| 摘要 |
PURPOSE: An apparatus for recognizing a marking letter is provided to prevent contamination of a wafer and to shorten an interval of process time, by recognizing the marking letter of the wafer while the wafer is not pulled out from a cassette. CONSTITUTION: Wafers(45) are loaded in a plurality of slots of a cassette(40) received in a cassette receiving plate(10). A marking letter recognizing unit(20) takes a picture of the marking letter(47) on the wafer, installed in a predetermined angle with the direction that the wafers are loaded in the slot. A marking letter recognition position modifying unit transfers the marking letter recognizing unit and the cassette receiving plate in a direction perpendicular to the direction that the wafers are loaded in the slot. The marking letter recognition position modifying unit modifies a recognition position where the marking letter on the wafer loaded in the cassette is recognized.
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