A second wafer carrier 51, a third wafer carrier 53, a fourth wafer carrier 55 and a fifth wafer carrier 57 are in storage on the storage locations 25 a, 25 b, 25 c and 25 d, respectively. [0034]FIG. 3 is a top plan view of the load buffer 11 of FIGS. 1 and 2 which shows a preferred footprint of the load buffer