JPH11121583A - Semiconductor wafer transfer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a semiconductor wafer from increasing in transfer time by a method, wherein high stokers where semiconductor wafers in production process are housed are arranged at each of semiconductor treating processes, semiconductor wafers required to be subjected to semiconductor treating processes are supplied to the high stokers, and the semiconductor wafers subjected to a semiconductor treatment are housed in the high stocker. SOLUTION: A semiconductor wafer transfer system is equipped with loop- type transfer lines 1a and 1b provided in a clean room 4a and loop-type transfer lines 1c and 1d provided on the ceiling 4b of the clean room 4a making right angles with the transfer lines 1a and 1b, whereby delays in the transfer of the semiconductor wafers can be lessened reducing a transfer lead time for any transfer carried out between loop lines to an irreducible minimum. Furthermore, even if three or more loop-type transfer lines are provided inside the clean room 4a on a request for a higher transfer capacity, one or more loop-type transfer lines are provided on the ceiling 4b of the clean room 4a, making right angles with the transfer lines which have been previously provided inside the clean room 4a, whereby delays in transfer of the semiconductor wafers between any loop-type transfer lines can be lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor wafer transfer system for transferring a semiconductor wafer between semiconductor processing steps in a semiconductor manufacturing line.

[0002]

2. Description of the Related Art Conventional semiconductor wafer transfer systems include:
The number of work-in-progress (the number of work-in-progress semiconductor wafers) determined by the production period required for all semiconductor processing steps and the number of semiconductor wafers put into the daily semiconductor production line were all stored in stockers for each semiconductor processing step installed in the clean room. . Further, since the conventional semiconductor production line has a small production capacity, the number of required loops of a loop-type transfer line installed in a clean room is two or less. An example of such a transport system is described in JP-A-6-199419.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to increase the number of semiconductor manufacturing apparatuses introduced in order to improve the production volume in a semiconductor production line. Since the in-process amount of semiconductor wafers also increases, if all the in-process semiconductor wafers are stored in a stocker for each semiconductor processing step installed in a clean room as in a conventional semiconductor wafer transfer system, the total installation area in the clean room will increase. There is a problem that a predetermined number of semiconductor manufacturing apparatuses cannot be introduced.

For this reason, a high-rise stocker for storing the number of in-process products (the number of in-process semiconductor wafers) determined by the production period required for all the semiconductor processing steps and the number of semiconductor wafers put into a daily semiconductor production line is stored in the clean room above the ceiling and in the clean room. And penetrates under the floor of the clean room, and is arranged for each semiconductor processing step, thereby minimizing the installation area of the high-rise stocker in the clean room and increasing the number of semiconductor manufacturing apparatuses introduced, thereby improving the productivity of the semiconductor manufacturing line.

Another object of the present invention is to improve the production capacity of a semiconductor manufacturing line, the number of semiconductor manufacturing apparatuses increases, the clean room itself becomes large-scale, and the required transfer capacity of a semiconductor wafer transfer system increases. However, the conventional loop-type transfer lines of 2 or less have a problem in that the transfer capability is insufficient, and when the number of loop-type transfer lines is increased, the transfer lead time exceeds the average tact time of the semiconductor manufacturing apparatus, and the productivity is reduced. .

For this reason, the required number of loop-type transfer lines is three.
In the above case, a loop-type transfer line in a clean room and a loop-type transfer line in the same direction or orthogonal to the loop-type transfer line are provided in the clean room or behind the ceiling of the clean room or under the floor of the clean room, and the loop-type transfer line is provided via a high-rise stocker. And the orthogonal loop-type transfer lines are connected to reduce the number of loop-type transfer lines used for transfer between the high-rise stockers to 3 or less to satisfy the transfer capability required for the semiconductor wafer transfer system and prevent an increase in transfer lead time.

[0007]

In order to achieve the above-mentioned object, the present invention relates to a production work in progress (a production work in progress semiconductor) which is determined by a production period required for all semiconductor processing steps and a daily number of semiconductor production lines. The high-rise stocker that stores the number of wafers passes through the back of the clean room, the inside of the clean room, and the bottom of the clean room, and is placed for each semiconductor processing step. By supplying to the high-layer stocker installed for each semiconductor processing step using the loop-type transfer line to be arranged, and by storing the semiconductor wafers for which semiconductor processing has been completed in the high-layer stocker in the same procedure as when supplying. Can be reached.

In addition, when the required number of loop-type transfer lines is 3 or more, which is a value obtained by dividing the transfer capacity of the entire semiconductor wafer transfer system (the number of transfers per unit time) by the transfer capacity of the one-loop transfer line, the clean room A loop-type transfer line and a loop-type transfer line in the same direction or orthogonal to the loop-type transfer line are provided in a clean room or behind a clean room ceiling or a clean room floor, and the same direction as the loop-type transfer line through a high-rise stocker or This is achieved by connecting orthogonal loop-type transport lines and reducing the number of loop-type transport lines used for transport between high-rise stockers to three or less.

That is, according to the present invention, the number of in-process products (the number of in-process semiconductor wafers) determined from the production period required for all semiconductor processing steps and the number of daily inputs to the semiconductor production line.
The high-rise stocker that stores the wastewater passes through the ceiling of the clean room, inside the clean room, and under the clean room floor, and is placed for each semiconductor processing step, minimizing the installation area of all stockers in the clean room and the number of semiconductor wafers required for the semiconductor processing step. Is supplied to a high-rise stocker installed for each semiconductor processing step using the loop-type transfer line arranged under the ceiling, in a clean room or under the floor of a clean room, and the same as when supplying a semiconductor wafer on which semiconductor processing has been completed. It can be transported to the high-rise stocker by a procedure.

In addition, when the required number of loop-type transfer lines is 3 or more, which is a value obtained by dividing the transfer capability (the number of transfers per unit time) of the entire semiconductor wafer transfer system by the transfer capability in a one-loop transfer line, the clean room A loop-type transfer line and a loop-type transfer line orthogonal to the loop-type transfer line are provided in a clean room or behind a clean room ceiling or a clean room floor, and the loop-type transfer line is orthogonal to the loop-type transfer line via a high-rise stocker. By setting the number of loop-type transfer lines used for transfer between the high-rise stockers to 3 or less, the transfer capability required for the semiconductor wafer transfer system can be satisfied, and an increase in transfer lead time can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIGS. 1A, 1B and 1C show layout diagrams of a semiconductor wafer transfer system according to the present invention. In FIG. 1, 12 semiconductor processing steps 3a1 to 3a12 are allocated to a semiconductor manufacturing line in a clean room 4a.
2 is provided with a semiconductor manufacturing apparatus, which is provided with a clean room floor 4c for supplying utilities of the semiconductor processing apparatus and an air filter for collecting a certain amount of foreign substances in the air used in the final stage of air supply to the clean room. A clean room ceiling 4b is provided. The semiconductor wafer transfer system already has a mechanism for maintaining cleanliness in low cleanliness environments such as the underside of the clean room floor 4b and the clean room floor 4c.

In each of the processing steps 3a1 to 3a12 as a semiconductor wafer transfer system, the high-rise stockers 2a1 to 2a12 are installed through the clean room ceiling 4b, the clean room 4a, and the clean room floor 4c for temporarily storing semiconductor wafers. Twelve units and each of the above-mentioned processing steps 3a installed on the ceiling of the clean room 4a
1 to 3a12, that is, high-rise stockers 2a1-2a12
Loop-type transfer lines 1a to 1b for connecting between and transferring semiconductor wafers, and the loop-type transfer lines 1a to 1b
b, a loop-type transfer line 1c-1d for connecting the high-rise stockers 2a1-2a12 and transferring the semiconductor wafers, which is installed on the back of the ceiling 4b of the clean room and a clean room in parallel with the loop-type transfer lines 1a-1b. It comprises loop-type transfer lines 1e to 1f installed under the floor 4c for connecting the high-rise stockers 2a1 to 2a12 and transferring semiconductor wafers.

In the present invention, the high-rise stockers 2a1-2
a12 is a minimum capacity for storing the minimum number of semiconductor wafers determined by the processing capacity of the semiconductor processing apparatus installed in each of the processing steps 3a1 to 3a12, and the total of twelve high-rise stockers 2a1 to 2a12 is It has a storage capacity capable of temporarily storing the number of in-process products (the number of in-process semiconductor wafers) determined by the production period required for the semiconductor processing step and the number of daily inputs to the semiconductor production line.

If the ratio of the height of the clean room 4a, the height of the back of the clean room 4b, and the height of the clean room floor 4c is 1: 1: 1, the installation area of the high-rise stocker is smaller than that of the conventional stocker. And the length of the high-rise stocker is about 3 times that of the conventional stocker.
Because it is 3%, the installation area of all high-rise stockers is about 33%
Is reduced to For this reason, the reduced area of about 67% can be used for the installation of the semiconductor manufacturing apparatus, and the number can be increased, so that the production amount of the semiconductor production line can be improved.

FIGS. 2A, 2B and 2C show a layout of a conventional semiconductor wafer transfer system. In FIG. 2, a loop-type transfer line 1 similar to FIG.
This is a semiconductor wafer transfer system including three lines 0a, 10ab, and 10b. In the conventional semiconductor wafer transfer system, a loop transfer line 10ab is further required to connect the loop transfer lines 10a to 10b. For this reason, for example, the stocker 20a1
When transporting the semiconductor wafer to 0a12, it is necessary to transport the semiconductor wafer across the loop transport lines 10a → 10ab → 10c.

The average processing time of the semiconductor manufacturing apparatus is about 30
Assuming that a transport lead time of about 20 minutes is required for transport over two loops, the transport lead time in the semiconductor wafer transport from the stocker 20a1 to the stocker 20a12 is three in this example. It will take about 30 minutes. If a higher transfer capacity is required and the number of loop-type transfer lines becomes 5, the transfer lead time for transferring semiconductor wafers across 5 loops takes about 50 minutes, and the semiconductor wafers required for processing by the semiconductor processing apparatus are delayed and cannot be started. However, there is a problem that the production amount of the semiconductor production line is reduced.

For this reason, FIG.
In the semiconductor wafer transfer systems (b) and (c), loop-type transfer lines 1a and 1b are provided in a clean room 4a, and loop-type transfer lines 1c and 1b, which are orthogonal to the loop-type transfer lines 1a and 1b, are provided behind the ceiling of the clean room 4b. 1d
Is provided, it is possible to reduce the transfer delay of the semiconductor wafer by keeping the transfer lead time within the time span between the two loops in the transfer between any loops. Even when three or more loop-type transfer lines are provided in the clean room 4a due to a demand for a higher transfer capacity, by providing one or more loop-type transfer lines orthogonal to the back of the clean room ceiling 4b, the transfer lead time can be obtained for any transfer between loops. Can be reduced to a time spanning three loops, thereby reducing the delay in transporting the semiconductor wafer.

If a high transfer capacity is required in the same direction as the loop transfer lines 1a and 1b installed in the clean room 4a as shown in FIG. 1 according to the transfer capacity of the entire semiconductor wafer, the clean room Loop transport lines 1e and 1f in the same direction as the loop transport lines 1a and 1b installed in the clean room 4c are provided below the clean room floor 4c. Otherwise, the loop transport lines 1e are provided.
By providing only the loop-type transfer line 1f or only the loop-type transfer line 1f, it is possible to cope with high transfer capacity and improve cost performance.

Further, if a high transfer capacity is required in a direction orthogonal to the loop transfer lines 1a and 1b installed in the clean room 4a in accordance with the transfer ability of the entire semiconductor wafer, the above-mentioned installation in the clean room 4a is required. High-conveyance is provided by providing loop-type transfer lines 1e, 1f in the direction perpendicular to the loop-type transfer lines 1a, 1b under the floor 4c of the clean room, otherwise providing only the loop-type transfer line 1e or only the loop-type transfer line 1f. It is possible to cope with the ability and improve cost performance.

[0021]

As described above, according to the present invention, the number of in-process products (the number of in-process semiconductor wafers) determined from the production period required for all semiconductor processing steps and the number of daily inputs to the semiconductor production line is stored. The high-rise stocker that passes through the ceiling of the clean room, inside the clean room and under the floor of the clean room, and arranges each semiconductor processing step, and sets the number of semiconductor wafers required for the semiconductor processing step to the ceiling or inside the clean room or the floor below the clean room. The high-rise stocker in the clean room is supplied to the high-rise stocker installed for each semiconductor processing step by using a transport line, and is stored in the high-rise stocker in the same procedure as when supplying the semiconductor wafer after the semiconductor processing is completed. By minimizing the installation area and increasing the number of semiconductor manufacturing equipment introduced, It is possible to improve the productivity of the forming line.

When the required number of loop-type transfer lines is 3 or more, which is a value obtained by dividing the transfer capability (the number of transfers per unit time) of the entire semiconductor wafer transfer system by the transfer capability of the one-loop transfer line, the clean room A loop-type transfer line and a loop-type transfer line orthogonal to the loop-type transfer line are provided under the ceiling of a clean room or under a clean room floor, and the loop-type transfer line and the orthogonal-type loop transfer line are connected via a high-rise stocker. ,
By setting the number of loop-type transfer lines used for transfer between the high-rise stockers to 3 or less, the transfer capability required for the semiconductor wafer transfer system can be satisfied and an increase in transfer lead time can be prevented.

Further, when the transfer capacity of the loop-type transfer line in the clean room is insufficient, a loop-type transfer line in the same direction as the loop-type transfer line is provided under the ceiling of the clean room or under the floor of the clean room, and is connected via a high-rise stocker. Connect the loop-type transfer line and the loop-type transfer line in the same direction, reduce the number of loop-type transfer lines used for transfer between high-rise stockers to 3 or less, and satisfy the transfer capability required for the semiconductor wafer transfer system and transfer lead time Can be prevented from increasing.

Further, two or more loop-type transfer lines perpendicular to the loop-type transfer line are provided under the ceiling of the clean room or under the floor of the clean room, and the loop-type transfer line and the orthogonal loop-type transfer line are connected via a high-rise stocker. Then, the semiconductor wafer is transported using one of the different orthogonal loop-type transport lines so that the transport distance from the currently stored high-layer stocker to the next destination high-layer stocker becomes the shortest, so that the high-layer stocker The number of loop-type transfer lines used for transfer
It is possible to satisfy the transfer capability required for the semiconductor wafer transfer system and prevent the semiconductor wafer transfer lead time from increasing.

It should be noted that the present invention is not limited to the embodiment shown in FIG. 1, and the present invention can be applied to a case where a loop type track line in the same direction or orthogonal direction is installed in a clean room, behind a clean room ceiling, or below a clean room floor. Various forms can be changed without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layout of a semiconductor wafer transfer system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a layout of a conventional semiconductor wafer transfer system.

[Explanation of symbols]

1. Loop transport line 2. High-rise stocker 3. Processing step 4. Clean room.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hideaki Shimamura, Inventor, Semiconductor Division, Hitachi, Ltd. 5-2-1, Josuihoncho, Kodaira-shi, Tokyo No. 20-1, Hitachi Semiconductor Co., Ltd.Semiconductor Division (72) Inventor Fumito Wakiyama 6-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. No. 6 Inside Hitachi, Ltd.

Claims (1)

[Claims] 1. A clean room in which a semiconductor manufacturing apparatus is installed, a clean room floor for supplying a utility of the semiconductor manufacturing apparatus, and a certain amount of foreign matter in the air used in a final stage of air supply to the clean room. High-rise stocker for temporarily storing semiconductor wafers installed in a semiconductor production line consisting of the ceiling behind a clean room with air filters spread over it, and loop-type transportation for transporting semiconductor wafers between high-rise stockers installed in the ceiling of a clean room It consists of a line, a loop-type transfer line installed under the floor of the clean room for transferring semiconductor wafers between high-rise stockers, and a loop-type transfer line installed behind the clean room ceiling for transferring semiconductor wafers between high-rise stockers. All semiconductor processing in semiconductor wafer transfer system The high-rise stocker that stores the number of production processes (the number of production semiconductor wafers) determined by the required production period and the number of daily input to the semiconductor production line penetrates through the ceiling of the clean room, inside the clean room and under the clean room floor. It is arranged for each semiconductor processing step, and the number of semiconductor wafers required for the semiconductor processing step is supplied to a high-rise stocker installed for each semiconductor processing step using the loop-type transfer line arranged above the ceiling, in a clean room, or below the clean room floor. And, by storing the semiconductor wafers after the semiconductor processing in the high-rise stocker in the same procedure as when supplying, by increasing the number of semiconductor manufacturing equipment by minimizing the installation area of the stocker installed in the clean room, A semiconductor wafer transfer system characterized by improving the productivity of a semiconductor production line. Temu.