Effect of dummy via on the SIV performance of narrow-wide copper interconnection

Based on the stress induced void theory, three kinds of narrow-wide two-layer copper interconnection structure with dummy via in M1 were designed and put under different high temperature conditions for test. Under the action of high temperature, influence of dummy vias in lower layer metal (M1) on the failure phenomenon of the interconnect structure was analyzed. The result shows, adding dummy via in M1 can effectively improve the SIV performance of copper interconnection. Based on this, a more accurate equation was put forward to describe the behavior of the vacancy in the structure with dummy via spreading from the diffusion source to the accumulation.