A hybrid hydrodynamic-Monte Carlo simulation of the transport of neutral radicals in low-pressure remote plasma sources

In low pressure electron cyclotron resonance and remote plasma enhanced chemical vapor deposition reactors (milliTorr to hundreds of milliTorr) the mean free path of excited state neutrals can be commensurate with the vessel dimensions. Deposition species may collide with the wall several times before encountering the substrate. While the movement of these particles is essentially ballistic, the advective flow of the background gas is a significant factor in the determination of the transport of the neutral radicals. To address these conditions, a hybrid hydrodynamic-Monte Carlo model has been developed. The advective flow field is calculated from the mass and momentum equations. Radical transport is then simulated using Monte Carlo techniques that include inelastic collisions with the background species and other MC particles, absorbing or reflective collisions with reactor surfaces, or momentum transfer with the advective fluid.Presented here are the results describing the effects of geometry, pressure and gas flow for gas mixtures containing SiH$\sb4$. Identity, uniformity, and angle of incidence of the radical flux to the substrate will be addressed with the goal of optimizing the fluxes of selected species.U of I OnlyETDs are only available to UIUC Users without author permissio