A model for the impact of chamber wall condition on oxide etch rate and particle performance

摘要

An abnormal drift of TEOS etch rate and particle count has been found during MERIE oxide etch for damascene process. Data indicate etch rate fluctuates between 2000 A/min. and 600 A/min. and particle count varies from 0 count to several thousand counts after the chamber is idled for few hours. Studies show normal TEOS etch rate and low particle count when the chamber wall is well coated with polymer deposition. On the other hand, low etch rate and high particle count appear when chamber has less deposition. A model is proposed to explain the impact of chamber wall polymer deposition on TEOS etch rate.