A thermal process system. The thermal process system comprises a thermal processor, a metrology tool, and a controller. The thermal processor performs a thermal process as defined by a heating model to form a film on a wafer surface. The metrology tool, interfaced with the thermal processor, inspects thickness of the film. The controller, coupled with the thermal processor and the metrology tool, generates the heating model of the thermal processor and calibrates the heating model according to a preset slope coefficient matrix and the measured thickness.