Method for controlling spatial temperature distribution across a semiconductor wafer

A method for controlling the spatial temperature across a semiconductor wafer during a multistep plasma etching process wherein wafer temperature is changed for the particular layer being etched comprising:

• maintaining a base at a constant temperature, said constant temperature being below the temperature of the substrate, said base having a layer of thermal insulation material mounted on top of said base;
• electrostatically clamping the substrate against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;
• plasma etching a layer on the wafer under conditions such that local concentration of reactants varies across the wafer;
• independently heating each spatial region of said flat support with a plurality of heaters mounted to an underside of said flat support so as to induce a radial temperature gradient which compensates for the local reactant concentration;
• and
• changing the temperature of at least one spatial region of said flat support during the multistep etching process at a rate of at least 1° C. per second.

A method for controlling the spatial temperature across a semiconductor wafer during a multistep plasma etching process wherein wafer temperature is changed for the particular layer being etched comprising:

• maintaining a base at a constant temperature, said constant temperature being below the temperature of the substrate, said base having a layer of thermal insulation material mounted on top of said base;
• electrostatically clamping the substrate against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;
• independently heating each spatial region of said flat support with a plurality of heaters embedded within said flat support so as to induce a radial temperature gradient which compensates for the local reactant concentration;
• and
• changing the temperature of at least one spatial region of said flat support during the multistep etching process at a rate of at least 1° C. per second.