Abstract
As ICs become more efficient, interconnect downscaling needs to be implemented in the back-end-of-line (BEOL) technology. As a result of the downscaling of the vias dimension, the metal resistivity is dominated by surface scattering. Herein, we investigated the functionalization of self-assembled monolayer (SAM) with ultrathin film thickness (1.3 nm) onto the dielectric surface in reducing interface scattering, thus reduces the overall metal conductivity. Specifically, designed BITES (benzyliminetriethoxysilane) and BIDMES (Benzyliminedimethylethoxysilane), in which the terminal aromatic could potentially reduce scattering via electron repulsion. According to the Fuchs−Sondheimer (FS) model1, the specularity parameter of the as deposited Ru/SAM interface was determined to be p ≈ 0.85 at room temperature. Upon thermal annealing at 400 C for X mins, the p value approaches p≈ 0.6 compared to 0.2 for TaN.