the invention relates to a wafer transfer system that achieves high efficiency , as measured by throughput rate . this is accomplished in one instance by the combination of reliable transfer of single wafers between ports while being simultaneously rotated to accomplish notch alignment . another instance allows for simultaneous tilting of a multitude of wafers , such as changing the entire load of a transfer cassette between horizontal and vertical orientations , rather than operating on individual wafers serially . furthermore , the design of this system renders it usable in both left - handed and right - handed workflow arrangements , not requiring construction of mirror - image systems and thereby achieving an economy of scale in production and inventory of the wafer transfer system itself .