Baseline particle reduction of downstream oxide etchers etching contacts and vias

摘要

In the process of etching contact and via openings with a downstream oxide etcher, plasma etch byproducts form polymer that collects on process chamber components. Polymer build up over time will begin to separate from chamber components and deposit on the wafer, blocking the etch and creating incomplete contact and via openings, which result in device failure. When this phenomena occurs, complete disassembling and cleaning of the chamber (wet clean) is required before particle levels are acceptable again for processing wafers. Over half of the time wet cleans are performed at or before 1500 wafers processed.