The big takeaway here is that N3E is a very different node from N3. While the nitty-gritty node details have not been disclosed, at a high-level it has different PPAs along with what the company claims are “very different” design rules intended to improve yield. The result of this is that N3E will not offer any direct migration path from N3, making N3 sort of a dead-end node for designers which is why TSMC expects most customers to utilize N3E instead. So why N3 exist at all? The easiest explanation is to satisfy customers’ commitment to those early technology adopters. Long term, the initial N3 node will likely fade into obscurity.
For customers, there is also no direct IP migration path for designs made on N3 to move to N3E. Put simply, N3E is everything N3 apparently was supposed to be. TSMC says the new node included “significant changes” over N3 that produced different PPAs along with better yield through “lower process complexity”. For this reason, TSMC’s broader IP ecosystem targets N3E. TSMC says that, unlike N3, N3E “will offer complete platform support for both smartphone and HPC applications.”
Offering a complete foundry IP ecosystem, N3E will serve as the main foundry node for TSMC 3-nanometer class chips. Like the original N3, the N3E node is also a FinFET device. TSMC says the node is already design-ready with PDK 0.9 already at the customer’s hand. N3E is scheduled for around one year after N3, putting it firmly around the second half of 2023. As we noted earlier, N3E differs significantly enough from N3 to be treated as an entirely different migration path from N5. TSMC also makes its comparisons for N3E against N5 and not N3 for this very reason.
TSMC mentioned a number of additional variants derived from the N3E node – N3P, N3X, N3S, and N3RF.
TSMC plans to introduce a higher-density variant of the N3E node called N3S. This node is said to feature the highest-density devices for lower-power applications through library optimizations. The N3S is said to ramp around 2 quarters after N3E, placing it at around the mid-2024 timeframe.
Both N3P and N3X target high-performance applications similarly to N5/N4P and N4X. Their PPA and concrete timeline was not disclosed.