In-situ carbon-doped aluminum metallization for VLSI/ULSI interconnections

Reliable Al metallization has been performed using a plasma CVD (chemical vapor deposition) technique. In-situ doping of carbon onto an Al film suppresses the growth of Al crystal grains, hillocks and spikes. MTFs (median times to failure) of the films due to electromigration are one order of magnitude greater than that of a pure Al film. The resistivity is reduced by a factor of 3 to 4 when carbon-doped Al is cooled from room to liquid-nitrogen temperature. Al films with mirror surface and fine grains are suitable for reliable VLSI/ULSI (ultra large scale integration) metallization.<
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