Abstract: y reliable high-temperature Al-Si-Cu sputter metallization, employing a Ti underlayer to prevent Si from precipitating has been developed, and complete filling of 0.15 $mu@m diameter vias with aspect ratio of 4.5 has been achieved. Degree of filling and via chain resistance were improved by increasing the Ti underlayer thickness. This is probably because of improvement in wettability of Al on via sidewall, which is caused by uniform interfacial reaction between Ti underlayers and Al-Si-Cu films. Transmission electron microscopy (TEM) combined with micro energy dispersive spectrometry (EDS) analysis revealed that reacted ball-like precipitates exist at the interface between the first metal and the second metal lines in the filled via, and that the precipitates particles are Al-Ti-Si compounds. No Si precipitation was observed in areas away from or near to the particles. Also, it was found that Al films in the vias consist of one or two single crystalline $LS@111$GRT textured normal to a substrate. The electrical resistance for the 0.3 $mu@m sputter filled via was 0.71 approximately ega@, which is about one order of magnitude lower than that for a non-filled (conventional) via. The electromigration (EM) resistance of 0.3 $mu@m filled vias was found to be four orders of magnitude greater than that for the 0.3 $mu@m conventional vias. Furthermore, we confirmed that the EM resistance for the 0.3 $mu@m filled via is comparable to the 0.9 $mu@m conventional via. Superior EM and stress-induced migration (SM) resistance for the lines have been confirmed.!17
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