Patent ID: 8185242

Claim:
A method to optimize wafer placement repeatability in a system with semiconductor manufacturing equipment using a controlled series of wafer movements, the method comprising: (a) performing a preliminary station calibration to teach a robot position for each station interfaced to facets of a vacuum transfer module (VTM) used in semiconductor manufacturing; (b) calibrating 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, the calibrating further including accessing a table having nominal sensor locations for each facet, and creating an offset table to compensate for error induced by the nominal sensor locations; (c) fine tuning the compensation parameters and robot position for each station by obtaining data from placing and picking of the wafer; and (d) placing wafers in stations during manufacturing using the compensation parameters.