I said before, Huawei is likely to give China what the Chinese government failed in decades, a bottom-up semiconductor industry. These penalties could backfire spectacularly.
@antonius123 bro I'm not an expert, but from what I learned 3D stacking is doable in DUVL and other processes but not in EUVL, I hope @tokenanalyst @krautmeister @WTAN @FairAndUnbiased can help me out.
no its doable in 3 nm. The question is how many 3 nm chips can you afford to stack when each wafer is worth 16k vs. 9k for a 7 nm wafer (even down to just 1k for older wafers), and with the understanding that as die shrinks occur the more and more transistors are useless due to thermal constraints?
Makes not economic sense when you have free access to cutting edge fabs and 3nm alone already offer enough performance over the last generation, 3d stacking at 3nm size will add interconect complexity way beyond 14nm or 7nm, this are not 2D dies in substrate anymore, this are stacks. For Huawei makes sense to invest in 3d stacking because is already stuck at 14nm and i think stacking mature nodes is not as complex as stacking GAAFET ICs.
It's doable whether as a fully EUV direct wafer bonding process or as a combination of EUV and DUV packaging. I'm not even sure they could have get 3D stacking working reliably in EUV at <=3nm. There's already so many issues with electron bleeding that yields might just make this a non-starter. Besides, the main issue is it's overly complex for relatively small gain vs big increase in cost. China is hitting the wall at 7nm until it has its own EUV. There is no choice and no other options. For everybody else, the cheaper, easier path is simply maxing out the EUV processes until they hit the silicon limit. Then they will be in the same boat as China is with their own wall. It's the same logic as why 450mm wafers aren't pursued seriously even though it is technically possible and could and would have superseded 300mm. The price performance curve doesn't warrant it.
Current SMIC 14nm chips are built with foreign equipment.