Search

Electromigration (EM) of metal interconnects is the continuous reliability concern for high-density integration beyond 5-nm technology, especially for the buried power rails in vertically stacked device structure. In this work, EM reliability of alternative metal interconnects based on complementary FET (CFET) is investigated by kinetic Monte Carlo (KMC) method. The microscopic evolutions of void formation in power rails can be well reproduced by considering the coupled effects of thermal and stress distribution during the EM simulation. The influences of grain boundary in different metal materials on EM lifetime are analyzed to provide the optimal strategy of process integration. Thermal-aware EM reliability is further predicted, indicating the importance of self-heating on EM evaluation of power rails in CFET. [ABSTRACT FROM AUTHOR]

Aggressively scaled devices with high power density wrapped around the low thermal conductivity material in narrow space are susceptible to self-heating effect, which includes serious mutual-heating due to proximity effect in multifinger/fin FETs. Obtaining local temperature instead of equivalent lumped temperature at device/circuit level quickly is crucial for designers to accurately predict front-end-of-line reliability (i.e., hot carrier injection, bias temperature instability, and time dependent dielectric breakdown) and achieve better thermal management. In this paper, we: 1) first propose an analytical model based on multistage thermal network to address effectively the self- and mutual-heating within the device; 2) validate the multistage network and proposed analytical model by COMSOL and SPICE simulation, respectively; and 3) utilize the model to investigate local temperature rise in multifinger and multifin FETs-based inverter and ring oscillator as well as provide thermal-aware IC design guideline for self-heating and reliability optimization. The results show that the analytical multistage thermal model can predict local temperature rise and quantify nonuniform temperature difference in full-frequency range, superior to the lumped thermal model. Moreover, the model can offer quick thermal analysis at the pre-Si stage for reliability prediction and thermal-aware design. [ABSTRACT FROM AUTHOR]

The self-heating aware electromigration (EM) reliability of back end of line (BEOL) is investigated by a developed kinetic Monte Carlo (KMC) simulator with consideration of the microscopic physical mechanisms including the migration of metal ions. The developed simulator can reproduce the void morphology and the evolution of metal wires resistance during EM simulation, which is validated by experimental results. The self-heating from the nanosheet MOSFETs is evaluated, adding the extra heat for interconnects. The EM degradation in different layers of metal wires is analyzed by utilizing KMC simulator. The impacts of power density and aspect ratio of metal wires on EM lifetime are discussed with the coupling effects of self-heating and Joule heat. • A kinetic Monte Carlo method to investigate self-heating aware electromigration • Physical mechanisms including the effects of electron wind, stress and temperature • Reproduce the void morphology and the evolution of metal wires resistance • Self-heating simulation in advanced technology node • Self-heating aware electromigration shortens the lifetime of interconnects. [ABSTRACT FROM AUTHOR]