TSMC and ASML are teaming up to overhaul a key part of chipmaking, a long-term positive for both companies and for cheaper advanced chips.

• The two plan to move the industry from today's 6-inch photomasks — the stencils used to print circuits onto chips — to bigger 12-inch ones.
• A test production line is targeted for 2031, with the full system ready for mass production by 2033.
• Bigger masks mean chip factories can print more in one shot and cut manufacturing costs.
• Today's High NA machines have to stitch two small masks together for one pattern; the bigger mask removes that limit.
• TSMC plans to start using ASML's High NA machines in mass production from 2030, and expects to need them on more chip layers as AI pushes designs to get more complex.

Outlook: Mask makers and equipment suppliers have signaled they will join in, so expect more of the chip supply chain to commit to the switch over the next few years.