Correlation Between Electron Temperature Uniformity And Charging Damage In High Density Plasma Etching Tool

We investigated the correlation between the charging damage and the plasma parameter’s uniformity in high density plasma etching tool. The spatially uniform ion current density (or plasma density) and plasma potential, which have been commonly used as an index of plasma uniformity, does not always guarantee charging damage-less plasma. We demonstrate that a uniform electron temperature distribution is one of the most important parameters to suppress the charging damage, as well as uniform plasma potentials and rf voltages distribution across the wafer.