Abstract: An improved wafer carrier adapted for use in storing and transferring semiconductor wafers is described. The carrier generally resembles prior art carriers in that it is an open topped basket with internal slots for receiving spaced apart semiconductor wafers. Rails having smooth upper surfaces are provided along two opposed edges of the open top. One rail has an elongated bar or ridge protruding from its upper surface and the other rail has a mating elongated groove recessed into its upper surface. To make a dump transfer, an empty carrier is inverted and placed face-to-face against a loaded carrier with the upper surfaces of the two carriers in contact. The ridge and groove of the empty carrier engage the groove and ridge of the full carrier thereby aligning the wafer slots of the two carriers. The two carrier unit is then inverted and the wafers smoothly dump from the full to the empty carrier.