Abstract
Self-heating induced by vias and metal/Si contacts in VLSI circuits is undoubtedly one of the most important reliability issues for microelectronic integrated circuits. In this study the thermal characteristics of Ni/poly-Si contacts subject to an electrical current stressing were investigated. The self-heating induced contact temperature rises were measured for the Ni/poly-Si contacts having different contact resistivity, poly-Si sheet resistance and contact geometry. A current crowding phenomenon inside the contact window was analysed numerically based on a two-dimensional computation model. The temperature rise at the Ni/poly-Si contacts was found to increase proportionally with the heating power density of the contact. The extent of current crowding inside the contact window shows a strong dependence on R s / ρ c ratio and contact size. The effect of contact misalignment on the thermal properties of the contact is also discussed. © 2005 IOP Publishing Ltd.