Process charging in ULSI: mechanisms, impact and solutions

This paper gives an overview of plasma charging problems in ULSI processing. Causes for charging are plasma nonuniformity and topography dependent changing. Damage is from current induced trap creation in thin oxides. For very thin oxides leakage is becoming more important than bulk trapped charge effects. Damage depends on many factors which include: plasma nonuniformity and density, device layout, aspect ratio of spaces, oxide thickness and quality, gate exposure and wafer temperature.