They did a presentation at Hot Chips, with all these details.

The core die is made with TSMC-N2P, while the SRAM die and the peripheral die are made with TSMC-N5.

Their CPU is designed in Japan, like the AMD CPUs or the Intel CPUs are designed in USA (the latest Panther Lake Intel CPUs have returned for fabrication to USA in 2026, but they also cost double than the corresponding Arrow Lake models made at TSMC in 2025, and their GPUs are still made at TSMC).