Leakage Degradation in n+ Si Contact Filled with Selective Chemical Vapor Deposition Tungsten Plug due to Aluminum Diffusion along the Plug Sidewall

In this paper, the thermal stability of the leakage of the n + -p diodes with AlSi/W/n + Si contacts has been investigated. A serious degradation of leakage characteristics occurred after annealing at 500 o C. Such a degradation is considered to be a severe drawback to the diodes with AlSi/W/n + Si contacts. In contrast, the diodes with WSi x /n + Si contacts did not fail even after 550 o C annealing. In order to investigate the role of the Al, the AlSi/W interface reaction was examined