A high-school student from New Jersey has started making integrated circuits in his parents' garage. Sam Zeloof from Flemington, NJ is a passionate electronics enthusiast who has managed to construct a semiconductor fabrication lab known as a fab in his parents' house using spare parts and materials bought off eBay. The talented teenager says he thought that trying to make chips would be useful as a “way of trying to learn what’s going on inside semiconductors and transistors.”
His says his journey started like all good DIY experiments by collecting research material. “I started reading old books and old patents because the newer books explain processes that require very expensive equipment,” he explains. In his research quest, Zeloof stumbled across Jeri Ellsworth's brilliant YouTube channel who documents their own DIY science experiments. One such video explained how she had made some silicon transistors. “After I saw [Ellsworth’s] videos I started to make a plan of how I could actually start to do this,” says Zeloof.
Essential equipment collected from eBay
But the path wasn’t easy. Zeloof says it took him more than three months to be able to copy Ellsworth’s transistors as he slowly became to understand what was going on inside the tiny chips. As he learned, so did his collection of equipment and materials. Zeloof describes his initial foray into his chip building adventure: “ That was getting my feet wet and learning the processes and everything, and acquiring all the equipment,” he says.
“My goals from there were to build on what she did and make actual ICs.” Zeloof has so far made some simple integrated circuits with a handful of components, but he has his eyes set on a bigger goal. The dedicated students are aiming to build a copy of the ur-microprocessor, that Intel 4004, released in 1971. “It’s got about 2,000 transistors at 10 micrometers.... I think that’s very attainable,” he says.
Teen uses old equipment aided by digital devices
We hope Zeloof's parents don’t want their garage back, as images from his blog reveal a very impressive setup consisting of all sorts of specialized equipment “Acquiring all the equipment and building and fixing all the stuff I take off eBay is half of the whole journey,” Zeloof explains. His equipment list includes a vacuum chamber built from surplus parts, a high-temperature furnace and a scanning electron microscope. While Zeloof is aiming to create a technology that was created in the 1970’s he has a few modern tricks up his sleeve that could potentially aid his goal.
One of them is a technique he developed to pattern the circuits on his chips.
Zeloof modified a digital video projector by adding a miniaturizing optical stage. He uses this to create a mask as a digital image and project it onto a wafer to expose a photoresist. It is this ingenious idea combined with lots of experiments that have allowed Zeloof to make exciting headway on his project. He is also an avid blogger documenting his journey along the way. Since starting the blog Zeloof has been noticed by the small by passionate electronics community and offered advice and research from engineers who worked on this technology when it was still brand new.