APPLICATION OF AN ISPM ON AN LAM ALLIANCE 9400 ETCHING PROCESS

摘要

Particle generation in production tools is the major source of wafer contamination resulting in killer defects in semiconductor manufacturing. To study the features of particle generation and yield effects during etching processes, an in situ particle monitor (ISPM) sensor was installed on the pumping line of an LAM Alliance 9400 etching chamber. Particle counts measured by the ISPM were found to be a useful indicator of chamber cleanliness and had a close relationship with the number of particles determined using the witness wafer method. An increasing trend of the particle count could be observed over the production interval between two dry-clean processes of the chamber. It was also shown that most of the byproduct particles were generated during the plasma-etching steps and different particle levels were created when adopting different etching-recipes. Consequently, the study has shown that an ISPM can be used to monitor the particle level in the etching chamber in a real-time fashion and to examine the process condition and product defects for semiconductor manufacturing.