The Fab Lab Next Door: DIY Semiconductors

You think you’ve got it going on because you can wire up some eBay modules and make some LEDs blink, or because you designed your own PCB, or maybe even because you’re an RF wizard. Then you see that someone is fabricating semiconductors at home, and you realize there’s always another mountain to climb.

We were mesmerized when we first saw [Sam Zeloof]’s awesome garage-turned-semiconductor fab lab. He says he’s only been acquiring equipment since October of 2016, but in that short time he’s built quite an impressive array of gear; a spin-coating centrifuge, furnaces, tons of lab supplies and toxic chemicals, a turbomolecular vacuum pump, and a vacuum chamber that looks like something from a CERN lab.

[Sam]’s goal is to get set up for thin-film deposition so he can make integrated circuits, but with what he has on hand he’s managed to build a few diodes, some photovoltaic cells, and a couple of MOSFETs. He’s not growing silicon crystals and making his own wafers — yet — but relies on eBay to supply his wafers. The video below is a longish intro to [Sam]’s methods, and his YouTube channel has a video tour of his fab and a few videos on making specific devices.

[Sam] credits [Jeri Ellsworth]’s DIY semiconductor efforts, which we’ve covered before, as inspiration for his fab, and we’re going to be watching to see where he takes it from here. For now, though, we’d better boost the aspiration level of our future projects.

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Gas containment for laser cutters

Tired of breathing all the noxious fumes your laser cutter puts out? Yeah… we don’t have a laser cutter either. But [Jeri Ellsworth] does and she needed a way to evacuate off-gases generated during cutting so that they don’t damage the laser cutter, or her lungs. What she came up with is a containment box that attaches to a pump system.

The problem is that you want to keep the gases away from the laser cutter hardware but you still need to be able to shoot the laser at your work material. Her clever solution is to use a silicone wafer like the ones with which she makes integrated circuits. They allow the infrared laser to pass through without being chopped in half. What you see in the image above is a red box with the round wafer in the center. Near the bottom of the image is a clear window so you can see what’s going on with your work piece. But to get the full idea you need to watch the video embedded after the break.

We can’t help but think she’s building this in preparation for some more chemistry hacking.

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Transistor fabrication: so simple a child can do it

If manufacturing printed circuit boards has become too easy you should try your hand at producing transistors. [Jeri Ellsworth] put together a collection of videos outlining the process. These go way beyond the IC fabrication we saw from her in the past. It doesn’t take much, a 1000 degree oven with steam option, silicone wafers, and a variety of chemicals. We’ve embedded the instructional video as well as two demonstrations of her N-style FET after the break. Continue reading “Transistor fabrication: so simple a child can do it”