SRAM bit-cell area is the number foundries cite to prove a new logic node actually shrank, because SRAM scales worse than logic and every fractional gain is hard-won. At Taiwan Semiconductor Manufacturing Co., Ltd., a striking amount of that bit-cell IP carries a single inventor name: Jhon Jhy Liaw. A 2022 portfolio sweep shows how one name anchors the foundry's SRAM cell strategy.
Take the fin-pitch slice. US11437385B2, "FinFET SRAM cells with reduced fin pitch" (issued 2022-09-06, CPC H01L 27/1104 and G11C 11/412), claims a cell layout that packs fins more tightly - directly attacking cell area. Reduced fin pitch is one of the few levers left for SRAM scaling once transistor count per cell is fixed at six.
Then the fin-topology slice. US11488966B2, "FinFET SRAM having discontinuous PMOS fin lines" (issued 2022-11-01), claims a cell where the PMOS fins are deliberately broken into discontinuous segments - a layout trick that relaxes patterning constraints and shrinks the cell. The discontinuity is the claimed limitation.
And the array slice. US11410719B2, "SRAM array" (issued 2022-08-09, CPC G11C 11/412 and H01L 27/1104), and US11342337B2, "Structure and method for FinFET SRAM" (issued 2022-05-24), extend from the single cell up to the array organization. Together they show Liaw's portfolio covering the cell and how cells assemble.
The facet data for SRAM-cell-fin queries in 2022 shows TSMC's various name-spellings collectively leading the class, with Liaw recurring across the grants. This concentration is unusual and strategically deliberate: SRAM cell design is a specialized art, and TSMC has kept it under a master practitioner whose name on a patent is itself a competitive signal.
For a competitive-intelligence analyst, the lesson is to track inventors, not just assignees. Liaw's grant cadence is a proxy for where TSMC's SRAM scaling effort is pointed - fin pitch, fin topology, then the move to GAA-based SRAM that shows up in his and others' later filings. The white space he leaves - exotic non-6T cells, gain-cell SRAM - is where competitors and research labs concentrate instead.