E-H Transitions in AR/O2 and AR/CL2 Inductively Coupled Plasmas-Modeling

Pulsing electronegative inductively coupled plasmas provides an additional parameter to control reactive fluxes to wafers for microelectronics fabrication.Due to the transition from low-to-high electron densities at the onset of a power pulse, there is often a transition between capacitive and inductive modes (E-H transition).Electronegative plasmas typically produce low electron densities at the start of the power pulse due to attachment reactions during the inter-pulse period, which can result in severe E-H transitions.One aspect of the E-H transition is a mismatch in the power delivery from conventional impedance matching networks- typically tuned for a particular reactor impedance.As a result, the circuit configuration can be an important factor in the E-H transitions. In this paper, we discuss results from a computational investigation using the Hybrid Plasma Equipment Model of E-H transitions in pulsed ICPs sustained in 10s mTorr of Ar/O 2 and Ar/Cl 2 mixtures for different duty cycles, frequencies,and power, bias voltages on the substrate electrode, and when using a laser for photo-detachment. Comparisons are made to 3D measurements of ion density during the onset of a pulse.The power distributions between capacitive and inductive modes, local and chamber averaged densities, energy and angle distributions of ions to chamber walls and wafer will be presented.