Physical, electrical, and reliability characterization of Ru for Cu interconnects

Thin film characterization, electrical performance, and preliminary reliability of physical, vapor-deposited (PVD) TaN/ chemical vapor-deposited (CVD) Ru bilayer were carried out to evaluate its feasibility as a liner layer for Back-End of Line (BEOL) Cu-low k integration. Adhesion and barrier strength, were studied using 4-point bend, x-ray diffraction. (XRD), and triangular voltage sweep (TVS) techniques. Electrical, yields and line/via resistances were measured at both single and dual damascene levels, with PVD TaN/Ta liner layer as a baseline control. Reliability studies included electromigration (EM) and current-voltage (I-V) breakdown tests. ©2006 IEEE.