Two-dimensional pulsed-plasma simulation of a chlorine discharge

Abstract

A two-dimensional (r,z) continuum model was developed to study the spatiotemporal dynamics of a pulsed power (square-wave modulated) chlorine discharge sustained in an inductively coupled plasma (ICP) reactor with a planar coil. The self-consistent model included Maxwell’s equations for the power deposition profiles coupled to the electron energy equation and the species mass balances. Simulation results showed separation of the plasma into an electronegative core and an electropositive edge during the active glow (power on) and the formation of an ion–ion plasma ∼15 μs into the afterglow (power off). During the early active glow, the negative ion flux was convection dominated near the quartz window of the ICP reactor due to the formation of large electrostatic fields, leading to a self-sharpening front propagating into the plasma. The negative ion density profiles were found to have a strong spatial dependence underlying the importance of spatial resolution in negative ion density measurements. The time dependent ion and radical flux uniformity was also studied. Simulation results were compared with experimental data and reasonable agreement was observed.

Global (volume-averaged) model of inductively coupled chlorine plasma: Influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

“…The setup is connected to a diffusion chamber with identical gas pressure. Ramamurthi et al [3] showed in a similar setup that the plasma does not diffuse into this chamber for the same modulation parameters. Since the period is very small compared with the flow time-scale, we also observed that a mass flow rate of 30 sccm and 0 sccm does not change the calculations.…”

Pulsed plasma etching for semiconductor manufacturing

“…Only the major ion Cl + 2 density is shown (Cl + is not included). From [76] wall sheath which contains only positive ions and electrons. For high enough negative-ion densities, the electropositive periphery is squeezed, and eventually the negative ions reach the sheath edge.…”

Parallel 2D Axisymmetric Fluid Modeling of CF4 Discharge in an Inductively Coupled Plasma Source During SiO2 Etching

“…The ambipolar diffusion approximation of the ions and electron are assumed, [35,37,38] which the electrostatic field can be written as…”

“…Instead, we have assumed ambipolar transport in the bulk (because of very thin sheath) and replaced the sheath effect by Bohm velocity in the modeling like the other researchers in the field. [35,37,38] All the discretized equations were solved semi-implicitly (with most updated information) and sequentially at each time step. In this study, a multi-scale time-marching approach is adopted to reduce the computational cost.…”