Wafer tray sorter with door coupled to detector

A wafer tray sorter comprising:

• a first wall having a plurality of doors, wherein the doors are configured to open to create a plurality of openings in the first wall, wherein one of the openings is configured to interface with a cassette having one or more trays, wherein one of the trays is configured to carry a wafer,
• a second wall that faces the first wall, wherein the second wall includes a plurality of slots, wherein one of the slots is configured to interface with an indexer;
• and
• a tray engine configured to move in a linear direction between the first wall and the second wall to facilitate a transfer of the one of the trays, wherein the transfer occurs between the one of the openings and one of the slots,
• wherein one of the doors is coupled to a detector configured to detect the one of the trays,
• wherein the detector is configured to identify the one of the trays by reading a plurality of numbers, or a barcode, or a combination of a barcode and numbers, or an EZ code, or an alphanumeric code on the one of the trays.