SIMS depth profile of copper in low-k dielectrics under electron irradiation for charge compensation

摘要

SIMS is a powerful technique to observe the low levels of copper diffusion. However, change in chemical structure of low-k dielectrics has been observed under electron irradiation for charge compensation using a magnetic sector instrument. The depth of implanted Cu peak from SIMS depth profiles decrease with increase of irradiation time. This peak shift to shallower direction is simply proportional to decrease in film thickness. Decrease in the thickness is ascribed to the formation of SiO_x (x ≤ 2) network via decomposition of CH_3 group as well as SiOH formation. These changes occurred uniformly throughout the films.