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An aluminum metallization process that combines blanket chemical vapor deposition and sputtering was developed for use in fabrication of future ultralarge scale integration interconnections. Blanket chemical vapor deposition of aluminum using dimethylaluminum hydride on titanium nitride, which provides superior step coverage and a smooth surface morphology for films of less than approximately 0.15 μm thickness, was only used for hole‐filling. Subsequent aluminum alloy sputtering, which has a high deposition rate and provides smooth surface films, was used for the thickening of the aluminum films. This combination process draws on the respective advantages of both chemical vapor deposition and sputtering, which mutually compensate for each other's drawbacks. As a result, via holes with a diameter of 0.3 μm and an aspect ratio of 2.7 were successfully filled. The resistance of contact holes fabricated by the combination process was slightly lower than that obtained in the conventional tungsten plug process due to low film resistivity of chemically vapor deposited aluminum. The contact resistivity for contacts to p‐ and n‐type Si were 1.0×10−7 and 2.9×10−8 normalΩ cm2 , respectively. Via hole resistance for 0.45 μm diameter holes was less than 1 Ω, which corresponds to a contact resistivity of less than 1.6×10−9 normalΩ cm2 between chemically vapor deposited aluminum and the underlayer titanium nitride.

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