Electromagnetic Design of Excitation Coils for an Inductively-Coupled Plasma Etching System

This paper presents the design and optimization of coils used for inductively coupled plasma at 13.56 MHz. Simulations of an existing ICP system for semiconductor etching using Ansys HFSS are compared with simulations using improved coil designs to reduce conduction loss, improve magnetic field uniformity, and increase RF power transferred to the plasma. This design considers different coil cross sections, effects of dielectric shielding, and the impact of coil spacing on magnetic field uniformity. The improved design is shown to achieve 98.5% efficiency of RF power delivered to the plasma through reduced coil conduction loss in addition to a more uniform distribution of the generated magnetic field.