Development and evaluation of a-SiC:H films using a dimethylsilacyclopentane precursor as a low-k Cu capping layer

Scaling of the Cu interconnect structures requires Cu capping layers with an increasingly lower dielectric constant (K) that still have adequate Cu and moisture barrier properties. In this work, we study the plasma enhanced chemical vapour (PE-CVD) deposition of amorphous silicon carbide films using dimethyl silacyclopentane (DMSCP) as a precursor, resulting in the incorporation of Si-(CH2)n-Si bridges. The effect of process parameters on film characteristics like K, mass density (p), and leakage behaviour is investigated, as well as their relation with the chemical bonding structure. Finally, Cu barrier properties and hermeticity are evaluated.