Jim Keller's Fab2 Aims to Mass-Produce Chip Fabs

Jim Keller and Sam Zeloof just renamed their semiconductor startup Atomic Semi to Fab2. The new name reflects a strange and ambitious premise: they want to build factories that build other factories.

Fab2’s plan is to design and manufacture every piece of equipment used inside its fabs — pumps, valves, gas lines, lithography systems, vacuum chambers, all in-house. Those components get assembled into machines, the machines get assembled into complete fabrication plants, and the company hopes to eventually mass-produce chip fabs at scale.

But Fab2 isn’t chasing the cutting edge. The company is not interested in pushing 300mm wafers through billion-dollar cleanrooms running EUV lithography. Instead, it’s focused on small, software-defined fabs built for chips far smaller than a full wafer. These facilities are designed to turn around a prototype in hours, not months.

Sam Zeloof proved the concept could work in 2022, when he was still a teenager. He built working chips with feature sizes down to roughly 300 nanometers using homemade equipment in his parents’ garage. That garage operation, crude as it sounds, became the technical foundation for the company he later co-founded with Keller.

The trade-off is throughput. Fab2 relies on electron-beam lithography, which writes patterns directly onto the substrate instead of projecting through a mask. The process is slow: patterning a single tiny chip can take longer than an EUV scanner needs to expose an entire 300mm wafer. This makes the technology practical for prototyping and small-batch production, but not for the kind of volume that TSMC or Samsung delivers.

Fab2 currently operates three facilities. The new headquarters and R&D center occupies a 120,000-square-foot site in Austin, while a dedicated 30,000-square-foot facility in Lockhart is purpose-built for the “fab factory” — the assembly line that assembles assembly lines. The original 25,000-square-foot “garage fab” in San Francisco is still running.