This work investigates electromigration (EM) in Al‐1 wt %Si, Al‐1 wt %Si‐0.5 wt % Cu and Al‐0.5 wt % Cu films with TiN barrier metals. The EM resistance of the Al‐0.5 wt % Cu layered metallization was found to be higher than that of the Al‐1 wt % Si‐0.5 wt % Cu layered metallization. The electromigration test results show that the reaction between Al films and underlying TiN layer degrades the electromigration performance of the Al‐1 wt % Si, Al‐1 wt % Si‐0.5 wt % Cu films. The reaction kinetics between Al alloys and TiN layers was studied by transmission electron microscopy and by investigating the resistance rise mechanism. Si was found to enhance thin intermetallic compound formation between the Al alloys and TiN on samples annealed at 450 °C.