Jim Keller's Fab2 (formerly Atomic Semi) rebrands to build a factory for mass-producing semiconductor fabs, pursuing distributed fab manufacturing.

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. The rebrand recasts the company around the concept of a "fab fab"—a factory designed to mass-produce small semiconductor fabs and the tools inside them.

Fab2 designs and builds every component in-house, from pumps, valves, and gas lines to lithography systems and vacuum chambers. The company integrates these components into machines, assembles machines into complete fabs, and aims to mass-produce the fabs themselves. The hardware is paired with Studio, an in-browser collaborative EDA tool for layout, schematic, and simulation work, previously known as Atomic Studio.

Rather than moving 300mm wafers through massive production lines, Fab2 targets small, software-defined fabs capable of patterning chips much smaller than a wafer and delivering prototypes in hours. Zeloof demonstrated the concept's viability as a teenager by fabricating lithographic chips in his parents' garage down to roughly 300nm features before co-founding the company with Keller in 2022.

The primary constraint of this approach is throughput. Electron-beam lithography writes patterns directly rather than projecting them through a mask, making it significantly slower than conventional methods—a single patterning step on a small chip can take far longer than an EUV scanner needs to expose an entire 300mm wafer. This tradeoff makes the technology well-suited for prototyping and low-volume runs rather than high-volume commercial production.

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. The startup shifted its hiring focus to Texas after four years in California and currently employs around 84 people as of May 2026.

The company raised a reported $15 million seed round in 2023, led by the OpenAI Startup Fund, at a valuation of approximately $100 million, with angel backing from Naval Ravikant, Nat Friedman, and Fred Ehrsam.

In relocating to Texas, Fab2's model of many small, replicable fabs now positions it alongside ventures like SpaceX's Terafab, announced in March, which targets a single Austin megafab capable of one terawatt of annual compute at a projected cost of up to $119 billion. Though operating in different market segments—Fab2 sells small fabs and prototyping speed while Terafab is built for high-volume AI production—both represent competing visions for how the U.S. should expand its chipmaking capacity: consolidating everything in massive manufacturing campuses or distributing production across many small, reproducible fabs.