JPH06105307B2 - Wafer carrier loading / unloading port obstacle detection method - Google Patents

Description

The present invention relates to a method for detecting an obstacle that has entered a detection space, and more particularly to a wafer carrier loading / unloading port in automation of a semiconductor manufacturing apparatus. And an obstacle detection method for a wafer carrier loading / unloading port for detecting an obstacle.

(Prior Art) Generally, a curtain-shaped obstacle detection device is used as a safety measure when a worker or a device enters an inaccessible area in a factory or an operation intervention prohibited area in a semiconductor manufacturing apparatus. There is.

FIG. 3 shows a curtain-shaped obstacle detecting device, which includes a light source 2 in which a plurality of light emitting portions 1 are arranged at equal intervals, and a light receiver 4 in which a plurality of light receiving portions 3 are arranged at equal intervals. Are arranged to face each other, and the light emitting portion 1 and the light receiving portion 3 correspond to each other in a one-to-one correspondence. The light source 2 and the light receiver 4 are arranged so as to face each other with the entry prohibition region and the operation intervention prohibition region sandwiched therebetween, and a plurality of light receiving units 3 corresponding to the light emitting units 1 are caused to emit infrared rays 5, for example. Respectively receives the infrared rays 5. At this time, when an operator or the like enters the space of the infrared rays 5 emitted from the plurality of light emitting units 1, that is, the detection space, the infrared rays are blocked, so that the operator or the like enters the detection space. Detect and prevent accidents.

On the other hand, in a semiconductor manufacturing apparatus, a wafer carrier accommodating a plurality of semiconductor wafers is carried into a loading / unloading port by an automatic transfer device such as a robot in a clean room, placed on the port, and automatically transferred to various processing devices. Although automation is in progress, it is not completely automated, and the operator's intervention to allow the operator to carry in the wafer carrier or correct the position of the wafer carrier that is not correctly placed at a predetermined position, if necessary. May be accompanied.

(Problems to be Solved by the Invention) However, in the conventional obstacle detection device described above,
Since a plurality of light emitting units and light receiving units are required and the light emitting units and light receiving units are further required for detecting the entry of a small object, there is a problem that the cost increases.

Further, it is conceivable to detect an obstacle at the loading / unloading port of the wafer carrier by using such a conventional obstacle detection device. Not only the wafer carrier that is not placed but also the loading and unloading work by the automatic carrying device is detected as an obstacle, and there is a problem that work efficiency is reduced.

The present invention has been made to solve the above problems, and is capable of detecting an obstacle at a port of a wafer carrier in automation of a semiconductor manufacturing apparatus at low cost without lowering work efficiency. There is an attempt to provide an obstacle detection method for the access port.

[Structure of Invention]

(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention is to carry a wafer carrier into a predetermined position of a loading / unloading port by an automatic carrying device,
At least one beam of light from the light source is sent out
An optical system for reflecting and receiving light twice is provided at the entrance of the loading / unloading port, and the detection by the optical system is released only during the automatic transfer by the automatic transfer device, and the wafer carrier which is not placed at the correct position by the optical system. The feature is that the intervention of the worker is detected as an obstacle.

The number of the optical system may be one, but a plurality of the optical systems may be provided in correspondence with the number of carriers placed at the predetermined position of the access port.

(Operation) According to the method of the present invention, the detection by the optical system provided at the entrance of the loading / unloading port of the wafer carrier is canceled only during the automatic transfer by the automatic transfer device. Therefore, the transfer work by the automatic transfer device is regarded as an obstacle. Without detecting
The work efficiency can be improved and the safety of the optical system can be improved by detecting the intervention of the wafer carrier and the operator which are not placed at the correct positions as obstacles by the optical system. Since the beam light is reflected at least once and received, it is possible to perform the above detection at low cost.

(Example) An example of the method of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 15 is a loading / unloading port for loading / unloading the wafer carrier 14 into / from a semiconductor manufacturing apparatus installed in a clean room, and the wafer carrier 14 is loaded / unloaded into / from the loading / unloading port 15 by an automatic carrier device such as a handling device. Are carried in and out.

The loading / unloading port 15 is provided on the carrier port base 13 so that a plurality of wafer carriers 14 can be placed in a row at a predetermined position in a row in the embodiment. An obstacle detection device including an optical system for detecting an obstacle is provided at the entrance of the access port 13.

The basic configuration of this obstacle detection device will be described with reference to FIG. 2. The sensor body 6 is provided with a single light source 7 of an optical sensor at one end and a single light receiver 8 at the other end in a separated state. ,
Between the light source 7 and the light receiver 8, a reflector whose surface is polished, such as a mirror 9, is provided.

A support 10 is provided at a position opposite to the sensor body 6 in parallel with the sensor body 6.
Is mounted, and a reflecting plate, for example, a mirror 11 having a polished surface is provided on the surface of the support 10 facing the sensor body 6. In the obstacle detecting device configured as described above, for example, the infrared light beam 12 is emitted from the light source 7 toward the mirror 11 at a slight angle, and the infrared light beam 12 is emitted from the support body 10. And the mirror 11 installed in
The light is reflected by the mirror 9 provided on the sensor body 6 a plurality of times and is received by the light receiver 8 provided on the sensor body 6. At this time, the angle at which the infrared light beam 12 is emitted from the light source 7 is
The angle is adjusted within a range where the light receiver 8 can receive light. However, as the irradiation angle is increased, the number of reflections between the mirror 11 and the mirror 9 is reduced, and a large number of small object undetectable regions are generated. The object may be detected by selecting the size of the obstacle or using the obstacle detecting device at a plurality of locations.

When applying the obstacle detection device composed of such an optical system to the detection of an obstacle in the access port 15,
As shown in FIG. 1, a light source 7a and an optical receiver 8a whose angle can be finely adjusted are arranged at the entrance of the port 15 with a slight interval. Between the light source 7a and the light receiver 8a, a reflector having a polished surface, such as a mirror 9a, is provided. A port ceiling portion 16 is provided at a position facing the mirror 9a, and a reflecting plate such as a mirror 11a having a polished surface is provided on a surface of the port ceiling portion 16 facing the mirror 9a.

Thus, the light source 7a, the light receiver 8a, the mirror 9a and the mirror 11a
The optical system (obstacle detection device) configured by detecting the space A corresponding to the wafer carrier placed at the left end of the illustrated example. Further, similarly to the above configuration, the light source 7b, the light receiver 8b,
An optical system including a mirror 9b and a mirror 11b detects a space B corresponding to the wafer carrier placed in the center of the illustrated example. Further, an optical system including a light source 7c, a light receiver 8c, a mirror 9c and a mirror 11c detects the space C corresponding to the wafer carrier placed at the right end of the illustrated example. These three optical systems cover the entire entrance of the access port 15.

In the above structure, first, when the infrared light beam 12 is irradiated from the light source 7a toward the mirror 11a at a slight angle, the infrared light beam reaches the mirror 11a and is reflected, and then the mirror 9a is further reflected. The light is sequentially reflected by the mirror 11a and received by the light receiver 8a. At this time, the mirror, the light source, and the light receiver, which are respectively arranged, are adjusted in angle so that the infrared beam 12 can reach. In this way, the obstacle in the space A is detected, and the space B and the space C are similarly detected.

In this way, during the detection of obstacles, if there is an operator's intervention as an obstacle that blocks the infrared beam light 12 in the spaces A, B, and C, a wafer carrier that is not properly placed, etc. The light receivers 8a, 8b, 8c cannot detect the infrared light beam due to an obstacle, recognize that it is an abnormal situation, and take an alarm display, stop the operation of the device, and respond with an alarm bell etc. To report.

By the way, as an unmanned and automated process in a clean room, there is automation involving an operator. And as an obstacle on the above-mentioned entrance / exit port 15,
It is conceivable that the wafer carrier 14, the automatic transfer device, and the operator who are not placed in the correct position are used. Scheduling of the automatic transfer by the automatic transfer device is performed by the host computer, and the in / out port 15 is in a reserved state outside the recognition of the operator. By storing the scheduling of the automatic conveyance by the automatic conveyance device at this time and canceling the detection by the optical system only during the automatic conveyance, the conveyance work by the automatic conveyance device is not detected as an obstacle, Further, the above optical system makes it possible to detect the intervention of the wafer carrier 14 and the operator, which are not placed at the correct positions, as an obstacle.

Therefore, when the wafer carrier 14 is carried in and out of a predetermined position of the loading / unloading port 15 by the automatic carrying device, an optical system for reflecting and receiving the beam light 12 from the light source at least once is provided at the entrance of the loading / unloading port 15. Then, the detection by the optical system is canceled only during the automatic transfer by the automatic transfer device, and the intervention of the wafer carrier and the operator not placed at the correct position by the optical system is detected as an obstacle.

By adopting such a detection method, the detection by the optical system provided at the entrance of the loading / unloading port 15 of the wafer carrier 14 is canceled only during the automatic transfer by the automatic transfer device, so that the transfer work by the automatic transfer device becomes an obstacle. In order to improve work efficiency without detection and to detect the intervention of the wafer carrier and the operator not placed in the correct position by the above optical system as an obstacle, shown in the loading / unloading port 15 shown. It is possible to prevent the wafer carrier from being damaged by the automatic opening / closing door.
The safety can be improved, and moreover, since the optical system reflects and receives the light beam from the light source at least once, the detection can be performed at low cost.

In the above embodiment, the infrared beam light is used for the obstacle detection device including the optical system, but the same effect can be obtained with visible light. In the above embodiment, 2
Although the obstacles are detected three-dimensionally, the obstacles may be detected three-dimensionally.

〔The invention's effect〕

As described above, according to the present invention, the detection by the optical system provided at the entrance of the loading / unloading port of the wafer carrier is canceled only during the automatic transfer by the moving transfer device. As a result, it is possible to improve the work efficiency and to detect the intervention of the wafer carrier and the operator, which are not placed at the correct positions by the optical system, as an obstacle, thereby improving the safety. Since the optical system reflects and receives the light beam from the light source at least once, the detection can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining an embodiment of the method of the present invention, FIG. 2 is a perspective view showing the basic structure of a detection device, and FIG.
FIG. 1 is a perspective view showing a conventional obstacle detection device. 7,7a, 7b, 7c …… Light source, 8,8a, 8b, 8c …… Receiver, 9,9a, 9b,
9c, 11,11a, 11b, 11c …… Mirror, 12 …… Infrared beam light, 14 …… Wafer carrier, 15 …… Access port.

Claims (2)

[Claims] 1. An optical system for reflecting and receiving a beam of light from a light source at least once when loading and unloading a wafer carrier to and from a predetermined position of an loading / unloading port by an automatic carrying device is provided at the entrance of the loading / unloading port. The wafer carrier loading / unloading is characterized in that the detection by the optical system is canceled only during the automatic transportation by the automatic transportation device, and the intervention of the wafer carrier and the operator not placed at the correct position by the optical system is detected as an obstacle. Port obstacle detection method. 2. The wafer carrier loading / unloading according to claim 1, wherein a plurality of said optical systems are provided in correspondence with the number of carriers placed at a predetermined position of said loading / unloading port. Port obstacle detection method.