JPH09260462A - Method and apparatus for carrying board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a good productive yield, by detecting a board, used as a reticle, or a cassette for storing the board and carrying the board cleanly while the board or the cassette is carried. SOLUTION: A carrying board apparatus includes a tray 2 for mounting a board or a cassette for storing the board during carrying movement, and a base plate 15 for supporting the tray 2 in desired movable states. A photoelectric sensor 7 made up of a light emitting means and a light receiving means is provided on the base plate 15 as a stationary side. A movable member 6 subjected to displacement according to whether the board or the cassette is mounted or not is provided on the tray 2 on the movable side. Then, the movable member 6 switches the shielding or the casting states of a sensor beam from the light emitting means to the light receiving means in all the position when the tray 2 is put in a carrying region. As a result, whether the board or the cassette is mounted or not is detected according to an output signal form the light receiving means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer apparatus and a substrate transfer method for transferring a substrate such as a photomask, a reticle, a wafer or a glass plate, or a cassette or a carrier in which they are stored. Such a substrate transfer apparatus and method are particularly suitably used for an exposure apparatus and a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In recent years, in a semiconductor manufacturing apparatus, all reticles required for semiconductor manufacturing are automatically conveyed in the apparatus in order to improve yield. In such a reticle transport apparatus, as shown in FIG. 6, a sensor 16 for detecting whether the cassette storing the reticle has fallen during transport or whether the reticle cassette has been delivered and received correctly. The sensor 16 was also conveyed together with the reticle cassette in preparation for the above. Therefore, the signal cables, power cables, etc. of the above-mentioned sensors arranged on the tray 2 on the transported side were wired by the flat cable 14.

[0003]

However, according to the prior art, as shown in FIG. 6, the transferred flat cable 14 is fixed to the fixed base plate 1 while the reticle cassette is being transferred.
Repeatedly contacting with No. 5 had a drawback of becoming a dust source.

In recent years, as devices have been miniaturized and the degree of integration has increased, a decrease in yield due to dust generation has become a problem.

The present invention has been made in view of the above circumstances, and carries out clean substrate transportation while carrying out detection of substrates and cassettes during transportation of substrates such as reticles and cassettes containing the substrates. It is an object of the present invention to realize and improve the manufacturing yield of semiconductor devices and the like.

[0006]

In order to achieve the above object, in the present invention, a tray on which a substrate or a cassette containing the substrate is placed and conveyed, and a base plate movably supporting the tray are provided. In the substrate transfer device, a photoelectric sensor including a light emitting means and a light receiving means for receiving light from the light emitting means is arranged on the base plate on the fixed side, and the substrate is placed on the tray on the transferred side. Alternatively, a moving member that is displaced according to the presence or absence of a cassette and switches between blocking and projecting the sensor beam from the light emitting means to the light receiving means is arranged regardless of the position of the tray in the transport area, and the output signal of the light receiving means is arranged. The presence or absence of the substrate or the cassette is detected according to the above. Preferably, a pin for positioning the substrate or the cassette is arranged on the tray, and the weight displaces the moving member only when the substrate or the cassette is placed in the correct position by the pin. Further, when the transport path is a straight line, the light-shielding portion of the moving member can be made small by arranging the sensor so that the sensor beam is parallel to the transport path. In this case, the sensors may be arranged on both sides of the transport path.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In order to achieve the above object, in one embodiment of the present invention, means for detecting whether the reticle cassette has dropped during conveyance of the reticle cassette or whether the reticle cassette has been delivered and received correctly. As a result, a light shielding plate that moves with or without a reticle cassette is arranged on the transported side. Then, a transmissive beam sensor was arranged on the fixed side so that the light shielding plate shields and transmits light with and without the reticle cassette.

By doing so, the reticle cassette is detected over the entire carrying position during the reticle cassette carrying without physical contact of the flat cable or the like.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of a semiconductor manufacturing apparatus (stepper) in which a reticle cassette transporting device according to an embodiment of the present invention is incorporated. 1 is a reticle cassette that stores the reticle, 2 is a tray that transports the reticle cassette, Reference numeral 3 is a stepper body.

FIG. 2 is a bird's-eye view of a tray unit for carrying a reticle cassette, 4 is a cassette receiver for placing the reticle cassette, 5 is a linear guide which is a guide when the tray 2 moves straight, and 6 is a cassette receiver. Four
It is a lever type light shielding plate for detecting the cassette 1 on the table. The light shield plate 6 is rotatable around an axis 6 '. Reference numeral 7 is a transmissive photoelectric sensor.

FIG. 3 is a diagram showing the relationship between the lever type light shielding plate 6 and the optical axis of the transmissive photoelectric sensor 7, 8 is the optical axis of the transmissive photoelectric sensor 7, and 9 is the posture of the light shielding plate 6. Stopper pins 10 for regulating the position of the cassette 1 are positioning pins for regulating the position of the cassette 1.

FIG. 4 is a diagram showing a second embodiment of the present invention. In the figure, 11 is a light-shielding plate which is a leaf spring, and 12 is a top mounted on the leaf spring 11.

FIG. 5 is a diagram showing a third embodiment of the present invention. In the figure, 8 is the optical axis of the transmission type photoelectric sensor 7,
Reference numeral 9 is a stopper pin that regulates the attitude of the light shielding plate 6, and 10 is a positioning pin that regulates the position of the cassette 1. Thirteen
Are substrates such as a reticle and a wafer.

FIG. 6 is a diagram showing a conventional example. Reference numeral 14 is a flat cable, 15 is a fixed side base plate, and 16 is a reflective sensor for cassette detection.

(First Embodiment) Next, the operation will be described based on the above configuration. FIG. 1 is a view in which a tray is projected to a transfer position in order to transfer a cassette with an operator. Reference numeral 1 is a reticle cassette. The tray 2 starts to move by a console operation (not shown), protrudes outside the apparatus, and the cassette is transferred at the transfer position. After the transfer, the tray 2 moves to a predetermined position, where the cassette is further transferred from the tray to a cassette transfer hand (not shown) and then automatically transferred to the reticle storage rack in the stepper body.

FIG. 2 is a bird's-eye view of the tray portion. When the operator delivers the reticle cassette onto the cassette receiver 4 of the tray 2, the tray 2 is automatically conveyed by an actuator (not shown) according to the linear guide 5.
At this time, the actuator may be a DC motor or a pulse motor, and the transmission mechanism may be a belt or a ball screw.
Further, the tray 2 is provided with a lever type light shielding plate 6, and its posture is changed depending on whether the cassette 1 is on the cassette receiver 4 or not. By detecting the light shielding plate 6 with the transmissive sensor 7, it is possible to determine whether the cassette 1 is placed on the cassette receiver 4. Further, instead of the transmissive sensor 7, a sensor such as a reflective sensor that detects a mechanical mechanism on the tray may be used.

The relationship between the movement of the light shielding plate and the sensor will be described in detail with reference to FIG. FIG. 3A shows a state in which the cassette 1 is placed on the cassette receiver 4. The upper end of the light shielding plate 6 is pushed downward by the cassette 1 and rotated in the CW (clockwise) direction about the shaft 6'to maintain the position shown in the figure. At this time, since the lower end of the light shield plate 6 moves upward, it does not interfere with the optical axis 8 of the transmissive sensor, and thus the transmissive sensor 7 is in the light projecting state (the light shield plate 6 is in the light transmitting state). FIG. 3B shows a state in which the cassette 1 is not placed on the cassette receiver 4. Since the light-shielding plate 6 is longer than the shaft 6 ', it is rotated CCW (counterclockwise) by its gravity and hits the stopper pin 9 to maintain the posture shown in the drawing. At this time, the lower end of the light shielding plate 6 moves downward to shield the transmission type sensor optical axis 8 from light. FIG. 3C shows a state in which the cassette 1 is not correctly placed on the cassette receiver 4 and is mounted on the positioning pin 10. At this time as well, similarly to FIG. 3B, the light shielding plate 6 rotates to CCW by its own weight to shield the transmission type sensor optical axis 8 from light. That is, when the cassette 1 is correctly placed on the cassette receiver 4, the transmissive sensor 7 is in a light projecting state, and when the cassette 1 is not or not properly placed on the cassette receiver 4, the transmissive sensor 7 is transparent. The sensor 7 is in a light blocking state.

The tray 2 moves straight in the horizontal direction, and the transmission type sensor optical axis 8 is set to be parallel and horizontal to the transport direction. Therefore, since the relationship between the light shielding plate 6 and the transmissive sensor beam 8 is established regardless of the transport position of the tray 2, it is possible to detect whether the cassette 1 is correctly placed over the entire transport position of the tray 2.

The transmissive sensor 7 is arranged at two places on the left and right. By doing so, not only the cassette can be detected more reliably, but also a sufficient space can be secured between the two sensors to transfer the cassette to the cassette carrying hand (not shown).

(Second Embodiment) FIG. 4 is a diagram showing a second embodiment of the present invention. FIG. 4A shows a state in which the cassette 1 is placed on the cassette receiver 4. Leaf spring shading plate 11
The top 12 attached above is pushed downward by the gravity of the cassette. Therefore, the leaf spring shading plate 11 bends downward,
The transmission type sensor optical axis 8 is shielded. 4 (b), 4 (c)
Contrary to FIGS. 3B and 3C, when the cassette 1 is not placed on the cassette receiver 4 or is not placed correctly, the transmissive sensor 7 is in a light projecting state (the light shielding plate 11 is transparent). Light state). Since these relationships are established regardless of the transport position of the tray 2, it is possible to detect whether or not the cassette 1 is correctly placed over the entire transport position of the tray 2.

(Third Embodiment) FIG. 5 is a diagram showing a third embodiment of the present invention. FIG. 5A shows a state in which the substrate 13 such as a reticle and a wafer is directly placed on the substrate receiver.
As in the case of FIG. 3, the upper end of the shading plate 6 is pushed downward by the substrate 13 and rotates in the CW direction around the shaft 6'to maintain the position shown in the figure. At this time, since the lower end of the light shield plate 6 moves upward, it does not interfere with the optical axis 8 of the transmissive sensor, and thus the transmissive sensor 7 is in the light projecting state (the light shield plate 6 is in the light transmitting state). Similar to FIGS. 3B and 3C, in FIGS. 5B and 5C, the transmissive sensor 7 shields light when the substrate 13 is not placed on the substrate receiver or is not placed correctly. It becomes a state. Since these relationships are established regardless of the transfer position of the substrate 13, it is possible to detect whether or not the substrate is correctly placed over the entire transfer position of the substrate 13.

[0022]

As described above, according to the present invention,
It is possible to detect the cassette or the substrate for the entire transport position during the transport of the cassette or the substrate without the physical contact of the flat cable or the like.

Therefore, a clean reticle cassette or substrate transfer can be realized, and the yield of semiconductor manufacturing can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a bird's-eye view of a tray unit that carries a reticle cassette in the apparatus of FIG.

FIG. 3 is a diagram illustrating in detail the relationship between the movement of the light shielding plate and the sensor in the apparatus of FIG.

FIG. 4 is a diagram showing a second embodiment according to the present invention.

FIG. 5 is a diagram showing a third embodiment according to the present invention.

FIG. 6 is a diagram illustrating a conventional example.

[Explanation of symbols]

1: Reticle cassette, 2: Cassette transport tray, 3:
Stepper body, 4: Cassette receiver, 5: Linear guide, 6: Lever type light shield plate, 6 ': Rotation axis, 7: Transmission type photoelectric sensor, 8: Optical axis of transmission type photoelectric sensor, 9: Stopper pin, 10: Reticle cassette positioning pin, 11: leaf spring light shielding plate, 12: frame, 13: reticle, substrate such as wafer, 14: flat cable, 15: fixed side base plate, 16: reflective sensor.

Claims (8)

[Claims] 1. A tray on which a substrate or a cassette containing the substrate is placed and conveyed, a base plate for movably supporting the tray, a light emitting means arranged on the base plate, and a light emitting means arranged on the base plate. A light receiving means for receiving light from the light emitting means, and a light receiving means for moving light from the light emitting means to the light receiving means irrespective of a position in the moving area of the tray that is displaced depending on the presence or absence of the substrate or the cassette on the tray. A substrate transfer device comprising: a moving member that switches between light shielding and light projection, and detects the presence or absence of the substrate or the cassette in accordance with an output signal of the light receiving means. 2. A pin for positioning a substrate or a cassette is arranged on the tray, and the moving member is displaced by the weight of the substrate or the cassette only when the pin places the substrate or the cassette in a correct position. The apparatus of claim 1 characterized. 3. The apparatus according to claim 2, wherein the tray moves in a straight line, and the sensor including the light emitting means and the light receiving means is arranged in parallel with the moving direction of the tray. . 4. The apparatus according to claim 3, wherein the sensors are arranged on both sides of a moving path of the tray. 5. A substrate transfer device comprising a photoelectric sensor for detecting a substrate or a cassette on a tray on which a substrate or a cassette accommodating the substrate is placed and conveyed, wherein the sensor is arranged on a fixed side and is a transferred side. A substrate transfer method, characterized in that a mechanical mechanism for blocking and projecting the sensor beam is arranged on the tray with or without a substrate or cassette, and the cassette is detected in the entire substrate or cassette transfer position. 6. A pin for positioning a substrate or a cassette is arranged on the tray, and the mechanical mechanism is operated only when the pin places the substrate or the cassette in a correct position to control the light-shielding projection state of the sensor beam. The method according to claim 5, wherein the switching is performed. 7. The method according to claim 6, wherein the sensor beam is set parallel to the transport direction. 8. The substrate transfer apparatus according to claim 7, wherein the sensors are arranged at two positions on the left and right of the transfer path.