Subsrate tray and ceramic blade for semiconductor processing apparatus

摘要

A semiconductor wafer processing system for processing wafers (22) from a wafer storage cassette (24) includes a wafer transfer chamber (14); a wafer storage elevator (20) within the transfer chamber; one or more wafer processing chambers (12); and a wafer transfer apparatus for transferring a wafer between a standard storage cassette adjacent and outside the transfer chamber and the elevator, and between the elevator and the processing chamber. The environment of the storage chamber varies in pressure between atmospheric when accepting wafers from outside, and a subatmospheric pressure when transferring wafers to or from a processing chamber. The transfer apparatus includes a robot arm (16); a thin flat wafer carrying blade (18) at the leading end of the robot arm and configured for engaging a wafer from the storage cassette or the elevator; and a wafer support tray (40) which is configured for removable engagement with the blade and for engaging and positively positioning a wafer (22) from the elevator, or a support pedestal within a processing chamber. When the transfer apparatus moves a wafer between the elevator and a processing chamber in an evacuated environment, the tray is engaged with the blade and helps retain the wafer during transit. When wafers are transferred between the cassette and the elevator at atmospheric pressure the tray is disengaged from the blade and placed in a rest position on the elevator, and the wafer transfer is performed by means of the blade alone with a vacuum pick integral to the blade. The blade includes upper (18') and lower (18'') halves together with defining vacuum channels and capacitive position sensors.