Investigation of electrical conduction in carbon-doped silicon oxide using a voltage ramp method

Abstract

Electrical conduction in carbon-doped silicon oxide (SiOC) is investigated over the electric field range of 0 MV/cm to the breakdown field at 300 K. Below 1.4 MV/cm, the dominant conduction mechanisms are electron hopping (<0.2 MV/cm) and Schottky emission (0.2 to 1.4 MV/cm). Poole–Frenkel emission at higher fields (>1.4 MV/cm) confirms the presence and role of electron traps in the conduction of SiOC. Near breakdown field (1.7 to 2.08 MV/cm), Fowler–Nordheim tunneling occurs and this is the major cause of dielectric breakdown in SiOC. The effective dielectric constant of SiOC in an integrated Cu damascene structure is derived from both experimental data and emission modeling.