Well China is banned from buying the NXT2150i, they are achieving 5nm with basically with the I think NXT1980i or the NXT2000i that is an old scanner. Has SMIC and Huawei had access to ASML latest immersion scanners I can bet money they would be already doing 3nm with decent yields.The learning curve for adding multiples of extra steps to stay with DUVi are not low either, and we can pretty much see which one is actually harder and yielding worse results from real world performance with different production lines. Just to re-emphasize this point I don’t think the last two years of process iterations we’ve seen coming out of the Huawei-SMIC partnership relative to the speed at which other fabs moved to 5 nm using EUV supports the idea that the effective performance difference between DUVi with multi-patterning and EUV are modest.
All the struggle that you see is because they are basically fighting hand tie.