an electrostatic chuck including at least one light pipe, the electrostatic chuck capable of receiving a substrate having a light sensing and temperature sensitive material deposited on at least one spot on a backside of the substrate;

a light source coupled to the at least one light pipe, the light source being configured to supply light to the at least one light pipe so as to apply a light to the light sensing and temperature sensitive material deposited on the at least one spot on the backside of the substrate when the substrate is present over the electrostatic chuck;

a detector coupled to the at least one light pipe, the detector being configured to collect a fluorescent light emitted from the light sensing and temperature sensitive material as a result of the light being applied on the light sensing and temperature sensitive material to determine a substrate temperature on the at least one spot on the backside of the substrate, wherein the substrate temperature is determined by measuring the decay of the emitted fluorescent light after the light source is turned off; and

a chamber controller utilizing the determined substrate temperature to adjust temperature controlling parameters of the electrostatic chuck to maintain desired substrate temperature ranges for a plurality of substrates to be processed over the electrostatic chuck.