Plasma etching process monitoring with optical emission spectroscopy

Stringent process control become an issue of growing importance in the integrated circuits manufacture. The in-suit monitoring and endpoint detection of very deep submicron meter size polysilicon gate etching is critical to the proper control of plasma etching. Process faults should be detected and corrected before the parts in etching tools are damaged. Real time monitoring with optical emission spectroscopy (OES) would allow for simultaneous correction, and OES endpoint detection is a most important means to end etching process. This paper discussed the plasma etching process control with OES, the PCA data reduction technique is used to compress the real time OES data, and endpoint detection algorithms which is used to trigger endpoint for etching process is investigated.