Jim Keller’s startup is building a factory to mass-produce small semiconductor fabs —Atomic Semi rebrands as ‘Fab2’ underlining intended role as a ‘fab fab’

Atomic Semi, the semiconductor tooling startup founded by chip architect Jim Keller and DIY fabrication pioneer Sam Zeloof, has rebranded as Fab2 and moved its operations to Texas, according to the company’s new site at fab2.com. The rebrand recasts the company around the idea they’re calling a “fab fab,” a factory that mass-produces small semiconductor fabs and the tools inside them.

Fab2 designs and builds every tool in its fabs in-house, from pumps, valves, and gas lines to lithography and the vacuum chambers that house it. The company assembles those components into machines, the machines into complete fabs, and then aims to mass-produce the fabs themselves. It pairs the hardware with Studio, an in-browser, collaborative EDA tool for layout, schematic, and simulation work, previously branded as Atomic Studio.

Rather than moving 300mm wafers through ginormous production lines, Fab2 targets small, software-defined fabs that pattern chips far smaller than a wafer and turn prototypes around in hours. Zeloof built the concept’s proof point as a teenager, fabricating lithographic chips in his parents’ garage down to roughly 300nm features before co-founding this company with Keller in 2022.

The method’s main constraint, however, is throughput. Electron-beam lithography writes patterns directly rather than projecting them through a mask, which makes it slow: a single patterning step on a small chip can take far longer than an EUV scanner needs to expose an entire 300mm wafer. That’s a big tradeoff that only really suits prototyping and low-volume runs rather than high-volume production at commercial foundries.

Fab2 now operates three sites: a 120,000 square foot facility in Austin serves as the new headquarters for research and production, a 30,000 square foot site in Lockhart houses the “fab fab” itself, and the original 25,000 square foot “garage fab” remains in San Francisco.

Fab2 said it shifted its hiring focus to Texas after four years in California, and Tracxn lists the company at around 84 employees as of May 2026. The startup raised a reported $15 million seed round in 2023, led by the OpenAI Startup Fund, at a valuation of about $100 million, with angel backing from Naval Ravikant, Nat Friedman, and Fred Ehrsam.

In moving to Texas, Fab2’s model of many small, printable fabs now sits beside the likes of Tesla and SpaceX, which announced Terafab back in March, a single Austin megafab targeting a terawatt of annual compute at a cost of up to $119 billion. The contrasting businesses are clearly not competitors; Fab2 sells small fabs and prototyping speed, while Terafab is built for high-volume AI. But they represent competing answers to the same question of how the U.S. should expand its chipmaking capacity — consolidate everything in massive manufacturing campuses, or distribute production across many small, replicable fabs?