IMPROVEMENT ON MONITORING AND REDUCTION OF CORROSION DEFECTS ON INTEGRATED CIRCUIT METALLIZATION

摘要

Integrated circuit metallization corrosion has been a manufacturing limitation. Plasma metal etched wafers corrode when Cl-species remain on the wafers and are exposed to moisture from cleanroom air. Tool processes used for the metal etch module operation were characterized and improved. These included an in situ post-metal corrosion prevention, photoresist ashing, and deionized water rinse. The delay time between each process was significant. Liquid ion chromatography was used to determine the amount of Cl-species reduction correlated to observed defect reduction, after tool process improvements. Humidity and other environmental conditions influenced corrosion stability. Changes in the manufacturing operations prior to the metal etch operation affected the corrosion robustness. Corrosion on bonding pads from polyimide processing was studied using EDS analysis to determine F and O levels.