JPH0580825B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a mechanism for transporting a semiconductor substrate, for example, a mechanism for transporting a semiconductor substrate in a tank that requires an ultra-high vacuum such as a molecular beam epitaxy device. be.

[Background of the invention]

Molecular beam epitaxy has an ultimate pressure of 1.3×10 ^-8 Pa
It is a technique for forming high-quality thin film crystals on semiconductor substrates in an ultra-high vacuum, and has received particular attention in recent years because of its excellent controllability of thin film structures.

Fig. 2 is a schematic diagram showing a molecular beam epitaxy system having a conventional semiconductor substrate transfer device, and Fig.
4 is a perspective view showing a cassette of the semiconductor substrate transport mechanism shown in FIGS. 2 and 3. FIG. In the figure, 2 is a semiconductor substrate transfer chamber;
3 is a semiconductor substrate inlet provided in the transfer chamber 2;
4 is a semiconductor substrate processing chamber connected to the transfer chamber 2; 6;
a and 6b are gate valves provided between the transfer chamber 2 and the processing chambers 3 and 4;
are evacuated by independent vacuum pumps (not shown). Reference numeral 11 denotes a rail provided in the transfer chamber 2, and 10 indicates a transfer carriage that runs on the rail 11. The carriage 10 is driven by a motor or the like via a chain or the like. Reference numeral 9 denotes a cassette placed on a cart 10, and two cassettes 9 are placed on the cart 10. 8 is a plurality of semiconductor substrates loaded on one cassette 9; 12 is a plurality of bayonet pins provided on the peripheral surface of the substrate 8; 13 is a groove provided in the cassette 9; the pin 12 is engaged with the groove 13; ing. 7a, 7b are manipulators 5 which bring the substrates 8 loaded in one cassette 9 into the processing chambers 3, 4, take out the processed substrates 8 from the processing chambers 3, 4, and load them into the other cassette 9; is transport room 2
This is the semiconductor substrate export port provided in the.

In this molecular beam epitaxy apparatus, first, with the gate valves 6a and 6b closed, the inlet port 1 is
is opened, a plurality of substrates 8 are loaded into one cassette 9, this cassette 9 is put into the transfer chamber 2 through the inlet 1, and placed on the trolley 10. Next, inlet 1
After closing, the inside of the transfer chamber 2 is evacuated. Next, the cart 10 is moved to the front of the processing chamber 3, the gate valve 6a is opened, and the substrate 8 loaded in one cassette 9 is brought into the processing chamber 3 by the manipulator 7a, and the gate valve 6a is closed and the processing begins. After the chamber 3 is evacuated to ultra-high vacuum, the substrate 8 is processed. Next, the gate valve 6a is opened, and the processed substrate 8 is transferred to the processing chamber 3 by the manipulator 7a.
Take it out from inside and load it into the other cassette 9. After processing all the substrates 8 in the processing chamber 3,
The gate valve 6a is closed, the cart 10 is driven to the front of the processing chamber 4, and the substrate 8 is processed in the processing chamber 4 by the same operation as described above. Next, after all the substrates 8 have been processed in the processing chamber 4, the cart 10 is driven to the exit 5, the exit 5 is opened, and the cassette 9 loaded with the substrates 8 is taken out from the exit 5.

In this way, in the conventional semiconductor substrate transport mechanism, the cart 10 transports the cassettes 9 loaded with the substrates 8.
When a large number of substrates 8 are loaded on the cassette 9, the cassette 9 itself becomes large and weighs more, so the weight to be transported by the trolley 10 increases, and therefore the drive of the trolley 10 becomes more difficult. As the device becomes larger, the operability of the trolley 10 decreases.

[Purpose of the invention]

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a semiconductor substrate transport mechanism in which the weight to be transported by a transport vehicle is small.

[Summary of the invention]

In order to achieve this object, in the present invention, in a semiconductor substrate transport mechanism that transports the semiconductor substrate within a transport chamber connected to a processing chamber for processing semiconductor substrates, a rail is provided in the horizontal direction within the transport chamber, and the A transport vehicle running on rails is provided, a cassette that is vertically movable and within which the transport vehicle can run is permanently placed, and a plurality of horizontal shelves are provided inside the cassette.

[Embodiments of the invention]

FIG. 5 is a schematic diagram showing a molecular beam epitaxy apparatus having a semiconductor substrate transport mechanism according to the present invention, and FIG.
The figure is a cross-sectional view taken along line B-B in Figure 5, and Figure 1 is C in Figure 5.
-C sectional view, FIG. 7 is a DD sectional view of FIG. 1, and FIG. 8 is a perspective view showing a part of the semiconductor substrate transport mechanism shown in FIG. 1. In the figure, 14 is a vacuum chamber connected to the transfer chamber 2, 19 is a semiconductor substrate insertion opening provided in the vacuum chamber 14, 17 is a rail provided in the horizontal direction in the transfer chamber 2, and 16 is a section on the rail 17. The carriage 16 is a traveling carriage and is driven by a drive device (not shown). 15 is a cassette provided vertically movably within the vacuum chamber 14;
The cassette 15 is driven vertically by a drive device (not shown), and the abfe surface of the cassette 15
The cdhg surface has a large opening, and the carriage 16 travels inside the cassette 15 through the opening. 2
1 is a plurality of horizontal shelves provided inside the cassette 15; 20 is a plurality of openings provided on the ABCD surfaces of the cassette 15; The fork 18 enters the cassette 15 through the opening 20.

In this semiconductor substrate transfer mechanism, first, the semiconductor substrate 8 is placed on the fork 18, and then the fork 18 is inserted into the vacuum chamber 14 from the insertion port 19.
Further, it is introduced into the cassette 15 through the opening 20. Next, the substrate 8 is placed on the shelf 21 by raising the cassette 15 by a predetermined distance, that is, by a fixed amount, and then the fork 18 is retreated to the position shown in FIG. 1, and the cassette 15 is raised by a fixed amount.
The next opening 20 is positioned at a position where the fork 18 can enter. After repeating these operations to place the substrates 8 on all the shelves 21 of the cassette 15, the insertion port 19 is closed and the inside of the transfer chamber 2 and the vacuum chamber 14 are brought into a vacuum state. Next, after the trolley 16 is advanced into the cassette 15, the cassette 15 is lowered by a certain distance to load the substrates 8 placed on the lowest shelf 21 onto the trolley 16, and the trolley 16 is moved into the processing chamber 3. The substrate 8 on the trolley 16 is raised by a certain distance by a substrate lifting device (not shown) provided in the transfer chamber 2, the fork 29 is entered into the transfer chamber 2, and the substrate lifting device (not shown) is installed in the transfer chamber 2. By lowering the substrate 8, the substrate 8 is placed on the fork 29.
Next, open the gate valve 6a and
The substrate 8 is brought into the processing chamber 3 by the fork 2.
9 to its original position, close the gate valve 6a,
After the processing chamber 3 is evacuated to ultra-high vacuum, the substrate 8 is processed. Next, the gate valve 6a is opened, the processed substrate 8 is taken out from the processing chamber 3 into the transfer chamber 2 by the fork 29, and the substrate 8 on the fork 29 is raised by the substrate lifting device, and the fork 29 is returned to its original position. , lower the board 8 using the board lifting device, and
The board 8 is loaded on the trolley 16, and the board 8 is loaded on the trolley 16.
transport to the designated location. Such operations are repeated to sequentially process the substrates 8.

In this way, since the substrates 8 are transported one by one by the trolley 16, the weight to be transported by the trolley 16 is very small. Furthermore, the substrate lifting device and the fork 29 allow the substrate 8 to be supplied from the trolley 16 into the processing chamber 3 with a simple operation. Furthermore, since the cassette 15 does not need to be taken out into the atmosphere as in the conventional case and is permanently placed in the vacuum chamber 14, gas and water adhering to the surface of the cassette 15 escape as outgas within the vacuum chamber 14.
It does not make it difficult to reach the ultra-high vacuum region of the processing chamber 3.

FIG. 9 is a partial sectional view showing another molecular beam epitaxy apparatus having a semiconductor substrate transport mechanism according to the present invention, FIG. 10 is a sectional view taken along line E-E in FIG. 9, and FIG. -F sectional view. In the figure, 4
14a to 14c are vacuum chambers connected to the transfer chamber 2, and 15a to 15c are provided within the vacuum chambers 14a to 14c. The structure of cassettes 15a to 15c is similar to the structure of cassette 15 shown in FIG. 22a
22c is a pre-evacuation chamber connected to the vacuum chambers 14a-14c, and a cassette (not shown) is provided in the pre-evacuation chamber 22a-22c, and a lid (not shown) is provided. The substrate 8 can be placed in the cassette by opening the cassette, and the preliminary evacuation chambers 22a to 22c can be evacuated by independent vacuum pumps (not shown). 28a~
28c is the vacuum chamber 14a to 14c and the preliminary exhaust chamber 22
A gate valve provided between a to 22c, 1
Reference numerals 6a and 16b refer to conveyance carts 2 that run between the cassettes 15a and 15b and the cassettes 15b and 15c;
9a to 29c are forks that can enter into the processing chambers 3, 4a, and 4b.

In this semiconductor substrate transfer apparatus, the lid of the pre-evacuation chamber 22a is first opened, the substrate 8 is placed in a cassette within the pre-evacuation chamber 22a, the lid is closed, and the interior of the pre-evacuation chamber 22a is evacuated. Then, open the gate valve 28a and open the fork 18a.
The substrate 8 is transferred from the cassette in the preliminary evacuation chamber 22a to the cassette 15a. Next, the substrate 8 is transported to the front of the processing chamber 3 by the cart 16a, and the substrate 8 is brought into the processing chamber 3 by the fork 29a. Next, the substrates 8 that have been processed by the fork 29a are loaded onto the cart 16a, the cart 16a is driven to the cassette 15b, and the substrate 8 is placed on the shelf 21 by raising the cassette 15b by a certain amount. By repeating such operations, the substrate 8 that has been processed in the processing chamber 3 is placed on the shelf 21 of the cassette 15b. Next, the substrate 8 is transported to the front of the processing chambers 4a, 4b by the trolley 16b, brought into the processing chambers 4a, 4b by forks 29b, 29c, and the substrates that have been processed in the processing chambers 4a, 4b are placed in the cassette 15c. Place it on the shelf 21. Next, after evacuating the pre-evacuation chamber 22c, the gate valve 28c is opened, the fork 18c is advanced into the cassette 15c, and the cassette 15c is lowered by a certain distance to place the substrate 8 on the fork 18c, and the fork 18c is returned to its original position, and the substrate on the fork 18c is transferred to the cassette in the preliminary evacuation chamber 22c. By repeating such operations, the substrate 8 placed on the shelf 21 of the cassette 15c
After all of the gas is transferred to the cassette in the preliminary exhaust chamber 22c, the gate valve 28c is closed and the preliminary exhaust chamber 22
Open the lid of c and take out the substrate 8 inside the preliminary evacuation chamber 22c. Note that the substrate 8 that has been processed in the processing chamber 3 may be taken out from the cassette 15b via the preliminary exhaust chamber 22b.

In this way, by providing the preliminary exhaust chambers 22a to 22c, the pressure inside the transfer chamber 2 does not reach atmospheric pressure, so it is extremely easy to reach the ultra-high vacuum region within the processing chambers 3, 4a, and 4b. . In addition, a cassette 15 is provided in the middle of the transfer chamber 2, and two carts 16a, 16
b, the traveling distance of the carts 16a, 16b can be shortened.
The driving device b becomes very simple, and the carriages 16a, 16b can be easily operated. Therefore, it becomes possible to create a production line that carries out integrated processing of multiple processes under vacuum.

In the above-mentioned embodiments, the semiconductor substrate transport mechanism of a molecular beam epitaxy apparatus has been described, but the present invention can also be applied to a semiconductor substrate transport mechanism of other vacuum apparatuses or a semiconductor substrate transport mechanism in the atmosphere.

〔Effect of the invention〕

As explained above, in the semiconductor substrate transport mechanism according to the present invention, by moving the transport vehicle into the cassette with the semiconductor substrate placed on the shelf of the cassette, and then lowering the cassette,
One semiconductor substrate can be loaded onto the carrier. Therefore, since the weight to be transported by the transport vehicle is very small, the drive device for the transport vehicle can be downsized, and the operability of the transport vehicle can be improved. As described above, the effects of this invention are remarkable.

[Brief explanation of drawings]

1 is a sectional view taken along the line CC in FIG. 5, FIG. 2 is a schematic diagram showing a molecular beam epitaxy apparatus having a conventional semiconductor substrate transport mechanism, and FIG. 4 is a perspective view showing a cassette of the semiconductor substrate transport mechanism shown in FIGS. 2 and 3, and FIG. 5 is a schematic diagram showing a molecular beam epitaxy apparatus according to the present invention.
6 is a sectional view taken along line BB in FIG. 5, FIG. 7 is a sectional view taken along line DD in FIG. 1, and FIG. 8 is a perspective view showing a part of the semiconductor substrate transport mechanism shown in FIG. FIG. 9 is a partial sectional view showing another molecular beam epitaxy apparatus having a semiconductor substrate transport mechanism according to the present invention, FIG. 10 is a sectional view taken along line EE in FIG. 9, and FIG. −
It is an F sectional view. 2... Semiconductor substrate transfer chamber, 8... Semiconductor substrate,
14, 14a to 14c...vacuum chamber, 15, 15a
~15c...Cassette, 16, 16a, 16b...
...Transportation truck, 17...Rail, 18, 18a~1
8c...fork.

Claims (1)

[Scope of Claims] 1. In a semiconductor substrate transport mechanism that transports the semiconductor substrate within a transport chamber connected to a processing chamber for processing semiconductor substrates, a rail is provided in the horizontal direction within the transport chamber, and the semiconductor substrate travels on the rail. A semiconductor substrate transport mechanism characterized in that a transport vehicle is provided, a cassette that is vertically movable and within which the transport vehicle can run is permanently placed, and a plurality of horizontal shelves are provided inside the cassette. . 2. Semiconductor substrate transport according to claim 1, characterized in that a fork capable of entering into the cassette from a direction perpendicular to the rail is provided, and an opening into which the entering means enters is provided in the cassette. mechanism.