Heated wafer carrier profiling

A method of characterizing a surface comprising:

• rotating a carrier about an axis of rotation, the carrier having a top surface adapted to hold at least one semiconductor wafer with a major surface of the wafer extending generally transverse to the axis of rotation;
• moving a surface characterization tool over a plurality of positions relative to the top surface of the carrier, whereby a measurement location over the top surface of the carrier is changed, while said top surface of the carrier is heated to a predetermined temperature;
• producing characterization signals over the plurality of positions with the surface characterization tool, the characterization signals containing information about the heated top surface of the carrier;
• determining values for position-dependent parameters characterizing the top surface of the carrier based on the characterization signals;
• comparing the position-dependent parameters characterizing the top surface of the carrier to a reference carrier top surface, wherein the reference carrier top surface is determined by performing the rotating, moving, producing, and determining steps on a randomly selected carrier;
• and
• reviewing the position-dependent parameters characterizing the top surface of the carrier based on the characterization signals against predetermined acceptable parameters.