Method and apparatus for measuring placement of a substrate on a heater pedestal

A placement controller, comprising:

• a sensor interface, wherein the sensor interface is configured to receive sensor information from a sensor wafer, the sensor wafer comprising a plurality of outward facing sensors along an edge surface of the sensor wafer, and the sensor wafer comprising a plurality of discrete recesses, each recess radially between a corresponding one of the plurality of outward facing sensor regions and a center of the sensor wafer, and each recess exposing an inner lateral edge of the corresponding one of the plurality of outward facing sensor regions, wherein each of the plurality of recesses is non-continuous with one another;
• and
• a center-point module, wherein the center-point module is configured to utilizes the sensor information to determine a center-point of the sensor wafer relative to a center-point of a pedestal on which the sensor wafer rests, and wherein the placement controller is configured to control a positioning robot that places the sensor wafer on the pedestal.