How does multi-threshold voltage (multi-Vt) design work?

Multi-Vt uses cells with different threshold voltages: High-Vt (HVT): Lower leakage, slower, used in non-critical paths; Low-Vt (LVT): Higher leakage, faster, used in critical timing paths; Standard-Vt (SVT): Balance between speed and leakage. Design flow: Start with HVT, swap to LVT/SVT on timing-critical paths during optimization. Typically 60-80% HVT, rest LVT/SVT. Implementation through cell library variants. Trade-off: Each LVT cell may leak 10x more than HVT. Multi-Vt is fundamental for balancing performance and power in advanced nodes.