In August, chip maker Intel revealed new details about its plan to build a “megafactory”in the US, a $100 billion factory where 10,000 workers will produce a new generation of powerful processors studded with billions of transistors. That same month, 22-year-old Sam Zeluf announced his semiconductor milestone. This was done alone in his family’s garage in New Jersey, about 30 miles from where the first transistor was manufactured at Bell Labs in 1947.
With a collection of salvaged and homemade hardware, Zeloof made a chip with 1200 transistors. He sliced silicon wafers, painted microscopic patterns on them with ultraviolet light, and dipped them in acid by hand, documenting the process on YouTube and on his blog. “It may be overconfidence, but I have the mentality that the other person has figured it out, so I can too, even if it takes me longer,” he says.
Zeloof now hopes to match the scale of Intel’s revolutionary 1971 4004 chip, the first commercial microprocessor that had 2,300 transistors and was used in calculators and other business machines. In December, he began work on a timing circuit capable of performing simple additions.
Outside of Zeluf’s garage, the pandemic has caused a global shortage of semiconductors, slowing the supply of products from cars to video game consoles. This sparked renewed interest from politicians in rebuilding the US’s capacity to produce its own computer chips after decades of offshoring.
Garage-built chips won’t help your PlayStation, but Zeluf says his offbeat hobby convinced him that society would benefit if chip production became more accessible to inventors without multi-million dollar budgets. “This really high barrier to entry will make you extremely risk averse, which is bad for innovation,” Zeluf says.
Zeluf started making his own chips in high school in 2016. He was impressed by YouTube videos of inventor and entrepreneur Jeri Ellsworth in which she made her own thumb-sized transistors, in a process that included cutting out templates. from vinyl stickers and a bottle of rust stain remover. Zeluf decided to replicate Ellsworth’s design and take what seemed like the logical next step: moving from single transistors to integrated circuits, a leap that historically took about a decade.
“He took another quantum leap,” says Ellsworth, now the CEO of an augmented reality startup called Tilt Five. “There is great value in reminding the world that these industries that seem so far out of reach started out with something a little more humble, and you can do it yourself.”
The production of computer chips is sometimes described as the most complex and precise manufacturing process in the world. When Zeluf started blogging about his goals for the project, some industry experts emailed him that it was not possible. “The reason for that was honesty, because I thought it would be funny,” he says. “I wanted to state that we should be more careful when we hear that something is impossible.”
Zeluf’s family supported him, but at the same time they were cautious. His father asked a semiconductor engineer friend for some safety advice. “My first reaction was that you can’t do it. It’s a garage,” says Mark Rothman, who has spent 40 years designing chips and now works for a company that develops technology for OLED screens. Rothman’s initial reaction softened when he saw Zeluf’s progress. “He did something that I would never have thought people could do.”
The Zeloof project includes both history and engineering. Modern chip manufacturing takes place in factories whose expensive HVAC systems remove every trace of dust that could damage their billion-dollar equipment. Zeluf was no match for these technologies, so he read patents and textbooks from the 1960s and 1970s, when engineers at pioneering companies like Fairchild Semiconductor were making chips in ordinary workplaces. “They describe methods using X-Acto blades, tape and a few glasses, not ‘We have this $10 million machine the size of a room,'”Zeluf says.
Zeluf also had to furnish his lab with antique equipment. On eBay and other auction sites, he found a ready-made shipment of cheap 1970s and 80s equipment that once belonged to recently closed California tech companies. Much of the equipment was in need of repair, but older machines are easier to mess with than modern lab machines. One of Zeluf’s best finds was a broken electron microscope that cost $250,000 in the early 90s; he bought it for $1,000 and refurbished it. He uses it to check his chips for defects, as well as the nanostructures on butterfly wings.