JPH0927532A - Substrate transfer method - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method of transferring a substrate, which prevents foreign substances such as dust from adhering to the substrate when the substrate is carried in and out of the storage and the pattern is destroyed by electric discharge. . [Structure] A cassette 1 before transfer (transportation source) and a cassette 2 after processing (transportation destination) are separately provided, and the substrates at the lowest position from the transport source cassette are sequentially arranged. Carry out and carry in to the destination cassette from the highest storage position. As a result, the photosensitive substrate does not always exist under the substrate that has been loaded and unloaded, and foreign matter such as dust does not drop onto the photosensitive substrate. Further, the transfer arm does not enter above the photosensitive substrate housed in the cassette, and discharge does not occur between the charged photosensitive substrate and the transfer arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of transferring a substrate, which is used for an exposure apparatus for manufacturing a semiconductor element or a liquid crystal display substrate, and is used for storing a plurality of substrates.
The present invention relates to a transportation method for loading and unloading substrates one by one.

[0002]

2. Description of the Related Art A conventional transfer method of this type has a plurality of slots (steps for storing), and an arm for transferring substrates in a storage box for storing a plurality of substrates, one for each slot. , The substrate was carried out by receiving only one of the plurality of substrates and retreating the arm from the storage.
Further, when the substrate is stored (loaded) in the storage, the arm holding the substrate is moved into the storage to transfer the substrate to the original slot and then exit from the storage.

[0003]

In the prior art as described above, since a plurality of accommodated substrates are carried in and out one by one, the carry-in is carried out except when carrying out the substrate housed in the lowest position. This means that another substrate is stored below the substrate to be ejected. Therefore, when the substrate is carried in and out, the dust generated when the substrate comes into contact with the storage or the arm falls onto the substrate stored below. When the substrate is a photosensitive substrate for manufacturing a semiconductor device or a liquid crystal display substrate, dust adhesion causes exposure failure and reduces product yield.

In addition, a substrate that has been subjected to a treatment such as exposure is generally charged, and when the charged substrate is stored in a storage case, the transfer arm is already stored for loading the next substrate. If you enter above the board,
In some cases, a discharge is generated between the transfer arm and the pattern formed by the exposure, which destroys the pattern. In view of the above problems, the present invention provides a method of transporting a substrate that prevents foreign matter such as dust from adhering to the substrate when the substrate is loaded and unloaded from the storage, and prevents the pattern from being destroyed by discharge. With the goal.

[0005]

In order to solve the above problems, the present invention has a plurality of storage positions along the vertical direction and stores a plurality of substrates (AE) at the plurality of storage positions. In the method of transporting a substrate in which the substrates are unloaded from the storage (1) one by one and are loaded into the storage one by one, the substrate (A) located at the lowest position in the storage is moved to the upper position. To the substrate (E) to be processed, and the substrates that have been carried out are different from the above-mentioned storage (1), and the second storage (2) in which no substrates are stored has a lower storage position than the uppermost storage position. It was decided to carry in in order toward the storage position.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a schematic structure of an exposure apparatus using a substrate transfer method according to an embodiment of the present invention. Initially, a plurality of (five in this case) photosensitive substrates A, B, C, D and E are stored in the cassette 1. The photosensitive substrates are stored in the order of A, B, C, D and E from the lowest storage position of the cassette 1 to the highest storage position. Further, the cassette 1 is placed on the lifting table 3, and initially,
The height is such that the transfer arm 7 can access the lowest storage position of the cassette 1. Then, the driving device 5 descends in the direction of the arrow α. As a result, the access position (height) of the transfer arm 7 with respect to the cassette 1 is changed.
That is, it is possible to select the photosensitive substrate to be accessed by the transfer arm 7.

The transfer arm 7 enters the cassette 1 to receive the photosensitive substrate from the cassette 1, and is moved toward the exposure stage 13 (in the direction of arrow β) by the driving device 9 while holding the photosensitive substrate. After that, the photosensitive substrate is transferred from the transfer arm 7 onto the exposure stage 13, and the image of the pattern of the mask 11 is exposed through the projection optical system 12 by the light flux from the illumination optical system (not shown).

The exposed photosensitive substrate is transferred to the transfer arm 8
Is received and is conveyed by the drive device 10 toward the cassette 2 (in the direction of arrow γ). Initially, the cassette 2 does not house the photosensitive substrate. In addition, the cassette 2 is a lifting table 4
It is placed on top and initially at a height such that the transfer arm 8 can access the highest storage position of the cassette. And
The drive device 6 moves upward in the direction of arrow δ. As a result, the access position (height) of the transfer arm 8 with respect to the cassette 2 is changed. That is, it is possible to select the storage position that the transfer arm 8 accesses.

FIG. 1 schematically shows a certain point in the carrying process of the apparatus. Now, the carrying arm 7 carries out the third photosensitive substrate C in the cassette 1. When the unloading of the photosensitive substrate C is completed, the elevating table 3 lowers the cassette 1 so that the photosensitive substrate D in the cassette 1 is at the same height as the access position of the transfer arm 7. And the transfer arm 7
Enter the cassette 1 again to receive the photosensitive substrate D.

On the other hand, the exposure processing of the first photosensitive substrate A has already been completed, and it is stored in the uppermost storage position in the cassette 2. Similarly, the exposure process of the second photosensitive substrate B has been completed, and the photosensitive substrate B is transported toward the cassette 2 by the transport arm 8. At the same time, the cassette 2 is raised by the elevating table 4 so that the second storage position from the top in the cassette 2 is at the same height as the access position of the transfer arm 8.

Thereafter, similarly, the photosensitive substrates D and E are similarly transported onto the exposure stage 13 and subjected to the exposure processing, and after the exposure processing is completed, they are carried into the cassette 2. After all the photosensitive substrates have been conveyed from the cassette 1 to the cassette 2, the storage order of the photosensitive substrates in the cassette 2 is the reverse of the storage order in the cassette 1, and is A, B, C, D from the top. , E in that order.

According to the present invention, the cassettes of the transfer source and the transfer destination are independent, and the cassettes of the transfer source are carried out in order from the lowest substrate, and the cassette of the transfer destination is the highest storage position. Since the substrates are loaded in order, the photosensitive substrate does not always exist below the loaded and unloaded photosensitive substrate when a substrate is loaded into or unloaded from the cassette, and foreign matter such as dust falls onto the photosensitive substrate. Never.

Further, according to the present invention, since the transfer arm does not enter above the photosensitive substrate housed in the cassette, there is no discharge between the charged photosensitive substrate and the transfer arm. .

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus that uses a substrate transfer method according to an embodiment of the present invention.

[Explanation of symbols]

 1 and 2 cassettes 3 and 4 elevators 5 and 6 drive device 7 and 8 transfer arm 9 and 10 drive device A to E photosensitive substrate

Claims (1)

[Claims] 1. A plurality of storage positions are provided along a vertical direction, and the substrates are carried out one by one from a storage container in which a plurality of substrates are stored at the plurality of storage positions, and the storage substrate is stored in the storage container. In a method of transporting a substrate in which the substrates are loaded one by one, in the storage, the substrates in the lowest position are sequentially transported to the substrates in a higher position, and the transported substrates are stored in the storage. Different from each other, the substrate is conveyed in order from the uppermost storage position of the second storage in which the substrates are not stored to the lower storage position.