Wafer position teaching method and teaching jig
An object is to provide a method for teaching the position of a semiconductor wafer automatically and accurately without relying on the sight of an operator as well as a teaching jig that is used for the above method. To this end, in the invention, a teaching jig 11 is detected by a first transmission-type sensor 6 that is provided at the tips of a wafer gripping portion 5 of a robot. The teaching jig 11 is composed of a large disc portion 12 that is the same in outer diameter as a semiconductor wafer and a small disc portion 13 that is concentric with the large disc portion 12 . The teaching jig 21 is detected by a second transmission-type sensor 18 that is provided on the wafer gripping portion 5 . The second transmission-type sensor 18 is mounted on a sensor jig 15 so as to be detachable form the wafer gripping portion 5.
1. A wafer position teaching method for teaching a position of a semiconductor wafer in a container or a processing apparatus to a robot for transporting the semiconductor wafer between the container and the processing apparatus or between processing apparatuses by moving a hand holding the semiconductor wafer in at least three directions of R, θ and Z,
the method comprising the steps of:
placing a first teaching jig at a position to which the semiconductor wafer in the container or the processing apparatus is placed, wherein the teaching jig comprises a large disc portion and a small disc portion connected to each other with the small disc portion overlapping the large disc portion and the large disc portion having a diameter same as a diameter of the semiconductor wafer;
detecting a height of the small disc portion by a first transmission-type sensor provided at tips of the hand by moving the hand in the Z-direction,
detecting the small disc portion by the first transmission-type sensor by moving the hand in the R-direction from plural values of θ; and
calculating a position of the small disc portion on the basis of the detection.
2. The wafer position teaching method according to claim 1 , wherein
a least-squares method is applied to results of detection.
3. The wafer position teaching method according to claim 1 wherein
in the step of placing the first teaching jig, the large disc portion and the small disc portion are concentric with each other.
4. A wafer position teaching method for teaching a position of a semiconductor wafer in a container or a processing apparatus to a robot for transporting the semiconductor wafer between the container and the processing apparatus or between processing apparatuses by moving a hand holding the semiconductor wafer in at least three directions of R, θ and Z,
the method comprising the steps of:
placing a sensor jig to which a second transmission-type sensor is fixed to the hand of which tips are provided with the first transmission-type sensor,
placing a second teaching jig at a position to which the semiconductor wafer in the container or the processing apparatus is placed, wherein the second teaching jig comprises a large disc portion having a diameter same as a diameter of the semiconductor wafer and a small diameter pin that erects from a center of the large disc portion,
detecting a height of the large disc portion by the first transmission-type sensor by moving the hand in the Z-direction,
detecting the small-diameter pin by a first transmission-type sensor by moving the hand in the R-direction from a plural values of θ; and
calculating a position of the small-diameter pin on the basis of detection.
5. The wafer position teaching method according to claim 4 , wherein
in the step of placing the sensor jig, an optical axis of the second transmission-type sensor is disposed approximately at the center of the sensor jig.
6. The wafer position teaching method according to claim 4 , wherein
in the step of placing the sensor jig, an optical axis of the second transmission-type sensor is set approximately perpendicular to an optical axis of the first transmission-type sensor.
7. The wafer position teaching method according to claim 5 , wherein
the second transmission-type sensor is disposed approximately at the center of a semiconductor wafer mounting portion of the hand.
8. The wafer position teaching method according to claim 5 , wherein
an optical axis of the second transmission-type sensor is set approximately perpendicular to an optical axis of the first transmission-type sensor.
9. The wafer position teaching method according to claim 6 , wherein
the sensor jig is formed with a cut for preventing interference with an optical axis of the first transmission-type sensor.