Plasma
Reactor-scale plasma simulation for semiconductor manufacturing
What is plasma simulation?
Plasma Kinetics
Drive a process gas into a discharge and you don’t get a gas at one temperature. Electrons and ions spread across a range of energies. Near the wafer, in the sheath, neither one behaves thermally.
Wafer Interaction
That sheath decides your profile. Ions do the etching, and the sheath field sets the energy and angle each one arrives with. Sidewall, depth and uniformity follow from those two numbers. A sheath model that’s off gives you a profile that’s off, whatever the chemistry says.
Reactor Optimization
Without simulation, you find out by building the chamber and running it, or by switching a working tool to a new gas. Both cost tool time and wafers. Plasma modeling moves that sweep into software. That’s the job VSim Plasma, Silvaco’s plasma simulator, was built to do.
VSim Plasma
A kinetic plasma code built on particle-in-cell methods. It tracks electrons, ions and neutrals through a background gas at any pressure, with the elastic, excitation and ionization collisions between them. What you get back is the ion energy and angle distribution at the wafer.
In semiconductor processing
Plasma wafer etching
Model the sheath field over the wafer and the dielectrics around it, which together set how evenly the ions arrive.
Magnetron sputtering
Thin-film deposition, with target erosion and deposition profiles computed from the charged-particle physics.
Plasma simulation applications
Plasma etch profile prediction
Compute the ion energy and angle distribution at the wafer and hand it to Victory Process, which builds the feature from it.
Sputter deposition
See where a magnetron target wears and how evenly the film builds up.
Chamber and reactor design
Try a new chamber geometry or drive waveform in the model and see how uniformity responds before any hardware exists.
Process optimization through FTCO
Connect reactor-scale conditions to feature-scale results in one loop, using surrogate models.
For Tech-X and VSim Plasma users
VSim Plasma is now part of Silvaco
Silvaco acquired Tech-X Corporation, the company behind VSim Plasma, in April 2025.
What hasn’t changed
VSim Plasma keeps its name, now as Silvaco’s plasma simulator. John Cary, CTO of Tech-X when the acquisition was announced, is now a Senior Director and Fellow at Silvaco.
Support, licenses and documentation
These still live on txcorp.com.
Where VSim has already held up
Before you trust a plasma code with your chamber, you’ll want to know what it has run on and who has relied on it.
National-scale machines
VSim Plasma has run on Artemis at the University of Sydney, Theta at Argonne National Laboratory, Cori at Lawrence Berkeley National Laboratory and Shaheen II at KAUST. It’s a parallel code, written to scale from a cluster up to the largest supercomputers.
Ion source modeling at CERN
“A substantial amount of the value of the software was the support we received and the help setting up the ion source models. This has made VSim Plasma really useful for our research.”
Bruce Marsh, Physicist, CERN
Plasma simulation webinars and talks
Webinar
July 2026
Simulation of plasma chambers for predictive simulation of semiconductor manufacturing
John Cary walks through pulling the ion energy and angular distribution out of an etch chamber, what the drive waveform does to it, and how to take the result into a device process model.
Conference talk
SURGE 2025
Machine learning for multi-scale plasma process integration and optimization
Dr. Lado Filipovic, director of the Silvaco-supported Christian Doppler Laboratory at TU Wien, on machine-learning models that bridge reactor scale and feature scale for high-aspect-ratio etch.
Where to go next with VSim Plasma
Evaluating VSim Plasma
Bring the chamber and the profile that won’t come out right. Silvaco’s application engineers help you set up the simulation and pull out the results you need to judge it.
Reading the manual
You’ll find the VSim Plasma documentation, with nearly 100 worked examples and tutorials, on txcorp.com.
Already running VSim Plasma
Open VSim Plasma cases in the Tech-X support portal. For other Silvaco tools, use Support and Downloads.
Plasma simulation questions
What is plasma simulation?
Plasma simulation computes a plasma particle by particle rather than as one temperature-averaged gas. A particle-in-cell code moves charged particles and neutrals through their own self-generated fields and tracks the collisions between them. You get distributions, not averages. That matters, because a process plasma isn’t in thermal equilibrium.
How does plasma simulation help with etch and deposition?
It comes down to what hits the surface. For etch, that’s the energy and angle of each ion at the wafer, set by the sheath field. For sputter deposition, it’s the erosion pattern on the target and the deposition profile that follows. Change the chamber or recipe in the model and both shift before you touch the tool.
How does plasma modeling connect to TCAD process simulation?
Through the ion flux at the wafer. VSim produces the particle distributions at chamber scale, and Victory Process reads them in to predict the etched feature. A change you make to the chamber carries straight through to the predicted device structure.
What happened to Tech-X and VSim Plasma?
Tech-X Corporation became part of Silvaco in April 2025, and VSim carries on as Silvaco’s plasma simulator. Tech-X’s former CTO, John Cary, now holds a Senior Director and Fellow role at Silvaco. Existing VSim users still get support and licensing through txcorp.com.
Can plasma simulation run on GPUs or supercomputers?
Yes, on supercomputers. The code runs in parallel on HPC systems, and national-scale machines such as Theta at Argonne and Shaheen II at KAUST have hosted it. On GPUs, Silvaco has stated that Tech-X brings multi-node GPU algorithms into its portfolio. Talk to an application engineer before you size a cluster.
How is plasma simulation used with FTCO and digital twins?
A full kinetic run is too slow to sit inside a co-optimization loop. Research shown at SURGE 2025 trains machine-learning models to bridge reactor and feature scales, which is the surrogate method FTCO uses on process data. More accurate digital twins were a stated goal of pairing Tech-X’s tools with Victory TCAD.