Patent attributes
Vertical batch furnace assembly for processing wafers comprising a cassette handling space, a wafer handling space, and a first wall separating the cassette handling space from the wafer handling space. The first wall has at least one wafer transfer opening in front of which a wafer transfer position for a wafer cassette is provided. The cassette handling space comprises a cassette storage, and a cassette handling mechanism. The cassette storage has a plurality of cassette storage positions and is configured to store a plurality of wafer cassettes. The cassette handling mechanism comprises a first cassette handler which is configured to transfer wafer cassettes between a first set of the cassette storage positions and the wafer transfer position. The cassette handling mechanism is provided with a second cassette handler which is configured to transfer wafer cassettes between a second set of the cassette storage positions and the wafer transfer position.