| 摘要 |
PROBLEM TO BE SOLVED: To provide a substrate positional misalignment detection system capable of detecting positional misalignment of a substrate, without moving a detector when using a bottom-opening pod. SOLUTION: The substrate positional misalignment detection system applied to the pod 1, having its body 2 having an opening in a bottom portion, a lid 3 capable of freely opening and closing the opening portion, and a cassette 4 mounted on the lid 3 to hold wafers, and a cassette module 5 having a support body 8 moving up and down the lid 3 together with the cassette 4, includes a detector having a recursive reflection type sensor 10, disposed on the supporting body 8 and adapted to emit and receive light in an upward/downward direction; a recursive reflection plate 12, provided on the ceiling portion of the body 2 so as to oppose the recursive reflection type sensor 10 and adapted to reflect the emitted light, and a light-transmitting window 11 disposed in the lid 3 and adapted to transmit the light, with the components of the detector being aligned linearly in the upward/downward direction, so that the light emitted by the recursive reflection type sensor 10 will not be blocked by the wafers W held in a predetermined storage position by the cassette 4. COPYRIGHT: (C)2009,JPO&INPIT |
