A plurality of projections 21 is disposed on a inner surface of a lid 20 which is detachably attached to a carrier body 10. Each projection 21 has a tapered end part 22 with inclined surfaces 23, 24. The surfaces 23, 24 are in the form of semitransparent mirror. A Light emitting device 47 projects light...http://www.google.de/patents/US6053983?utm_source=gb-gplus-sharePatent US6053983 - Wafer for carrying semiconductor wafers and method detecting wafers on carrier
