Methods and systems to optimize wafer placement repeatability in
semiconductor manufacturing equipment using a controlled series of wafer
movements are provided. In one embodiment, a preliminary station
calibration is performed to teach a robot position for each station
interfaced to facets of a vacuum transfer module used in semiconductor
manufacturing. The method also calibrates the system to obtain
compensation parameters that take into account the station where the
wafer is to be placed, position of sensors in each facet, and offsets
derived from performing extend and retract operations of a robot arm. In
another embodiment where the robot includes two arms, the method
calibrates the system to compensate for differences derived from using
one arm or the other. During manufacturing, the wafers are placed in the
different stations using the compensation parameters.