Atomic‐layer‐deposited Ir thin film as a novel diffusion barrier layer in Cu interconnection

Abstract

AbstractAtomic‐layer‐deposited iridium (Ir) thin films were successfully grown on a silicon substrate using Ir(EtCp)(COD) and oxygen as precursors between 240 and 420 °C. The optimal temperature range for the formation of a smooth and uniform Ir thin film was obtained. At 330 °C, specific ALD process conditions were found to yield a smooth Ir thin film with a thickness of 12 nm. The growth mechanism of ALD iridium thin films was investigated as a function of deposition cycle. In the early stage of ALD growth, Ir firstly nucleated after 100 cycles and continuous films of Ir fully covered the silicon substrate after 300 deposition cycles. These results indicate that the Ir ALD process has a long incubation period in contrast with other general ALD processes (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)