How the Plasma Module Improves Your Modeling
Low-temperature plasmas combine elements of fluid mechanics, reaction engineering, physical kinetics, heat transfer, mass transfer, and electromagnetism. The Plasma Module primarily focuses on modeling these low-temperature plasmas and provides specialized physics interfaces tailored to the most common types of plasma reactors and plasma processes, as outlined below.
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Inductively coupled plasmas (ICP)
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Capacitively coupled plasmas (CCP)
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Inductively coupled plasmas with RF bias
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Microwave plasmas
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Light sources
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Electrical breakdown
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DC discharges
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Plasma-enhance chemical vapor deposition (PECVD)
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Plasma Enhanced Etching
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Dielectric barrier discharges (DBD)
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Electron cyclotron resonance (ECR)
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Reactive gas generators
The complexity of plasma modeling arises from its integration of reaction engineering, statistical physics, fluid mechanics, physical kinetics, heat transfer, mass transfer, and electromagnetism. This creates a true multiphysics problem, with intricate coupling between these diverse fields. The Plasma Module is designed to streamline the process of creating a self-consistent model for low-temperature and thermal plasmas.
The physics interfaces provide all the essential tools needed to model plasma discharges, starting with a Boltzmann Equation solver using the Two-Term Approximation. This interface calculates electron transport properties and source coefficients based on a set of electron impact collision cross sections. By inputting parameters such as the electric field and electron impact reactions that define the plasma chemistry, this interface enables the determination of many key discharge characteristics without requiring a space-dependent solution.
For space-dependent models, the plasma chemistry is conveniently managed within the Model Builder. Users can add reactions and species manually or import them from a file. The platform supports defining electron impact reactions, heavy species reactions, and surface reactions. Electron impact reactions can be specified using electron impact cross sections, from which rate constants are derived by integrating the cross sections over the electron energy distribution function. This distribution can either be defined analytically or obtained from solving the Boltzmann Equation using the Two-Term Approximation.
When the fluid velocity and gas temperature are of interest, there are physics interfaces available for laminar flow and heat transfer. There are several options available when coupling the charged species transport to the electromagnetic fields. Poisson’s equation for the electrostatic potential is always solved in the Plasma or Plasma, Time Periodic interfaces. Modeling inductively coupled plasmas, where induction currents are responsible for sustaining the plasma, requires the AC/DC Module. For microwave plasmas, the RF Module is required.
Modeling the interaction between the plasma and an external circuit is an important part of understanding the overall characteristics of a discharge. This module has tools to add circuit elements directly to a 1D, 2D, or 3D model Component node, or import an existing SPICE netlist into the model.