Heated stage with variable thermal emissivity method and apparatus

A method for controlled cooling of a heated stage, the method comprising:

• setting a stage coupling to a predetermined maximum value;
• heating the stage to a predetermined process temperature;
• providing a wafer on the heated stage in a process chamber, the process chamber having the heated stage and a showerhead, the heated stage at a first heated stage temperature, the showerhead at a first showerhead temperature, and the wafer at a first wafer temperature;
• performing a process on the wafer;
• reducing the heated stage coupling to a predetermined minimum value;
• reducing the heated stage temperature;
• and
• removing the wafer from the heated stage and the process chamber,
• wherein the heated stage is covered with a pixel array including multiple adjacent pixels, each one of the pixels of the pixel array includes a level of emissivity and is equipped with an emissivity control device configured to independently adjust the level of emissivity of the respective pixel, and
• wherein the heated stage coupling is configured to achieve a predetermined mapping of radiative coupling to spatially control a wafer cooling rate and a target temperature, and control wafer temperature distribution based on a radiation reflectivity profile of the pixel array.