Backside power delivery - routing a chip's power and ground rails on the back of the wafer instead of competing for space with signal wires on the front - is the headline architectural change of the 2nm generation. It frees front-side routing tracks and reduces the voltage drop that plagues dense logic. Taiwan Semiconductor Manufacturing Co., Ltd.'s late-2021 grant is one of the earlier foundational claims in the area.
US11195930B1, "Semiconductor devices with backside power rail and methods of fabrication thereof" (issued 2021-12-07), is classified in H01L 23/535 (interconnect arrangements for power) with H01L 21/28097 and H01L 29/78696 (GAA fabrication). The claim covers both the backside power-rail structure and the method that builds it - placing the rail on the wafer's back side and connecting it to the device.
Construe the structural limitation. The value is in how the backside rail connects to the transistor - typically through a backside contact or via that reaches the source/drain or a buried rail - and in the wafer-thinning-and-reveal sequence that exposes the back side for metallization. The claim's scope is set by the specific connection scheme it requires.
The design-around space here is consequential because the entire industry is converging on backside power. IBM, Intel, and imec all have competing backside schemes. The differentiators are whether the connection uses a buried power rail reached from the back, a direct backside source/drain contact, or a nano-TSV, and which thinning approach is used. Each is a distinct claimable variant.
Because TSMC filed early (the B1 kind code and 2021 issue date put priority well before volume 2nm), this family has strong positioning. Later grants - including TSMC's own 2023 backside-interconnect patents - elaborate on it, which is the signature of a foundational claim spawning a family.
For an IP strategist tracking the 2nm race, this is a priority-date anchor. Any backside-power product needs to be read against TSMC's, Intel's, and IBM's early-2020s families, and this 2021 grant is one of the dates that matters.