Modelling of heat conduction and thermal stersses in multilevel interconnects

摘要

The effects of metal Joule heating in interconnects were studied numerically. Particular attention is devoted to the multilevel nature of interconnects in modern microelectronic devices. Heat conduction analyses were carried out to quantify the temperature rise in structures composed of various levels of metal lines under diferent electric current densities. Two type of metallization (aluminum and copper) and two types of interlevel dielectric (silicon dixide and polyimide) were considered. It was found that increasing the total nubmer of metal level and/or switching the dielectric from silicon dioxide to polymer-based low-k dielectrics can cause substantial temperature increases, pointing out that interconect Joule heating can become a major reliability threat in future applications. Thermal stresses induced by the nonuniform temperature field were also analyzed.