Valence and conduction band offsets at low-ka-SiO_xC_y:H/a-SiC_xN_y:H interfaces

摘要

In order to understand the fundamental electrical leakage and reliability failure mechanisms in nano-electronic low-k dielectric/metal interconnect structures, we have utilized x-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy to determine the valence and conduction band offsets present at interfaces between non-porous and porous low-k a-SiO_xC_y:H interlayer dielectrics and a-SiC_xN_y:H metal capping layers. The valence band offset for such interfaces was determined to be 2.7 ± 0.2 eV and weakly dependent on the a-SiOC:H porosity. The corresponding conduction band offset was determined to be 2.1 ± 0.2 eV. The large band offsets indicate that intra metal layer leakage is likely dominated by defects and trap states in the a-SiOC:H and a-SiCN:H dielectrics.