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What lith node is that?

The most advanced optical lithography for 6 inch wafers is I-line (365 nm wavelength). For compound semiconductor fabs, they can use e-beam lithography which allows for shorter gate lengths. Some companies are also clever about taking I line lithography and patterning tricks to make smaller features for gates.

> Some companies are also clever about taking I line lithography and patterning tricks to make smaller features for gates.

Well that's the critical question. Is that being used?

Lithography using 193nm light varies from 130nm down to 10nm, if not wider.

365nm probably doesn't vary as much, but just saying the wavelength doesn't give a clear answer about the node size.

A lot of the tricks used on 193 immersion tools for lithography scaling requires sophisticated deposition and etch processes which are not available on old 6 inch tools. Given that this factory was used for faceID parts, I suspect it was making VCSELs or other optoelectronics. These components don’t require fine lithography so it’s probably a 0.35 um capable fab.

All I can find is that the plant works with 6 inch Gallium Arsenide wafers.

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