Metal eFuse Test-Key Design with Electro-Thermal Modeling for 28 HKMG Technology

This paper employs a novel electro-thermal modeling methodology to assist eFuse test-key design. The temperature distribution for eFuse is simulated based on electrical Joule-heating and thermal heat conduction in eFuse and surrounding materials. The electrical Joule-heating strongly depends on the contact pads and wiring shapes. The thermal heat conduction is important for the hot-spot to reach the burn-out temperature range. The final temperature distribution and hot-spot for each type of test-key under preset electrical operation condition depend on material electrical and thermal properties. Thermal boundary conditions are applied to establish thermal equivalent surrounding effects. Test structure design splits include anode/cathode shapes, wiring sizes, and via configurations. Simulated test-key designs with hot-spots in the desired position and failing in the melting temperature range are then selected to build actual test vehicles. This electro-thermal modeling assisted test-key design methodology effectively speeds up the turnaround time and reduces the development cost.