Process variations in nanometer technologies are becoming an important issue for cutting-edge FPGAs with a multimillion gate capacity. Considering both die-to-die and withindie variations in effective channel length, threshold voltage, and gate oxide thickness, we first develop closed-form models of leakage and timing variations at the FPGA chip level. Experiments show that our models are within 3% from Monte Carlo simulation, and the leakage and delay variations can