Photonics chips don't need bleeding-edge process nodes like 3nm or 5nm. 90nm and 45nm nodes are totally sufficient for current photonic integrated circuits.
Why? Photonic components (waveguides, modulators, photodetectors) are physically larger than transistors. They operate with light wavelengths around 1550nm, so sub-10nm lithography doesn't help. The critical specs are optical loss, modulation bandwidth, and coupling efficiency—not transistor density.
45nm nodes give you enough precision for passive photonic structures while keeping costs way down. You're not trying to pack billions of transistors here. You're routing light and converting it to electrical signals.
This is why companies like Intel and GlobalFoundries use mature nodes for silicon photonics. The real engineering challenge is hybrid integration with electronics, not shrinking the photonics themselves.
Why? Photonic components (waveguides, modulators, photodetectors) are physically larger than transistors. They operate with light wavelengths around 1550nm, so sub-10nm lithography doesn't help. The critical specs are optical loss, modulation bandwidth, and coupling efficiency—not transistor density.
45nm nodes give you enough precision for passive photonic structures while keeping costs way down. You're not trying to pack billions of transistors here. You're routing light and converting it to electrical signals.
This is why companies like Intel and GlobalFoundries use mature nodes for silicon photonics. The real engineering challenge is hybrid integration with electronics, not shrinking the photonics themselves.