Patent ID: 6914233
Filing Date: 2005-07-05
Classification: H01L

Abstract:
1. A wafer mapping system that is provided with an access port for transferring in and out a wafer, and performs a detection operation of an accommodated wafer to a cassette in which slots for accommodating and holding substantially level a plurality of inserted wafers are disposed in a plurality of tiers, comprising: a receiver that is fixed to a member facing to the access port and formed of receiving elements arranged serially along a height direction of the cassette; and a transmitter that is disposed movably in a up and down direction of the cassette and transmits a signal toward a wafer accommodated in each of the slots of the cassette; wherein the receiver receives a signal transmitted from the transmitter, and thereby presence or absence and a state of a wafer accommodated in each of the slots of the cassette are detected.