US Patent 11367641 Wafer storage device, carrier plate and wafer cassette

A wafer storage device includes a wafer cassette and a carrier plate. The wafer cassette includes a housing and a plurality pairs of retaining members disposed on lateral walls of the housing. The carrier plate is placed into the housing, is supported by one pair of the retaining members, and includes a plate body carrying the wafer thereon, and having a periphery formed with two slots extending respectively in two different radial directions of the wafer. Two positioning members respectively and radially correspond in position to the slots, and abut against an outer rim of the wafer.