A system for regulating temperature of a post exposure baking process is provided. The system includes one or more light sources, each light source directing light to one or more gratings being baked and hardened on a wafer. Light reflected from the gratings is collected by a measuring system, which processes the collected light. Light passing through the gratings may similarly be collected by the measuring system, which processes the collected light. The collected light is indicative of the baking and hardening of the respective portions of the wafer. The measuring system provides baking and hardening related data to a processor that determines the baking and hardening of the respective portions of the wafer. The system also includes a plurality of temperature controlling devices, each such device corresponds to a respective portion of the wafer and provides for the heating and/or cooling thereof. The processor selectively controls the temperature controlling devices so as to regulate temperature of the respective portions of the wafer.