Method and apparatus for process control of material emitting radiation

摘要

A method and apparatus are disclosed for controlling a physical property such as deposited film thickness to a desired value of control in a high temperature process using a desired emissivity power ratio and an emissivity power ratio measured from detected radiation energy. The measured emissivity power ratio is obtained on-line from detection signals of radiation sensors. A desired value of control is converted to the desired emissivity power ratio using predetermined relationships established by theory or experiment. The desired emissivity power ratio and the measured emissivity power ratio are compared to achieve the desired value of control.