Vacuum System Simulations Webinar and Videos

November 1, 2012

Since I joined COMSOL in 2010 I’ve presented about half a dozen webinars. Last week we held a webinar on Vacuum System Simulations and it was definitely the most fun webinar to-date. Historically, simulation has not been used extensively in the vacuum industry, so I was nervous that there wouldn’t be much interest in such a specialized topic.

Once the event started I was relieved and excited that over 125 people joined the webinar. Many of the attendees tuned in from Europe, at 8pm local time. Nearly 40% of our webinar attendees had never used a simulation tool for vacuum applications. Only a third used simulation software on a monthly basis or more frequently. I was excited to see so much interest from a community that has not been used to doing simulation.

Both in my contact with our customers and in my previous position as a design engineer, I have seen the tremendous value that simulation tools add to the product design process. I am excited to see COMSOL breaking new ground in the field of vacuum simulation. Vacuum systems are expensive: a single tool usually costs tens of thousands of dollars, and they are often custom designed. Leveraging simulation tools in the design process really makes sense in this industry.

One of the things I love about being a developer with COMSOL is that occasionally I get to see some of the amazing things that our customers do with the software. I’m looking forward to seeing a new generation of vacuum engineers making an impact on their industry with COMSOL. The videos below show the demonstration that was a part of the webinar, which shows how to build a model of an ion implant vacuum system. Ion implantation is used extensively in the semiconductor industry to implant dopants into wafers. The dopant ions arrive at the wafer as an ion beam, which is accelerated through the vacuum system along a curved path by both electric and magnetic fields. When the beam strikes the wafer, the photoresist mask outgases, giving off a variety of organic compounds, which interact negatively with the beam itself. In this case the outgassing of hydrogen is studied in detail, with a particular emphasis on the number density of the species along the beam line. One way to reduce the number density of outgassed species along the beam line is to tilt the wafer away from the incident beam. This effect is quantified in the model.

Chapter 1

Chapter 2

Comments (8)

Leave a Comment
Log In | Registration
Wilhelm Estrada
February 4, 2013


I am new to Comsol and have just received my new license. I would like to do a simulation of my scientific vacuum system, but I realize that I don’t have access to the rarefied gas flow tab on my license. Can you help me get this added to my license?

Thank you,
Wil at KMLabs

Phil Kinnane
February 5, 2013

Hi Wil,

Thanks for your feedback. Right now, Physics Interfaces for Rarefied Gas Flow are a part of the Microfluidics Module. But I have passed your message on to your Sales Rep, who will soon be in touch.

Kenneth Lillemo
November 18, 2013

It is helpful to many that work for a company that blocks Youtube access to flag these videos as Educational. Otherwise we are only left to view the tantalizing preview frame.

Fanny Littmarck
November 19, 2013

Hi Kenneth,

You can also find these two videos in our Video Center:

Hope that helps for now.

Also, if you’re interested, the webinar mentioned in this blog post is occurring again on November 21:

Sheng-Yung Chen
November 19, 2013

It’s helpful for me to study an ion-implant vacuum system. However, the simulation just simulates the distributions of incident molecular flux, number density and pressure. Would you be so kind to add the particle tracing of the ion beams on this module? Thank you very much!

Christopher Boucher
November 21, 2013

Hi Sheng-Yung,

With the Particle Tracing Module, you can model the trajectory of an ion beam due to electric and magnetic fields using the Charged Particle Tracing interface. The following examples show how you can set up such a model: (requires AC/DC Module)

Michael Junker
November 21, 2013

I have a real-world problem, as is typical it is a dirty, uncertain constraints situation. I am interested in the vacuum regime which is about 30 to maybe 10 Torr. The application is the pump-down of petroleum pipelines that run under the Gulf of Mexico to shore or to the platform. The goal is to verify that the pipeline integrity (no holes) is intact and to flush the line of hydrocarbons. The line will then be flooded with sea water and sealed and abandoned. The critical feature is to ensure adequate removal of hydrocarbons to ensure an ecologically safe pipe to flood, seal and abandon. What I am interested in is whether it is possible to model this situation accurately enough that 2 things can be certain 1) that evacuation of such lines can be made secure with evacuation which is limited to at best 29 inches of vacuum (~25 Torr) at the pump and 2) can the performance of the evacuation procedure be determined from either time or the performance characteristics of the evacuation system? Needless to say there will have to be a lot of assumed parameters.

James Ransley
November 22, 2013

Hi Michael, at the pressures you are talking about the mean free path of air is of order 1 mm, which means that your system is likely in the slip flow (mean free path/system size<0.1) or even the continuum flow (mean free path/system size<0.01) regime (I assume that the pipes have a diameter on the length scale of cm to m in your case). You might want to consider using conventional fluid flow for modeling your system in this instance – rather than the specific tools we have for rarefied gas flows.