Lam Research Corporation
USE OF VOLTAGE AND CURRENT MEASUREMENTS TO CONTROL DUAL ZONE CERAMIC PEDESTALS

Abstract:

A method for controlling temperature of a substrate support includes receiving first and second currents corresponding to first and second heater elements, respectively, of a substrate support, receiving first and second voltages corresponding to the first and second heater elements, respectively, calculating a first resistance of the first heater element based on the first voltage and the first current, calculating a second resistance of the second heater element based on the second voltage and the second current, calculating a first temperature of a first zone of the substrate support based on the first resistance and stored data correlating resistances to temperatures, calculating a second temperature of a second zone of the substrate support based on the second resistance and the stored data, and selectively adjusting the stored data based on a comparison between a sensed temperature and at least one of the calculated first temperature and second temperature.