored in the stocker 3, but four of them are production cassettes, and
One is an inspection cassette for storing the process inspection wafers, and the other one is a recovery cassette for recovering the inspection wafers after the processing is completed. The cassette 1 is placed in the stocker 3 in such a manner that the semiconductor wafer 2 is horizontal and the wafer take-out surface of the cassette 1 faces inward.

When the start switch is pressed in this state, first, the transfer machine 7 makes a traveling motion in the direction of arrow X so that the transfer hand 7a is located in front of the cassette to which the transfer hand 7a is first transferred. Next, the semiconductor wafer 2 in the cassette 1
Since the taking-out order is generally performed sequentially from the lower side of the cassette 1, the transfer hand 7a moves forward in the direction of the arrow Y ₁ and is moved below the lowermost semiconductor wafer 2 of the desired cassette 1. invade. After completion of the forward movement, the semiconductor wafer 2 is slightly lifted in the direction of arrow Z to levitate the semiconductor wafer 2 from the groove of the cassette 1 and at the same time sucked by vacuum. Wafer 2
When sucked, the transfer hand 7a moves backward in the direction of the arrow Y ₂ to return to the original position, and turns in the direction of the arrow θ to horizontally flip 180 °.

Next, the transfer machine 7 performs a traveling operation in the direction of arrow X so that the transfer hand 7a is located in front of the heat treatment boat 4. Since the order of inserting the semiconductor wafers 2 into the heat treatment boat 4 is generally from the upper side of the heat treatment boat 4, the transfer hand 7a is not included in the semiconductor wafer 2
After performing an ascending (descending) operation in the arrow Z direction so that the groove and the groove (not shown) of the heat treatment boat 4 coincide with each other, the arrow Y ₂
Move forward in the direction. Then, after the advancing operation is completed, the vacuum suction is released and the minute descending operation is performed in the arrow Z direction, so that the semiconductor wafer 2 is transferred to the groove of the heat treatment boat 4. Next, the transfer hand 7a moves in the direction of the arrow Y ₂ to return to the original position, and makes a turning motion in the direction of the arrow θ to horizontally flip 180 °. With the above operation, the transfer operation of one semiconductor wafer 2 from the cassette 1 to the heat treatment boat 4 is completed, and by repeating this operation, all the semiconductor wafers 2 in the cassette 1 are stored in the heat treatment boat 4. Are sequentially transferred to. In this case, a plurality of inspection wafers are also transferred to a predetermined position of the heat treatment boat 4 by the same operation.

When the above transfer operation is completed, the elevator 5 rises and the heat treatment boat 4 is inserted into the diffusion furnace 6 to start the diffusion process. Then, when the diffusion process in the diffusion furnace 6 is completed, the elevator 5 descends and the heat treatment boat 4 is taken out of the diffusion furnace 6, which is the reverse of the above-described transfer operation from the cassette 1 to the heat treatment boat 4. Then, the transfer operation of the semiconductor wafer 2 from the heat treatment boat 4 to the cassette 1 is started. Here, the semiconductor wafer 2 is stored in the stocker 3
The inspection wafer is returned to the original groove of the original cassette 1 in the inside. When all of the semiconductor wafers 2 in the heat treatment boat 4 are returned to the predetermined cassette 1 in the stocker 3, the worker ejects the semiconductor wafers 2 from the stocker 3 and extracts the inspection wafer from the recovery cassette to verify the diffusion process. After that, the production cassette is sent to the next step.

[0007]

Since the conventional transfer device is configured as described above, the storage capacity of the stocker 3 is low and the operation rate of the diffusion furnace 6 is lowered, so that the worker is required to operate the diffusion furnace 6. There was a problem that the cassette 1 had to be put in and taken out while continuously monitoring the operation status of the.

The present invention has been made to solve the above problems, and provides a transfer device capable of significantly improving the operation rate of a diffusion furnace and automating the loading and unloading of cassettes. The purpose is.

[0009]

[Means for Solving the Problems] Claim 1 according to the present invention
The transfer device can store at least as many semiconductor wafer cassettes as can accommodate at least one semiconductor wafer throughput, and can accommodate a plurality of cassette stages and cassette stages for exchanging cassettes with external transfer equipment. Stocker and a transfer stage, which is arranged between the stocker and a processing boat that accommodates semiconductor wafers by a processing amount for one time and introduces the semiconductor wafers into the processing furnace, on which at least two cassettes can be placed, and a cassette stage. First cassette carrying means for carrying the upper cassette to the stocker, second cassette carrying means for carrying the cassette in the stocker to the transfer stage, and semiconductor wafers in the processing boat from inside the cassette on the transfer stage. And a wafer transfer means for transferring the wafer. The transfer device according to claim 2 is the transfer device according to claim 1, wherein A production cassette that stores semiconductor wafers of a throughput of at least two times, a dummy cassette that stores dummy wafers to supplement the shortage of the production cassette, and an inspection cassette that stores inspection wafers for process verification. And a recovery cassette for recovering the inspection wafer after processing.

[0010]

The cassette stage of the transfer device according to the present invention automatically transfers the cassette to and from the external carrier device, and the stocker stores a plurality of cassettes, so that the unprocessed production cassette is always processed. Secure.

[0011]

EXAMPLES Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a plan view, respectively, showing the configuration of a transfer device according to a first embodiment of the present invention. In the figure, a cassette 1, a semiconductor wafer 2,
The heat treatment boat 4, the elevator 5 and the diffusion furnace 6 are shown in FIG.
The same as that of the conventional device in. Reference numeral 8 denotes a cassette stage for loading and unloading the cassette 1 with an external carrier (not shown) or an operator, and the cassette stage 8 can store at least one processing amount of the semiconductor wafer 2. The number can be placed. 9 is a stocker, and as shown in FIG. 3, the production cassettes 1a and 1b for two diffusion treatments are provided in the parts A and B, respectively.
Further, a dummy cassette 1c for supplementing the shortage of the production cassettes 1a and 1b is provided in the C section, and an inspection cassette 1d for accommodating an inspection wafer for process verification is further provided in the D section. In the E section, recovery cassettes 1e for recovering the inspection wafers after the completion of the diffusion process are housed, respectively.

Reference numeral 10 is a cassette 1 on the cassette stage 8.
Is transferred to the stocker 9 and is stored in the respective parts shown in FIG. 3, 11 is a transfer stage on which at least two cassettes 1 can be placed, and 12 is each cassette 1a-in the stocker 9. A second transfer robot that transfers 1e onto the transfer stage 11 in a predetermined order, 1
A transfer machine 3 transfers the semiconductor wafers 2 in the cassette 1 on the transfer stage 11 into the heat treatment boat 4, and has the same function as the transfer machine of the conventional apparatus in FIG.

Next, the operation of the transfer apparatus according to the first embodiment having the above-mentioned structure will be described. First, the cassette 1 is loaded onto the cassette stage 8 by an external carrier or an operator. Since the loaded cassette 1 is placed with the semiconductor wafer 2 standing vertically, the handling is facilitated when the semiconductor wafer 2 is transferred to the heat treatment boat 4 by the transfer machine 13. Then, the cassette stage 8 is tilted by 90 ° by a mechanism (not shown) so that the semiconductor wafer 2 becomes horizontal in the cassette 1 as shown by the one-dot chain line in the figure.

Next, the cassette 1 is handled by the first transfer robot 10 and transferred to a predetermined position (A portion) of the stocker 9. Now heat treatment boat 4
If the semiconductor wafer 2 is ready for receiving, the wafer transfer operation is automatically started. First, the second transfer robot 12 handles one production cassette 1a stored in the A section of the stocker 9 and transfers it to the X section of the transfer stage 11 shown in FIG. And the transfer machine 1
The production cassette 1a on the transfer stage 11 depending on 3.
The transfer of the semiconductor wafers 2 from the inside to the heat treatment boat 4 is sequentially taken out from the lower semiconductor wafer 2 in the production cassette 1a and sequentially inserted from the upper groove of the heat treatment boat 4 as in the conventional apparatus. Done.

While the transfer operation is being performed, the other Y part on the transfer stage 11 is empty, so that the second transfer robot 12 continues to stock the next production cassette 1a. 9 part A to transfer stage 11 Y
To the department. Then, when the transfer of the semiconductor wafers 2 in the first production cassette 1a placed in the X section of the transfer stage 4 is completed, the transfer machine 13 continues to store the second production cassette 1a in the Y section. The transfer operation of the semiconductor wafer 2 is started. At the same time, an empty production cassette 1 in the X section
a is A of the stocker 9 by the second transfer robot 12.
The second transfer robot 12 transfers the third production cassette 1a from the A section of the stocker 9 to the X section of the transfer stage 11 after being returned to the original position of the section.

By repeating the above operation,
Production cassettes 1a and D stored in section A of stocker 9
After the transfer of the semiconductor wafers 2 stored in the inspection cassette 1d stored in the unit is completed, the heat treatment boat 4 is guided into the diffusion furnace 6 by the elevator 5 and the diffusion process is started. If the number of semiconductor wafers 12 in the production cassettes 1a and 1b are all transferred and the amount of the semiconductor wafers 12 is less than one diffusion process, the dummy cassette 1c is used.
The transfer to the heat treatment boat 4 is performed in the same manner as a and 1b.

When the diffusion process in the diffusion furnace 11 is completed,
The elevator 5 descends, and the processed semiconductor wafer 2 in the heat treatment boat 4 is returned to the original groove of the original cassette of the stocker 9 except for inspection. First, since this returning operation is sequentially performed from the semiconductor wafer under the heat treatment boat 4, the corresponding empty cassette 1a in the A section of the stocker 9 is transferred by the second transfer robot 12 to the transfer stage 1.
Then, the transfer device 13 starts the wafer returning operation. In parallel with this operation, the second transfer robot 12
Transports the corresponding empty cassette 1a next to the A section in the stocker 9 to the Y section of the transfer stage 11.

When the cassette 1a in the X section is filled with the semiconductor wafers 2, the second transfer robot 12 operates the cassette 1a.
a is conveyed to the A section of the stocker 9, and then the third empty cassette 1a is conveyed to the X section of the transfer stage 11. By repeating the above operation, all the production wafers are returned to the production cassette 1a in the stocker 4, and the inspection wafers are returned to the collection cassette 1e, and the transfer operation is completed.

If the actual cassette 1b to be subjected to the next diffusion processing is stored in the B section of the stocker 9 during the operation so far, the semiconductor wafers 2 are continuously transferred to the heat treatment boat 4.
And the diffusion process of the diffusion furnace 6 can be performed, so that the operation rate of the diffusion furnace 6 is improved. In addition, in parallel with the transfer operation of the next stored production cassette 1b, the first transfer robot 10
As a result, it is possible to dispense the recovery cassette 1e in which the inspection wafer of the E part in the stocker 9 has been recovered, and subsequently the production cassette 1a of the A part. Therefore, the diffusion process verification by the inspection wafer, the production cassette The progress to the next step of 1a can be swiftly achieved.

Example 2. In the first embodiment,
The cassette 1 on the cassette stage 8 is placed in a state in which the semiconductor wafer 2 to be stored stands vertically, but the semiconductor wafer 2 is placed in a horizontal position by changing the function of the external carrier. If set, the cassette stage 8 can be set to 9
Needless to say, there is no need to incline by 0 °, and the same effect as in Example 1 is obtained.

[0021]

As described above, according to the first aspect of the present invention, the number of cassettes for storing semiconductor wafers can be set at least as large as the amount of processing for one semiconductor wafer can be stored, and external cassettes and cassettes can be installed. At least two cassette stages are provided for transferring and receiving, a stocker capable of accommodating a plurality of cassettes, and a stocker and a processing boat for accommodating a semiconductor wafer of a processing amount for one time and guiding the semiconductor wafer into a processing furnace. A transfer stage on which a cassette can be placed and a first stage that conveys the cassette on the cassette stage to a stocker
Cassette transport means, second cassette transport means for transporting the cassette in the stocker to the transfer stage, and wafer transfer means for transferring the semiconductor wafer from the cassette on the transfer stage to the processing boat. , And claim 2
According to claim 1, in the stocker, the process verification is performed on the production cassette that stores the semiconductor wafers of the processing amount of at least two times, the dummy cassette that stores the dummy wafers to supplement the shortage of the production cassette. Since the inspection cassette for storing the inspection wafer and the recovery cassette for recovering the inspection wafer after processing are accommodated, the operation rate of the diffusion furnace is significantly improved and the cassette is loaded. It is possible to provide a transfer device capable of automated payout.

[Brief description of drawings]

FIG. 1 is a front view showing a configuration of a transfer device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a transfer device in FIG.

FIG. 3 is a diagram showing a storage state of a cassette in a stocker that constitutes a main part of the transfer device in FIG.

FIG. 4 is a front view showing a configuration of a conventional transfer device.

5 is a plan view showing the configuration of the transfer device in FIG.

FIG. 6 is a perspective view showing a configuration of a cassette applied to a transfer device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 cassette 1a, 1b production cassette 1c dummy cassette 1d inspection cassette 1e recovery cassette 2 semiconductor wafer 4 heat treatment boat 6 diffusion furnace (processing furnace) 8 cassette stage 9 stocker 10 first transfer robot (first cassette transfer means) ) 11 transfer stage 12 second transfer robot (second cassette transfer means) 13 transfer machine (wafer transfer means)

Claims (2)

[Claims] 1. A cassette stage for storing semiconductor wafers, the cassette stage being capable of mounting at least a number of semiconductor wafers capable of storing a throughput of one semiconductor wafer, and a cassette stage for exchanging the cassettes with an external carrier, and a plurality of the cassettes. A possible stocker, and a transfer stage which is arranged between the stocker and a processing boat that accommodates the semiconductor wafer in a processing amount for one time and introduces the semiconductor wafer into the processing furnace and on which at least two cassettes can be mounted. A first cassette carrying means for carrying the cassette on the cassette stage to the stocker, a second cassette carrying means for carrying the cassette in the stocker to the transfer stage, and a second cassette carrying means on the transfer stage. Wafer transfer means for transferring the semiconductor wafer from the cassette to the processing boat is provided. Transfer device. 2. The stocker comprises a production cassette for storing semiconductor wafers having a throughput of at least two times, a dummy cassette for storing dummy wafers for replenishing a shortage of the production cassette, and an inspection for process verification. 2. The transfer device according to claim 1, further comprising: an inspection cassette that stores wafers; and a collection cassette that collects the inspection wafers after processing.