New dielectric barrier for damascene Cu interconnection: trimethoxysilane-based SiO/sub 2/ film with k=3.9

We have developed a new Cu-barrier dielectric film suitable for Cu/low-k integration. The film has an SiO ₂ composition and is deposited using trimethoxysilane and N ₂O chemistry. The Cu barrier properties of the film are as good as those of the conventional barrier material (P-SiN). The dielectric constant (k) of the film is 3.9, which is about half the dielectric constant of P-SiN film (k=17.5). The new film has been successfully integrated into damascene Cu interconnections as a Cu cap-layer material. The Cu interconnections had remarkably low line-to-line leakage current (<10 pA/cm ²) and sufficient dielectric breakdown lifetime under normal operating conditions.