SYSTEM AND METHOD FOR CONTROLLING PROCESS END-POINT UTILIZING LEGACY END-POINT SYSTEM

摘要

Embodiments in accordance with the present invention allow a second end-point determination (EPD) system to actively control the end-pointing of a semiconductor process chamber, by leveraging a legacy EPD system that is already integrated with the chamber. In one embodiment, the second EPD system controls a shutter that regulates the amount of light transmitted between a plasma light source and an optical emission spectroscopy (OES) sensor of the legacy OES EPD system. In this embodiment, the legacy OES EPD system is pre-configured to call end-point when an artificial end-point condition occurs, i.e. the intensity of light falls below a pre-set threshold. When the second EPD system determines an actual end-point condition has been reached, it closes the shutter which, causes the light intensity being read by the OES sensor to fall below the pre-set threshold. This in turn triggers an end-point command to the chamber from the legacy OES EPD system.