US SB1642

Expands the Section 48D advanced manufacturing investment tax credit to include facilities manufacturing semiconductor materials, in addition to semiconductors and semiconductor manufacturing equipment

Defines "direct production materials" as materials physically incorporated into finished semiconductors, including substrates (silicon, silicon carbide, gallium nitride), thin film/layering materials, packaging substrates, and bonding/interconnect materials

Defines "indirect production materials" as specialized materials used in production but not incorporated into finished chips, including process chemicals, photolithography materials, cleaning/planarization agents, testing equipment, and packaging process materials

Requires the Treasury Secretary, in consultation with the Commerce Secretary, to publish within 180 days and annually thereafter a list specifying which materials qualify for the credit, with a petition process for materials not yet listed

Applies to property placed in service after the date of enactment; introduced May 7, 2025 with bipartisan sponsorship (Sens. Blackburn, Bennet, Tillis, Coons) and referred to the Senate Finance Committee