A system for protecting wafers from damage caused by an
inaccurately-positioned wafer transfer robot blade during the transfer of
wafers typically from a wafer cassette to a processing tool. The wafer
protection system includes a conductor foil which is electrically
separated from the robot blade through a space or gap and is connected to
a relay circuit that is normally closed to facilitate flow of electrical
power to the robot blade motor. Upon initial contact of the robot blade
with the edge of a wafer, the conductor foil deforms and contacts the
blade through the space or gap, completing a circuit between the blade
and the relay circuit. The relay circuit opens, thereby terminating
further power flow to the robot blade motor and immediately preventing
further movement of the robot blade against the wafer.