Reliability study of doped aluminum conductor films

A reliability study of silicon doped aluminum conductor films for semiconductor device use is presented. The solid state dissolution process of silicon in aluminum is discussed and the morphology of etch pits that can form in silicon due to these processes are described. Processes for depositing Al/Si alloy films are briefly mentioned and the structure of the films as deposited and after various heat treatments is studied. The electromigration failure mode of metal induced by high current densities and temperatures is presented along with the results of previous studies of pure aluminum, other aluminum alloys and aluminum silicon alloys. Current results on low temperature (- 210 C) studies of small grained and glassed Al/Si alloys indicate that they fail by an electrical open circuit due to the growth of voids resulting from the electromigration of Al in Al.