An experimental methodology for the in-situ observation of the time-dependent dielectric breakdown mechanism in Copper/low-k on-chip interconnect structures

• Published in: 2013 IEEE International Reliability Physics Symposium (IRPS) pp. 2F.1.1 - 2F.1.5
• Main Authors: Kong Boon Yeap, Gall, M., Sander, C., Niese, S., Zhongquan Liao, Ritz, Y., Rosenkranz, R., Muhle, U., Gluch, J., Zschech, E., Aubel, O., Beyer, A., Hennesthal, C., Hauschildt, M., Talut, G., Poppe, J., Vogel, N., Engelmann, H., Stauffer, D., Major, R., Warren, O.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.04.2013
• Subjects: Cu/Low-k; damage kinetics; Dielectric breakdown; Dielectrics; Imaging; in-situ TEM; Kinetic theory; Materials; Nanoparticles; organosilicate glass component; Reliability; Time-dependent dielectric breakdown
• ISBN: 9781479901128; 1479901121
• ISSN: 1541-7026; 1938-1891
• DOI: 10.1109/IRPS.2013.6531966

This study captures the time-dependent dielectric breakdown kinetics in nanoscale Cu/low-k interconnect structures, applying in-situ transmission electron microscopy (TEM) imaging and post-mortem electron spectroscopic imaging (ESI). A "tip-to-tip" test structure and an experimental methodology were established to observe the localized damage mechanisms under a constant voltage stress as a function of time. In an interconnect structure with partly breached barriers, in-situ TEM imaging shows Cu nanoparticle formation, agglomeration and movement in porous organosilicate glasses. In a flawless interconnect structure, in-situ TEM imaging and ESI mapping show close to no evidence of Cu diffusion in the TDDB process. From the ESI mapping, only a narrow Cu trace is found at the SiCN/OSG interface. In both cases, when barriers are breached or still intact, the initial damage is observed at the top interface of M1 between SiCN and OSG.