Abstract
The integration of copper, diffusion barrier nano-cluster TaSix and low-k dielectric SiOC were investigated. We fabricated diffusion barrier layer, nano-cluster TaSix, low-k dielectric SiOC, develop the processes integration for Cu metallization and investigated the conduction mechanism of line-to-line leakage current for damascene structure. The dielectric constant of HDPCVD SiOC film obtained by high frequency C-V measurement was 2.77. Fourier transform infrared (FTIR) spectroscopy was performed in order to analyze the chemical structures of SiOC films. The residual stress and stress hysteresis of SiOC were measured during the thermal cycle of a temperature 300℃. The I-V characteristics of nano-cluster TaSix film were performed at various temperatures(30℃~200℃). The resistivity of the film is decreasing as the temperature rises. Auger electron spectroscopy characterizes the chemical compositions of the thin barrier film. The Cu damascene structures with diffusion barrier TaSix and low-k dielectric SiOC were fabricated. From leakage current measurements, the dominant conduction mechanism of the Cu/TaSix/SiOC damascene structure is Schottky emission. And the straight lines were fitted to the data points of Ln(J/T2) v.s. (1/T) plots. It also gave the information of the barrier height. The barrier height of TaSix/SiOC is about 0.35eV ~ 0.38eV.