I’m well aware of the kinds of reasons that can lead to decisions like relaxing cell densities or other feature sizes, spacing parameters, etc. Yield, manufacturability, and transistor performance all present constraints you need to optimize for at those smaller node scales. Sometimes relaxing some dimensional constraints improves transistor performance so it’s not a complete positive correlation. This is why actually addressing the physics and not just the measurement matters for assessment.
Employing “similar process” does not necessarily mean the details around transistor designs and features will be comparable. For example it’s entirely possible SMIC chose to relax certain feature spacings and sizes to preserve better transitor performance and manufacturability based on specifics of their transistor design or manufacturability limits (likely some combination of both).
I am not saying that there isn’t a reason to track those specific feature dimensions. I am just saying those aren’t the only factors that will shape performance. It is worthwhile imo to not discard the actual transistor performance itself when trying to assess transistor performance since transistors are not only their dimensional measurements.
I don’t have data per say but I seem to recall that 1) you were very adamant a few years ago arguing that Intel 7, even though it was still “10 nm” should be counted as comparable to TSMC 7 nm based in part on transistor performance, 2) we know some of Samsung’s recent node shrinks (I recall their 5 nm process but also their 3 nm process) have had performance issues despite more aggressive feature shrinking than TSMC.
I don’t expect N+2 to have comparable performance to TSMC 5 nm, but that is not what I’m arguing here. I’m simply pointing out that reducing everything to feature sizes is not the whole picture. It is a tad more complicated than that and I don’t think that should be obfuscated or hand waved at if you want to be serious about comparative assessment.
If there wasn’t an immersion system we wouldn’t be seeing orders for immersion control equipment.
