Self-Heating And Parasitics Challenge Multi-Tier CFET Scaling (TU Munich, IIT Kanpur)

Core judgment: the multi-tier CFET bottleneck is not the transistor—it is the physical limit of thermal-interconnect coupling. When nanosheets stack vertically, the bottom tier's heat path is occluded by upper structures, driving nonlinear self-heating; simultaneously, MOL and BEOL parasitics shift from engineering-negligible to deterministic in 3D interconnects. This invalidates foundational assumptions in EDA thermal-electric co-simulation and elevates advanced packaging from optional to mandatory—offloading dissipation to the package layer is the only viable compromise. If the thermal budget cannot converge by 2027, TSMC's and Intel's 1.4nm roadmaps face material slippage. Lam Research and ASM International must recalibrate MOL deposition and etch windows; low-k dielectric and alternative interconnect metal R&D gets pulled forward. Thermal interface and micro-fluidic cooling suppliers gain new strategic leverage. Samsung's aggressive V-Cache 3D stacking exposes a structural fragility in thermal management; Intel, pivoting toward thermal-aware heterogeneous integration, could actually widen its 2nm lead. The EDA triad will ship CFET-specific thermal-parasitic solvers within two quarters—a new differentiation battleground. Within 18 months, capex will accelerate toward advanced packaging and thermal subsystems. CFET will not fail, but its commercial form will be flatter than current roadmaps imply: tier count constrained, lateral heterogeneous integration as the true primary arena.