Practical Plasma For Thin-Film Deposition

[Nixie] wants to sputter. We know, who doesn’t? But [Nixie] has a specific purpose for his sputtering: thin-film deposition, presumably in support of awesome science. But getting to that point requires a set of tools that aren’t exactly off-the-shelf items, so he’s building out a DIY sputtering rig on the cheap.

If you’re not familiar with sputtering, that’s understandable. In this context, sputtering is a process that transfers particles from one solid to another by bombarding the first solid with some sort of energetic particles, usually electrons or a plasma. When properly controlled, sputtering has applications from mass spectrometry to the semiconductor industry, where it’s used to either deposit thin films on silicon wafers or etch them away selectively.

No matter the application, sputtering needs a stable stream of plasma. [Nixie] has posted a series of articles on his blog walking us through his plasma experiments, from pulling a really strong vacuum to building a high-voltage power supply from a microwave oven transformer. It’s a project that needs a deep well of skills and tools, like glassworking, machining, and high-voltage electronics. Check out the plasma in the video below.

Will [Nixie] be using this for a DIY fab lab? Will it be used to make homebrew LEDs? The world waits to hear.

32 thoughts on “Practical Plasma For Thin-Film Deposition

  1. Sputtering..,,, same as plasma etching? We work with high voltage a lot, obviously potting is important, but, we have to plasma etch the polypropylene so epoxy will stick. A large plasma etcher is expensive, I wonder if this would work the same but for smaller quantities, like lab stuff onesy, twosy kind of stuff.

    1. In principle sputtering systems can have the polarity of the gun reversed and thus sputter (etch) the substrate. Some small microscopy sputter coating systems have a control knob for just this purpose. I’ve attempted to do surface modification in etch mode with O2 in the gas mix, and it does work on all the plastics I tried. It also works on Si wafers and marginally on crystalline quartz.

      FYI sticking a hard drive magnet in a sputter coater in etch mode is very cool: Homebrew northern lights.

  2. I just found this article which reminded me of a place I worked making thin film resistors , briefly fixing stuff and then running a laser trimmer. The sputtering system was made by one of the company founders and handled 15 ceramic plates at a time. I wasn’t an engineer but had frequent chats with them and one issue was the vacum pump has the nasty habit of belching oil back onto the plates occasionally. The engineer suggested using a cryo pump (the impeller looked like a corkscrew) and the owner of the company took it personally HOW DARE YOU SUGGEST MY CREATION ISN’T PERFECT attitude lol.
    They got bought out by a bigger company but are still there

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