Pulse plasma assisted atomic layer deposition of W–C–N thin films for Cu interconnects

Abstract W–C–N films have been deposited on a tetraethylorthosilicate (TEOS) interlayer dielectric with atomic layer deposition (ALD) cycles of WF6–N2–CH4 gases and the exposure cycles of N2 and CH4 are synchronized with a pulse plasma. The W–C–N films on TEOS layer follow the ALD mechanism, keep a constant deposition rate of 0.2 nm/cycle from 10 to 100 cycles, and have fairly low resistivity (300 µΩ cm). As a diffusion barrier for Cu interconnection the W–C–N films maintain the amorphous phase and no Cu interdiffusion occurs even at 800 °C for 30 min. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)