When IBM and Tessera were filing device-level GAA IP, TSMC was doing its own foundry-level work, and the 2021 record shows it. The difference matters: a device patent claims the transistor; a foundry structure patent claims how that device fits into a manufacturable cell layout.

The grant US10923474B2 (issued February 16, 2021; Taiwan Semiconductor Manufacturing Co., Ltd.; CPC H01L 27/0922 CMOS structure, H01L 27/0207 cell layout, H01L 29/78696 GAA transistor) claims a semiconductor structure built around gate-all-around devices. The inventor, Jhon Jhy Liaw, is one of TSMC's most prolific standard-cell architects - his name on a patent usually signals layout-level IP.

“An integrated circuit includes gate-all-around (GAA) nanowire transistors and GAA nanosheet transistors on the same substrate. An array of cells including GAA nanowire transistors and cells including nanosheet transistors are provided.”— U.S. Patent No. 10,923,474 source

The H01L 27/0207 classification - integrated-circuit cell geometry - is the tell that this is about how GAA devices are arranged on the die, not just the physics of a single transistor. Foundries win or lose on density, and density lives in the cell structure.

Timing again undercuts the roadmap narrative. This is a 2021 grant; TSMC's N2 (its first GAA node) entered volume only in the mid-2020s. The structural IP was locked down years ahead, which is exactly what you would expect from a foundry that intends to be first and wants the patent moat in place before the product.

It is also a useful corrective to foundry-marketing nodes. "2nm" is a marketing label, not a measured dimension; what actually changes is the device architecture - the move to GAA - and the cell structures that exploit it. This grant is a piece of that real change, dated and attributable.

Follow the inventor and the CPC, not the node name. A Jhon Jhy Liaw GAA cell-structure grant from 2021 tells you more about TSMC's leading-edge intentions than any roadmap slide - because it is the filed, examined, granted record of what they were actually building.