On the determination of the multi-temperature SF₆plasma composition

Abstract

We have calculated the multi-temperature SF6 plasma composition by two different methods. One method is based on the mass action law whereas the other method uses a kinetic chemical reaction scheme. The first approach is furthermore split up in two different calculations. One is based on the multi-temperature Saha equation and the other is based on the excitation temperature of the involved species. With respect to the electron density we conclude that the multi-temperature Saha equation results in appreciable higher number densities compared to both the kinetic scheme and the excitation-temperature-based calculations. The difference increases with decreasing gas temperature and increasing electron temperature (i.e. with increasing degree of kinetic non-equilibrium). The kinetic scheme and the excitation-temperature-based calculation yield comparable results for higher gas temperatures. In this region the excitation-temperature-based method is preferable over the kinetic method. However, for the dielectric case (i.e. lower gas temperature) we find different results at higher electron temperatures. The excitation-temperature-based calculation method requires additional modelling at this point.

Advanced Plasma Processing: Etching, Deposition, and Wafer Bonding Techniques for Semiconductor Applications

“…As described earlier, when the SF 6 is injected into the chamber, the plasma ionizes and radicalizes the gas molecules to create a mixture of SF x and F y ions and neutrals, where x and y range from 0 to 6 and 1 to 2, respectively (Cliteur et al, 1999). The potential established between the plasma and the substrate, due in part to the ICP and the CCP power, causes the electric field that drives the ions down to the substrate.…”

Environmental, thermal, and electrical susceptibility of black phosphorus field effect transistors

“…During the Si dry etch process, sulfur hexafluoride (SF 6 ) is ionized and radicalized by the plasma and creates a mixture of SF x and F y ions and neutrals, where x and y can range from 0 to 6 and 1 to 2, respectively. 26 The process is a combination of physical (anisotropic) and chemical (isotropic) etching. The physical process mostly sputters materials off the bottom of the trench, and could lead to material redeposition on…”

Non-uniqueness of the multi-temperature law of mass action. Application to 2T plasma composition calculation by means of a collisional-radiative model

“…-Gibbs free enthalpy minimization vs kinetic model [68]; -Gibbs free enthalpy minimization vs 2T law of mass action [69]; -2T law of mass action vs kinetic model [70][71][72].…”