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Indexed by:期刊论文

Date of Publication:2014-11-01

Journal:JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A

Included Journals:SCIE、EI、Scopus

Volume:32

Issue:6

ISSN No.:0734-2101

Abstract:To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless Cu-Ni-M (M = Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M = Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5 mu Omega cm for the (Ti1.5/13.5Ni12/13.5)(0.3)Cu-99.7 film and 2.8 mu Omega cm for the (Ta1.1/13.1Ni12/13.1)(0.4)Cu-99.6 film after annealing at 500 degrees C for 1 h. After annealing at 500 degrees C for 40 h, the two films remained stable without forming a Cu3Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of M-Ni is more negative than that of M-Cu. (C) 2014 American Vacuum Society.