TSMC started mass-producing chips using its first N3 (3nm-class) fabrication process many months after Samsung Foundry began high-volume production using its 3GAE (3nm-class, gate-all-around early) node. However, TSMC’s yields are noticeably higher, according to a Business Next story that names several industry analysts and experts, though TSMC hasn’t verified the findings.
According to analysts and subject-matter experts in semiconductors contacted by Business Next, TSMC’s N3 yields might range from 60% to 80%, which is excellent for the first batch. Financial analyst Dan Nystedt tweeted that the N3 yields at TSMC are comparable to the N5 yields early in the ramp-up, which, per the media, may be as high as 80%.
Media calculate TSMC's yield on 3nm to be nearly 80% based on the 5nm comparison (same yield as 5nm when it was ramping up), and say it means TSMC is beating Samsung, adding that yield improvement is based on 1000 small details. $TSM https://t.co/68nq5ZwJbv?
— Dan Nystedt (@dnystedt) December 30, 2022
In contrast, according to the article that cites industry sources without more detail, Samsung Foundry’s 3GAE yields in the early phases were from 10% to 20% and have not improved. According to the research, chip quality had a high degree of fluctuation.
TSMC’s N3 Yield Rates Are Speculations For Now Due to Factors Surrounding it
Despite the wide range of forecasts, there are various points to keep in mind concerning TSMC’s current N3 yields. First of all, we are still determining how yields are determined for commercial wafers passing through TSMC’s Fab 18 and for commercial and shuttle (test) wafers carrying different intellectual properties (IPs) of TSMC’s clients. Second, at this time, TSMC and its customers need to learn the precise yield rate of commercial or shuttle wafers. Thirdly, let’s take into account commercial wafers. TSMC’s N3 is now only employed to produce a minimal number of designs for early adopter(s), even if this is based on market rumors.
It is not unexpected that early yields might reach as high as 80% when you consider that TSMC often develops its cutting-edge production methods with Apple’s needs in mind. Apple is the company’s largest client for advanced nodes. A yield rate of 60%, however, would not be all that impressive for a chip intended to power mass-market goods.
In any case, since the number of N3 designs TSMC commercially produces is currently limited and the yields-related data is a closely guarded trade secret of the foundry and its clients, we cannot make any conclusions about the yields of TSMC’s N3.
Modern semiconductor manufacturing methods rely on many materials, fab equipment tools, process recipes, and other elements and can include thousands of process steps. Since there may be many methods to raise or reduce yields, it is crucial to understand how each part interacts in great detail. Remember that TSMC did not comment on the news piece, so all the statistics are just speculations.