A New Mechanism of Failure in Silicon p⁺/n Junction Induced by Diffusion Barrier Metals

Abstract

The mechanism of failure of p + /n and n + /p junctions under Al-Si/TiN/Ti and Al-Si/ZrN/Zr systems at contact holes has been investigated. When the total force of the barrier metal in the metallization system, which is defined as the product of the film stress and the film thickness, is larger than 3×10 5 dyn/cm, the junction leakage current increases on p + /n diodes, but not on n + /p diodes after annealing at 500°C. This increase is caused by the formation of dislocation loops in p + -Si. The formation depends on the annealing temperature, the total force of barrier metal and the B concentration.