Who makes fab equipment for AI data centers

Fab equipment is the capital equipment layer behind the advanced-node foundry step: the lithography, deposition, etch, and inspection and metrology tools installed on a fab floor to actually pattern and build chips. None of it ships inside a finished accelerator — it's sold to the foundries themselves, and its order book is a forward indicator of future foundry capacity rather than a reflection of current chip shipment volume. A small number of vendors dominate specific tool categories, with lithography in particular concentrated in a single supplier for the most advanced nodes. For investors, this sub-layer offers a longer, more capital-cycle-driven view of AI accelerator demand than any part further downstream: a fab capacity expansion decision, and the equipment order that funds it, is made years ahead of the wafers that expansion will eventually produce. That makes equipment order backlogs and disclosed capital spending plans a genuinely forward-looking read on where accelerator supply is headed, at the cost of being one more step removed from the finished product than foundry capacity itself.