Taiwan Semiconductor Manufacturing Co. today officially introduced its N2 (2nm class) manufacturing technology, its first node that will use gate-all-around field-effect transistors (GAAFETs), at its 2022 TSMC Technology Symposium. The new fabrication process will offer a [full node's] performance and power benefits, but when it comes to transistor density, it will barely impress in 2025 when it comes online.
Being an all-new process technology platform, TSMC's N2 brings in two essential innovations: nanosheet transistors (which is what TSMC calls its GAAFETs) and backside power rail that both serve the same goal of increasing performance-per-watt characteristics of the node. GAA nanosheet transistors feature channels surrounded by gates on all four sides, which reduces leakage; furthermore, their channels can be widened to increase drive current and boost performance or shrunken to minimize power consumption and cost. To feed these nanosheet transistors with enough power and now waste any of it, TSMC's N2 uses backside power delivery, which the foundry considers to be among the best solutions to fight resistances in the back-end-of-line (BEOL).
Indeed, when it comes to performance and power consumption, TSMC's nanosheet-based N2 node can boast of a 10% to 15% higher performance at the same power and complexity as well as a 25% to 30% lower power consumption at the same frequency and transistor count when compared to TSMC's N3E. However, the new node increases chip density by only around 1.1X compared to N3E.
N2 vs N3E N3E vs N5 N3 vs N5 N5 vs N7 Speed Improvement @ Same Power 10% ~ 15% +18% +10% ~ 15% +15% Power Reduction @ Same Speed -23% ~ -30% -34% -25% ~ -30% -30% Chip Density >1.1X 1.3X ? ? HVM Start H2 2025 Q2/Q3 2023 H2 2022 Q2 2022
I'll wait until takyon does a review - he has a knack of sorting out useful figures from manufacturer's hype.