Ion and neutral inertial effects in inductively coupled plasmas

Abstract

Summary form only given. Inductively coupled plasmas (ICPs) are currently being investigated as high plasma density (>10/sup 11/-10/sup 12/ cm/sup -3/), low gas pressure (<10-20 mTorr) sources for semiconductor etching and deposition. Development of models for these devices has been challenging due to neutral and ion transport being in a transition regime between continuum and molecular flow. A 2-dimensional (r,z) hybrid model has previously been developed to study ICP sources. The simulation consists of an electromagnetic module, an electron Monte Carlo simulation, and a fluid-chemical kinetics simulation; and offline hydrodynamic and plasma chemistry Monte Carlo simulations. In the parameter space of interest, inertial effects, momentum transfer between advectively hot ions and neutrals, and jetting of input gases is expected to be important. In this work, we have improved upon the fluid-chemical kinetics simulation by including ion and neutral momentum equations for all species. In doing so, time dependent and inertial transport effects are included. Momentum transfer collisions between all heavy species (neutral-neutral, neutral-ion, ion-ion) are accounted for. The advective flow field is established by specifying flow rates at the input and output ports as part ofthe boundary conditions. The output flow is dynamically adjusted to keep the average pressure in the reactor constant.