Fab2 rebrands Atomic Semi, pivots to mass-producing semiconductor mini-fabs from Texas

Jim Keller's Atomic Semi, co-founded with DIY chip maker Sam Zeloof, has rebranded to Fab2 and shifted operations to Texas in a strategic pivot toward manufacturing small semiconductor fabs—what the company calls a 'fab fab.' The startup designs and builds every tool in-house: pumps, valves, gas lines, lithography equipment, and vacuum chambers. Instead of shipping 300mm wafers through traditional production lines, Fab2 targets compact, software-defined fabs that pattern chips smaller than a wafer and turn prototypes around in hours.

Fab2 now operates three facilities: a 120,000-square-foot headquarters in Austin for R&D and production, a 30,000-square-foot 'fab fab' in Lockhart that manufactures fabs themselves, and the original 25,000-square-foot 'garage fab' in San Francisco. The company raised a $15 million seed round in 2023 at roughly $100 million valuation, led by OpenAI Startup Fund. Tracxn lists roughly 84 employees as of May 2026. The method's main constraint is throughput: electron-beam lithography writes patterns directly rather than projecting through a mask, making each patterning step far slower than EUV scanners processing a 300mm wafer, which suits prototyping and low-volume runs rather than high-volume commercial production.

Fab2's Texas move aligns it alongside Tesla and SpaceX, which announced Terafab in March targeting terawatt-scale AI compute capacity. The two represent contrasting answers to U.S. chipmaking expansion: Fab2 sells small replicable fabs and prototyping speed; Terafab pursues high-volume manufacturing in a single megafab. For infrastructure architects, Fab2's model signals a parallel bet that distributed, software-defined fabrication can address capacity bottlenecks in specialized and emerging-geometry chip production where large fabs lack flexibility.